Estimating the heritability of female dispersal in yellow-bellied marmots - M. N. Edic (2022)

From legacy contamination to watershed systems science: a review of scientific insights and technologies developed through DOE-supported research in water and energy security - Dipankar Dwivedi; Carl I. Steefel; Bhavna Arora; Jillian F. Banfield; John R. Bargar; M. I. Boyanov; S. C. Brooks; X. Chen; S. S. Hubbard; David Kaplan; K. M. Kemner; P. Nico; et al. (Environmental Research Letters, 2022)
Abstract Water resources, including groundwater and prominent rivers worldwide, are under duress because of excessive contaminant and nutrient loads. To help mitigate this problem, the United States Department of Energy (DOE) has supported research since the late 1980s to improve our fundamental knowledge of processes that could be used to help clean up challenging subsurface problems. Problems of interest have included subsurface radioactive waste, heavy metals, and metalloids (e.g. uranium, mercury, arsenic). Research efforts have provided insights into detailed groundwater biogeochemical process coupling and the resulting geochemical exports of metals and nutrients to surrounding environments. Recently, an increased focus has been placed on constraining the exchanges and fates of carbon and nitrogen within and across bedrock to canopy compartments of a watershed and in river–floodplain settings, because of their important role in driving biogeochemical interactions with contaminants and the potential of increased fluxes under changing precipitation regimes, including extreme events. While reviewing the extensive research that has been conducted at DOE’s representative sites and testbeds (such as the Oyster Site in Virginia, Savannah River Site in South Carolina, Oak Ridge Reservation in Tennessee, Hanford in Washington, Nevada National Security Site in Nevada, Riverton in Wyoming, and Rifle and East River in Colorado), this review paper explores the nature and distribution of contaminants in the surface and shallow subsurface (i.e. the critical zone) and their interactions with carbon and nitrogen dynamics. We also describe state-of-the-art, scale-aware characterization approaches and models developed to predict contaminant fate and transport. The models take advantage of DOE leadership-class high-performance computers and are beginning to incorporate artificial intelligence approaches to tackle the extreme diversity of hydro-biogeochemical processes and measurements. Recognizing that the insights and capability developments are potentially transferable to many other sites, we also explore the scientific implications of these advances and recommend future research directions.

Maternal survival costs in an asocial mammal - R. Kanaziz; K. P. Huyvaert; Caitlin P. Wells; D. H. Van Vuren; L. M. Aubry (Ecology and Evolution, 2022)
Maternal characteristics, social dynamics, and environmental factors can all influence reproduction and survival and shape trade-offs that might arise between these components of fitness. Short-lived mammals like the golden-mantled ground squirrel (GMGS; Callospermophilus lateralis) tend to maximize effort toward current reproduction at the expense of survival but may be complicated by other aspects of the species' life history and environment. Here, we use 25 years of data (1995-2020) collected from a population of GMGS at the Rocky Mountain Biological Research Laboratory in Gothic, Colorado, to test the effect of several maternal characteristics (e.g., age, experience, and timing of litter emergence), social context (e.g., litter sex ratio and kin density), and environmental context (e.g., date of bare ground and length of vegetative growing season) on survival of reproductive female GMGS using Cox proportional hazard models. Our results indicated that social dynamics (i.e., density) and environmental conditions (i.e., standardized first day of permanent snow cover and length of growing season) explained significant variation in annual maternal survival, while maternal characteristics did not. A higher density of related breeding females and the total number of females (both related and unrelated to the focal mother) were associated with an increase in the mortality hazard. A later standardized date of the first day of permanent snow cover and a shorter growing season both reduced the maternal mortality hazard. Together, our results suggest that factors extrinsic to the squirrels affect maternal survival and thus may also influence local population growth and dynamics in GMGS and other short-lived, territorial mammal species.

Sulfur Biogeochemical Cycling and Redox Dynamics in a Shale-Dominated Mountainous Watershed - P. M. Fox; Sergio Carrero; C. Anderson; Christian Dewey; Marco Keiluweit; M. Conrad; H. R. Naughton; Scott Fendorf; R. W. H. Carroll; Baptiste Dafflon; H. Malenda-Lawrence; Dipankar Dwivedi; et al. (Journal of Geophysical Research: Biogeosciences, 2022)
AbstractSulfur (S) is an essential macronutrient and important component of the earth’s crust, and its cycling has critical impacts on trace metal mobility, water quality, and human health. Pyrite weathering is the primary pathway by which sulfur enters surface waters. However, biogeochemical cycling of sulfur in soils and the river corridor mediates sulfate exports. In this study, we identified the major forms of sulfur across multiple compartments and scales in a pristine mountainous watershed, including shale bedrock weathering profiles, hillslope soils, and alluvial floodplain sediments, in order to provide insight into biogeochemical sulfur cycling in a hydrologically variable alpine system. X‐ray absorption near‐edge spectroscopy (XANES) analysis of shale weathering profiles showed clear evidence of pyrite oxidation to sulfate, with large accumulations of intermediate S(0) (20%–53%). Micro‐scale XANES showed evidence of reprecipitation of pyrite at fracture surfaces within the permanently saturated zone. Organic sulfur dominated S speciation in shallow hillslope soil and floodplain sediment, with little evidence of reduced inorganic S. However, mackinawite formation, representing active sulfate reduction, was observed in saturated oxbow sediments and saturated weathered shale underlying floodplain sediments. Further evidence of sulfate reduction from aqueous sulfur isotopic analysis was observed in shallow groundwater transects across an Fe‐reducing meander, whereas increases in pore water sulfate concentrations implied sulfur oxidation at other locations. The data present an integrated picture of sulfur cycling in a shale‐dominated watershed, where riverine sulfate exports are mediated by biological cycling, particularly in redox‐stratified and temporally dynamic hyporheic zone sediments.

Ecological Drivers and Consequences of Bumble Bee Body Size Variation - J. L. Fitzgerald; Jane E. Ogilvie; Paul J. CaraDonna (Environmental Entomology, 2022)
Body size is arguably one of the most important traits influencing the physiology and ecology of animals. Shifts in animal body size have been observed in response to climate change, including in bumble bees (Bombus spp. [Hymenoptera: Apidae]). Bumble bee size shifts have occurred concurrently with the precipitous population declines of several species, which appear to be related, in part, to their size. Body size variation is central to the ecology of bumble bees, from their social organization to the pollination services they provide to plants. If bumble bee size is shifted or constrained, there may be consequences for the pollination services they provide and for our ability to predict their responses to global change. Yet, there are still many aspects of the breadth and role of bumble bee body size variation that require more study. To this end, we review the current evidence of the ecological drivers of size variation in bumble bees and the consequences of that variation on bumble bee fitness, foraging, and species interactions. In total we review: (1) the proximate determinants and physiological consequences of size variation in bumble bees; (2) the environmental drivers and ecological consequences of size variation; and (3) synthesize our understanding of size variation in predicting how bumble bees will re- spond to future changes in climate and land use. As global change intensifies, a better understanding of the factors influencing the size distributions of bumble bees, and the consequences of those distributions, will allow us to better predict future responses of these pollinators.

An analytical pipeline to support robust research on the ecology, evolution, and function of floral volatiles - K. E. Eisen; J. M. Powers; Robert A. Raguso; Diane R. Campbell (Frontiers in Ecology and Evolution, 2022)
Research on floral volatiles has grown substantially in the last 20 years, which has generated insights into their diversity and prevalence. These studies have paved the way for new research that explores the evolutionary origins and ecological consequences of different types of variation in floral scent, including community-level, functional, and environmentally induced variation. However, to address these types of questions, novel approaches are needed that can handle large sample sizes, provide quality control measures, and make volatile research more transparent and accessible, particularly for scientists without prior experience in this field. Drawing upon a literature review and our own experiences, we present a set of best practices for next-generation research in floral scent. We outline methods for data collection (experimental designs, methods for conducting field collections, analytical chemistry, compound identification) and data analysis (statistical analysis, database integration) that will facilitate the generation and interpretation of quality data. For the intermediate step of data processing, we created the R package bouquet , which provides a data analysis pipeline. The package contains functions that enable users to convert chromatographic peak integrations to a filtered data table that can be used in subsequent statistical analyses. This package includes default settings for filtering out non-floral compounds, including background contamination, based on our best-practice guidelines, but functions and workflows can be easily customized as necessary. Next-generation research into the ecology and evolution of floral scent has the potential to generate broadly relevant insights into how complex traits evolve, their genomic architecture, and their consequences for ecological interactions. In order to fulfill this potential, the methodology of floral scent studies needs to become more transparent and reproducible. By outlining best practices throughout the lifecycle of a project, from experimental design to statistical analysis, and providing an R package that standardizes the data processing pipeline, we provide a resource for new and seasoned researchers in this field and in adjacent fields, where high-throughput and multi-dimensional datasets are common.

Imputation of contiguous gaps and extremes of subhourly groundwater time series using random forests - Dipankar Dwivedi; Utkarsh Mital; Boris Faybishenko; Baptiste Dafflon; Charuleka Varadharajan; Deb Agarwal; K. H. Williams; Carl I. Steefel; S. S. Hubbard (Journal of Machine Learning for Modeling and Computing, 2022)
Machine learning can provide sustainable solutions to gap-fill groundwater (GW) data needed to adequately constrain watershed models. However, imputing missing extremes is more challenging than other parts of a hydrograph. To impute missing subhourly data, including extremes, within GW time-series data collected at multiple wells in the East River watershed, located in southwestern Colorado, we consider a single-well imputation (SWI) and a multiple-well imputation (MWI) approach. SWI gap-fills missing GW entries in a well using the same well's time-series data; MWI gap-fills a specific well's missing GW entry using the time series of neighboring wells. SWI takes advantage of linear interpolation and random forest (RF) approaches, whereas MWI exploits only the RF approach. We also use an information entropy framework to develop insights into how missing data patterns impact imputation. We discovered that if gaps were at random intervals, SWI could accurately impute up to 90% of missing data over an approximately two-year period. Contiguous gaps constituted more complex scenarios for imputation and required the use of MWI. Information entropy suggested that if gaps were contiguous, up to 50% of missing GW data could be estimated accurately over an approximately two-year period. The RF-feature importance suggested that a time feature (months) and a space feature (neighboring wells) were the most important predictors in the SWI and MWI. We also noted that neither SWI nor MWI methods could capture the missing extremes of a hydrograph. To counter this, we developed a new sequential approach and demonstrated the imputation of missing extremes in a GW time series with high accuracy.

The effects of spatial and temporal resolution of gridded meteorological forcing on watershed hydrological responses - X. Chen; Pin Shuai; Utkarsh Mital; E. T. Coon; Dipankar Dwivedi (Hydrology and Earth System Sciences, 2022)
Abstract. Meteorological forcing plays a critical role in accurately simulating the watershed hydrological cycle. With the advancement of high-performance computing and the development of integrated watershed models, simulating the watershed hydrological cycle at high temporal (hourly to daily) and spatial resolution (tens of meters) has become efficient and computationally affordable. These hyperresolution watershed models require high resolution of meteorological forcing as model input to ensure the fidelity and accuracy of simulated responses. In this study, we utilized the Advanced Terrestrial Simulator (ATS), an integrated watershed model, to simulate surface and subsurface flow and land surface processes using unstructured meshes at the Coal Creek Watershed near Crested Butte (Colorado). We compared simulated watershed hydrologic responses including streamflow and distributed variables such as evapotranspiration, snow water equivalent (SWE), and groundwater table driven by three publicly available, gridded meteorological forcings (GMFs) – Daily Surface Weather and Climatological Summaries (Daymet), the Parameter-elevation Regressions on Independent Slopes Model (PRISM), and the North American Land Data Assimilation System (NLDAS). By comparing various spatial resolutions (ranging from 400 m to 4 km) of PRISM, the simulated streamflow only becomes marginally worse when spatial resolution of meteorological forcing is coarsened to 4 km (or 30 % of the watershed area). However, the 4 km-resolution has much worse performance than finer resolution in spatially distributed variables such as SWE. Using the temporally disaggregated PRISM, we compared models forced by different temporal resolutions (hourly to daily), and sub-daily resolution preserves the dynamic watershed responses (e.g., diurnal fluctuation of streamflow) that are absent in results forced by daily resolution. Conversely, the simulated streamflow shows better performance using daily resolution compared to that using sub-daily resolution. Our findings suggest that the choice of GMF and its spatiotemporal resolution depends on the quantity of interest and its spatial and temporal scale, which may have important implications for model calibration and watershed management decisions.

Beaver dams overshadow climate extremes in controlling riparian hydrology and water quality - Christian Dewey; P. M. Fox; Nicholas J. Bouskill; Christian Dewey; Nicholas J. Bouskill; Dipankar Dwivedi; P. M. Fox; P. Nico; Scott Fendorf; Dipankar Dwivedi; Scott Fendorf; P. Nico (Nature Communications, 2022)
Hydrologic extremes dominate chemical exports from riparian zones and dictate water quality in major river systems. Yet, changes in land use and ecosystem services alongside growing climate variability are altering hydrologic extremes and their coupled impacts on riverine water quality. In the western U.S., warming temperatures and intensified aridification are increasingly paired with the expanding range of the American beaver-and their dams, which transform hydrologic and biogeochemical cycles in riparian systems. Here, we show that beaver dams overshadow climatic hydrologic extremes in their effects on water residence time and oxygen and nitrogen fluxes in the riparian subsurface. In a mountainous watershed in Colorado, U.S.A., we find that the increase in riparian hydraulic gradients imposed by a beaver dam is 10.7-13.3 times greater than seasonal hydrologic extremes. The massive hydraulic gradient increases hyporheic nitrate removal by 44.2% relative to seasonal extremes alone. A drier, hotter climate in the western U.S. will further expand the range of beavers and magnify their impacts on watershed hydrology and biogeochemistry, illustrating that ecosystem feedbacks to climate change will alter water quality in river systems.

Modeling snow dynamics and stable water isotopes across mountain landscapes - R. W. H. Carroll; Jeffrey Deems; Matthias Sprenger; R. M. Maxwell; W. Brown; Alexander W. Newman; Curtis A. Beutler; K. H. Williams (Geophysical Research Letters, 2022)
Abstract A coupled hydrologic and snowpack stable water isotope model assesses controls on isotopic inputs across a mountainous basin. Annually, the most depleted isotope conditions occur in the upper subalpine where snow accumulation is high, and rainfall is low. Snowmelt isotopic evolution over time indicates fractionation processes account for <25% snowmelt enrichment. Meltwater isotopic inputs are largely determined by controls on the amount, phase and isotopic mass of precipitation coincident with the ablation period. Effect of vapor loss from the snowpack on d‐excess in snowmelt is a balance between energy and snow‐availability. It is highest above treeline, and in the grass and aspen‐dominated portions of the upper montane where vegetation shading is low. Deep snowpack in conifer forests limit the influence of vapor loss in the subalpine. Wet years reduce the effects of vapor loss on snowmelt across the basin, except in the lower montane where added snowfall bolsters snow‐limited conditions.

Remote sensing of cytotype and its consequences for canopy damage in quaking aspen - B. Blonder; Philip G. Brodrick; J. A. Walton; K. Dana Chadwick; Ian K Breckheimer; S. Marchetti; C. A. Ray; K. E. Mock (Global Change Biology, 2022)
AbstractMapping geographic mosaics of genetic variation and their consequences via genotype x environment interactions at large extents and high resolution has been limited by the scalability of DNA sequencing. Here, we address this challenge for cytotype (chromosome copy number) variation in quaking aspen, a drought‐impacted foundation tree species. We integrate airborne imaging spectroscopy data with ground‐based DNA sequencing data and canopy damage data in 391 km2 of southwestern Colorado. We show that (1) aspen cover and cytotype can be remotely sensed at 1 m spatial resolution, (2) the geographic mosaic of cytotypes is heterogeneous and interdigitated, (3) triploids have higher leaf nitrogen, canopy water content, and carbon isotope shifts (δ13C) than diploids, and (4) canopy damage varies among cytotypes and depends on interactions with topography, canopy height, and trait variables. Triploids are at higher risk in hotter and drier conditions.

Species-specific traits predict whole-assemblage detritus processing by pond invertebrates - J. A. Balik; C. Leitz; Washko S. E.; B. Cleveland; D. M. Krejsa; M. E. Perchik; A. Stogsdill; M. Vlah; L. M. Demi; H. S. Greig; I. D. Shepard; B. W. Taylor; et al. (Oecologia, 2022)
Functional trait diversity determines if ecosystem processes are sensitive to shifts in species abundances or composition. For example, trait variation suggests detritivores process detritus at different rates and make different contributions to whole- assemblage processing, which could be sensitive to compositional shifts. Here, we used a series of microcosm experiments to quantify species-specific coarse and fine particulate organic matter (CPOM and FPOM) processing for ten larval cad- disfly species and three non-caddisfly species in high-elevation wetlands. We then compared trait-based models including life history, dietary, and extrinsic traits to determine which traits explained interspecific variation in detritus processing. Finally, we compared processing by mixed caddisfly assemblages in microcosms and natural ponds to additive predictions based on species-specific processing to determine if single-species effects are additive in multi-species assemblages. We found considerable interspecific variation in biomass-specific CPOM (13-fold differences) and FPOM (8-fold differences) processing. Furthermore, on a mass-specific basis, amphipods, chironomids, and caddisflies processed similar amounts of detritus, suggesting non-shredder taxa could process more than previously recognized. Trait models including dietary percent detritus, development rate, body size, and wetland hydroperiod explained 81 and 57% of interspecific variation in CPOM and FPOM processing, respectively. Finally, species-specific additive predictions were strikingly similar to mixed- assemblage processing in microcosms and natural ponds, with the largest difference being a 15% overestimate. Thus, additiv- ity of species-specific processing suggests single-species rates may be useful for understanding functional consequences of shifting assemblages, and a trait-based approach to predicting species-specific processing could support generating additive predictions of whole-assemblage processing.

Modeling Spatial Distribution of Snow Water Equivalent by Combining Meteorological and Satellite Data with Lidar Maps - Utkarsh Mital; Dipankar Dwivedi; Ilhan Özgen-Xian; J. B. Brown; Carl I. Steefel (Artificial Intelligence for the Earth Systems, 2022)
Abstract An accurate characterization of the water content of snowpack, or snow water equivalent (SWE), is necessary to quantify water availability and constrain hydrologic and land surface models. Recently, airborne observations (e.g., lidar) have emerged as a promising method to accurately quantify SWE at high resolutions (scales of ∼100 m and finer). However, the frequency of these observations is very low, typically once or twice per season in the Rocky Mountains of Colorado. Here, we present a machine learning framework that is based on random forests to model temporally sparse lidar-derived SWE, enabling estimation of SWE at unmapped time points. We approximated the physical processes governing snow accumulation and melt as well as snow characteristics by obtaining 15 different variables from gridded estimates of precipitation, temperature, surface reflectance, elevation, and canopy. Results showed that, in the Rocky Mountains of Colorado, our framework is capable of modeling SWE with a higher accuracy when compared with estimates generated by the Snow Data Assimilation System (SNODAS). The mean value of the coefficient of determination R 2 using our approach was 0.57, and the root-mean-square error (RMSE) was 13 cm, which was a significant improvement over SNODAS (mean R 2 = 0.13; RMSE = 20 cm). We explored the relative importance of the input variables and observed that, at the spatial resolution of 800 m, meteorological variables are more important drivers of predictive accuracy than surface variables that characterize the properties of snow on the ground. This research provides a framework to expand the applicability of lidar-derived SWE to unmapped time points. Significance Statement Snowpack is the main source of freshwater for close to 2 billion people globally and needs to be estimated accurately. Mountainous snowpack is highly variable and is challenging to quantify. Recently, lidar technology has been employed to observe snow in great detail, but it is costly and can only be used sparingly. To counter that, we use machine learning to estimate snowpack when lidar data are not available. We approximate the processes that govern snowpack by incorporating meteorological and satellite data. We found that variables associated with precipitation and temperature have more predictive power than variables that characterize snowpack properties. Our work helps to improve snowpack estimation, which is critical for sustainable management of water resources.

Habitat selection in a fluctuating ground squirrel population: Density - dependence and fitness consequences - J. R. Aliperti; K. Jenderseck; D. H. Van Vuren (Ecology and Evolution, 2022)
Investigating individual-based habitat settlement decisions is a central theme in ecology, yet studies that quantify density-dependent habitat selection or tie fitness to resource selection decisions remain rare. We quantified habitat selection in golden-mantled ground squirrels (Callospermophilus lateralis) across two spatial scales (home-range placement, and occurrence within the home range) by using 11 consecutive years of data on individual space use, and we used resource selection functions and multilevel modeling to address how habitat preferences may be influenced by density or linked to fitness outcomes. Squirrels preferred dry meadow over other habitat types (wet meadow, aspen, spruce, and willow) at both spatial scales. Squirrels were more likely to use dry meadow that contained shorter vegetation and vision-enhancing prominences such as rocks ("perches"). The use of dry meadow at each scale was not influenced by changes in density. The use of dry meadow did not lead to increased litter size, pre-hibernation mass, or survival. However, squirrels that experienced a greater number of perches or lower local densities had higher survival rates. Our results suggest that a lack of visual obstruction, probably facilitating detection of predators, drives habitat selection in this system. Surprisingly, squirrels maintained their preference for dry meadow as density increased, and they experienced reduced survival as a result. This work furthers our understanding about the causes and consequences of changes in habitat use, informing wildlife management and conservation.

On the similarity of hillslope hydrologic function: a clustering approach based on groundwater changes - Fadji Maina; Haruko M. Wainwright; P. James Dennedy-Frank; Erica R. Siirila-Woodburn (Hydrology and Earth System Sciences, 2022)
Abstract. Hillslope similarity is an active topic in hydrology because of its importance in improving our understanding of hydrologic processes and enabling comparisons and paired studies. In this study, we propose a holistic bottom-up hillslope clustering based on a region's integrative hydrodynamic response quantified by the seasonal changes in groundwater levels ΔP. The main advantage of the ΔP clustering is its ability to capture recharge and discharge processes. We test the performance of the ΔP clustering by comparing it to seven other common hillslope clustering approaches. These include clustering approaches based on the aridity index, topographic wetness index, elevation, land cover, and machine-learning that jointly integrate multiple data. We assess the ability of these clustering approaches to identify and categorize hillslopes with similar static characteristics, hydroclimate, land surface processes, and subsurface dynamics in a mountainous watershed – the East River – located in the headwaters of the Upper Colorado River Basin. The ΔP clustering performs very well in identifying hillslopes with six out of the nine characteristics studied. The variability among clusters as quantified by the coefficient of variation (0.2) is less in the ΔP and the machine learning approaches than in the others (> 0.3 for TWI, elevation, and land cover). We further demonstrate the robustness of the ΔP clustering by testing its ability to predict hillslope responses to wet and dry hydrologic conditions, of which it performs well when based on average conditions.

Trout Creek Lycopsid Fossil Forest, Chaffee County, Colorado - Mike Viney; George Mustoe (Rocks & Minerals, 2022)

Borgs are giant genetic elements with potential to expand metabolic capacity - Basem Al-Shayeb; M. C. Schoelmerich; Jacob West-Roberts; Luis E. Valentin-Alvarado; Rohan Sachdeva; Susan Mullen; A. Crits-Christoph; Michael J. Wilkins; K. H. Williams; Jennifer Doudna; Jillian F. Banfield (Nature, 2022)
Anaerobic methane oxidation exerts a key control on greenhouse gas emissions1, yet factors that modulate the activity of microorganisms performing this function remain poorly understood. Here we discovered extraordinarily large, diverse DNA sequences that primarily encode hypothetical proteins through studying groundwater, sediments and wetland soil where methane production and oxidation occur. Four curated, complete genomes are linear, up to approximately 1 Mb in length and share genome organization, including replichore structure, long inverted terminal repeats and genome-wide unique perfect tandem direct repeats that are intergenic or generate amino acid repeats. We infer that these are highly divergent archaeal extrachromosomal elements with a distinct evolutionary origin. Gene sequence similarity, phylogeny and local divergence of sequence composition indicate that many of their genes were assimilated from methane-oxidizing Methanoperedens archaea. We refer to these elements as 'Borgs'. We identified at least 19 different Borg types coexisting with Methanoperedens spp. in four distinct ecosystems. Borgs provide methane-oxidizing Methanoperedens archaea access to genes encoding proteins involved in redox reactions and energy conservation (for example, clusters of multihaem cytochromes and methyl coenzyme M reductase). These data suggest that Borgs might have previously unrecognized roles in the metabolism of this group of archaea, which are known to modulate greenhouse gas emissions, but further studies are now needed to establish their functional relevance.

Bumble bee queen plasticity and social regulation of traits - E. M. S. Sarro (2022)
Studies on the physiological states of wild-caught organisms are essential to uncovering the links between ecological and physiological processes. Bumble bee queens emerge from overwintering in the spring. At this time, queens develop their ovaries and search for a nest site in which to start a colony. Whether these two processes, ovary development and nest-searching, interact with or influence one another remains an unresolved question in behavioral physiology. We explored the hypothesis that ovary development and nest-searching might be mechanistically connected, by testing whether (1) ovary development precedes nest-searching behavior; (2) nest occupation precedes ovary development; or (3) ovary development and nest-searching occur independently, in bumble bee (Bombus vosnesenskii) queens. We collected queens either nest-searching (and thus prior to occupying a nest) or pollen-collecting (and thus provisioning an occupied nest) and measured their degree of ovary activation. We further screened these queens for parasites or other symbionts, 7 to identify additional factors that may impact their reproductive success at this time. We found that queens searched for and occupied nests at all stages of ovary development, indicating that these processes occur independently in this system. Nest-searching queens were more likely to have substantial mite loads than pollen-collecting queens, who had already located and occupied a nest. However, mite loads did not significantly predict ovary developmental status. Collectively, our work shows that nesting status and symbionts alone are insufficient to explain the variation in spring bumble bee queen ovary development. We propose that ovary development and nest-searching occur opportunistically, which may enable queens to begin laying eggs earlier in the season than if these processes occurred in discrete succession.

The ecology and evolution of pathogens in a changing world - I. Miller (2022)
Infectious diseases are an integral part of natural ecosystems but also pose a serious threat to human health and agriculture. Understanding the multitude of factors shaping the epidemiology and evolution of pathogens is crucial for predicting and mitigating their effects, especially in a rapidly changing world. In this dissertation, I present four studies about how vaccination, emerging pathogens, and climate change affect the epidemiology and evolution of infectious disease. In the first chapter I consider the effects of toxin targeting vaccines, such as acellular pertussis vaccines, on the evolution of pathogen virulence. In the second chapter I map projections of the expected burden of the novel coronavirus SARS-CoV-2. In the third chapter I assess the risk for COVID-19 vaccines to drive the evolution of increased viral virulence. In the fourth chapter I investigate how climate change will alter the epidemiology of fungal plant pathogens using the flax rust system as a model. 3 Abstract.......................................................................................................................................... 3

Effects of Temperature on Voltinism in Subalpine Potter Wasps (Vespidae: Eumeninae) - A. Zuber (2022)
Voltinism, the number of generations produced per year, is under both genetic and environmental control in insects. The rapid temperature increases associated with climate change could distort the information insects are obtaining from environmental cues and possibly alter the number of generations produced per year. This summer I investigated the effects of temperature on voltinism in potter wasps (Vespidae: Eumeninae). Previous observations suggest that some eumenines around RMBL are bivoltine, while most are univoltine. I focused on whether variables such as temperature, time of year at which an egg was laid, source population, or taxon may be responsible for this variation. I observed individual wasps building nests at multiple study sites varying in elevation, collected completed nests from said sites, isolated eggs or larvae from these nests and subjected them to one of two temperature conditions (boxes exposed to warm or cool temperatures) to observe the effects on development and time until an individual began cocooning. Warm boxes experienced average maximum daily temperatures 4-18°C warmer than cooler boxes. A generalized linear mixed model showed that while site of origin, date laid and box pair had no effect on rates of cocooning, final age, temperature treatment, and source nest did. These results demonstrate how environmental factors influence wasp development. While genetic effects may factor in as well, more work must be done to conclude that the effect of source nest isn't merely a result of additional environmental factors such as those experienced in early life (before the start of experimental treatments) or maternal effects. These results add to our understanding of the broader consequences of climatic warming for insect life-history strategies and potential changes in eumenine wasp populations. 1

Nest Distribution of Bombus spp. Across Different Habitat Types - Wynn R. Walker (2022)
Despite bumble bees’ critical importance as pollinators throughout the montane regions of Colorado, little research has been done on their nesting habits. In order to conserve the populations of Bombus spp. in the West, better knowledge of their nest density and nesting habitats is needed. I hypothesized that (1) a nest searching technique would be successful, (2) Bombus spp. nests would be identified in three distinct habitats, and (3) there would be a difference in nest densities across habitats depending on the bumble bee species. The habitats that I searched were classified as wet meadow, dry meadow, and aspen forest. Across three separate sites, each habitat had a total of 9 plots. Each of these plots was 150 square meters. I spent 30 minutes at each site once a week searching for nests and Bombus activity. Results of this study showed success of the nest searching technique and identification of Bombus nests in all three habitat types, but there was insufficient data to form a conclusion regarding the nesting habitat preferences of different species. The conclusion of this study is that dry meadow has the highest nesting density and should be preserved. Because this habitat also functions as foraging habitat for Bombus species, the conservation of this land is beneficial for the whole life cycle of the pollinators

Effects of clumping of Delphinium barbeyi on pollination - J. Troper (2022)
The spatial clustering of plants occurs for a variety of reasons, including the evolution of concentrated floral displays to attract more pollination. Within clusters, traits that attract pollinators may differ from non-cluster conditions– such as increasing floral display size andscent, which can cause an increase in pollinator visitation, which in turn increase the reproductive success of plants. In this study I focused on plant neighborhood density, one potential driver of pollination, to further understand pollination systems in times of change and challenge to these structures. More specifically, I examined the question of whether higher density clumping of Delphinium barbeyi increases pollination, and at what spatial scales this effect occurs. I used drone remote sensing, and spatial analysis to choose research sites and measure global densities of D. barbeyi, and collected additional data on local density with manual measurements. In order to measure pollination, I used pollen count, determined through pollen smashing. I found that the most significant global density that impacts the pollination of D. barbeyi is at a 40 meter to 70 meter scale, when comparing global scales of 20 meters to 80 meters. The relationship between pollen count and global density along with pollen count and local density were both found to be significant across scales of 20 meters to 80 meters. In addition, after adding plant fitness to the regression, the relationship across all scales remained significant.

Determining changes in floral volatile composition of Ipomopsis aggregata in response to nectar robbing and its associated microorganisms - J. Stryker (2022)
Mutualisms involve complex relationships between multiple types of organisms. Traditionally, mutualisms like pollination have been studied using a pairwise perspective – only focusing on two individual species or groups of species with similar functions involved in the relationship. Including third-party organisms in pollination research allows for a greater understanding of how those mutualisms can persist or break down depending on the different types of interactions. Studying these dynamics are essential to maintaining the ecosystem services provided by pollination and understanding how these mutualisms are able to persist despite interference and exploitation. Ipomopsis aggregata, a hummingbird pollinated montane herb, experiences nectar robbing from native bumble bees, Bombus occidentalis and Bombus mixtus, which reduces hummingbird visitation, pollen transfer, and the reproductive success of I. aggregata. In this study, I examined how nectar robbers and the microbes they disperse alter the chemical phenotype of Ipomopsis aggregata. While volatiles of microbial origin were detected in a subset of microbe-inoculated samples, there were no detectable differences in volatile composition across a combination of robbed and unrobbed flowers with either a sterile sucrose solution, live yeast or bacteria, or dead yeast or bacteria. The lack of distinct volatile differences is likely due to confounding variables including chemical and microbial contamination and the high variability of I. aggregata floral volatiles, along with limited sample sizes. This research offers valuable insights into the difficulties of floral and microbial volatile analysis in the field and suggests that sampling single treated flowers from more controlled populations might reduce contamination and general phenotypic volatile variation.

Rates of Cannibalism in Asynarchus Nigriculus based on Sedge Nutrient Content - M. Saab (2022)
Understanding the dynamic interactions between aquatic invertebrates is critical in forming an accurate illustration of mountain stream ecology. Aquatic detritivores, such as A. Nigriculus, form the majority of the biomass in mountain ponds and rivers around Colorado, as they are usually the primary consumers of aquatic detritus. However, certain species of caddisflies in these sub-alpine ponds, such as Asynarchus nigriculus larvae, feed on other caddisflies and cannibalize one another as well. This is probably a supplementation for caddisfly larvae to grow as rapidly as they do in these temporary ponds up in the Mexican Cut, at around 11500 feet in subalpine elevation, which is notorious for having a nutritionally poor environment (Fig. 4). In our study, we manipulate the number of nutrients in the water, enhancing their diet, to observe if the additional nutrients cause a shift in A. nigriculus larvae feeding behavior. The main nutrients we are studying, and which we are supplementing, are nitrogen and phosphorus since these are what have been studied in previous similar experiments regarding Asynarchus nigriculus. Through our experiment, we found the average body size, behavior, and mortality of caddisfly larvae in the function of the treatment ( additional Phosphorus, additional Nitrogen, additional Phosphorus, and Nitrogen, or control) they were receiving. It is difficult to predict mortality and behavior between each of the treatments, or if the sedge detritus (or the microorganisms inhabiting their surface) have taken up the nutrients at all.

How understory bee communities compare to open meadows in the Rocky Mountains - A. Rosenberg (2022)
Forest associated species, bees and otherwise, are among the world's most vulnerable species due human activity such as deforestation. Even though bees are significant to ecosystem health by providing such important services as pollination, basic information on bee biodiversity and factors driving their distributions in temperate coniferous forest ecosystems are relatively scarce. It is likely that there are a minority of bee species that are associated with forest habitats; however, very few have been described. In Colorado, 34% of the landscape is forested. Montane regions such as the Gunnison Valley are predicted to experience the most extreme changes in climate, potentially making bee communities vulnerable. The goals of this research were to determine at which site (meadow or forest) and at what time of day were social and solitary bees most abundant around Gothic, Colorado. We used catch rate as a proxy for abundance. We found that social bees (Bombus spp.) have the same abundance in the meadow as the forest at any time of the day. Solitary bees, on the other hand, are more abundant in the meadow regardless of the time of day. This research project provides a baseline for further investigation of forest associated bees.

Comparison of Bee Bowls and Netting for Monitoring Native Bees - M. Mitchell (2022)
This study looked at the differences in bee community composition between estimates obtained from pan traps vs. netting. Comparing species richness, evenness and community composition between the two sampling types from the years 2009-2017 and 2009-2021. Based on a rate of bees caught per hour, without the Bombus genus, bee bowls were more efficient, however, the catch rate of the Bombus genus alone was much higher than the catch rate of the bowls. However, bee bowls still caught a wider range of genus, with the netting still missing around 50 species over the course of the years studied. However, the nets were able to catch larger bodied bees that were missed by the bowls. Overall, it was determined that to get a full understanding of the bee genus/species populations, both bee bowls and netting is needed.

The Effect of Climate Change on Soil Organic Carbon over an Elevational Gradient - T. Issa (2022)
Climate change will increasingly impact ecosystem functioning due to shifts in species distributions as they seek their optimal climatic conditions. Plants rely on phenotypic plasticity of leaf traits to tolerate a change in their climate. Plant leaf traits also affect the carbon cycle of the local area, which may impact the carbon sequestration of the soils. For this project, I measured soil organic carbon over time using space-for-time substitution to study plant communities along an elevational gradient. I collected soil moisture, carbon, and efflux and, in addition, conducted a community survey of the plant species. Both soil carbon and soil moisture significantly increase across an elevational gradient. Additionally, soil carbon is best explained through a combination of soil moisture and biomaterial weight. As soil organic carbon is vulnerable to environmental changes, monitoring soil organic carbon is necessary to determine if there is a loss of carbon sequestration in the area, which can accelerate climate change.

The Impacts of Changing Temperature on Plant Water Use - V. Lenis (2022)
The movement of water through a plant’s parts, out its stomata, and into the atmosphere begins with moisture available in the soil. Soil water availability is determined by rates of evaporation from the Earth’s surface, which increases with temperature. Alteration of water content determines the soil’s water potential, the tendency of water to move from one area to another due to physical pressure forces. The means by which plants utilize and transport water occurs along a water potential gradient in a soil-plant-atmosphere-continuum. Water eventually exits the plant via transpiration when the leaves’ stomata open to release vapor and receive carbon dioxide. Water availability is critical for plants’ physiological processes and is determined by a mixture of environmental abiotic factors. Thus, the plots in the Reciprocal Transplant Experiment have been moved to different sites along the Washington Gulch elevation gradient to experience different warming or cooling temperatures. Water potential patterns are mainly studied in woody plant species and the water potential of herbaceous species is heavily understudied. My observational study focused on five different herbaceous species at these turf sites. At each site and their experimental treatment plots, I recorded weather observations, measured the soil moisture of the turfs, and water potential of the individual plants. At the intermediate site that had both cooled and warmed plots, I measured leaf gas exchange for the plant individuals which accounts for their stomatal conductance rates. I hypothesized that plants do not have an acclimated response and rather, as warming temperatures increase, soil becomes drier which leads to more negative water potential values and lower transpiration rates: the inverse for cooling temperatures. Results found that, although water potential did vary along the elevation gradient in the hypothesized way, soil moisture was highest at the lowest elevation site and lowest at the highest site. Moreover, along the warming and cooling treatments, there was no significant difference in plant water stress: there was no significant difference in stomatal conductance either. These outcomes suggest inter-annual variability in water availability, the plants have an ability to converge with their surroundings, and a complex model that accounts for climatic conditions should occur in the future.

Temporal correlations among demographic parameters are ubiquitous but highly variable across species - Rémi Fay; Sandra Hamel; Martijn van de Pol; Gaillard J-M; N. G. Yoccoz; P. Acker; M. Authier; Benjamin Larue; C. Le Coeur; Kirsty Macdonald; A. Nicol-Harper; Christophe Barbraud; et al. (Ecology Letters, 2022)
Abstract Temporal correlations among demographic parameters can strongly influence population dynamics. Our empirical knowledge, however, is very limited regarding the direction and the magnitude of these correlations and how they vary among demographic parameters and species’ life histories. Here, we use long‐term demographic data from 15 bird and mammal species with contrasting pace of life to quantify correlation patterns among five key demographic parameters: juvenile and adult survival, reproductive probability, reproductive success and productivity. Correlations among demographic parameters were ubiquitous, more frequently positive than negative, but strongly differed across species. Correlations did not markedly change along the slow‐fast continuum of life histories, suggesting that they were more strongly driven by ecological than evolutionary factors. As positive temporal demographic correlations decrease the mean of the long‐run population growth rate, the common practice of ignoring temporal correlations in population models could lead to the underestimation of extinction risks in most species.

Dynamics of male inconstancy in Valeriana edulis in the abiotic and mating environment - D. Pham (2022)
This study investigated inconstancy in the sex-expression of male flowers across populations of Edible Valerian (Valeriana edulis) as well as potential drivers of its variation. Though Valeriana edulis is dioecious (individuals typically have separate sexes), plants showing dominant male sex-expression may also produce female reproductive structures (stigmas). As such, we aimed to (1) characterize variation in male inconstancy in V. edulis populations and explore the influence of the (2) abiotic environment and (3) mating environment on the distribution of inconstant sex expression in what is considered a dioecious system. To address these goals, we conducted flower surveys in multiple populations to determine the degree, frequency, and variation in expression of inconstancy (i.e. how inconstancy varies between individuals or flowers). We also tested potential abiotic drivers of inconstancy using remotely sensed datasets for growing degree days as a proxy for temperature and snowmelt date to represent soil moisture. Finally, we obtained operational sex ratios (proportion of flowering individuals that are primarily male-expressing) through demographic surveys of the populations to examine its effect on male inconstancy. These results have implications for potentially reclassifying Valeriana edulis as a dioecious species, exploring the limitations of binary thinking, and gaining a better understanding of how differential effects of the environment on individuals may in turn affect population biodiversity, performance, and persistence. Key words: Dioecy, subdioecy, sex ratios, labile sex-expression, binary thinking, climate change, elevation gradient, Valeriana edulis

A Meteorology and Snow Data Set From Adjacent Forested and Meadow Sites at Crested Butte, CO, USA - Hannah M. Bonner; Eric Smyth; Mark S. Raleigh; E. Small (Water Resources Research, 2022)
AbstractWe present meteorology and snow observation data collected at sites in the southwestern Colorado Rocky Mountains (USA) over three consecutive water years with different amounts of snow water equivalent (SWE) accumulation: A year with above average SWE (2019), a year with average SWE (2020), and a year with below average SWE (2021). This data set is distinguished by its emphasis on paired open‐forest sites in a continental snow climate. Approximately once a month during February–May, we collected data from 15 to 20 snow pits and took 8 to 19 snow depth transects. Our sampling sites were in open and adjacent forested areas at 3,100 m and in a lower elevation aspen (3,035 m) and higher elevation conifer stand (3,395 m). In total, we recorded 270 individual snow pit density and temperature profiles and over 4,000 snow depth measurements. These data are complimented by continuous meteorological measurements from two weather stations: One in the open and one in the adjacent forest. Meteorology data—including incoming shortwave and longwave radiation, outgoing shortwave radiation, relative humidity, wind speed, snow depth, and air and infrared surface temperature—were quality controlled and the forcing data were gap‐filled. These data are available to download from Bonner, Smyth, et al. (2022) at https://doi.org/10.5281/zenodo.6618553, at three levels of processing, including a level with downscaled, adjusted precipitation based on data assimilation using observed snow depth and a process‐based snow model. We demonstrate the utility of these data with a modeling experiment that explores open‐forest differences and identifies opportunities for improvements in model representation.

Combined Effects of Aridity and Herbivory on Plant Performance - L. Duncan (2022)

Building Resilience in the Face of a Dwindling Colorado River - Jane Palmer (Eos, 2022)
Policymakers, industry and conservation professionals, and tribal members explore pathways to a sustainable future for the millions of people reliant on the “lifeblood of the American West.”

Balancing model generality and specificity in management-focused habitat selection models for Gunnison sage-grouse - D. Joanne Saher; Michael S. O’Donnell; Cameron L. Aldridge; Julie A. Heinrichs (Global Ecology and Conservation, 2022)
Identifying, protecting, and restoring habitats for declining wildlife populations is foundational to conservation and recovery planning for any species at risk of decline. Resource selection analysis is a key tool to assess habitat and prescribe management actions. Yet, it can be challenging to map suitable resource conditions across a wide range of ecological contexts and use the resulting models to identify effective and universal habitat improvement actions. We developed a management-centric modeling approach that sought to balance the need to evaluate the consistency of key habitat conditions and improvement actions across multiple, distinct populations, while allowing context-specific environmental variables and spatial scales to nuance selection responses that form the basis of location-specific management prescriptions. To demonstrate this approach, we developed a set of habitat selection models for Gunnison sage-grouse (Centrocercus minimus), a threatened species under the U.S. Endangered Species Act. Conservation, species recovery, and habitat management efforts are needed in six isolated satellite populations (San Miguel, Crawford, Piñon Mesa, Dove Creek, Cerro Summit-Cimarron-Sims, and Poncha Pass) where environmental conditions differ, and the already small number of birds are declining. We used multi-scale and seasonal resource selection analyses to quantify relationships between environmental conditions and sites used by animals. All models included key habitat variables often altered through management actions to assess their differential influences across models. We found important similarities and differences among satellites, indicating that, although some rules of thumb are generally well-grounded, the consideration of population-specific environmental differences could increase the efficiency of local habitat improvement actions. Sage-grouse also had diverse responses to resource conditions at different scales, indicating that regional spatial (e.g., landscape) and local patch scale can differentially influence expected habitat improvements associated with where such management actions are implemented. Although context variables such as topography cannot be manipulated, sage-grouse associations revealed information that could guide the siting of improvement actions. This approach to balancing management objectives associated with habitat assessment may benefit spatially-structured populations with different environmental contexts and species with complex habitat needs and associations.

Snowmelt Timing Leads to Plasticity and Alters Natural Selection on Leaf Traits in Ipomopsis - Justin Kipness (2022)
Anthropogenic climate change is altering environments, which in turn has the potential to influence plant traits (through phenotypic plasticity) and natural selection. The effect of changing climate on the strength and direction of selection remains unresolved. In this study we quantified the plasticity and strength of selection on vegetative traits of the subalpine herbs Ipomopsis aggregata, Ipomopsis tenuituba, and hybrids. We used long-term data to quantify phenotypic plasticity in these traits and their effects on fitness over 12 years with varying dates of snowmelt in the Colorado Rocky Mountains. We hypothesized that the vegetative traits would be under selection that depended on snowmelt date, which affects early-season water availability and temperature. Specific leaf area (SLA) responded plastically to snowmelt timing, with lower SLA found in early snowmelt years and larger SLA found in late snowmelt years. Natural selection on water use efficiency (WUE) changed based on snowmelt date, with early snowmelt correlating with more positive selection on WUE and late snowmelt correlating with negative selection on WUE. Both plant traits and selection were affected by snowmelt timing and both responded in ways that theoretically should aid in acclimation and adaptation to drier conditions for Ipomopsis. Our results highlight how climate change can impact traits and alter natural selection by modifying abiotic factors such as snowmelt timing.

Ant Behavioral Responses to Aphids Colonizing Ligusticum porteri - C. Kennamer (2022)
Ant-aphid mutualisms are keystone interactions that, if altered, have the potential to cause cascading, multitrophic effects on local arthropod and plant communities. In our study system, the flowering stalks of Ligusticum. porteri (Apiaceae) are colonized by the aphid Aphis asclepiadis, which relies on a protection mutualism with ants. We examined the mediating role of phenology in the host plant L. porteri on mutualistic ant behavior in the subalpine zone of the Rocky Mountains in Colorado, USA. To accomplish this, we utilized three tiers of observational data to infer the role of host plant phenology on ant abundance and behavior. First, we compiled six years of census data taken over June through August from 2017-2022 to determine ant abundance during pre-flowering, flowering, and post-flowering phenological stages. In 2022, we recorded focused observations of tending behavior in ants, adding to the census data collected in previous years. Lastly, we used an ethogram to examine effect of advanced, post-flowering phenology in aphid-colonized host plants on a range of 26 different ant behaviors divided among 6 behavioral categories. Ant abundance increased during the flowering stages of L. porteri. Additionally, ant tending behavior also increased during the flowering stages. Finally, during the post flowering stages (fruit initiation and maturation), ants spent the highest proportion of their time on communication, exploration, and grooming behaviors. Increased time spent during these stages on non-tending behaviors such as grooming suggests that ants may budget less time for aphid tending as host plant phenology advances, reducing protective benefits conferred by ants during this time. Taken together, these results suggest that, in years where early season snowmelt leads to advanced phenology of L. porteri, early season aphid colonies arriving in June will encounter host plant conditions that are less conducive to attracting the ants needed to protect them.

Early-life trade-offs in golden-mantled ground squirrel sociality and growth rate - R. Hart (2022)
The golden-mantled ground squirrel (Callospermophilus lateralis) was first classified as an asocial sciurid in 1983, and little follow-up research has effectively challenged this notion since the early literature. The only recognized social behavior in the species has been documented between young littermates, between a mother and her litter, and occasionally across unrelated or partially related litters of overlapping home ranges. However, little research has been conducted on the potential impacts of pup sociality on early life fitness. In this study, the early-life behaviors of golden-mantled ground squirrels were observed in eight litters in the Gothic Townsite of the Rocky Mountain Biological Laboratory during the first two weeks after pup emergence when sociality is at a peak. A multiple linear regression model was used to compare the relationship between time spent socializing and pup growth rate. This model also accounted for the additive effect of pup age on growth rate and the potential interaction between sociality and litter size (i.e., having more littermates may impact sociality). While the final study model was just shy of significant (p= 0.0565), the estimate value of -2.127 showed a consistent, meaningful negative effect (-2.127 ± std. =1.030 = -1.097 or -3.157). Unfortunately, due to high predation rates, roadkill events, and natural loss of litters, the low sample size limits conclusions we can draw from these results. Patterns of early-life sociality in an asocial species such as the golden-mantled ground squirrel are important to understand as they may play an important role in juvenile fitness or later life success. Key words: Golden-mantled ground squirrel (Callospermophilus lateralis), social behavior, growth rates, juvenile fitness, early life trade-offs

High-Resolution Snow-Covered Area Mapping in Forested Mountain Ecosystems Using PlanetScope Imagery - A. John; A. F. Cannistra; K. Yang; A. Tan; D. Shean; J. Hille Ris Lambers; N. Cristea (Remote Sensing, 2022)
Improving high-resolution (meter-scale) mapping of snow-covered areas in complex and forested terrains is critical to understanding the responses of species and water systems to climate change. Commercial high-resolution imagery from Planet Labs, Inc. (Planet, San Francisco, CA, USA) can be used in environmental science, as it has both high spatial (0.7–3.0 m) and temporal (1–2 day) resolution. Deriving snow-covered areas from Planet imagery using traditional radiometric techniques have limitations due to the lack of a shortwave infrared band that is needed to fully exploit the difference in reflectance to discriminate between snow and clouds. However, recent work demonstrated that snow cover area (SCA) can be successfully mapped using only the PlanetScope 4-band (Red, Green, Blue and NIR) reflectance products and a machine learning (ML) approach based on convolutional neural networks (CNN). To evaluate how additional features improve the existing model performance, we: (1) build on previous work to augment a CNN model with additional input data including vegetation metrics (Normalized Difference Vegetation Index) and DEM-derived metrics (elevation, slope and aspect) to improve SCA mapping in forested and open terrain, (2) evaluate the model performance at two geographically diverse sites (Gunnison, Colorado, USA and Engadin, Switzerland), and (3) evaluate the model performance over different land-cover types. The best augmented model used the Normalized Difference Vegetation Index (NDVI) along with visible (red, green, and blue) and NIR bands, with an F-score of 0.89 (Gunnison) and 0.93 (Engadin) and was found to be 4% and 2% better than when using canopy height- and terrain-derived measures at Gunnison, respectively. The NDVI-based model improves not only upon the original band-only model’s ability to detect snow in forests, but also across other various land-cover types (gaps and canopy edges). We examined the model’s performance in forested areas using three forest canopy quantification metrics and found that augmented models can better identify snow in canopy edges and open areas but still underpredict snow cover under forest canopies. While the new features improve model performance over band-only options, the models still have challenges identifying the snow under trees in dense forests, with performance varying as a function of the geographic area. The improved high-resolution snow maps in forested environments can support studies involving climate change effects on mountain ecosystems and evaluations of hydrological impacts in snow-dominated river basins.

Sweet and salty: Pollinators and sodium-enriched nectar - Ethan VanValkenburg (2022)

Production of hydrogen peroxide in an intra-meander hyporheic zone at East River, Colorado - X. Yuan; T. Liu; P. M. Fox; Amrita Bhattacharyya; Dipankar Dwivedi; K. H. Williams; J. A. Davis; T. D. Waite; P. Nico (Scientific Reports, 2022)
Abstract The traditionally held assumption that photo-dependent processes are the predominant source of H 2 O 2 in natural waters has been recently questioned by an increrasing body of evidence showing the ubiquitiousness of H 2 O 2 in dark water bodies and in groundwater. In this study, we conducted field measurement of H 2 O 2 in an intra-meander hyporheic zone and in surface water at East River, CO. On-site detection using a sensitive chemiluminescence method suggests H 2 O 2 concentrations in groundwater ranging from 6 nM (at the most reduced region) to ~ 80 nM (in a locally oxygen-rich area) along the intra-meander transect with a maxima of 186 nM detected in the surface water in an early afternoon, lagging the maximum solar irradiance by ∼ 1.5 h. Our results suggest that the dark profile of H 2 O 2 in the hyporheic zone is closely correlated to local redox gradients, indicating that interactions between various redox sensitive elements could play an essential role. Due to its transient nature, the widespread presence of H 2 O 2 in the hyporheic zone indicates the existence of a sustained balance between H 2 O 2 production and consumption, which potentially involves a relatively rapid succession of various biogeochemically important processes (such as organic matter turnover, metal cycling and contaminant mobilization). More importantly, this study confirmed the occurrence of reactive oxygen species at a subsurface redox transition zone and further support our understanding of redox boundaries on reactive oxygen species generation and as key locations of biogeochemical activity.

Within Day Temporal Variation Within Plant-Pollinator Networks - D. Gascon (2022)
Plant-pollinator networks are useful tools for understanding species interactions and biodiversity. The structure of interactions within plant-pollinator networks have provided insight into the potential stability and persistence of ecological communities. Current studies of plant- pollinator networks have primarily focused on a temporally static view. These studies have given insight on general patterns within networks, however the temporally static view they take gives less insight on the various temporal scales at which interactions can change, form, and dissolve. If networks have temporally dependent variables, then constructing networks at different time scales can provide information on structural changes that could be overlooked at different temporal scales. Therefore we want to know if plant-pollinator networks change within a day. What we do know is that plant-pollinator network structure and stability can change over years and within seasons, but we know a lot less about the assembly and disassembly of interactions within days. By focusing on the temporal variation within a day, we improve our understanding of changes to structure and stability of plant-pollinator networks that are meaningful for plant and pollinator ecology. With the use of network metrics like nestedness, connectance, and specialization we can acquire empirical data to show whether there is change to the structure and stability of the network. We find that there seems to be changes occurring between the plant and pollinators, suggesting dynamic aspects.

Is flight initiation distance associated with longer-term survival in yellow-bellied marmots ( Marmota flaviventer )? - M. Sanchez (2022)
The distance at which animals move away from threats, flight initiation distance (FID), is often used to study antipredator behavior and risk assessment. Variation in FID is explained by a variety of internal and external biotic and physical factors, including anthropogenic activities. Most prior studies focused on unidentified individuals, so our understanding of the fitness consequences of FID is relatively limited. We asked whether consistent individual differences in variation in flight initiation distance is associated with variation in summer survival or winter survival in an individually- marked population of yellow-bellied marmots (Marmota flaviventer). We found no clear association between flight initiation distance and summer survival or flight initiation distance and winter survival. This suggests that FID decisions, while demonstrably optimizing current survival, may not have longer-term fitness consequences. Our results may have been explained by the relatively modest repeatability of FID or it may have emerged from our attempt to explain longer-term measures of fitness. Future studies of the fitness consequences of personality traits should pay particular attention to the time between which individuality of traits are measured and the fitness consequences are studied.

Quantifying Subsurface Flow and Solute Transport in a Snowmelt-Recharged Hillslope With Multiyear Water Balance - Tetsu Tokunaga; Anh Phuong Tran; Jiamin Wan; Wenming Dong; Alexander W. Newman; Curtis A. Beutler; W. Brown; A. N. Henderson; K. H. Williams (Water Resources Research, 2022)
AbstractQuantifying flow and transport from hillslopes is vital for understanding water quantity and quality in rivers, but remains obscure because of limited subsurface measurements. Using measured hydraulic conductivity K profiles and water balance over a single year to calibrate a transmissivity feedback model for a hillslope in the East River watershed (Colorado) proved unsatisfactory for predicting flow over the subsequent years. Well‐constrained field‐scale K were obtained by optimizing subsurface flux predictions over years having large differences in recharge, and by including estimates of interannual transfer of excess snowmelt recharge. Water and solute exports during high snowmelt recharge occur predominantly via shallow groundwater flow through weathered rock and soil because of their enlarged transmissivities under saturated conditions. Conversely, these shallow pathways are less active in snow drought years when the water table remains deeper within the weathering zone. Hillslope soil water monitoring showed that rainfall does not infiltrate deeply during summer and fall months, and revealed water losses consistent with model ET predictions. By combining water table‐dependent fluxes with pore water chemistry in different zones, time‐dependent rates of solute exports become predictable. As an example, calibrated K were combined with dissolved nitrogen concentrations in pore waters to show the snowmelt‐dependence of reactive nitrogen exported from the hillslope, further supporting the recent finding that the weathering zone is the dominant source of reactive nitrogen at this site. Subsurface export predictions can now be obtained for wide ranges of recharge based on measurements of water table elevation and profiles of pore water chemistry.

Phenotypic plasticity and selection on leaf traits in response to snowmelt timing and summer precipitation - Jocelyn Navarro; J. M. Powers; Ayaka Paul; Diane R. Campbell (New Phytologist, 2022)
Summary Vegetative traits of plants can respond directly to changes in the environment, such as those occurring under climate change. That phenotypic plasticity could be adaptive, maladaptive, or neutral. We manipulated the timing of spring snowmelt and amount of summer precipitation in factorial combination and examined responses of specific leaf area (SLA), trichome density, leaf water content (LWC), photosynthetic rate, stomatal conductance and intrinsic water‐use efficiency (iWUE) in the subalpine herb Ipomopsis aggregata. The experiment was repeated in three years differing in natural timing of snowmelt. To examine natural selection, we used survival, relative growth rate, and flowering as fitness indices. A 50% reduction in summer precipitation reduced stomatal conductance and increased iWUE, and doubled precipitation increased LWC. Combining natural and experimental variation, earlier snowmelt reduced soil moisture, photosynthetic rate and stomatal conductance, and increased trichome density and iWUE. Precipitation reduction reversed the mortality selection favoring high stomatal conductance under normal and doubled precipitation, and higher LWC improved growth. Earlier snowmelt is a strong signal of climate change and can change expression of leaf morphology and gas exchange traits, just as reduced precipitation can. Stomatal conductance and SLA showed adaptive plasticity under some conditions.

Comparative impacts of long-term trends in snowmelt and species interactions on plant population dynamics - Diane R. Campbell; Mary V. Price; Nickolas M. Waser; R. E. Irwin; Alison K. Brody (Journal of Ecology, 2022)
Abstract Climate change can impact plant fitness and population persistence directly through changing abiotic conditions and indirectly through its effects on species interactions. Pollination and seed predation are important biotic interactions that can impact plant fitness, but their impact on population growth rates relative to the role of direct climatic effects is unknown. We combined 13 years of experiments on pollen limitation of seed set and pre‐dispersal seed predation in Ipomopsis aggregata , a subalpine wildflower, with a long‐term demographic study that has documented declining population growth with earlier spring snowmelt date. We determined how pollen limitation and seed predation changed with snowmelt date over 21 years and incorporated those effects into an integral projection model to assess relative impacts of biotic factors on population growth. Both pollen limitation and the difference in stigma pollen load between pollen‐supplemented and control plants declined over years. Neither pollen limitation nor seed predation changed detectably with snowmelt date, suggesting an absence of indirect effects of that specific abiotic factor on these indices of biotic interactions. The projected biotic impacts of pollen limitation and seed predation on population growth rate were small compared to factors associated with snowmelt date. Providing full pollination would delay the projected date when earlier snowmelt will cause populations to fall below replacement by only 14 years. Synthesis . Full pollination and elimination of seed predation would not compensate for the strong detrimental effects of early snowmelt on population growth rate, which in I. aggregata appears driven largely by abiotic environmental factors. The reduction over two decades in pollen limitation also suggests that natural selection on floral traits may weaken with continued climate change. These results highlight the value of studying both abiotic factors and biotic interactions to understand how climate change will influence plant populations.

Effects of Experimental Water Addition on Floral Nectar Traits - M. Ferguson (2022)
Plant-pollinator interactions rely on the exchange of nectar and pollen for pollination services. Nectar traits can be influenced by changes in abiotic factors such as water availability, and such variation may in turn influence interactions with pollinators. This experiment investigated how the nectar traits in subalpine plant species responded to increased water availability compared to control conditions. We collected data on three components of floral nectar traits: nectar volume (µl), nectar sugar concentration (mg/µl), and total nectar sugar (mg) for four different wildflower species: Delphinium nuttallianum (Ranunculaceae), Delphinium barbeyi (Ranunculaceae), Eremegone congesta (Caryophyllaceae), and Erigeron speciosus (Asteraceae). Delphinium nuttalianum, Delphinium barbeyi, and Erigeron speciosus all showed no pattern between the control and water addition plots, suggesting these species can maintain nectar traits across variable water availability conditions. Erigeron speciosus showed a marginal increase in sugar content, which was not previously predicted in our hypotheses. We found that Eremegone congesta was the most sensitive to changes in water availability, with a significant decrease in nectar volume and sugar content due to water addition treatment.

Assessing the Impact that the Keystone Species, the Red Naped Sapsucker ( Sphyrapicus nuchalis ), has on the Community of Species in the East River - V. Cruz (2022)
The Red naped sapsucker (Sphyrapicus nuchalis) is considered a double keystone species. The first method is by creating nesting cavities that other species are unable to replicate, so when the cavities are abandoned, that community of species is able to utilize the space for their own reproductive site. The second method is by creating sap well sites that a different select group of species makes use of by visiting the wells and robbing the sap that is exuded. Here in the East River Valley, I reassesed the claim of S. nuchalis being a double keystone species by performing an observational study (in-person and using motion-activated cameras) of the visitors to the sap wells. I identified eight species (birds, insects, rodents) that fed from the sap wells, measured frequency of visits, quality of the sap, sapsucker behaviors. I detected a reduction in population numbers of sapsuckers and warblers but not of hummingbirds using 20 years of data from Rocky Mountain Biological Laboratory Breeding Bird survey. I compared my results to Gretchen Daily and Paul Ehrlich’s study conducted in 1987 and reevaluated the claim that Sphyrapicus nuchalis is a double keystone species. Low visitation by saprobbers suggests that wells are only used opportunistically and sap feeders are not dependent on this resource to the extent that the sapsuckers are key to their abundance.

Effects of Floral Abundance, Pollinator Interactions, and Floral Morphology on Stigmatic Pollen Deposition - M. Cathcart (2022)
Pollination is a major driver of plant reproductive success and facilitates the growth of many of our major crops and is a foundation to the diversity of many ecosystems. Understanding the ecology of pollination will help preserve this important ecosystem service and predict the changes that will come with climate change. During pollination a pollinator transfers pollen to the stigma of a plant and the plant’s reproductive success is determined by the receipt of conspecific pollen. Many factors can determine the ratio of conspecific to heterospecific pollen that is deposited on the stigma of an individual plant. The available pollinator community and their level of specialization, flower morphology, and the composition of the floral community all can interact in complex ways to influence the composition of pollen deposition. I hypothesize that in subalpine meadows of the Rocky Mountains the most significant driver of conspecific pollen deposition is relative floral abundance. My results show that both relative interaction abundance and relative floral abundance had insignificant effects on the deposition of conspecific pollen and that flower morphology could be the strongest driver.

Carry-over effects of larval food stress on adult energetics and life history in a nectar-feeding butterfly - K. Niitepold; C. L. Boggs (Ecological Entomology, 2022)

Marmot mass gain rates relate to their group’s social structure - Conner S. Philson; Sophia Todorov; Daniel T. Blumstein (Behavioral Ecology, 2022)

Community College Students in the Field: A review of a Community Conversation on Successful Programs and Strategies - A. N. Robin; A. A. Farmer; K. O'Connell; A. K. Varty; J. A. Hewlett; J. W. Lee (2022)
To explore how field experiences can be designed to engage more community college students, the Undergraduate Field Experience Research Network (UFERN) held a "community conversation" (Community Colleges in the Field: Successful Programs and Strategies) on 15 October 2021. The hour-long virtual meeting featured a panel of instructors who are involved in creating opportunities for community college students to learn in field environments. The goal was to offer insights and foster a conversation about successful strategies, unique challenges, and concrete practices for participants to use in their classes, programs, or institutions. Forty-one people from field stations and marine laboratories, community colleges, and various public universities from within the United States participated in the community conversation. Undergraduate field experiences (UFEs), where student learning occurs in nature, can take a variety of forms, from field laboratories embedded within on-campus courses, day-long or multi-day field trips, weeks-long residential field courses to paid research internships (O'Connell et al. 2021). Undergraduate field experiences of a variety of formats are associated with a litany of positive outcomes and are perceived as critical pathways to career and graduate opportunities in the field-based sciences (Petcovic et al. 2014, Fleischner et al. 2017, Klemow et al. 2019). For example, field courses for undergraduates are associated with higher major retention rates (in this case Ecology and Evolutionary Biology), and the narrowing of achievement gaps for underrepresented minority (URM) students (Beltran et al. 2020). In addition, students participating in field courses tend to graduate with higher GPAs and show gains in their sense of scientific self-efficacy (Beltran et al. 2020). Patrick (2010) found that field trip experiences strengthened students' understanding of process of science and positively influenced students' attitude toward biology. A field-based research experience was shown to also increase student self-efficacy and feeling of belonging in their discipline, in this case the geosciences (Kortz et al. 2020). However, UFEs are not equally accessible to all interested students and can be laden with unique barriers to entry, particularly for URM students and students from low socioeconomic backgrounds (Morales et al. 2020, Zavaleta et al. 2020, Flowers et al. 2021, O'Connell et al. 2021). For community college students, these challenges are magnified and accompanied by institutional-specific barriers (Hewlett, 2018). Community college students make up a large portion of the undergraduate student population in the United States. In the 2019–2020 academic year, an estimated 7.7 million students (around 35% of U.S. undergraduates) attended community colleges (US DOE 2020a). Almost half of all students graduating with a STEM degree in 2020 had attended community college at some point; however, degree completion and transfer rates for community college students remain low, especially in STEM fields (Zhang 2021). Students starting in community college switch out of STEM majors at higher rates than students who start at 4-year universities (NASEM 2016). Of students entering community college in a STEM program over a 7-year study period, 69% left, either by switching to non-STEM programs or leaving college altogether in comparison with 48% for 4-year college students (Chen 2013). Further, the probability of attaining a bachelor's degree in a STEM field was more than four times higher for students starting at a 4-year institution compared with students starting at 2-year institutions (Wang 2015). The student populations of 2-year institutions are typically far more diverse than their 4-year counterparts. United States community colleges serve higher percentages of URM students (US DOE 2020b), students over the age of 24 (US DOE 2020c), low-income students (US DOE 2016), students working more than 30 hours per week (US DOE 2016), first-generation college students (US DOE 2016), and students who are parents (Noll et al. 2017, Reed et al. 2021). Given the broad and well-established benefits for students who participate in field experiences, and an urgent need to increase the inclusion and retention of a diverse student population in the natural sciences, it is valuable to target interventions, such as field research programs and field-based courses, at the community college level. Amanda Robin is a PhD candidate at the University of California, Los Angeles (UCLA), and the director of the Community College Field Biology Alliance (CCFBA). The CCFBA is an all student-run organization established in 2018 that provides community college students with the opportunity to design and enact research projects with ecological and animal behavior components. Cohorts of interns from 15 community colleges in the greater Los Angeles area are assigned a graduate and an undergraduate student mentor. Over 9 months, the teams move through the entire scientific process from exploring the literature, developing a hypothesis, experimental design, data collection and analysis, and the presentation of a research poster. Additionally, interns attend monthly workshops aimed at providing practical skills. Community college students are recruited to apply for the program through advertisements at their home campuses. Over the past 4 years, the CCFBA has developed a contact list of community college deans, department chairs, faculty, academic counselors, and STEM program administrators. On a yearly basis, recruitment materials are sent via email to this list. In addition, the program has also developed more formalized working relationships with STEM programs at several 2-year institutions nearby to the UCLA campus. These institutions incorporate direct links to the program application on their undergraduate research websites and facilitate more extensive recruitment outreach. Occasionally, they facilitate information sessions and have provided supplemental funding to support their students' CCFBA programming. Each year the number of applications received has increased and the program currently averages about 60 per cycle, of which 10–15 students are accepted. The CCFBA does not have any course prerequisites or GPA requirements and prioritizes accepting interns to the program with no previous research experience. This is considered a program strength in that it provides access to research for a broad range of students. The CCFBA programming aims to provide a foundational experience upon which students can build, and purposefully seeks students who may not otherwise be ready for larger, more competitive research experiences. The CCFBA attempts to increase program accessibility through the extended nature of the program's timeline. By requiring small monthly time commitments over 9 months, interns can maintain outside commitments while engaging with research. The program emphasizes exposure to the scientific process over the resulting research product, allowing interns to scale back the scope of their projects when needed. This emphasis provides the flexibility necessary to tailor the experience to the needs of individuals. Alongside research experiences, the CCFBA also provides transfer-student-focused programming, including Q&A panels with graduate students who are former community college students and one-on-one support with application preparation. Further, each intern's undergraduate mentor is a transfer student. Graduate student mentors attend a workshop prior to starting the program that provides an overview of the transfer process. The CCFBA has found challenges in the areas of interpersonal support for interns, maintaining accessibility, ensuring mentor engagement, and sourcing funding. Holistically supporting interns and ensuring accessible programming is a key goal but poses challenges. Many interns have actively struggled with food and housing insecurities and/or faced personal or familial health crises while in the program. The program found it challenging as a student organization separate from where the community college students live and attend college to aid with personal crises. In response, the CCFBA has attempted to balance program rigor with the flexibility required to make the program realistically completable for the highest number of interns. Students do not receive course credit because of the logistical challenges of arranging this with each student's college, as each cohort comes from multiple individual institutions. Additionally, the quality and quantity of engagement from mentors has been difficult to standardize. More time spent communicating leadership expectations and the unique needs of community college students to mentors has mitigated some of these challenges. Finally, it has been a struggle to obtain funding that would support the expansion of the program in key ways, such as the provision of stipends for interns. Currently, a majority of program funding is secured through grants from student associations at UCLA. The average cost per intern for a remote program is ~200 dollars (USD), and the cost per intern during in-person programming is ~600 USD. All programming is provided at no cost to the community college students. Prior to the COVID-19 pandemic, program meetings were held in person and included a trip to a field station managed by the University of California Natural Reserve System ~2 hours outside of Los Angeles to collect data. Two cohorts have now been completed remotely with fieldwork conducted in the interns' neighborhoods. Technologies like Zoom and communication applications like Slack have helped to facilitate an engaged online community. This program model has proven to be flexible and could likely be successful in any location, even in areas with distinct seasons, as it designed to have data collection focused in the summer months. Furthermore, there is potential to use open-source ecological data sets or data collected by remote sensors if the prospective program needs to be conducted during times when weather may be unsuitable for outdoor field research or students are unable or unwilling to conduct research outside. While working remotely has presented challenges in maintaining student engagement, assisting interns with data collection, and providing the appropriate equipment for them to safely do so, there have been benefits. Remote programming has highlighted the synergy between ecological field research and online internships for community college students by enabling a higher number of interns to participate, securing guest speakers that otherwise would not have been able to speak in person, and making our program open to those unable to travel (regardless of pandemic restrictions). Further, conducting fieldwork within their own communities illuminates for interns that ecological fieldwork is not something only reserved for "far off" places. Alison Varty is a faculty member and chair of the Environmental Science major at College of the Siskiyous, a publicly funded community college in a rural California mountain town. Like most community college students, those at College of the Siskiyous struggle to fit traditional field experiences (summer field classes or extracurricular activities) into their schedules due to their responsibilities outside of school. To address this challenge, Professor Varty integrated field experiences into several credit-based classes offered during the academic year. Further, she instituted a requirement for students in the Environmental Science major to complete a discipline-related science research or work-related project prior to graduation. Most students fulfill this requirement through for-credit field experiences. Their work has included internships at the local research station (Castle Lake Research Station), the Shasta-Trinity or Klamath National Forest, local native plant nurseries, private forestry companies, and at the local fish hatchery. These kinds of field experiences are popular because they often lead to long-term employment. Professor Varty has reached an even broader audience by creating hybrid and fully online courses that include field experiences. Her hybrid field botany course engages students in the study of plants through online asynchronous activities, including autonomous asynchronous field trips. During these trips, students take weekly excursions on their own to collect plants to practice keying using commercially available field guides and to perform floral or fruit dissections. In addition, students attend four all day face-to-face, synchronous group field trips. These trips complement the asynchronous work by helping students learn to identify plants they encounter in the field and providing them with hands-on experience collecting overstory and understory plant community data using quadrat and point-centered quarter sampling, respectively, that they later analyze and summarize on their own. Varty also teaches a fully online environmental science class, which involves many field-based laboratory activities. She has observed that field laboratories can actually be more equitable than traditional "cookbook" laboratories, because all students can get outside to a school or park or lawn, whereas not every student may have the required supplies (e.g., measuring spoons) in their home. James Hewlett is a Professor of Biology at Finger Lakes Community College (FLCC) in Canandaigua, New York. In 2001, FLCC conducted an internal study to better understand the barriers to developing Undergraduate Research Experiences (UREs) and potential strategies for establishing an undergraduate research program. The study uncovered several interesting and unanticipated hurdles to establishing an undergraduate research program at a community college that were unrelated to the oft-cited financial barriers or ill-prepared students. For example, the weak connection between community colleges, external networks, and science researchers was found to be a serious barrier. The results were compiled and used to create a model for integrating research experiences into a community college. After an initial rollout at FLCC, these principles were tested at six partner institutions with support from the National Science Foundation. The result was the establishment of the Community College Undergraduate Research Initiative (CCURI) in 2007. Community College Undergraduate Research Initiative is currently a national network of 142 community colleges in 39 states and two countries focused on the development and implementation of undergraduate research programs. The CCURI model, which was originally constructed to address barriers at FLCC, has been modified and expanded for implementation throughout the CCURI network. In its current form, the CCURI model incorporates solutions to the known barriers to integrating research into the student experience at community colleges. The CCURI model involves three levels. The first, "Engage," aims to immerse students in research from the moment they enter the classroom as freshman and is designed to promote conceptual understanding while also exposing students to ongoing CCURI research projects. Student-centered activities are used to teach basic scientific concepts within the context of an ongoing research project. The second level of the program is called "Explore." After engaging students in research questions as part of the freshman courses, the CCURI model creates opportunities for students to explore those questions in greater depth. These opportunities allow the students to continue these projects as a part of embedded regular course offerings at the college (CUREs; Course Undergraduate Research Experiences), a degree program (PURE; Program Undergraduate Research Experience), or as part of a credit-bearing summer experience (SURE; Summer Undergraduate Research Experience). The third component of the CCURI model, "Connect," involves connecting community college faculty and students to larger research communities. The growing CCURI network has become a rich source of collaboration on both the curricular and research sides of the CCURI model. At this level, students are connected to research opportunities and prospects to transfer their experience to a four-year institution as they continue to pursue their STEM career. Community College Undergraduate Research Initiative has built a nationwide network of community colleges who are committed to offering undergraduate research experiences at their home institutions. Community College Undergraduate Research Initiative partner institutions can access a suite of course curricula and professional development opportunities focused on student research. Further, the CCURI team shares data from meta-analyses of CCURI institutions as a way to develop best practices that can be shared both inside and outside the network. The goal is to continue to broaden participation in undergraduate research at our nation's community colleges. Jimmy Lee is an associate professor at East Los Angeles College, a large community college located near downtown Los Angeles that serves a primarily Hispanic and Asian student population. During a summer when he was not teaching, Prof. Lee participated in the Research Experience for Teachers (RET) program at the Rocky Mountain Biological Laboratory (RMBL). The RET program embeds teachers from community colleges within research teams to strengthen the scientific expertise of teachers and create lasting partnerships between educators and NSF-funded researchers. Following his RET experience, RMBL hired Lee to serve as its Education Program Coordinator. This is part of a RMBL initiative to recruit URM students by engaging with faculty from community colleges. RMBL has spent many years networking with community college instructors like Prof. Lee to build a pipeline that attempts to prioritize the recruitment of URM students for their summer research program. These connections result in roughly 15% of the 40 students in the undergraduate research program being composed of community college students each year. Professor Lee has found that community college students are often unaware of the benefits associated with participating in large, funded research internship programs, such as those provided by the National Science Foundation's Research Experiences for Undergraduates (REU). He finds that sharing stories and testimonials is an effective strategy to engage community college students and expose them to the potential advantages of applying to these types of opportunities. In these conversations, he talks about his own experience as an RET program participant at RMBL. Lee's work highlights how RET and REU programs can work in tandem to achieve greater diversity in participation. In addition to sharing his own experiences, he also invites past REU students from RMBL to talk with prospective students about their research projects and overall experience. Seeing and hearing from peers who have successfully participated in these programs provides students with strategies that they can then incorporate into their own academic trajectories. Community conversation participants' questions focused on (1) the concrete challenges of funding—who receives funding, and from what sources, and (2) anticipating and responding to students' needs in the field or at field stations. Specific program funding sources: Field research and learning experiences are important teaching and developmental tools for retaining students in STEM fields. Providing these experiences for community college students presents some unique challenges. Presenters in the UFERN Community Conversation spotlighted examples of how their institution, organization, or classes addressed these challenges. A major challenge discussed was students' family, community, and job commitments, which make participation in long-duration traditional field and research programs difficult. College of Siskiyous responds to these obstacles by providing course credit for students' internships or field experiences that take place in the community where they live. The CCFBA attempts to address this issue by spreading the research and workshop commitment over 9 months, which keeps the time required for any one activity more manageable. The CCURI program offers students opportunities to engage with research in a variety of ways from classroom-based experiences, summer long trips, and full degree programs. Further, CCURI found that there was insufficient communication between community colleges and research institutions. They responded by creating a network for community college faculty and administrators interested in providing research experiences to their students and connecting them to larger academic research networks. Another challenge participants noted was that "research" as a concept can at times feel alien and intimidating to students, or that students may not think participating in research is possible for them. Prof. Lee encouraged community college faculty to discuss the benefits and accessibility of formal programs like REUs with their students, and provide information, encouragement, and support to students who might not otherwise consider these experiences. Where possible, faculty are encouraged to share their own or past students' first-hand accounts of research program participation to normalize the experience. Further, offering local opportunities for students to engage in research that is connected to the student's community or location can help increase accessibility of field-based learning and highlight the potential relevance of conducting fieldwork for students. Lastly, funding is a critical challenge for programming success. Community college students overall do not typically have the same financial resources as students at 4-year colleges. Any program that hopes to have community college student participants should take the financial needs of students into serious consideration when designing programming and establishing expected time commitments and when travel is required be prepared to offer funding at, or above, the level provided to students from 4-year colleges before the program begins. Looking toward the future, research institutions and field stations should consider creating authentic partnerships and connections with community college campuses. Community college faculty and administrators can award credit for field-based internship or work experiences, and/or they can connect with national networks like CCURI to introduce research experiences to their own campuses. Faculty are encouraged to experiment with course formats to include fieldwork in students' own neighborhoods, group field trips, and even overnight excursions. Research groups at 4-year institutions like the CCFBA, as well as field stations, can work to provide students with flexible and accessible longer, mentored research experiences. Programming that is specifically designed to be thoughtful about the unique barriers community college students face will benefit the field as whole by fostering the early careers of this currently underrepresented student population in our broader community of scholars. This paper was initiated based on a high degree of interest from the UFERN community in engaging community college students in field learning experiences. We thank all the participants in the 15 October 2021 Community Conversation and other conversations at UFERN network meetings for inspiring this paper. This work was supported by the National Science Foundation under RCN-UBE grant no. 1730756 to K. O'Connell, A.R. Berkowitz, G. Bowser, and J. Branchaw.

Effects of a range-shifting caddisfly on life histories of a top predator in high elevation ponds - L. Crayton (2022)
Climate change is creating the opportunity for various species to undertake range expansion, both geographically and elevationally. There has been relatively little research into the ecological effects of these climate-driven range expansions on predators, particularly when the new species to a community fills a phenological gap in prey. The opportunity to learn more about these effects comes in a recent range expansion of a caddisfly species, Nemotaulius hostilis, into a well-studied, high elevation pond complex. I explored how this new species might be influencing the growth and life history of a top keystone predator, paedomorphic tiger salamanders. Using mark and recapture and comparing current collected data to that collected before N. hostilis was abundant, I tested how abundance of a new prey source is affecting salamander ecology. By understanding how a range extension influences top predators, we can gain insight into the direct and indirect effects of climate change on aquatic ecosystems.

Predicting the effects of climate change on the cross? scale epidemiological dynamics of a fungal plant pathogen - I. Miller; Juliana Jiranek; M. Brownell; S. Coffey; B. Gray; M. Stahl; C. J. E. Metcalf (Scientific Reports, 2022)

Temporal variation in high elevation plant-pollinator communities - D. Bernal (2022)
Plant-pollinator communities contribute to global diversity and are a good indicator of the health of an ecosystem. Climate change is causing phenological changes of flowering plants and pollinators. Changes in plant phenology can lead to a pollinator not being able to find sufficient pollen and nectar resources, while plants may produce fewer seeds. The focus of this study is to compare species diversity of a plant-pollinator community across three years in Virginia Basin, CO. Species richness and species diversity were greater in 2021 and 2022 compared to 2000. These results support the idea that insects are moving to higher elevation due to climate change. Increasing our sampling effort could give us different results. Further study of plant-pollinator networks across a range of temporal scales is needed, as the ability for plants and pollinators to adapt to mismatch remains unclear.

Floral phenotypic response of Ipomopsis aggregata and related hybrids to changing soil moisture and nitrogen enrichment - A. Aguilar (2022)
Plants are products of their environment. This is also true for flowers, which can be shaped through abiotic factors that lead to plastic response or natural selection. Both floral morphological traits and volatile organic compounds (VOCs) have the potential to be impacted by environmental conditions. Floral morphology has long been understood to shape pollinator- plant interactions. VOCs emitted by floral tissues compose a plant’s floral scent, which is important for a variety of reproductive-related interactions. Namely, both the concentration and type of VOCs influence the activity of associated pollinators and herbivores. Learning more about floral morphology and VOCs and their response to abiotic conditions is essential due to their significance to plant reproduction and the current trends in global change. To contribute to this growing collection of knowledge, we investigated the effects of differing soil moisture conditions and nitrogen enrichment on the floral traits and VOC profiles of the well- studied Ipomopsis aggregata and related hybrids. To achieve this, we performed two experiments. The first was an observational study which monitored in situ soil moisture and attempted to correlate that to the emissions of compound. The second experiment was a manipulative study where nitrogen fertilizer was added to understand the effects of increased nitrogen on floral traits and VOCs. In response to nitrogen and water treatments we observed increased corolla width within the hybrid population. In terms of VOCs, the main effect was a larger increase in emission of alpha-pinene and beta-myrcene at night when nitrogen was applied, an effect seen only in the I. aggregata population. We did not detect associations of the floral traits with soil moisture. Understanding the effect of environmental conditions on floral traits is essential if we wish to know more about the future of plant-related biotic interactions under climate change.

Life history consequences of climate change in hibernating mammals: a review - Caitlin P. Wells; R. Barbier; Stephen T. Nelson; R. Kanaziz; L. M. Aubry (Ecography, 2022)
Climatic shifts to warmer and often drier conditions are challenging terrestrial species worldwide. These shifts are occurring more rapidly at higher elevations and latitudes, likely causing disproportionate effects to mammalian hibernators there. While there is some information about how these species' ranges are responding to climatic shifts, we lack an understanding of how climate components are affecting species' life history variation, which is key to individual success and population‐level resilience. We reviewed the literature to identify the direction of life history responses to climate change in mammalian hibernators along three axes: latitudinal, elevational and temporal. We found 39 studies involving 27 species that reported climate effects on our four target life history traits – phenology, body mass/condition and growth, reproduction and survival. We found warmer temperatures are advancing hibernator phenology and increasing reproductive success. By contrast, warming and drying trends are having uncertain effects on body condition, and complex effects on survival – depending on season, age class, latitude and elevation. We found no pattern of significant climate‐trait outcomes by duration or decade of study. More research on drought conditions – particularly in relation to resource availability – would help inform hibernator susceptibility to increased drying trends expected to intensify globally. Notably, our results are highly biased towards small mammal hibernators in Northern Hemisphere alpine/mountain ecosystems, with few long‐term studies conducted on Southern Hemisphere hibernators. This review highlights that phenological shifts constitute one of the most obvious consequences of climate change, yet, the timing of life history events (e.g. timing of migration, reproduction, hibernation) remains poorly understood. Further integration of insights from physiologists, evolutionary biologists and population ecologists working on wild populations will improve our collective understanding of the effects of seasonal climatic shifts on mammalian hibernator life history traits, key drivers of their population‐level persistence.

Surface parameters and bedrock properties covary across a mountainous watershed: Insights from machine learning and geophysics - Sebastian Uhlemann; Baptiste Dafflon; Haruko M. Wainwright; K. H. Williams; Burke J Minsley; K. Zamudio; B. Carr; Nicola Falco; Craig Ulrich; S. S. Hubbard (Science Advances, 2022)
Bedrock property quantification is critical for predicting the hydrological response of watersheds to climate disturbances. Estimating bedrock hydraulic properties over watershed scales is inherently difficult, particularly in fracture-dominated regions. Our analysis tests the covariability of above- and belowground features on a watershed scale, by linking borehole geophysical data, near-surface geophysics, and remote sensing data. We use machine learning to quantify the relationships between bedrock geophysical/hydrological properties and geomorphological/vegetation indices and show that machine learning relationships can estimate most of their covariability. Although we can predict the electrical resistivity variation across the watershed, regions of lower variability in the input parameters are shown to provide better estimates, indicating a limitation of commonly applied geomorphological models. Our results emphasize that such an integrated approach can be used to derive detailed bedrock characteristics, allowing for identification of small-scale variations across an entire watershed that may be critical to assess the impact of disturbances on hydrological systems.

Carrying the moral burden of safe fieldwork - B. Blonder (Bulletin of the Ecological Society of America, 2022)
Fieldwork in ecology and the environmental sciences often leads to negative physical and emotional outcomes for workers. I argue that this is largely due to an abdication of responsibility on the part of their supervisors, and that supervisors are charged with carrying three interlinked moral burdens: first, the duty of promoting safety; second, the duty of ensuring safe experiences are accessible to all; and third, the duty of continuing to learn and improve. To help, I offer a set of safety actions that supervisors can easily implement. I then offer a set of personal reflections on how we should think about failure, accountability, learning, repair, and forgiveness in the scientific workplace. Key words: field safety; field work; equity; inclusion; ethics; supervisor.

Reconsidering the 1922 Colorado River Compact at 100 - Lawrence MacDonnell (SSRN Electronic Journal, 2022)

Forest Fuels and Management Considerations at the Willey Conservation Easement, Colorado - M. Philips (2022)

The Boechera model system for evolutionary ecology - Catherine Rushworth; Maggie Wagner; T. Mitchell-Olds; J. T. Anderson (American Journal of Botany, 2022)

Predators balance consequences of climate-change-induced habitat shifts for range-shifting and resident species - I. D. Shepard; S. A. Wissinger; Z. T. Wood; H. S. Greig (Journal of Animal Ecology, 2022)

Effects of an introduced mustard, Thlaspi arvense, on soil fungal communities in subalpine meadows - A. N. Trautwig; M. A. Anthony; S. D. Frey; K. A. Stinson (Fungal Ecology, 2022)

The effects of environmental variation on daily abundance patterns and diet breadth of bumble bee species - M. Gorchkova (2022)

Causes and consequences of pre-hibernation body mass in golden-mantled ground squirrels (Callospermophilus lateralis) - S. Howland (2022)
Mammals that cope with harsh environmental conditions by hibernating show seasonal variation in body mass, as fat reserves are accumulated during summer and depleted during winter. Hence, pre-hibernation mass is often considered a key phenotypic trait in hibernating species that can be an indicator of future survival and reproductive success. We used 30 years of demographic data from a high-elevation population of golden-mantled ground squirrels (Callospermophilus lateralis) to identify life-history and environmental variables that influence pre-hibernation mass in females, and to determine if pre-hibernation mass influences overwinter survival or subsequent reproduction. Growth curves revealed female-biased size dimorphism, with adult mass not attained until age 2 years, so we considered three age classes of females, juveniles, yearlings, and adults (≥2 years). We found that earlier snow melt during spring is associated with higher pre-hibernation masses of yearlings and adults, and that juveniles emerging earlier from their natal burrows had higher pre-hibernation masses than later-emerging juveniles. Measures of food quantity or quality did not affect pre-hibernation mass for any age class, nor was there an effect of reproductive status. Juvenile females with greater per- hibernation mass were more likely to survive overwinter and reproduce as yearlings, but we found no such effect for yearlings or adult females. We did not find an effect of snow depth or winter duration on either survival or reproduction. Our results indicate that time appears to be the key variable for golden-mantled ground squirrels to acquire sufficient body mass to survive and reproduce, but the effects vary by age class. ii

Perturbations in plant-pollinator networks: Integrating theoretical and empirical approaches to understand responses to global change - C. N. Morozumi (2022)
Perturbations in plant-pollinator networks: integrating theoretical and empirical

Climate change and phenology - David W. Inouye (WIREs Climate Change, 2022)
Climate change is a defining element of the current ecological landscape, with consequences ranging from global to local environments. One of the first indices of the ecological impact of the ongoing environmental changes was measurement of their effects on phenology, the seasonal timing of Crested Butte, Colorado, 81224, USA. Email: inouye@umd.edu recurring annual events such as the beginning of the growing season, timing of flowering, and breeding seasons of animals. Research has moved beyond Funding information simple descriptions of these temporal changes to investigations of their root National Science Foundation, Grant/ Award Numbers: DEB-0922080, DEB-1354104, DEB-1912006 causes, impacts, and consequences at both ecological and evolutionary time scales. This changing landscape, environmental, ecological, and evolution- ary, makes this an exciting, albeit sometimes depressing, time to be a scientist. Edited by Brendon M.H. Larson, Domain Editor, and Mike Hulme, Editor-in-Chief This article is categorized under: Assessing Impacts of Climate Change > Observed Impacts of Climate Change Climate, Ecology, and Conservation > Observed Ecological Changes

Microvirus Genomes Identified in Fecal Samples from Yellow - Bellied Marmots - C. L. Tijerino; Daniel T. Blumstein; S. Kraberger; A. Varsani (Microbiology Resource Announcements, 2022)

Evolution of foraging traits in hummingbirds - N. M. Alexandre (2022)

DEFINING THE ENDMEMBER SYSTEM OF US SOILS AND QUANTIFYING RELATIONSHIPS, AND A HYPERSPECTRAL APPROACH TO THE ALTERATION STRENGTH INDEX - Rachel Rulison (2022)
Soils form a complex part of the environment, providing important functions in systems such as food production, groundwater movement, and ecosystem health. There have been numerous studies on soil geochemistry and the origin of elements within soils, but few studies into quantifying the relationships between elements and geographical data on a national scale. Using geochemical data obtained by the USGS, the surficial soils of the US were defined by a 13-endmember system using Polytopic Vector Analysis and mapped in GIS. Correlation matrices provided Pearson’s correlation coefficients for elements in the Top 5 cm soil profile, the A horizon, and the C horizon. The Top 5 cm element concentrations were also correlated with the endmembers, and geographical data for land cover, soil order, and soil pH. The quantification of these relationships supported many of the spatial patterns shown in maps and provided insight into other relationships, especially where correlation is weaker. The high spectral resolution of hyperspectral imagery has provided revolutionary advancements in many fields, including mineral identification. Hyperspectral core data from the company Corescan allowed for quantifiable mineral proportions for core sections from Karaha Telaga-Bodas, in Indonesia, and Lake City Caldera, in Colorado. The Alteration Strength Index (ASI) is a value based on mineral parameters that correlate to rock strength. The incorporation of hyperspectral data in the ASI aimed to improve the accuracy of the mineralogical parameters and provide more reliable strength data which in turn would reduce the need for time-consuming lab testing. Results showed that for the Telaga Bodas and Lake City samples, the ASI was not able to provide rock strength estimates within a reasonable range, and calibration of mineralogical parameters may be needed for samples with low ASI values. Though hyperspectral data may be a valuable tool in this venture, other issues with the current ASI would need to be resolved.

Effects of Environmental Pond Drying Cues on Asynarchus nigriculus Cannibalism Rates - M. Tainatongo (2022)
Mexican Cut Preserve in the Elk Mountains is home to a unique system of ponds with a high diversity of aquatic life. Many species of caddisflies inhabit the various temporary, semi- permanent, and permanent ponds, including Asynarchus nigriculus. A. nigriculus is an aggressive caddisfly species that occasionally engages in cannibalism. The factors that cause A. nigriculus to go from a detritivore diet to cannibalism are not fully known. However, there is evidence that pond drying events may prompt a shift to cannibalistic behaviors to provide A. nigriculus individuals with the nutrients necessary to develop quickly. My research tested whether some of the environmental factors associated with pond drying events induce cannibalism. Specifically, I evaluated increased presence of other caddisfly species, increased conductivity, and greater temperature fluctuations as potential cues for cannibalistic behavior. First, species density tests were used to determine how the presence of another species, Agrypnia deflata, affects cannibalism rates in A. nigriculus. Here, one treatment contained both A. nigriculus and A. deflata, while the other two treatments contained a population of only A. nigriculus and a population of A. deflata. Second, I used a 2x2 factorial design experiment to evaluate temperature and conductivity as cues for cannibalism. Thus, I used these two experiments to gather data on several abiotic and biotic environmental factors that could alter cannibalism rates in the species A. nigriculus.

Abundance and Identification of Hymenopteran Parasitoids in Euphydryas gilletti - C. Rodriquez (2022)
Introduced species are thought to be free of natural enemies when they are brought into a new area. Euphydryas gilletti was introduced to RMBL to the south of its native range in the northern Rockies. I used this butterfly to examine whether it has fewer parasitoids in its new environment. To check, this study focuses on a butterfly species (Euphydryas gillettii) introduced experimentally in the vicinity of the RMBL and the potential ecological interactions it has with the other insects in its novel habitat. This butterfly has been studied since it was introduced in 1977 but not much is known about its interactions with parasitoids in the area. I conducted a survey at RMBL of the presence of lepidopteran parasitoids and the amount of parasitism on the butterfly egg masses. I surveyed and located parasitoids by sweep-netting and bagged egg masses to check if parasitoids used the eggs as hosts. There were no significant differences in parasitoids found across subsites or when comparing collections between plant or the ground and no parasitoids emerged from Euphydryas gillettii egg masses. In conclusion, my observations suggest that although parasitoids are present, the introduced species E. gillettii does not interact with any parasitoids in this location, supporting the idea that introduced species may escape their natural enemies.

The Effect of Snowmelt Timing on Pollinator Visitation to Subalpine Wildflowers - J. Moloney (2022)
The plant and pollinator mutualism is under increased stress due to climate change, especially in subalpine ecosystems. Climate change is altering the timing of snowmelt in subalpine ecosystems, which changes the flowering phenology and possible the floral abundance of subalpine plants and therefore can impact plant and pollinator interactions. Data gathered at RMBL shows that the date of earliest snowmelt and mean summer temperature are increasing at an unsustainable rate. To better understand the consequences of snowmelt timing on plant-pollinator interactions, an early snowmelt manipulation was performed and pollinator observations were conducted on four subalpine species at the Rocky Mountain Biological Laboratory. The study consists of a numerous pollinator observation sessions in control and early snowmelt plots on 4 species of wildflowers: Delphinium nuttallianum (DENU), Geum triflorum (GETR), Linum lewisii (GETR), and Delphinium barbeyi (DEBA). The four species represent a gradient of phenological flower timing across the growing season beginning with DENU and ending with DEBA. This study aims to allow us to more accurately predict the changes to plant-pollinator interactions in the future as climate change accelerates plant and animal phenology. It was hypothesized that increased likelihood of frost, decreased water availability, and loss of phenological synchrony between wildflowers and pollinators would lead to a lower mean visitation rate and probability of visits in early snowmelt plots compared to the controls. I found that DENU experienced a significantly lower mean visitation rate in early snowmelt plots while LILE experienced significantly higher mean visitation rate. Only DEBA differed significantly the in probability of receiving visit, with a higher probability in early snowmelt. It is possible that as climate change becomes more severe, there will be differential impacts for subalpine plant species and therefore both positive and negative effects on plant and animal interactions. Species that are more resilient to frost and phenological mismatch like LILE may be able to outcompete other more frost and phonologically sensitive species such as DEBA and DENU. More years of study as well as further investigation of species’ reproductive efficacy is needed to support this hypothesis.

Does an achromatic border alter color discrimination of male Speyeria mormonia butterflies during mate searching? - S. Maass (2022)
Larval food stress for the butterfly Speyeria mormonia causes less pigmentation in female butterflies. For this reason, males may approach females with higher pigmentation more often because it is a sign that they are healthier. Past studies have shown that this could be true, but they have not taken into account the markings on the butterflies’ wings. The achromatic black markings in contrast with the orange color stimulus of the wing could cause the male butterflies to perceive the color stimulus differently than they would without the markings. I added a black border to butterfly decoys made from three different colored Pantone papers, representing a super stimulus, high pigmentation, and low pigmentation, and observed approaches by males to see whether the achromatic border makes a difference in the way males perceive the color stimulus. I hypothesized that I would see a 1:1 ratio of approaches to butterfly decoy pairs with the border, and that the ratio for decoy pairs with the border would not differ from those without the border. Only the super stimulus and high pigment pair with borders did not deviate from a 1:1 ratio of approaches by males. Comparing results for decoy pairs with the border and without the border, only the high pigment and low pigment pairs differed, with more approaches to the low pigment decoy with the border than without the border. This suggests that while pigmentation does matter in the likelihood of approach by a male, so does the black border and markings. Females with low pigmentation will still be approached because of their achromatic markings causing the male butterflies to perceive the color stimulus differently.

Testing for competition, facilitation, and intraguild predation between two co-dominant detritivores: the caddisfly Limnephilus externus and chironomid midges - Mark Ivan Jacobson (2022)
Most living organic material goes through the detrital pathway. Detritovores are incredibly important in ecosystems for the recycling of nutrients and energy. This project explores the inter- and intraspecies relationships between two co-dominant detritovores that inhabit the high-elevation rocky mountain ponds: the caddis fly, Limnephlus externus, and chironomid midges. Specifically, we are trying to determine if there is competition, facilitation, or intraguild predation between Limnephilus externus and chironomid midges. With climate change, the permanent and semipermanent ponds are becoming increasingly temporary. The issue this presents is that L.externus cannot survive in temporary ponds due to their long development time. Therefore, identifying the relationships between the two taxa can help us understand how detrital processing may change with the possible loss of L. externus or shifts in species abundances. For this experiment, we used a response surface design and altered the relative abundances to test for the relationships between the two taxa. Add summary sentence of findings

The Impact of Carrion Insects on Human Impacted Soil - B. Guijosa (2022)
Carrion plays an important role in maintaining ecosystems and providing resources for different forms of life, returning key nutrients to the environment and serving as a food source for animals. While vertebrates who consume carrion are well studied, invertebrates are not as well studied, primarily carrion insects. With the decline of mammalian scavengers due to human impact and removal of large vertebrate carcasses from ecosystems, there is a need to understand how effective insects are as scavengers, as they are common on carrion sources. In this experiment, different carrion insects were placed into containers containing poor soil, and after 3 weeks were removed and seeds were planted into the soil as a bioassay, where the root weight fraction was calculated and used to determine the quality of the soil. The results showed that carrion insects have varying influences on soil nutrients, with carrion beetles having more impact compared to flies and carrion alone.

Golden-Mantled Ground Squirrel ( Spermophilus lateralis ) and Yellow-Bellied Marmot ( Marmota flaviventris ) Intraspecific and Interspecific Perch Use and Interaction Dynamics in Gothic, Colorado - A. Dorr (2022)
Golden-mantled ground squirrels (Spermophilus lateralis) and yellow-bellied marmots (Marmota flaviventris) can both be found in abundance at high elevation meadows in the Rocky Mountains. Though different in behavior, both species inhabit and utilize the open meadows of Gothic in very similar ways. Both species utilize perches and respond to each other’s alarm calls. Additionally, here in the Gothic town site, both species’ have been studied and recorded for many years. This research project aims to examine how golden-mantled ground squirrels share habitat features and interact with yellow-bellied marmots in the Gothic town site. This was done by collecting observational data during the summer of 2022 in Gothic, Colorado. Using the

Limnephilus externus Case Grazing Effects on Predation - G. Bobo (2022)
Predator prey interactions are essential components of ecosystems, especially in lower trophic levels as they fuel many other organisms. Many prey organisms have developed tactics to decrease the rate of predation. For example, larval caddisflies build cases out of sedge and other detritus in their environment. These cases provide caddisflies with more protection from predators relative to other aquatic invertebrates. However, one species of caddisfly, Limnephilus externus, has been observed grazing on its case. The reason for this is unknown, but I hypothesized that it could make them more vulnerable to predation. Here, I tested how grazed and ungrazed cases influenced rates of salamander predation on L. externus. Based on the results of the experiment, case grazing does not have a significant effect on predation rates. These results narrow down the possible reasons that L. externus case grazes, but further research needs to be done to determine to why case grazing occurs.

Hibernation slows epigenetic ageing in yellow-bellied marmots - G. M. Pinho; J. G. A. Martin; C. Farrell; Amin Haghani; J. Zoller; J. Zhang; S. Snir; M. Pellegrini; R. K. Wayne; Daniel T. Blumstein; S. M. Horvath (Nature Ecology & Evolution, 2022)
Abstract Species that hibernate live longer than would be expected based solely on their body size. Hibernation is characterized by long periods of metabolic suppression (torpor) interspersed by short periods of increased metabolism (arousal). The torpor-arousal cycles occur multiple times during hibernation, and it has been suggested that processes controlling the transition between torpor and arousal states cause aging suppression. Metabolic rate is also a known correlate of longevity, we thus proposed the ‘hibernation-aging hypothesis’ whereby aging is suspended during hibernation. We tested this hypothesis in a well-studied population of yellow-bellied marmots (Marmota flaviventer), which spend 7-8 months per year hibernating. We used two approaches to estimate epigenetic age: the epigenetic clock and the epigenetic pacemaker. Variation in epigenetic age of 149 samples collected throughout the life of 73 females was modeled using generalized additive mixed models (GAMM), where season (cyclic cubic spline) and chronological age (cubic spline) were fixed effects. As expected, the GAMM using epigenetic ages calculated from the epigenetic pacemaker was better able to detect nonlinear patterns in epigenetic age change over time. We observed a logarithmic curve of epigenetic age with time, where the epigenetic age increased at a higher rate until females reached sexual maturity (2-years old). With respect to circannual patterns, the epigenetic age increased during the summer and essentially stalled during the winter. Our enrichment analysis of age-related CpG sites revealed pathways related to development and cell differentiation, while the season-related CpGs enriched pathways related to central carbon metabolism, immune system, and circadian clock. Taken together, our results are consistent with the hibernation-aging hypothesis and may explain the enhanced longevity in hibernators.

“We Are Only Activators” – Virginia Satir and the Mystery of Human Life: A Reflection - Barbara Jo Brothers (2022)
Edited transcription of three lectures, given by Virginia Satir, on the same topic, but presented in three different ways. Lectures were each a part of a month-long seminar given in 1981, 1982, and 1983 during module I of the Avanta Process Community Meetings in Crested Butte, Colorado. [Article copies available for a fee from The Haworth Document Delivery Service: 1-800-342-9678. E-mail address: getinfo@haworthpressinc.com <Website: https://www.haworthpressinc.com>]

An equation of state unifies diversity, productivity, abundance and biomass - J. Harte; M. Brush; E. Newman; K. Umemura (Communications Biology, 2022)
To advance understanding of biodiversity and ecosystem function, ecologists seek widely applicable relationships among species diversity and other ecosystem characteristics such as species productivity, biomass, and abundance. These metrics vary widely across ecosystems and no relationship among any combination of them that is valid across habitats, taxa, and spatial scales, has heretofore been found. Here we derive such a relationship, an equation of state, among species richness, energy flow, biomass, and abundance by combining results from the Maximum Entropy Theory of Ecology and the Metabolic Theory of Ecology. It accurately captures the relationship among these state variables in 42 data sets, including vegetation and arthropod communities, that span a wide variety of spatial scales and habitats. The success of our ecological equation of state opens opportunities for estimating difficult-to-measure state variables from measurements of others, adds support for two current theories in ecology, and is a step toward unification in ecology.

Obituary: Kenneth Barclay Armitage (1925—2022) - C. M. Salsbury; D. H. Van Vuren; W. S. Fairbanks; E. L. Barthelmess; Daniel T. Blumstein; J. L. Koprowski; R. M. Timm (Journal of Mammology, 2022)

BASIN-3D: A brokering framework to integrate diverse environmental data - Charuleka Varadharajan; Valerie Hendrix; D. S. Christianson; Madison Burrus; C. Wong; S. S. Hubbard; Deb Agarwal (Computers & Geosciences, 2022)
Diverse observational and simulation datasets are needed to understand and predict complex ecosystem behavior over seasonal to decadal and century time-scales. Integration of these datasets poses a major barrier towards advancing environmental science, particularly due to differences in the structure and formats of data provided by various sources. Here, we describe BASIN-3D (Broker for Assimilation, Synthesis and Integration of eNvironmental Diverse, Distributed Datasets), a data integration framework designed to dynamically retrieve and transform heterogeneous data from different sources into a common format to provide an integrated view. BASIN-3D enables users to adopt a standardized approach for data retrieval and avoid customizations for the data type or source. We demonstrate the value of BASIN-3D with two use cases that require integration of data from regional to watershed spatial scales. The first application uses the BASIN-3D Python library to integrate time-series hydrological and meteorological data to provide standardized inputs to analytical and machine learning codes in order to predict the impacts of hydrological disturbances on large river corridors of the United States. The second application uses the BASIN-3D Django framework to integrate diverse time-series data in a mountainous watershed in East River, Colorado, United States to enable scientific researchers to explore and download data through an interactive web portal. Thus, BASIN-3D can be used to support data integration for both web-based tools, as well as data analytics using Python scripting and extensions like Jupyter notebooks. The framework is expected to be transferable to and useful for many other field and modeling studies.

Intraspecific Variation in Responses of a Montane Grass, Festuca thurberi , to Simulated Biological Invasion - A. N. Trautwig; E. A. Cousins; K. A. Stinson (Frontiers in Forests and Global Change, 2022)

Sex-specific reproductive strategies in wild yellow-bellied marmots ( Marmota flaviventer ): senescence and genetic variance in annual reproductive success differ between the sexes - S. St. Lawrence; M. N. Dumas; M. B. Petelle; Daniel T. Blumstein; J. G. A. Martin (Behavioral Ecology and Sociobiology, 2022)
Owing to sex-specific reproductive strategies, the mean and variance in annual offspring production may differ between the sexes. In addition, there may be sex-specific changes in reproductive performance with age (e.g. senescence). We used 20 and 50 years of longitudinal data on male and female yellow-bellied marmots, respectively, to investigate sex-specific age effects and genetic variance in annual reproductive success. In both sexes, annual offspring production increased linearly with age until a peak was reached at 7 years. This was followed by a decline in annual offspring production in both sexes, indicative of reproductive senescence. However, the initial increase and the subsequent decline (senescence) in reproductive success were both faster in males compared to females. Genetic variance in annual offspring production was higher in males than in females, but heritability was low for both sexes. Additionally, we found no cross-sex genetic correlation in the number of offspring produced, possibly reflecting sex-specific selection related to the inter-sexual differences in reproductive strate- gies. There was an effect of year on annual offspring production in both sexes, with a high yearly correlation between the sexes emphasizing the importance of environmental variation in determining fitness. Overall, these results demonstrate the impact of sex-specific reproductive strategies on annual offspring production and suggest that male and female marmots may be evolving to separate phenotypic optima. This study further demonstrates the value and limitations of long-term studies investigating sex-based patterns of ageing in the wild. Significance This study on yellow-bellied marmots demonstrates the key constraints surrounding the research of age-related changes in reproduction in wild populations, which is especially challenging in males. Among these challenges are high immigration rates which prevent the estimation of exact age and maternal identity. Genetic analysis—the only reliable way to estimate paternity—has only been a recent development, limiting the number of father-son relationships available for analysis. The dataset used in this study is long term (20 years of data on males and 50 on females), partially overcoming these obstacles. Results show that reproductive success declines with age in both sexes, with a faster rate of decline in males compared to females, and is influenced by the environment. Genetically, male and female reproductive success is not correlated, revealing that both sexes may be following separate evolutionary trajectories.

Confluence: The Colorado River Compact's Centennial - Jason Anthony Robison (Wyoming Law Review, 2022)
Many thanks to Remi Bullock for that introduction and, more broadly, to the Potter

New Upper Cretaceous Microvertebrate Assemblage from the Williams Fork Formation, northwestern Colorado, U.S.A., and its Paleoenvironmental Implications - Nickolas Brand; Andrew Heckert; Israel Sanchez; John R. Foster; ReBecca K. Hunt-Foster; Jaelyn Eberle (Acta Palaeontologica Polonica, 2022)
We describe a microvertebrate assemblage from the J&M site, of the Upper Cretaceous (Campanian-Maastrichtian) Williams Fork Formation. Breakdown of fossil bearing matrix was achieved with the use of heated dimethyl sulfoxide. Nine of the recovered taxa are new to both the J&M site and the Williams Fork Formation. The sharks Lonchidion griffisi, Chiloscyllium sp., and Cantioscyllium markaguntensis are the first non-batoid elasmobranchs reported from the Williams Fork Formation and are all represented by teeth. The rays Cristomylus and Psuedomyledaphus are also newly reported from teeth. The most common identifiable fossils were teeth of indeterminate amiids, most likely belonging to Melvius. Osteichthyan fossils new to the Williams Fork Formation include teeth of Paralbula, an indeterminate pycnodontid tooth plate fragment, and an indeterminate lungfish tooth fragment. A tooth of the teiid Peneteius is also the first reported from within the Williams Fork Formation. Alligatoroid teeth are relatively common and are extremely similar to those of the contemporaneous durophage Brachychampsa but are generically indeterminate. Terrestrial taxa were recovered in much smaller numbers. Theropod dinosaur fossils included isolated tooth fragments belonging to an indeterminate dromaeosaurid and, possibly, to Richardoestesia. We recovered both multituberculate and metatherian fossils in the form of isolated teeth. Some of these taxa are known from marine and estuarine deposits and, given that so many of these marine associated taxa have been recovered together, it seems likely that the J&M site is recording marine or estuarine influence within at least part of its depositional history. The mammalian taxa suggest a Judithian-Lancian age for the site, while records of the squamate Peneteius and the ray Myledaphus, suggest that the J&M site may be temporally transitional between other late Campanian and late Maastrichtian-aged localities.

Integrating natural gradients, experiments, and statistical modeling in a distributed network experiment: An example from the WaRM Network - C. M. Prager; Aimee T Classen; M. K. Sundqvist; M. N. Barrios-Garcia; E. K. Cameron; L. Chen; C. Chisholm; T. W. Crowther; J. R. Deslippe; K. Grigulis; He J-S; Jeremiah A Henning; et al. (Ecology and Evolution, 2022)
A growing body of work examines the direct and indirect effects of climate change on ecosystems, typically by using manipulative experiments at a single site or performing meta-analyses across many independent experiments. However, results from single-site studies tend to have limited generality. Although meta-analytic approaches can help overcome this by exploring trends across sites, the inherent limitations in combining disparate datasets from independent approaches remain a major challenge. In this paper, we present a globally distributed experimental network that can be used to disentangle the direct and indirect effects of climate change. We discuss how natural gradients, experimental approaches, and statistical techniques can be combined to best inform predictions about responses to climate change, and we present a globally distributed experiment that utilizes natural environmental gradients to better understand long-term community and ecosystem responses to environmental change. The warming and (species) removal in mountains (WaRM) network employs experimental warming and plant species removals at high- and low-elevation sites in a factorial design to examine the combined and relative effects of climatic warming and the loss of dominant species on community structure and ecosystem function, both above- and belowground. The experimental design of the network allows for increasingly common statistical approaches to further elucidate the direct and indirect effects of warming. We argue that combining ecological observations and experiments along gradients is a powerful approach to make stronger predictions of how ecosystems will function in a warming world as species are lost, or gained, in local communities.

Removing flowers of a generalist plant changes pollinator visitation, composition, and interaction network structure - J. A. Bain; R. Dickson; A. M. Gruver; Paul J. CaraDonna (Ecosphere, 2022)
Abstract Pollination is essential for ecosystem functioning, yet our understanding of the empirical consequences of species loss for plant–pollinator interactions remains limited. It is hypothesized that the loss of abundant and generalized (well‐connected) species from a pollination network will have a large effect on the remaining species and their interactions. However, to date, relatively few studies have experimentally removed species from their natural setting to address this hypothesis. We investigated the consequences of losing an abundant, generalist native species from a series of plant–pollinator networks by experimentally removing the flowers of Helianthella quinquenervis (Asteraceae) from half of a series of 10 paired plots (15 m diameter) within a subalpine ecosystem. We then asked how the localized loss of this species influenced patterns of pollinator visitation, floral visitor composition, and interaction network structure. The experimental removal of Helianthella flowers led to an overall decline in plot‐level pollinator visitation rates and shifts in pollinator composition. Species‐level responses to floral removal differed between the two other abundant, co‐flowering plants in our experiment: Potentilla pulcherrima received higher visitation rates, whereas Erigeron speciosus visitation rates did not change. Experimental floral removal altered the structural properties of the localized plant–pollinator networks such that they were more specialized, less nested, and less robust to further species loss. Such changes to interaction network structure were consistently driven more by species turnover than by interaction rewiring. Our findings suggest that the local loss of an abundant, well‐linked, generalist plant can bring about diverse responses within intact pollination networks, including potential competitive and facilitative effects for individual species, changes to network structure that may render them more sensitive to future change, but also numerous changes to interactions that may also suggest flexibility in response to species loss.

Genetic and spatial variation in vegetative and floral traits across a hybrid zone - Diane R. Campbell; Robert A. Raguso; Maya Midzik; Mascha Bischoff; Geoffrey Broadhead (American Journal of Botany, 2022)
AbstractPremiseGenetic variation influences the potential for evolution to rescue populations from impacts of environmental change. Most studies of genetic variation in fitness‐related traits focus on either vegetative or floral traits, with few on floral scent. How vegetative and floral traits compare in potential for adaptive evolution is poorly understood.MethodsWe measured variation across source populations, planting sites, and genetic families for vegetative and floral traits in a hybrid zone. Seeds from families of Ipomopsis aggregata, I. tenuituba, and F1 and F2 hybrids of the two species were planted into three common gardens. Measured traits included specific leaf area (SLA), trichomes, water‐use efficiency (WUE), floral morphology, petal color, nectar, and floral volatiles.ResultsVegetative traits SLA and WUE varied greatly among planting sites, while showing weak or no genetic variation among source populations. Specific leaf area and trichomes responded plastically to snowmelt date, and SLA exhibited within‐population genetic variation. All aspects of floral morphology varied genetically among source populations, and corolla length, corolla width, and sepal width varied genetically within populations. Heritability was not detected for volatiles due to high environmental variation, although one terpene had high evolvability, and high emission of two terpenes, a class of compounds emitted more strongly from the calyx than the corolla, correlated genetically with sepal width. Environmental variation across sites was weak for floral morphology and stronger for volatiles and vegetative traits. The inheritance of three of four volatiles departed from additive.ConclusionsResults indicate stronger genetic potential for evolutionary responses to selection in floral morphology compared with scent and vegetative traits and suggest potentially adaptive plasticity in some vegetative traits.

Future Colorado River Basin Drought and Surplus - Rama Bedri; Thomas C. Piechota (Hydrology, 2022)
Historical and future drought and surplus periods in the Colorado River basin are evaluated based on eight climate scenarios. Unimpaired streamflow from 17 stations in the Colorado River are evaluated based on U.S. Geological Survey, Bureau of Reclamation, and Coupled Modeled Intercomparison Projection 5 downscaled data from 1950–2099. Representative Concentration Pathway (RCP) 4.5 and 8.5 emission scenarios are considered for four climate models (HadGEM2-ES, CNRM-CM5, CanESM2, MI-ROC5). Drought (surplus) quantities, magnitudes, severities, and water year flows are compared for the historical and future periods. Results indicate that there is a significant difference between the historical record and future projections. The results are not consistent in terms of increase of drought or surplus; however, the intensity (as measured by magnitude and duration) will likely increase for both RCP 4.5 and 8.5. The CanESM2 and CNRM-CM5 models project wetter scenarios, and HadGEM2 and MI-ROC5 models project drier scenarios. For the critical Lees Ferry station, models indicate a chance of higher drought and surplus length and magnitude on the order of two times the historical period. In addition, basin wide flow at Lees Ferry had a shift in the future mean ensemble of approximately 3–10% for the water year. Future hydrologic changes will heighten the need for appropriate management and infrastructure options available to adapt to these changes.

Variability in observed stable water isotopes in snowpack across a mountainous watershed in Colorado - R. W. H. Carroll; Jeffrey Deems; R. M. Maxwell; Matthias Sprenger; W. Brown; Alexander W. Newman; Curtis A. Beutler; Markus Bill; S. S. Hubbard; K. H. Williams (Hydrological Processes, 2022)
AbstractIsotopic information from 81 snowpits was collected over a 5‐year period in a large, Colorado watershed. Data spans gradients in elevation, aspect, vegetation, and seasonal climate. They are combined with overlapping campaigns for water isotopes in precipitation and snowmelt, and a land‐surface model for detailed estimates of snowfall and climate at sample locations. Snowfall isotopic inputs, describe the majority of δ18O snowpack variability. Aspect is a secondary control, with slightly more enriched conditions on east and north facing slopes. This is attributed to preservation of seasonally enriched snowfall and vapour loss in the early winter. Sublimation, expressed by decreases in snowpack d‐excess in comparison to snowfall contributions, increases at low elevation and when seasonal temperature and solar radiation are high. At peak snow accumulation, post‐depositional fractionation appears to occur in the top 25 ± 14% of the snowpack due to melt‐freeze redistribution of lighter isotopes deeper into the snowpack and vapour loss to the atmosphere during intermittent periods of low relative humidity and high windspeed. Relative depth of fractionation increases when winter daytime temperatures are high and winter precipitation is low. Once isothermal, snowpack isotopic homogenization and enrichment was observed with initial snowmelt isotopically depleted in comparison to snowpack and enriching over time. The rate of δ18O increase (d‐excess decrease) in snowmelt was 0.02‰ per day per 100‐m elevation loss. Isotopic data suggests elevation dictates snowpack and snowmelt evolution by controlling early snow persistence (or absence), isotopic lapse rates in precipitation and the ratio of energy to snow availability. Hydrologic tracer studies using stable water isotopes in basins of large topographic relief will require adjustment for these elevational controls to properly constrain stream water sourcing from snowmelt.

A distributed temperature profiling system for vertically and laterally dense acquisition of soil and snow temperature - Baptiste Dafflon; Stijn Wielandt; Jack Lamb; P. McClure; I. Shirley; Sebastian Uhlemann; C. Wang; S. Fiolleau; C. Brunetti; F. H. Akins; J. Fitzpatrick; S. Pullman; et al. (The Cryosphere, 2022)
Abstract. Measuring soil and snow temperature with high vertical and lateral resolution is critical for advancing the predictive understanding of thermal and hydro-biogeochemical processes that govern the behavior of environmental systems. Vertically resolved soil temperature measurements enable the estimation of soil thermal regimes, frozen-/thawed-layer thickness, thermal parameters, and heat and/or water fluxes. Similarly, they can be used to capture the snow depth and the snowpack thermal parameters and fluxes. However, these measurements are challenging to acquire using conventional approaches due to their total cost, their limited vertical resolution, and their large installation footprint. This study presents the development and validation of a novel distributed temperature profiling (DTP) system that addresses these challenges. The system leverages digital temperature sensors to provide unprecedented, finely resolved depth profiles of temperature measurements with flexibility in system geometry and vertical resolution. The integrated miniaturized logger enables automated data acquisition, management, and wireless transfer. A novel calibration approach adapted to the DTP system confirms the factory-assured sensor accuracy of ±0.1 ∘C and enables improving it to ±0.015 ∘C. Numerical experiments indicate that, under normal environmental conditions, an additional error of 0.01 % in amplitude and 70 s time delay in amplitude for a diurnal period can be expected, owing to the DTP housing. We demonstrate the DTP systems capability at two field sites, one focused on understanding how snow dynamics influence mountainous water resources and the other focused on understanding how soil properties influence carbon cycling. Results indicate that the DTP system reliably captures the dynamics in snow depth and soil freezing and thawing depth, enabling advances in understanding the intensity and timing in surface processes and their impact on subsurface thermohydrological regimes. Overall, the DTP system fulfills the needs for data accuracy, minimal power consumption, and low total cost, enabling advances in the multiscale understanding of various cryospheric and hydro-biogeochemical processes.

Perils of life on the edge: Climatic threats to global diversity patterns of wetland macroinvertebrates - L. B. Epele; M. G. Grech; E. A. Williams-Subiza; C. Stenert; K. McLean; H. S. Greig; L. Maltchik; M. M. Pires; M. S. Bird; A. Boissezon; D. Boix; E. Demierre; et al. (Science of the Total Environment, 2022)
Climate change is rapidly driving global biodiversity declines. How wetland macroinvertebrate assemblages are responding is unclear, a concern given their vital function in these ecosystems. Using a data set from 769 minimally impacted depressional wetlands across the globe (467 temporary and 302 permanent), we evaluated how temperature and precipitation (average, range, variability) affects the richness and beta diversity of 144 macroinvertebrate families. To test the effects of climatic predictors on macroinvertebrate diversity, we fitted generalized additive mixed-effects models (GAMM) for family richness, and generalized dissimilarity models (GDMs) for total beta diversity. We found non-linear relationships between family richness, beta diversity and climate. Maximum temperature was the main climatic driver of wetland macroinvertebrate richness and beta diversity, but precipitation seasonality was also important. Assemblage responses to climatic variables also depended on wetland water permanency. Permanent wetlands from warmer regions had higher family richness than temporary wetlands. Interestingly, wetlands in cooler and dry-warm regions had the lowest taxonomic richness, but both kinds of wetlands supported unique assemblages. Our study suggests that climate change will have multiple effects on wetlands and their macroinvertebrate diversity, mostly via increases in maximum temperature, but also through changes in patterns of precipitation. The most vulnerable wetlands to climate change are likely those located in warm-dry regions, where entire macroinvertebrate assemblages would be extirpated. Montane and high-latitude wetlands (i.e., cooler regions) are also vulnerable to climate change, but we do not expect entire extirpations at the family level.

Statistical framework to assess long-term spatio-temporal climate changes: East River mountainous watershed case study - Boris Faybishenko; Bhavna Arora; Dipankar Dwivedi; E. L. Brodie (Stochastic environmental research and risk assessment, 2022)
Evaluation of long-term temporal and spatial climatic change in mountainous regions is a critical challenge because of the interactive effects of multiple land and climatic factors and processes. Here we present the application of the statistical framework to the assessment of changes of climatic conditions, using data from 17 meteorological stations across the East River watershed near Crested Butte, Colorado, USA, and spanning the period from 1966 to 2021. The framework is developed based on (1) a time-series analysis of daily, monthly, and yearly averaged meteorological parameters (tem- perature, relative humidity, precipitation, wind speed, etc.), (2) evaluation and time series analysis of potential evapo- transpiration (ETo), actual evapotranspiration (ET), aridity index (AI), standard precipitation index (SPI) and standard precipitation-evapotranspiration index (SPEI), and (3) a temporal-spatial climatic zonation of the studied area based on the hierarchical clustering and PCA analysis of the SPEI, because the SPEI can be considered an integrative characteristic of the changes of climatic conditions. The Budyko model, with the application of the Penman–Monteith equation for the estimation of ETo, was used to determine the ET. The time series analysis of the AI is used to identify the periods with energy limited and water limited conditions. Hierarchical clustering of site locations for the three temporal segments of the SPEI showed a significant temporal-spatial shifts, indicating that dynamic climatic processes drive zonation patterns. Therefore, the watershed climatic zonation requires periodic re-evaluation based on the structural time series analysis of meteorological and water balance data.

Does expanding access to cannabis affect traffic crashes? County‐level evidence from recreational marijuana dispensary sales in Colorado - Christian Gunadi (Health Economics, 2022)
AbstractThis article examines the effect of recreational cannabis dispensary sales on traffic crashes by employing difference‐in‐differences model that exploits the variation in the timing of recreational marijuana dispensary entry across counties within Colorado. Using marijuana‐related hospital discharge as a measure of marijuana abuse/misuse, the results indicate a sizable rise in marijuana‐related hospital discharges after the entry of retail cannabis stores. However, there is a lack of evidence that traffic crash incidents are affected by the entry. The preferred estimate suggests that, at 90% confidence level, a large increase in traffic crashes by more than 5% can be ruled out.

Revisions to the Wanakah Formation in and around Ouray County, Colorado - Lawrence S. Jones; Cassandra R. Fenton (Mountain Geologist, 2022)
A well-defined type section and consistent nomenclature are fundamental requirements for successful correlation of stratigraphic units and subsequent accurate paleogeographic reconstructions. The exact location of the original type section of the Middle Jurassic Wanakah Formation of the eastern Colorado Plateau was found in Ouray County, Colorado. Two nearby reference sections are described that supplement the lithologic descriptions in the original type section. These reference sections and the original type section constitute a “principal reference section” for the Wanakah Formation. Informal names “upper shale beds”, “marl member”, and “beds at Sawpit” have been used to describe the uppermost member of the Wanakah. These terms are replaced with the formal name, “Crooked Tree Member of the Wanakah Formation”, in the reference sections to avoid confusion, foster consistent usage, and facilitate litho-stratigraphic correlation.

Legume germination is delayed in dry soils and in sterile soils devoid of microbial mutualists: Species-specific implications for upward range expansions - A. M. Keeler; Nicole E. Rafferty (Ecology and Evolution, 2022)
Climate change is affecting species and their mutualists and can lead to the weakening or loss of important interspecific interactions. Through independent shifts in partner phenology and distribution, climatic stress can separate mutualists temporally or spatially, leading to alterations in partner functional traits and fitness. Here, we explored the effects of the loss of microbial mutualists on legume germination success and phenology. In particular, we assessed the effects of mutualism loss via soil sterilization, increased drought, and introduction to novel soils found beyond the current distributions of two focal legume species in subalpine environments. Through common garden experiments in controlled environments, we found evidence that soil sterilization (and consequent microbial absence) and dry soils caused species-specific phenological delays of 2-5 weeks in germination, likely as a result of interaction loss between legumes and specialized germination-promoting soil microbes, such as mutualistic rhizobia. Delays in germination caused by a mismatch between legumes and beneficial microbes could negatively affect legume fitness through increased plant-plant competition later in the season. Additionally, we found evidence of the presence of beneficial microbes beyond the current elevational range of one of our focal legumes, which may allow for expansion of the leading edge, although harsh abiotic factors in the alpine may hinder this. Alterations in the strength of soil microbe-legume mutualisms may lead to reduced fitness and altered demography for both soil microbes and legumes.

Column-Test Data Analyses and Geochemical Modeling to Determine Uranium Reactive Transport Parameters at a Former Uranium Mill Site (Grand Junction, Colorado) - Raymond H. Johnson; Aaron D. Tigar; C. Doc Richardson (Minerals, 2022)
The long-term release of uranium from residual sources at former uranium mill sites was often not considered in prior conceptual and numerical models, as contaminant removal focused on meeting radiological standards. To determine the reactive transport parameters, column tests were completed with various influent waters (deionized water, site groundwater, and local river water) on sediment from identified areas with elevated uranium on the solid phase in (1) vadose-zone (VZ) sediments, (2) saturated-zone sediments with higher organic carbon content, and (3) both vadose- and saturated-zone sediments with additional gypsum content. The gypsum was precipitated when low-pH, high-sulfate, tailings fluids or acidic waste disposal water were buffered by natural aquifer calcite dissolution. In general, the resulting uranium release was higher in the sediments with greater uranium concentrations. However, the addition of deionized water (DI) to the VZ sediments delayed the uranium release until higher-alkalinity groundwater was added. Higher-alkalinity river water continued to remove uranium from the VZ sediments for an extended number of pore volumes, with the uranium being above typical standards. Thus, river flooding is more efficient at removing uranium from VZ sediments than precipitation events (DI water in column tests). Organic carbon provides a stronger uranium sorption surface, which can be explained with geochemical modeling or a larger constant sorption coefficient (Kd). Without organic carbon, the typical sorption in sands and gravels is easily measurable, but sorption is stronger at lower, water-phase uranium concentrations. This effect can be simulated with geochemical modeling, but not with a constant Kd. Areas with gypsum create situations in which geochemical sorption is more difficult to simulate, which is likely due to the presence of uranium within mineral coatings. All the above mechanisms for uranium release must be considered when evaluating remedial strategies. Column testing provides initial input parameters that can be used in future reactive transport modeling to evaluate long-term uranium release rates and concentrations.

Population Growth and Municipal Water Insecurity in Mesa County, Colorado - William Wallace; null null (John Heinrichs Scholarly & Creative Activities Day, 2022)
The purpose of this project was to utilize GIS software to develop a population and daily domestic water resource requirement analysis for Mesa County, Colorado by answering the question of what municipalities within the county have the highest potential of developing water insecurities between the years 2000 and 2019. The methods for developing the spatiotemporal population change of Mesa County, Colorado utilize attribute manipulation and statistical tools within ArcGIS Pro. The four municipalities, Clifton, Loma, Fruita , Grand Junction, and Orchard Mesa experienced the greatest population increase and daily water resource requirement increase marking these areas as the most likely to develop water insecurities in the future. While substantial population growth has taken place over the past twenty years through the county, most of the of growth occurred between 2000 and 2010, allowing for municipalities to adapt to the increase in population over the past decade. This project took a broad view of the county’s daily water use and found that the county has access to enough fresh water to support a growing population, and that other factors such as surface water quality and management are a more pressing line of study.

Dye Tracing and the Effects of Infrastructure in Hidden River Cave, Horse Cave, KY - Alexa Franks (2022)
Hidden River Cave is a stream cave system found in Horse Cave, KY with continuous water flow of its two branches, Wheet River and East River. The infrastructure of the city of Hose Cave, KY was originally designed to utilize natural sinkholes for drainage of all wastewaters. The city uses many of these, now modified, sinkholes for wastewater disposal and storm water drainage. Historically, Hidden River Cave has been severely impacted by unmonitored dumping of contamination. To better understand and identify specific flow paths from sinkholes and infrastructure into Hidden River Cave, this study documented various sinkholes and other infrastructure, such as storm drains, sewer systems, and other undocumented pipes, that could send water from the surface to Hidden River Cave. The study focused on using fluorescent dyes injected into four sites in order to document how the water carrying these dyes moved through the cave system. These dyes were identified using charcoal dye receptors placed at six locations within Hidden River Cave. Additionally, passage cross-sections of two major branches of the cave were measured, while depth and velocity measurements were taken to calculate the discharge of the river in these branches of the cave. Dye trace results identified two flow paths and hypothesized a small groundwater basin based on the detection of various dyes within the cave from multiple injection sites. Discharge results appear to agree with the flow path interpretation derived from the dye traces. The most significant findings of this research include: 1) identifying multiple flow paths from various injection points, 2) determining the relationship between discharge of the Wheet River and East River in Hidden River Cave, and 3) hypothesizing a flow route based on a lack of detection from a previously unidentified injection point. These findings improve the understanding of the relationship between surface water catchment in the city of Horse Cave and the flow into Hidden River Cave.

Variability of Snow and Rainfall Partitioning Into Evapotranspiration and Summer Runoff Across Nine Mountainous Catchments - Matthias Sprenger; R. W. H. Carroll; P. James Dennedy-Frank; Erica R. Siirila-Woodburn; Michelle Newcomer; W. Brown; Alexander W. Newman; Curtis A. Beutler; Markus Bill; S. S. Hubbard; K. H. Williams (Geophysical Research Letters,, 2022)
AbstractUnderstanding the partitioning of snow and rain contributing to either catchment streamflow or evapotranspiration (ET) is of critical relevance for water management in response to climate change. To investigate this partitioning, we use endmember splitting and mixing analyses based on stable isotope (18O) data from nine headwater catchments in the East River, Colorado. Our results show that one third of the snow partitions to ET and 13% of the snowmelt sustains summer streamflow. Only 8% of the rainfall contributes to the summer streamflow, because most of the rain (67%) partitions to ET. The spatial variability of precipitation partitioning is mainly driven by aspect and tree cover across the sub‐catchments. Catchments with higher tree cover have a higher share of snow becoming ET, resulting in less snow in summer streamflow. Summer streamflow did not contain more rain with higher rainfall sums, but more rain was taken up in ET.

Winters are changing: snow effects on Arctic and alpine tundra ecosystems - C. Rixen; T. T. Hoye; P. Macek; R. Aerts; J. M. Alatalo; J. T. Anderson; P. A. Arnold; I. C. Barrio; J. W. Bjerke; M. P. Björkman; D. Blok; G. Blume-Werry; et al. (Arctic Science, 2022)
Snow is an important driver of ecosystem processes in cold biomes. Snow accumulation determines ground temperature, light conditions, and moisture availability during winter. It also affects the growing season’s start and end, and plant access to moisture and nutrients. Here, we review the current knowledge of the snow cover’s role for vegetation, plant-animal interactions, permafrost conditions, microbial processes, and biogeochemical cycling. We also compare studies of natural snow gradients with snow experimental manipulation studies to assess time scale difference of these approaches. The number of tundra snow studies has increased considerably in recent years, yet we still lack a comprehensive overview of how altered snow conditions will affect these ecosystems. Specifically, we found a mismatch in the timing of snowmelt when comparing studies of natural snow gradients with snow manipulations. We found that snowmelt timing achieved by snow addition and snow removal manipulations (average 7.9 days advance and 5.5 days delay, respectively) were substantially lower than the temporal variation over natural spatial gradients within a given year (mean range 56 days) or among years (mean range 32 days). Differences between snow study approaches need to be accounted for when projecting snow dynamics and their impact on ecosystems in future climates.

The Evolution and Ecology of Interactions Between Ants and Honeydew-Producing Hemipteran Insects - A. S. Nelson; K. A. Mooney (The Annual Review of Ecology, Evolution, and Systematics, 2022)
The interactions between ants and certain sap-feeding insects in the order Hemiptera are classic examples of food-for-protection mutualisms. In these associations, herbivorous hemipterans use a highly specialized, straw-like mouthpart to consume sap directly from plant phloem and xylem and, as a result, excrete a sugar-rich waste product called honeydew. Ant foragers use specialized adaptations to collect and share honeydew with nestmates and, in exchange, protect hemipterans against predators. The two key innovations underlying this interaction—hemipteran sap feeding and ant harvesting of honeydew—have driven the evolutionary success and ecological dominance of ants. These interactions also carry unique costs and benefits for each partner and are highly context dependent. Understanding the factors mediating this mutualism is critical, as these interactions have broader ecological consequences for the natural and agricultural ecosystems in which they are embedded.

The influence of orbital parameters on the North American Monsoon system during the Last Interglacial Period - Nadja Insel; Max Berkelhammer (Journal of Quaternary Science, 2021)
ABSTRACTThe response of summer precipitation in the western United States to climate variability remains a subject of uncertainty. For example, palaeoclimate records indicate the North American Monsoon (NAM) was stronger and spatially more extensive during the Holocene, whereas recent modelling suggests a weakened NAM response to increasing temperatures. These illustrate diverging pictures of the NAM response to warming. Here, we examine summer precipitation in the southwestern US related to Last Interglacial insolation forcing. Using a high‐resolution climate model, we find that Eemian insolation forcing results in overall wetter conditions throughout most of the southwestern US, but significantly drier than present conditions over Arizona. The overall wetter conditions are associated with a northward shift of the anticyclonic circulation aloft and increased moisture in the lower and mid‐troposphere during the Eemian. Increased advection of Gulf of Mexico moisture is responsible for increasing precipitation in New Mexico and the northern edges of the NAM region. Drier conditions over Arizona are likely related to reduced local convection associated with reduced vertical moisture transport. These results highlight the spatial complexity of the NAM response to increasing radiative forcing and allow a better understanding of monsoon dynamics and variability in response to a warming climate.

Effects of early snowmelt on plant phenophase timing and duration across an elevation gradient - Chelsea Wilmer (2021)
EFFECTS OF EARLY SNOWMELT ON PLANT PHENOPHASE TIMING AND DURATION ACROSS AN

Comparison of Drought Response between Taraxacum officinale and Delphinium nuttallianum - P. Daly (2021)

Global Warming, Advancing Bloom and Evidence for Pollinator Plasticity from Long-Term Bee Emergence Monitoring - J. Cane (Insects, 2021)
Global warming is extending growing seasons in temperate zones, yielding earlier wildflower blooms. Short-term field experiments with non-social bees showed that adult emergence is responsive to nest substrate temperatures. Nonetheless, some posit that global warming will decouple bee flight and host bloom periods, leading to pollination shortfalls and bee declines. Resolving these competing scenarios requires evidence for bees’ natural plasticity in their annual emergence schedules. This study reports direct observations spanning 12–24 years for annual variation in the earliest nesting or foraging activities by 1–4 populations of four native ground-nesting bees: Andrena fulva (Andrenidae), Halictus rubicundus (Halictidae), Habropoda laboriosa and Eucera (Peponapis) pruinosa (Apidae). Calendar dates of earliest annual bee activity ranged across 25 to 45 days, approximating reported multi-decadal ranges for published wildflower bloom dates. Within a given year, the bee H. rubicundus emerged in close synchrony at multiple local aggregations, explicable if meteorological factors cue emergence. Emergence dates were relatable to thermal cues, such as degree day accumulation, soil temperature at nesting depth, and the first pulse of warm spring air temperatures. Similar seasonal flexibilities in bee emergence and wildflower bloom schedules bodes well for bees and bloom to generally retain synchrony despite a warming climate. Future monitoring studies can benefit from several simple methodological improvements.

Producer-scrounger relationships in yellow-bellied marmots - A. W. Evans; D. M. Williams; Daniel T. Blumstein (Animal Behaviour, 2021)

Can flowers affect land surface albedo and soil microclimates? - Amy M. Iler; A. Walwema; Heidi Steltzer; A. Blazquez-Castro (International Journal of Biometeorology, 2021)
The phenology of vegetation, namely leaf-out and senescence, can influence the Earth’s climate over regional spatial scales and long time periods (e.g., over 30 years or more), in addition to microclimates over local spatial scales and shorter time periods (weeks to months). However, the effects of flowers on climate and microclimate are unknown. We investigate whether flowers can influence light reflected by the land surface and soil microclimate in a subalpine meadow. We conducted a flower removal experiment with a common sunflower species, Helianthella quinquenervis, for 3 years (2015, 2017, and 2019). The flower removal treatment simulates the appearance of the meadow when Helianthella flowers earlier under climate change and loses its flowers to frost (other plant structures are not damaged by frost). We test the hypotheses that a reduction in cover of yellow flowers leads to a greener land surface, lower reflectance, warmer and drier soils, and increased plant water stress. Flower removal plots are greener, reflect less light, exhibit up to 1.2 °C warmer soil temperatures during the warmest daylight hours, and contain ca. 1% less soil moisture compared to controls. However, soils were warmer in only 2 of the 3 years, when flower abundance was high. Helianthella water use efficiency did not differ between removal and control plots. Our study provides evidence for a previously undocumented effect of flowers on soil microclimate, an effect that is likely mediated by climate change and flowering phenology. Many anthropogenic environmental changes alter landscape albedo, all of which could be mediated by flowers: climate change, plant invasions, and agriculture. This study highlights how further consideration of the effects of flowers on land surface albedo could improve our understanding of the effects of vegetation on microclimate.

Review of Vesicular Stomatitis in the United States with Focus on 2019 and 2020 Outbreaks - Angela M. Pelzel‐McCluskey; Brad Christensen; John Humphreys; Miranda R. Bertram; Robert Keener; Robert L. Ewing; Lee W. Cohnstaedt; Rachel M. Tell; Debra P. C. Peters; Luis L. Rodrı́guez (Pathogens, 2021)
Vesicular stomatitis (VS) is a vector-borne livestock disease caused by vesicular stomatitis New Jersey virus (VSNJV) or vesicular stomatitis Indiana virus (VSIV). The disease circulates endemically in northern South America, Central America, and Mexico and only occasionally causes outbreaks in the United States. Over the past 20 years, VSNJV outbreaks in the southwestern and Rocky Mountain regions occurred with incursion years followed by virus overwintering and subsequent expansion outbreak years. Regulatory response by animal health officials is deployed to prevent spread from lesioned animals. The 2019 VS incursion was the largest in 40 years, lasting from June to December 2019 with 1144 VS-affected premises in 111 counties in eight states (Colorado, Kansas, Nebraska, New Mexico, Oklahoma, Texas, Utah, and Wyoming) and was VSIV serotype, last isolated in 1998. A subsequent expansion occurred from April to October 2020 with 326 VS-affected premises in 70 counties in eight states (Arizona, Arkansas, Kansas, Missouri, Nebraska, New Mexico, Oklahoma, and Texas). The primary serotype in 2020 was VSIV, but a separate incursion of VSNJV occurred in south Texas. Summary characteristics of the outbreaks are presented along with VSV-vector sampling results and phylogenetic analysis of VSIV isolates providing evidence of virus overwintering.

Relationships matter: How the social environment affects individual fitness-related behaviors - D. M. Williams (2021)
Individuals respond to predators through an array of anti-predator behaviors that can be influenced by their social environment, specifically through protection from predators or by altering risk-resource trade-offs through competitive exclusion from resources. While social effects like group size are well studied, the specific ways in which different types of relationships, such as number of interaction partners or centrality in their group, influence consistent anti-predator behaviors is less understood. However, the effects of social relationships on behavior are not uniform between species or even between individuals. Here, we examined how an individual’s affiliative and agonistic social relationships impacted two personality traits related to anti-predator behavior (boldness and docility) in yellow-bellied marmots (Marmota flaviventer ), a facultatively social species with unusual negative impacts of affiliative relationships. We found that docile individuals were less involved in aggressive interactions either by avoiding or being excluded from aggressive interactions. Boldness was not associated with aggression, suggesting that individuals are either not resource limited by social aggression or are not willing to risk more predator exposure to secure those resources. Affiliative relationships were not associated with docility or boldness, contributes to other findings that marmots have a limited sense of social security from affiliative relationships.

Firmicutes and Bacteroidetes explain mass gain variation in an obligate hibernator - G. C. Johnson; S. Degregori; P. H. Barber; Daniel T. Blumstein; G. C. Johnson (bioRxiv, 2021)
Abstract Body condition is an important life history challenge that directly impacts individual fitness and is particularly important for hibernating animals, whose maintenance of adequate body fat and mass is essential for survival. It is well documented that symbiotic microorganisms play a vital role in animal physiology and behaviour. Recent work demonstrates that gut microbes are associated with fat accumulation and obesity; Firmicutes is consistently associated with obesity while Bacteroidetes is associated with leanness both in humans and other animals. The focus of most microbiome studies has been on human health or involved lab reared animals used as a model system. However, these microbes likely are important for individual fitness in wild populations and provide potential mechanistic insights into the adaptability and survival of wildlife. Here we test whether symbiotic microorganisms within the phyla of Firmicutes and Bacteroidetes are associated with summer mass gain in an exceptionally well-studied wild population of yellow-bellied marmots ( Marmota flaviventer ) by quantifying microbial abundance over five years of fecal samples (2015 – 2019) collected during their summer active season. Results show that marmots with higher mass gain rates have a greater abundance of Firmicutes . In contrast, higher abundance of Bacteroidetes was associated with lower mass gain rates, but only for marmots living in harsher environments. Similar patterns were found at the family level where Ruminococcaceae , a member of Firmicutes , was associated with higher mass gain rates, and Muribaculaceae , a member of Bacteroidetes , was associated with lower mass gain rates, and similarly in harsher environments. Although correlative, these results highlight the importance of symbiotic gut microbiota to mass gain in the wild, a trait associated with survival and fitness in many taxonomic groups.

The Colorado East River Community Observatory Data Collection - Zarine Kakalia; Charuleka Varadharajan; Erek Alper; E. L. Brodie; Madison Burrus; R. W. H. Carroll; D. S. Christianson; Wenming Dong; Valerie Hendrix; M. Henderson; S. S. Hubbard; D. Johnson; et al. (Hydrologic Processes, 2021)
Abstract The U.S. Department of Energy's (DOE) Colorado East River Community Observatory (ER) in the Upper Colorado River Basin was established in 2015 as a representative mountainous, snow‐dominated watershed to study hydrobiogeochemical responses to hydrological perturbations in headwater systems. The ER is characterized by steep elevation, geologic, hydrologic and vegetation gradients along floodplain, montane, subalpine, and alpine life zones, which makes it an ideal location for researchers to understand how different mountain subsystems contribute to overall watershed behaviour. The ER has both long‐term and spatially‐extensive observations and experimental campaigns carried out by the Watershed Function Scientific Focus Area (SFA), led by Lawrence Berkeley National Laboratory, and researchers from over 30 organizations who conduct cross‐disciplinary process‐based investigations and modelling of watershed behaviour. The heterogeneous data generated at the ER include hydrological, genomic, biogeochemical, climate, vegetation, geological, and remote sensing data, which combined with model inputs and outputs comprise a collection of datasets and value‐added products within a mountainous watershed that span multiple spatiotemporal scales, compartments, and life zones. Within 5 years of collection, these datasets have revealed insights into numerous aspects of watershed function such as factors influencing snow accumulation and melt timing, water balance partitioning, and impacts of floodplain biogeochemistry and hillslope ecohydrology on riverine geochemical exports. Data generated by the SFA are managed and curated through its Data Management Framework. The SFA has an open data policy, and over 70 ER datasets are publicly available through relevant data repositories. A public interactive map of data collection sites run by the SFA is available to inform the broader community about SFA field activities. Here, we describe the ER and the SFA measurement network, present the public data collection generated by the SFA and partner institutions, and highlight the value of collecting multidisciplinary multiscale measurements in representative catchment observatories.

Bigger is not always better: Viability selection on body mass varies across life stages in a hibernating mammal - A. H. M. Jebb; Daniel T. Blumstein; P. Bize; J. G. A. Martin (Ecology and Evolution, 2021)
Body mass is often viewed as a proxy of past access to resources and of future survival and reproductive success. Links between body mass and survival or reproduction are, however, likely to differ between age classes and sexes. Remarkably, this is rarely taken into account in selection analyses. Selection on body mass is likely to be the primary target accounting for juvenile survival until reproduction but may weaken after recruitment. Males and females also often differ in how they use resources for reproduction and survival. Using a long-term study on body mass and annual survival in yellow-bellied marmots (Marmota flaviventer), we show that body mass was under stabilizing viability selection in the first years of life, before recruitment, which changed to positive directional selection as age increased and animals matured. We found no evidence that viability selection across age classes on body mass differed between sexes. By investigating the link between running speed and body mass, we show that the capacity to escape predators was not consistent across age classes and followed a quadratic relationship at young ages only. Overall, our results indicate that mature age classes exhibit traditional patterns of positive viability selection on body mass, as expected in a hibernating mammal, but that mass in the first years of life is subjected to stabilizing selection which may come from additional predation pressures that negate the benefits of the largest body masses. Our study highlights the importance to disentangle selection pressures on traits across critical age (or life) classes.

Diverse cressdnaviruses and an anellovirus identified in the fecal samples of yellow-bellied marmots - A. Khalifeh; Daniel T. Blumstein; R. S. Fontenele; K. Schmidlin; C. Richet; S. Kraberger; A. Varsani (Virology, 2021)
Over that last decade, coupling multiple strand displacement approaches with high throughput sequencing have resulted in the identification of genomes of diverse groups of small circular DNA viruses. Using a similar approach but with recovery of complete genomes by PCR, we identified a diverse group of single-stranded viruses in yellow-bellied marmot (Marmota flaviventer) fecal samples. From 13 fecal samples we identified viruses in the family Genomoviridae (n = 7) and Anelloviridae (n = 1), and several others that ware part of the larger Cressdnaviricota phylum but not within established families (n = 19). There were also circular DNA molecules identified (n = 4) that appear to encode one viral-like gene and have genomes of <1545 nts. This study gives a snapshot of viruses associated with marmots based on fecal sampling.

Biotic interactions at species’ range limits in a changing climate - I. D. Shepard (2021)

Estimation of Evapotranspiration Rates and Root Water Uptake Profiles From Soil Moisture Sensor Array Data - W. Li; Haruko M. Wainwright; Qina Yan; H. Zhou; Baptiste Dafflon; Yuxin Wu; Roelof Versteeg; D. M. Tartakovsky (Water Resources Research, 2021)
AbstractEvapotranspiration is arguably the least quantified component of the hydrologic cycle. We propose two complementary strategies for estimation of evapotranspiration rates and root water uptake profiles from soil‐moisture sensor‐array data. One is our implementation of ensemble Kalman filter (EnKF); it treats the evapotranspiration sink term in the Richards equation, rather than soil moisture, as the observable to update. The other is a maximum likelihood estimator (MLE) applied to the same observable; it is supplemented with the Fisher information matrix to quantify uncertainty in its predictions. We use numerical experiments to demonstrate the accuracy and computational efficiency of these techniques. We found our EnKF implementation to be two orders of magnitude faster than either the standard EnKF or MLE, and our MLE procedure to require an order of magnitude fewer iterations to converge than its counterpart applied to soil moisture. These findings render our methodologies a viable and practical tool for estimation of the root water uptake profiles and evaporation rates, with the MLE technique to be used when the prior knowledge about evapotranspiration at the site is elusive.

Understanding pollen specialization in mason bees: a case study of six species - M. McAulay; S. Killingsworth; J. R. K. Forrest (Oecologia, 2021)
Many bee species are dietary specialists and restrict their pollen foraging to a subset of the available flowers. However, the reasons for specialization—and the reasons certain plant taxa support numerous specialists—are often unclear. Many bees specialize on the plant family Asteraceae, despite evidence its pollen is a poor food for non-specialists. Here, we studied six mason bee (Osmia) species, including three Asteraceae specialists, to test whether observed pollen-usage patterns reflect larval nutritional requirements, to investigate what aspects of Asteraceae pollen make it unsuitable for non-specialists, and to understand how Asteraceae specialists tolerate their seemingly low-quality diet. We reared larval bees on host and nonhost pollen and found that Asteraceae specialists could develop on nonhost provisions, but that other bees could not survive on Asteraceae provisions. These effects did not seem related to nutritional deficiencies, since Asteraceae provisions were not amino acid deficient, and we found no consistent differences in digestive efficiency among pollen types. However, Aster- aceae specialists completed more foraging flights per larva, generally collected relatively larger provisions, and produced more frass (waste) than the other species, suggesting quantitative compensation for low food quality. Toxins, deficiencies in unmeasured nutrients, or aspects of pollen grain structure might explain poor survival of non-specialists on Asteraceae provisions. Our results suggest that floral host selection by specialist bees is not related to optimizing larval nutrition. We recommend further investigation of host-selection behaviour in adult bees and of pollen digestion in larvae to better under- stand the evolution of bee–flower associations.

Modeling the Impact of Riparian Hollows on River Corridor Nitrogen Exports - David Brian Rogers; Michelle Newcomer; J. H. Raberg; Dipankar Dwivedi; Carl I. Steefel; Nicholas J. Bouskill; P. Nico; Boris Faybishenko; P. M. Fox; M. Conrad; Markus Bill; E. L. Brodie; et al. (Frontiers in Water, 2021)
Recent studies in snowmelt-dominated catchments have documented changes in nitrogen (N) retention over time, such as declines in watershed exports of N, though there is a limited understanding of the controlling processes driving these trends. Working in the mountainous headwater East River Colorado watershed, we explored the effects of riparian hollows as N-cycling hotspots and as important small-scale controls on observed watershed trends. Using a modeling-based approach informed by remote sensing and in situ observations, we simulated the N-retention capacity of riparian hollows with seasonal and yearly hydrobiogeochemical perturbations imposed as drivers. We then implemented a scaling approach to quantify the relative contribution of riparian hollows to the total river corridor N budget. We found that riparian hollows primarily serve as N sinks, with N-transformation rates significantly limited by periods of enhanced groundwater upwelling and promoted at the onset of rainfall events. Given these observed hydrologic controls, we expect that the nitrate ( NO3- ) sink capacity of riparian hollows will increase in magnitude with future climatic perturbations, specifically the shift to more frequent rainfall events and fewer snowmelt events, as projected for many mountainous headwater catchments. Our current estimates suggest that while riparian hollows provision ~5–20% of NO3- to the river network, they functionally act as inhibitors to upland NO3- reaching the stream. Our work linking transient hydrological conditions to numerical biogeochemical simulations is an important step in assessing N-retaining features relative to the watershed N budget and better understanding the role of small-scale features within watersheds.

The genome of the Margined White butterfly (Pieris macdunnoughii): sex chromosome insights and the power of polishing with PoolSeq data - Rachel A Steward; Y. Okamura; C. L. Boggs; H. Vogel; C. W. Wheat (Genome Biology and Evolution, 2021)
We report a chromosome-level assembly for Pieris macdunnoughii, a North American butterfly whose involvement in an evolutionary trap imposed by an invasive Eurasian mustard has made it an emerging model system for studying maladaptation in plant-insect interactions. Assembled Downloaded from https://academic.oup.com/gbe/advance-article/doi/10.1093/gbe/evab053/6178793 by guest on 15 April 2021 using nearly 100X coverage of Oxford Nanopore long reads, the contig-level assembly comprised 106 contigs totaling 316,549,294 bases, with an N50 of 5.2Mb. We polished the assembly with PoolSeq Illumina short-read data, demonstrating for the first time the comparable performance of individual and pooled short reads as polishing datasets. Extensive synteny between the reported contig-level assembly and a published, chromosome-level assembly of the European butterfly Pieris napi allowed us to generate a pseudo-chromosomal assembly of 47 contigs, placing 91.1% of our 317 Mbp genome into a chromosomal framework. Additionally, we found support for a Z chromosome arrangement in P. napi, showing that the fusion event leading to this rearrangement predates the split between European and North American lineages of Pieris butterflies. This genome assembly and its functional annotation lay the groundwork for future research into the genetic basis of adaptive and maladaptive egg-laying behavior by P. macdunnoughii, contributing to our understanding of the susceptibility and responses of insects to evolutionary traps.

Predispersal Seed Predation Obscures the Detrimental Effect of Dust on Wildflower Reproduction - Mary V. Price; Nickolas M. Waser; D. Lopez; V. Ramirez; C. Rosas (International Journal of Plant Sciences, 2021)

Social position indirectly influences the traits yellow-bellied marmots use to solve problems - D. M. Williams; C. A. Wu; Daniel T. Blumstein (Animal Cognition, 2021)
Animals adapt to changing environments by behaving flexibly when solving problems. Traits, such as sex and age, and spe- cifically behavioral traits like persistence–the amount of time spent attempting to solve a problem, are positively associated with successful problem-solving. However, individuals face social pressures, such as aggression, which may directly alter an individual’s behavior or interact with sex or age, when they attempt to problem-solve. We examined the direct and indirect effects of social position and individual behavioral traits on solving a novel puzzle box in facultatively social yellow-bellied marmots (Marmota flaviventer), using both generalized linear mixed models and confirmatory path analysis. We found strong support that marmots who used a diversity of behaviors were more successful problem-solvers and weak support that those who received more aggression were less successful. Additionally, marmots who received more aggression were less behaviorally diverse, less behaviorally selective and less persistent while trying to open the puzzle box. Thus, we show that aggression indirectly decreases problem-solving success by acting on the behavioral traits that an individual uses. We conclude that specific social relationships, including the type of interaction and whether they are recipients or initiators, influences the ways in which an individual interacts with cognitive tests and should be considered in analysis of individual problem-solving.

Cold adaptation drives population genomic divergence in the ecological specialist, Drosophila montana - R. A. W. Wiberg; V. Tyukmaeva; A. Hoikkala; M. Ritchie; M. Kankare (Molecular Ecology, 2021)

Impacts of brood parasites, floral abundance, and bee age on maternal investment in a solitary bee, Osmia iridis - L. Heinrich (2021)
Parents can adjust both the size and number of offspring they produce in order to maximize their own fitness payoff (Smith & Fretwell 1974). Optimal parental investment is dependent in part on likelihood of offspring survival, which is impacted by predation and parasitism. When risk of predation or parasitism is high, it may be adaptive for parents to reduce either the number of offspring they produce or their investment in individual offspring. Brood parasitism by sapygid wasps represents a significant fitness cost for Osmia bees. Sapygid wasps enter brood cells during the provisioning or brood cell construction stages, when mother bees are absent collecting pollen and nectar provisions for their larvae or materials for constructing brood cell walls. In order to avoid losing their investment in offspring, Osmia bees should reduce provisioning time when parasitism risk is high, providing pollen provisions smaller than what would be optimal for offspring development. Alternatively, instead of investing less per offspring, bees may produce fewer offspring overall when they detect parasites. In this study, we tested these predictions in a naturally occurring population of Osmia iridis bees at the Rocky Mountain Biological Laboratory in Gothic, Colorado, measuring the response of O. iridis to both spatial and temporal variation in sapygid wasp abundance. In addition, we measured other factors which might impact provisioning efficiency, including floral abundance and bee age, and uniquely marked individuals to control for bee identity. Floral abundance was found to be most predictive of pollen provision size, while Sapyga abundance was most predictive of the number of brood cells per nest a bee constructed. These results suggest that bees respond to parasite presence by reducing the number of offspring they produce per nest rather than investing less per offspring. Further research is needed to confirm these findings and to investigate the impacts this investment strategy may have on both lifetime reproductive success and nesting site selection.

Empirical studies of escape behavior find mixed support for the race for life model - K. Wrensford; J. Gutierrez; W. E. Cooper; Daniel T. Blumstein (Current Zoology, 2021)
Escape theory has been exceptionally successful in conceptualizing and accurately predicting effects of numerous factors that affect predation risk and explaining variation in flight initiation distance (FID, predator-prey distance when escape begins). Less explored is the relative orientation of an approaching predator, prey, and its eventual refuge. The relationship between an approaching threat and its refuge can be expressed as an angle we call the “interpath angle” or “Φ”, which describes the angle between the paths of predator and prey to the prey’s refuge and thus expresses the degree to which prey must run towards an approaching predator. In general, we might expect that prey would escape at greater distances if they must flee toward a predator to reach its burrow. The ‘race for life’ model makes formal predictions about how interpath angle should affect FID. We evaluated the model by studying escape decisions in yellow-bellied marmots Marmota flaviventer, a species which flees to burrows. We found support for some of the model’s predictions, yet the relationship between interpath angle and FID was less clear. Marmots may not assess interpath angle in a continuous fashion; but we found that binning angle into four 45° bins explained a similar amount of variation as models that analyzed angle continuously. Future studies of interpath angle, especially those that focus on how different species perceive relative orientation, will likely enhance our understanding of its importance in flight decisions. Key words: escape behavior, escape trajectory, escape theory, antipredator behavior, race for life model

Water - John Harner (University Press of Colorado eBooks, 2021)

A community‐supported weather and soil moisture monitoring database of the Roaring Fork catchment of the Colorado River Headwaters - E. Osenga; J. Vano; James C. Arnott (Hydrological Processes, 2021)
AbstractLocal community interest in better understanding regional climate change impacts has motivated the establishment of a long‐term soil moisture and weather observation network in the Roaring Fork catchment of the Colorado River Headwaters. This catchment‐wide suite of 10 stations, installed between 2012 and 2020, collects frequent, fixed‐interval data on soil moisture, soil temperature, rain, air temperature, relative humidity, and (at some stations) snow across an elevational gradient from 1800 to 3680 m. In this paper we provide a description of the data this network provides, how data are accessed, and how this community‐supported effort has resulted in data that support mountain hydrology research with applications for resource management and climate change adaptation decision making. All data from this network are publicly available.

Testing how density affects caddisfly distribution along a detritus quality gradient - A. Adams (2021)
As ecosystems continue to change, the ability to find high-quality habitats is becoming a valuable skill. Caddisflies are often found in pond environments with a variety of habitat qualities, such as food (detritus) quality. Asynarchus nigriculus, being highly mobile and having a unique dietary need for protein are a prime subject for testing the ability of caddisflies to find high-quality habitats when given a range of detritus qualities. A. nigriculus showed a preference for high-quality habitats both individually and in groups. Density was a relatively insignificant factor in their distribution, and aggressive interactions did not increase with density. This indicates that their distribution is based more on the availability of resources than on intraspecific interference interactions.

The effect of cytotype on radial growth rate in quaking aspen ( Populus tremuloides ) across environmental gradients - I. Banka (2021)
Quaking aspen (Populus tremuloides) trees are a foundation species that is widely distributed across all North America. Since the early 2000s, high levels of mortality have been observed in these forests. In recent decades, many quaking aspen forests have been experiencing high mortality rates. This large-scale mortality has been the subject of many studies attempting to ascertain the cause and gather knowledge which could aid in future forest management efforts. There have been observed differences between aspen ramets’ (individual stems) drought-response at small spatial scales under similar environmental conditions, which suggests intraspecific (within species) variation in drought mortality risk. Aspen ramets grow in genetically identical clones (genets) that have either two (diploid) or three (triploid) copies of each chromosome. My project investigated the effect of ploidy level on drought response in quaking aspen and sought to gather data on aspen cytotype growth rate differences across a larger environmental gradient. I collected stem core samples from both aspen cytotypes, compared their radial growth for each year, and analyzed their responses to drought years using historical drought data for the area. While my data analysis did show cytotype to be a significant factor in aspen radial growth, the diploids sampled were measured to have a wider average ring width than triploids in the same areas, counter to the original hypothesis. Elevation, aspect, and slope were all found to have a significant impact on aspen growth rates for both cytotypes, These findings and future studies into polyploidy’s impact on growth rates could prove useful in future forest management efforts through an understanding of which aspen trees may be more vulnerable, or more successful, in future droughts.

Abundance and elevational range shifts of three species of burying beetle in Gunnison County, Colorado and importance of stridulation during reproduction in burying beetles - A. Rawinski (2021)

Temperature Selection in the Arizona Tiger Salamander ( Ambystoma mavortium nebulosum ) - C. Bohus (2021)
High-elevation ecosystems are experiencing rapid warming and severe impact of global climate change. The Arizona Tiger Salamander (Ambystoma mavortium nebulosum) occurs in high elevation ponds in the West Elk Mountains of Colorado and offers a compelling system to test context-dependent responses to climate change. Larval salamanders either metamorphose into terrestrial metamorphs or become gilled, aquatic paedomorphs, thus, the morphs may be differentially affected by climate change. To determine how the different thermal environments experienced by the morphs affects their physiology, we will compare the preferred temperature of metamorphic adult salamanders from high-elevation ponds. A comparison of paedomorphs and metamorphs was initially desired but due to not being able to find any this summer only metamoprhs were used. The first objective is to construct and test a water-filled thermal gradient runway. The thermal gradient design will be improved until we can establish a reliable range and distribution of temperatures, we will place a single salamander in the gradient for 3.5 hours and will record horizontal position in the gradient and water temperature next to the animal’s middlebody every 5 minutes. We will also compare the horizontal position of salamanders in the chamber without the temperature gradient as a control to test for evidence of active thermoregulation by the animals in temperature gradient trials. We will calculate the mean, and upper and lower 10% of temperatures and horizontal positions for each individual and utilize an ANOVA test in order to see what effect sex, collection site and mass have on minimum, maximum and average temperature selection.

Expanding in-stream flow rights as a mechanism for water conservation and aquatic ecosystem preservation - M. C. Buckelew (2021)

Comparative study on pollinator visits to high elevation plant communities in Virginia Basin, Gothic, Colorado - D. Gascon (2021)
Plant-pollinator networks are intricate systems that can give insight on a location’s biodiversity and response to environmental changes. By studying pollination networks at different elevations, researchers can evaluate how varying environmental conditions influence how plant and pollinator species interact with one another. In this project, I assessed two plant- pollinator communities in the Virginia Basin at 3500m and at 3350m. Plant-pollinator interactions were recorded by sampling 20x1m transects at each site while censusing flower abundance for five weeks during the summer of 2021. When looking at the overall abundance of flowers at both sites there was no difference between sites abundance or mean visitation per abundance. However, when analyzing the plant species found at both site there was a significant difference between the mean visitation, with plants at the mid site receiving more visits. This difference may be due to harsh conditions at the higher site or the greater plant diversity there, which results in the dilution of visits to each plant species. Further studies could look into how other factors like weather variables and climate change affect these plant-pollinator communities.

How worthwhile are pollination networks? - J. D. Thomson (Journal of Pollination Ecology, 2021)

Investigating the relationship between Bombus appositus abundance and its overlap with key floral resources - E. Gitter (2021)
Many species of bumble bees (Bombus spp.) are experiencing population declines. In subalpine ecosystems, climate change is altering floral phenology by causing an earlier blooming period, which creates a growing season with sparser resources. Since bumble bees and their floral resources depend on phenological overlap for their mutualistic relationship to function, it is possible that changing floral phenologies could negatively impact pollinators. Bombus appositus is a pollinator of concern due its relatively narrow diet breadth and variable population abundance in the past seven years of study in the subalpine ecosystems near the Rocky Mountain Biological Laboratory (RMBL). In this study, we explored the relationship between B. appositus worker abundance and the number of weeks of phenological overlap between bees and floral resources from 2015 - 2020. We also compared B. appositus worker abundance with the total floral abundance of B. appositus’ four key floral resources. We found no relationship between the number of weeks of phenological overlap and worker abundance, but we found a strong positive relationship between worker abundance and floral resource abundance. Overall, years with more floral resources gave rise to greater colony growth as measured in worker abundance. Floral abundance is strongly tied to climate conditions, which means that in the future, it will be increasingly important to understand how floral abundance varies with climate since the quantity of floral resources will ultimately impact bumble bee populations.

Modeling geogenic and atmospheric nitrogen through the East River Watershed, Colorado Rocky Mountains - Taylor Maavara; Erica R. Siirila-Woodburn; Fadji Maina; R. M. Maxwell; James E. Sample; K. Dana Chadwick; R. W. H. Carroll; Michelle Newcomer; Wenming Dong; K. H. Williams; Carl I. Steefel; Nicholas J. Bouskill (PloS one, 2021)
There is a growing understanding of the role that bedrock weathering can play as a source of nitrogen (N) to soils, groundwater and river systems. The significance is particularly apparent in mountainous environments where weathering fluxes can be large. However, our understanding of the relative contributions of rock-derived, or geogenic, N to the total N supply of mountainous watersheds remains poorly understood. In this study, we develop the High-Altitude Nitrogen Suite of Models (HAN-SoMo), a watershed-scale ensemble of process-based models to quantify the relative sources, transformations, and sinks of geogenic and atmospheric N through a mountain watershed. Our study is based in the East River Watershed (ERW) in the Upper Colorado River Basin. The East River is a near-pristine headwater watershed underlain primarily by an N-rich Mancos Shale bedrock, enabling the timing and magnitude of geogenic and atmospheric contributions to watershed scale dissolved N-exports to be quantified. Several calibration scenarios were developed to explore equifinality using >1600 N concentration measurements from streams, groundwater, and vadose zone samples collected over the course of four years across the watershed. When accounting for recycling of N through plant litter turnover, rock weathering accounts for approximately 12% of the annual dissolved N sources to the watershed in the most probable calibration scenario (0–31% in other scenarios), and 21% (0–44% in other scenarios) when considering only “new” N sources (i.e. geogenic and atmospheric). On an annual scale, instream dissolved N elimination, plant turnover (including cattle grazing) and atmospheric deposition are the most important controls on N cycling.

Effects of climate change on the elevational distribution of bumble bees near Crested Butte, CO: comparing data across 47 years - S. Gram (2021)
As climate change continues to alter the abiotic environment, many organisms must adapt to survive. In montane systems where changes in elevation can present noticeable changes in temperature and moisture, many organisms may adapt to climate change by migrating to higher elevations. Bumble bees, which are diverse and abundant in temperate montane ecosystems, may be vulnerable to climate change as changing environments alter the composition of plants. However, it’s unclear whether the elevational ranges of bumble bees have shifted over time. Here, we analyze a new survey in the context of a long-term project monitoring the elevational distributions of bumble bee communities near Crested Butte, Colorado. Our findings suggest that some species may be shifting to higher elevation, but many appear to be stable.

Investigating the comparison between bird diversity and apex aquatic predators in sub-alpine beaver ponds - A. Haeseler (2021)
Predation of native salamanders by non-native trout in Colorado is a wildlife concern. Understanding the dynamics of how the different species interact is important. Cascade effects in the environment are caused by declines of species in a community. Birds, fish, and amphibians are deeply connected, therefore observing birds may help understand the ecosystem. Bird diversity is a crucial indicator to understand environmental changes and health. The research focused on the effects of different apex aquatic predators and the number of different bird species near beaver ponds. Point counts were conducted to observe birds visually and aurally for 15 minutes. The comparison between pond type and number of different species was significant, suggesting that different aquatic predators may affect bird communities. In future research, analyzing the tree canopy and pond depth would provide a useful distinction of each pond.

Power of place and landscape - J.M. Scott (2021)
This chapter presents and compares three military landscapes encountered by the United States (US) Army’s Second World War 10th Mountain Division, the only wartime US formation dedicated to mountain warfare. The Division’s training in the Rocky Mountains was more than adequate for their task of scaling mountain heights at the centre of the German Wehrmacht Gothic Line in 1945. This chapter is concerned with the military landscapes of specialized mountain training and mountain battle-zones. It proceeds from the view that landscapes are not just a material concept but exist also as memories which can be recalled to navigate physical as well as social landscapes. Signs and symbols associated with and found within the landscape are rarely universal; their meanings are culturally, contextually, and temporally determined.

Mammalian herbivores restrict the altitudinal range limits of alpine plants - J. S. Lynn; T. E. X. Miller; Jennifer A. Rudgers (Ecology Letters, 2021)
Abstract Although rarely experimentally tested, biotic interactions have long been hypothesised to limit low‐elevation range boundaries of species. We tested the effects of herbivory on three alpine‐restricted plant species by transplanting plants below (novel), at the edge (limit), or in the centre (core) of their current elevational range and factorially fencing‐out above‐ and belowground mammals. Herbivore damage was greater in range limit and novel habitats than in range cores. Exclosures increased plant biomass and reproduction more in novel habitats than in range cores, suggesting demographic costs of novel interactions with herbivores. We then used demographic models to project population growth rates, which increased 5–20% more under herbivore exclosure at range limit and novel sites than in core habitats. Our results identify mammalian herbivores as key drivers of the low‐elevation range limits of alpine plants and indicate that upward encroachment of herbivores could trigger local extinctions by depressing plant population growth.

Effects of Native and Non-native Predators on Aquatic Communities - E. Kerr (2021)
Predators impact the ecosystem in a top-down manner; however, we are not sure how non-native predators differ from native ones. In Colorado beaver ponds, non-native trout can change aquatic communities by preying on macroinvertebrates and excluding the native predator, tiger salamanders. Beaver ponds have high macroinvertebrate density, provide habitat for tiger salamanders, and support introduced trout populations thus providing a system to study macroinvertebrate communities based on the predator present. I sampled the macroinvertebrates in 18 beaver ponds; 6 containing fish, 6 containing salamanders, and 6 with no predators within the Gunnison Valley. My analysis revealed that there is no significant difference in the aquatic invertebrate communities between beaver ponds with trout, salamanders, or no predators, although there may be differences in diversity among pond types. The other analyses are currently ongoing, but so far it appears that trout and salamanders may be complementary predators in this system.

Effects of Climate Variation and Nesting Traits on Sex Ratios of Adult Solitary Bees - W. Lovecky (2021)
In the face of environmental change, including climate change, many organisms’ biological and ecological processes are being altered. Adult sex ratios are directly related to an organisms’ reproductive success and long-term viability. Understanding what influences sex ratios in the face of these changes may help us to predict the success of an organism. Here we investigated how climate variation influences the adult sex ratios of twelve species of solitary bees present in what is now the Gothic, Colorado area. We looked at how climate variation, specifically snowmelt timing, may influence their adult sex ratios. We also explored how nesting traits may provide protection or susceptibility to climatic influence. Using long-term data collected by Dr. Rebecca Irwin’s lab and billy barr, we ran generalized linear models to understand the relationship between snowmelt timing and the sex ratios of each of the twelve selected bee species. We also ran these same models, but categorized bee species based on nesting type (above-ground vs. below-ground nesters). Across all species, we found that in years with early snowmelt, the following year had a smaller proportion of females. The same trend was seen significantly with below-ground nesters. Above ground nesters exhibited the same pattern but the pattern lacked significance. We hypothesize that snowmelt does not have a direct effect on the sex ratios of solitary bees, but rather that it influences floral abundance which affects the ability of females to provision female vs. male offspring. Future studies should further explore this as it may have a direct influence on the long-term viability of solitary bees.

The Influence of Summer Precipitation and Temperature on Golden Mantled Ground Squirrel Pup Foraging. - M. Nickson (2021)
Golden-mantled ground squirrels (GMGS) at the Rocky Mountain Biological Laboratory (RMBL) spend the majority of the year, from October to May, hibernating in order to save energy during the winter seasons in Gothic, Colorado. Once the winter season is over, the squirrels emerge from their burrows and spend spring and summer foraging in preparation for next winter. Foraging behavior is highly important during these months since food only starts to become available when snow melts, stimulating green vegetation growth. However, vegetation quality may depend on weather conditions: drier years may decrease vegetation quality, while wetter years may increase vegetation quality. Though behavioral flexibility is one of the most common modes of response across most mammal species, there is a lack of knowledge on how acute climate stress changes animals’ foraging behavior. Behavioral flexibility is the ability of having diverse behavioral traits, which is important for species to adapt to any changes and survive in their environment. In conclusion, small mammals such as the golden-mantled ground squirrel, must constantly balance foraging and avoiding factors that increase mortality, including disadvantageous weather conditions. They can modify foraging patterns and overall daily activity when the weather changes (Stokes, 2001). Foraging activity was greatly affected by precipitation and temperatures in the month of July. With hotter temperatures more common in the future, I expect this effect to cause a negative shift in the pups foraging behavior, causing them to have to adapt in new ways. Key Words: Golden-Mantled Ground Squirrel, Temperature, Precipitation, Behavioral Flexibility, Dry/Wet Years

Massive DNA "BORG" Structures Perplex Scientists - A. Dance (Nature, 2021)

On the structure and significance of ecological niche breadth - Kelly A Carscadden (2021)

The influence of human recreational trail use has on rodent and predator activity using motion triggered cameras - V. Rodriguez (2021)
The recreational trails in Gunnison County, Colorado near the Rocky Mountain Biological Laboratory (RMBL) are a valuable resource for the community. RMBL is a prominent field station surrounded by a largely intact ecosystem whose diverse native plants and animals are key to its scientific research and education programs. Human recreation near these areas generates touristic income for the surrounding cities. However, human recreation can lead to behavioral changes in wild animals. Knowing whether the current regulations being implemented on the trails are sufficient to protect the wildlife is imperative. Utilizing methods from RMBL studies conducted in 2019 and 2020, we studied the effects of human use of recreational trails on small mammals and predators. This three-part study used motion triggered cameras to (1) compare the effectiveness of the non-invasive bucket camera traps with live rodent trapping, (2) measure the impact that human activity on trails has on rodents, and (3) measure the impact that human activity on trails has on predators. We found that bucket traps and live-trapping both capture the same nocturnal species, but bucket traps also capture diurnal species. We determined that human recreation (hiking, biking, dogs) had no significant negative impact on rodents (either nocturnal or diurnal) or on the number of predators. There was a marginally significant increase of predators at Deer Creek Trail with human recreation, but no relationship between predator numbers and rodent numbers. We conclude that recreation in the vicinity of RMBL is not having a detectable negative effect on wildlife species diversity or activity.

Apendix - Brian N. Andrews; David J. Meltzer; Mark Stiger (University Press of Colorado eBooks, 2021)
which, following Aldenderfer (2006), we define as locations at elevations greater than 2,500 meters above sea level (e.g.,

Morph and Sex differences in prey selectivity of tiger salamanders ( Ambystoma mavortium nebulosum ) - G. Sánchez Ruiz (2021)
The tiger salamander is the top predator of the benthic invertebrate in the ponds at the Mexican Cut Nature Preserve, and hence, one of the main influential factors on the benthic invertebrate community structure. Recent phenomena observed at the MCP, like earlier snowmelt dates of some of the ponds in response to climate change, could potentially result in changes to the community structure by affecting the timeline of encounters between salamanders and their usual prey. To assess changes in predation selectivity of the tiger salamander in response to climate change and how sex and morph alter this feeding relationships, feeding trials were conducted at the MCP. The salamanders representing both morphs and sexes were starved for 24 hours before the trials and placed in 52 cm × 36 ½ cm plastic boxes with different types of their usual prey. The results did not support our hypothesis of shifting diet preferences, fairy shrimp is still the preferred food source for metamorphs, and unexpectedly, also for paedomorphic salamanders. The subsequent preferred prey differentiated between the morphs. An influence of sex on amount of prey consumed was not observed, it is most likely that this is due to the trials being conducted out of mating season. The importance of the study lies in assessing how climate change will affect feeding relationships and community structure of subalpine ponds at the MCP wetland or similar ecosystems.

The spatial variation of leaf traits in Ipomopsis according to soil moisture and snow depth - F. Talaba (2021)
This study analyzed how soil moisture and snow depth correlates with leaf traits of Ipomopsis aggregata across and within populations in the Crested Butte and Gothic, Colorado area. Earlier snowmelt due to global warming is lessening soil moisture in early summer in the Rocky Mountains and potentially affecting leaf traits that aid in photosynthesis. We expected that I. aggregata plants with low water availability to have leaf traits that more efficiently photosynthesize and conserve water. Variation in soil moisture within sites had weak or no effects on the leaf traits, except that stomatal density increased with soil moisture in sites that also had low snowpack. Sites with lower snow depth had lower leaf water content, lower specific leaf area (SLA), and trichome density but showed no average change in stomatal density and diameter. The variation across sites in leaf water content, SLA, and trichome density could be attributed to aiding in efficient photosynthesis and less transpiration in areas where there is drought-stress.

From animals to ecosystem processes: Predicting functional outcomes of climate-driven changes in animal communities through species traits - J. A. Balik (2021)
Functional trait diversity within species assemblages ultimately determines whether or not ecosystem processes are sensitive to shifts in relative abundances or species composition. For example, trait variation suggests detritivores process detritus at different rates and make different relative contributions to whole-assemblage processing, which is therefore likely sensitive to global change-driven shifts in assemblage composition. Here, we address three main questions: 1) what is the magnitude of interspecific variation in detritus processing within the detritivore guild in high-elevation wetlands, 2) which traits drive interspecific variation in processing among larval caddisflies, 3) are larval caddisflies’ single-species effects additive in multi-species assemblages? We used a series of microcosm experiments to quantify species-specific coarse and fine particulate organic matter (CPOM and FPOM) processing for ten closely-related larval caddisfly species and three non-caddisfly species. Next, we compared trait-based models including life history, dietary, and extrinsic trait predictors to determine which intrinsic and extrinsic traits best explain the interspecific variation among the larval caddisflies. Finally, we compared processing by mixed caddisfly assemblages in microcosms and in natural ponds to additive predictions based on individual species processing rates. We found considerable interspecific variation in biomass-specific CPOM (thirteen-fold differences) and FPOM (eight- fold differences) processing. Furthermore, on a mass-specific basis, amphipods and chironomids processed a similar amount of detritus as caddisflies, suggesting the importance of non-shredder taxa for processing CPOM may be greater than previously recognized. Next, the best trait model of CPOM processing included development rate, percent CPOM in the diet, and primary case material. Similarly, the best model for FPOM processing included development rate and percent of total detritus in the diet. Finally, additive predictions were strikingly similar to realized 21 processing in mixed caddisfly assemblages in both microcosms and natural ponds, with the largest difference being a 15% overestimate of CPOM processing in one microcosm experiment. Thus, as global change drives species range shifts, invasions, and extinctions, additivity of species-specific processing suggests that single-species rates may be useful for understanding functional consequences of shifting detritivore assemblages. Furthermore, a trait-based approach to predicting species-specific processing could support preparation of additive estimates of whole-assemblage processing. 22

The effects of anthropogenic change on pollination in plant-pollinator communities - L. Xingwen (2021)
The effects of anthropogenic change on pollination in plant-pollinator communities by Loy Xingwen Pollinators facilitate reproduction in ~80% of global plant species, making them integral to many agricultural and natural ecosystems. For over 200 years, western scientists have been fascinated by the intimate partnerships between pairs of plant and pollinator species. However, current pollinator declines and biodiversity loss have brought to attention the ecology of multi-species plant-pollinator communities. Now more than ever, we need to understand how diverse communities of plants and pollinators sustain one another, and how human activities threaten them. To this end, we must first have clarity on how pollinator diversity benefits plant pollination. Numerous studies have shown that increasing pollinator diversity improves pollination function. Yet this positive relationship is not always detectable, and even when it is, we are often unable to definitively explain why it manifests. In Chapter 2, I synthesized current empirical evidence of pollinator diversity-function relationships, highlighting problems, pitfalls and possibilities for advancing enquiry. Following this in-depth analysis of the value of pollinator diversity, I then examined two ways in which humans can impact natural pollination: i) through changes in pollinator diversity, and ii) through changes in plant- pollinator interactions. Chapter 3 examines how changes to land-use in the southeastern United States may affect the diversity of bees, a globally important insect pollinator. The U.S. government aims to convert the country’s southeastern pine plantations from producing timber to bioenergy feedstock. I showed how changing the management of pine plantations from to bioenergy feedstock could have drastic effects on local bee communities. Nevertheless, results suggest that some

Animal-Driven Nutrient Supply Declines Relative to Ecosystem Nutrient Demand Along a Pond Hydroperiod Gradient - J. A. Balik; E. Jameson; S. A. Wissinger; H. H. Whiteman; B. W. Taylor (Ecosystems, 2021)

Open-top warming chambers reduce animal pollination of two subalpine herbs - C. Adamson; Amy M. Iler (Journal of Pollination Ecology, 2021)
Open top chambers (OTCs) are a popular method for studying the biological effects of climate change through passive heating, but their effects on biotic interactions are poorly understood, especially for pollination. Here we use the subalpine plants Delphinium nuttallianum and Potentilla pulcherrima to examine the possibility that the effects of OTCs on plant reproduction are not the result of warming but rather OTCs acting as barriers to pollinator movement. Pollinator observations were conducted and stigmas collected from plants inside and outside of OTCs in a meadow in the Rocky Mountains of Colorado, USA. Very few visitors were observed inside of OTCs, which led to severe reductions in visitation rates, by 92% in Delphinium and 85% in Potentilla. The number of conspecific pollen grains on stigmas was 73% lower in OTCs for Delphinium but not Potentilla, likely because it is capable of autogamous self-pollination. This study clearly shows that OTCs can reduce animal pollination, which is also likely to reduce plant reproductive output of outcrossing plants via decreases in the quantity or quality of pollen. OTCs may therefore confound effects of warming on plant reproduction with pollination effects. Although the unintended effects of OTCs on abiotic conditions are well-studied, this study highlights that their effects on biotic interactions require further investigation.

Cytotype and genotype predict mortality and recruitment in Colorado quaking aspen ( Populus tremuloides ) - B. Blonder; C. A. Ray; J. A. Walton; Marco Castaneda; K. Dana Chadwick; Michael Clyne; P. Gauzere; L. L. Iversen; Madison Lusk; G. Richard Strimbeck; Savannah Troy; K. E. Mock (Ecological Applications, 2021)
Accepted Article Species responses to climate change depend on environment, genetics, and interactions among these factors. Intraspecific cytotype (ploidy level) variation is a common type of genetic variation in many species. However, the importance of intraspecific cytotype variation in determining demography across environments is poorly known. We studied the tree species quaking aspen (Populus tremuloides), which occurs in diploid and triploid cytotypes. This widespread species is experiencing contractions in its western range, which could potentially be linked to cytotype- dependent drought tolerance. We found that interactions between cytotype and environment drive mortality and recruitment across 503 plots in Colorado. Triploids were more vulnerable to mortality relative to diploids and had reduced recruitment on more drought-prone and disturbed plots relative to diploids. Furthermore, there was substantial genotype-dependent variation in demography. Thus, cytotype and genotype variation are associated with decline in this foundation species. Future assessment of demographic responses under climate change will require knowledge of how genetic and environmental mosaics interact to determine species’ ecophysiology and demography. Key words Populus tremuloides, demography, cytotype, ploidy level, drought mortality, forest This article is protected by copyright. All rights reserved

Meanders as a scaling motif for understanding of floodplain soil microbiome and biogeochemical potential at the watershed scale - P. B. M. Carnevali; A. Lavy; A. D. Thomas; A. Crits-Christoph; S. Diamond; R. Meéheust; M. R. Olm; A. Sharrar; S. Lei; Wenming Dong; Nicola Falco; Nicholas J. Bouskill; et al. (Microbiome, 2021)
Abstract Biogeochemical exports of C, N, S and H 2 from watersheds are modulated by the activity of microorganisms that function over micron scales. This disparity of scales presents a substantial challenge for development of predictive models describing watershed function. Here, we tested the hypothesis that meander-bound regions exhibit patterns of microbial metabolic potential that are broadly predictive of biogeochemical processes in floodplain soils along a river corridor. We intensively sampled floodplain soils located in the upper, middle, and lower reaches of the East River in Colorado and reconstructed 248 draft quality genomes representative at a sub-species level. Approximately one third of the representative genomes were detected across all three locations with similar levels of abundance, and despite the very high microbial diversity and complexity of the soils, ~15% of species were detected in two consecutive years. A core floodplain microbiome was enriched in bacterial capacities for aerobic respiration, aerobic CO oxidation, and thiosulfate oxidation with the formation of elemental sulfur. We did not detect systematic patterns of gene abundance based on sampling position relative to the river. However, at the watershed scale meander-bound floodplains appear to serve as scaling motifs that predict aggregate capacities for biogeochemical transformations in floodplain soils. Given this, we conducted a transcriptomic analysis of the middle site. Overall, the most highly transcribed genes were amoCAB and nxrAB (for nitrification) followed by genes involved in methanol and formate oxidation, and nitrogen and CO 2 fixation. Low soil organic carbon correlated with high activity of genes involved in methanol, formate, sulfide, hydrogen, and ammonia oxidation, nitrite oxidoreduction, and nitrate and nitrite reduction. Thus, widely represented genetic capacities did not predict in situ activity at one time point, but rather they define a reservoir of biogeochemical potential available as conditions change.

Porewater Lead Concentrations Limited by Particulate Organic Matter Coupled With Ephemeral Iron(III) and Sulfide Phases during Redox Cycles Within Contaminated Floodplain Soils - Christian Dewey; John R. Bargar; Scott Fendorf (Environmental Science & Technology, 2021)
Lead contamination in soils and sediments is a major threat to water quality. In surface and near-surface environments, Pb is not redox active; however, common Pb hosts, including Fe(III)-(hydr)oxides and sulfides, dissolve and precipitate as redox conditions change. Dissolution of Pb hosts may release Pb to porewater, leading to spikes in dissolved Pb concentrations and potential transport into surface or groundwater. Here, we examine the impacts of hydrologically coupled redox transitions on Pb partitioning in contaminated floodplain soils. We find that the affinity of Pb for particulate organic matter (POM), inclusive of mineral-associated organic matter, ensures that across redox transitions Pb is retained in the solid phase, despite host-phase (Fe(III)-(hydr)oxide and sulfide) dissolution. As seasonal hydrologic dynamics shift porewater redox conditions, Pb-bearing Fe(III)-(hydr)oxides (Pb-HFO) and sulfides (PbS) are dissolved and (re)precipitated. However, despite these shifts in redox conditions and associated host-phase transformations, Pb retention on POM, coupled with the formation of PbS and Pb-HFO, maintains dissolved Pb concentrations below 17 μg L-1. Importantly, the predominance of Pb adsorbed on POM alongside low dissolved Pb concentrations indicates that Pb released from HFO and PbS is retained by POM. Thus, despite host-phase dissolution during redox transitions, partitioning of Pb to the aqueous phase is minimal and, therefore, transport of dissolved Pb is unlikely.

Do microorganisms obey macroecological rules? - J. Dickey; R. Swenie; S. Turner; C. Winfrey; D. Yaffar; A. Padukone; K. K. Beals; K. S. Sheldon; Stephanie N. Kivlin (Authorea, 2021)
Understanding the factors controlling the relative abundance, distribution, and diversity of organisms is a fundamental challenge in ecology. For plants and animals, macroecological rules have been developed that describe these large-scale distributional patterns and attempt to explain the underlying physiological and ecological processes behind them. Similarly, microorganisms exhibit patterns in relative abundance, distribution, and diversity across space and time, yet it remains unclear the extent to which microorganisms follow macroecological rules initially developed for macroorganisms. With rapid advancements in sequencing technology, we have seen a recent increase in microbial studies that utilize macroecological frameworks. Here we review and synthesize these macroecological microbial studies with two main objectives: (1) to determine to what extent macroecological rules explain the distribution of host-associated and free-living microorganisms, and (2) to understand which environmental factors and stochastic processes may explain these patterns among microbial clades (archaea, bacteria, fungi, protists) and habitats (host-associated and free living; terrestrial and aquatic). Our review is the first, to our knowledge, that examines whether or not the same environmental drivers contribute to similar trends to macroecological studies when rules are upheld for microorganisms. Further, we outline several outstanding questions and recommendations for future studies in microbial ecology.

Challenging problems of quality assurance and quality control (QA/QC) of meteorological time series data - Boris Faybishenko; Roelof Versteeg; Gilberto Pastorello; Dipankar Dwivedi; Charuleka Varadharajan; Deb Agarwal (Stochastic environmental research and risk assessment, 2021)
Representativeness and quality of collected meteorological data impact accuracy and precision of climate, hydrological, and biogeochemical analyses and predictions. We developed a comprehensive Quality Assurance (QA) and Quality Control (QC) statistical framework, consisting of three major phases: Phase I—Preliminary data exploration, i.e., pro- cessing of raw datasets, with the challenging problems of time formatting and combining datasets of different lengths and different time intervals; Phase II—QA of the datasets, including detecting and flagging of duplicates, outliers, and extreme data; and Phase III—the development of time series of a desired frequency, imputation of missing values, visualization and a final statistical summary. The paper includes two use cases based on the time series data collected at the Billy Barr meteorological station (East River Watershed, Colorado), and the Barro Colorado Island (BCI, Panama) meteorological station. The developed statistical framework is suitable for both real-time and post-data-collection QA/QC analysis of meteorological datasets.

Snow melt timing acts independently and in conjunction with temperature accumulation to drive subalpine plant phenology - Diana K Jerome; William K. Petry; K. A. Mooney; Amy M. Iler (Global Change Biology, 2021)
AbstractOrganisms use environmental cues to align their phenology—the timing of life events—with sets of abiotic and biotic conditions that favor the successful completion of their life cycle. Climate change has altered the environmental cues organisms use to track climate, leading to shifts in phenology with the potential to affect a variety of ecological processes. Understanding the drivers of phenological shifts is critical to predicting future responses, but disentangling the effects of temperature from precipitation on phenology is often challenging because they tend to covary. We addressed this knowledge gap in a high‐elevation environment where phenological shifts are associated with both the timing of spring snow melt and temperature. We factorially crossed early snow melt and passive warming treatments to (1) disentangle the effects of snow melt timing and warming on the phenology of flowering and fruiting and reproductive success in three subalpine plant species (Delphinium nuttallianum, Valeriana edulis, and Potentilla pulcherrima); and (2) assess whether snow melt acts via temperature accumulation or some other aspect of the environment (e.g., soil moisture) to affect phenological events. Both the timing and duration of flowering and fruiting responded to the climate treatments, but the effect of snow melt timing and warming varied among species and phenological stages. The combined effects of the treatments on phenology were always additive, and the snow melt treatment often affected phenology even when the warming treatment did not. Despite marked responses of phenology to climate manipulations, the species showed little change in reproductive success, with only one species producing fewer seeds in response to warming (Delphinium, −56%). We also found that snow melt timing can act both through temperature accumulation and as a distinct cue for phenology, and these effects are not mutually exclusive. Our results show that one environmental cue, here snow melt timing, may act through multiple mechanisms to shift phenology.

From the ground up: Building predictions for how climate change will affect belowground mutualisms, floral traits, and bee behavior - A. M. Keeler; Nicole E. Rafferty; A. Rose-Person (Climate Change Ecology, 2021)
Climate change affects species and their interactions, resulting in novel communities and modified ecosystem processes. Through shifts in phenology and distribution, climatic change can disrupt interactions, including those between mutualists. Mutualisms influence the structure and stability of communities and can link species to a common fate. However, research on climate change has focused on pairwise mutualisms, neglecting the higher-order interactions that can arise when species interact with multiple mutualists. We explore the effects of climate change on tripartite interactions involving belowground mutualists, namely soil bacteria and fungi, flowering plants, and pollinators. We outline how climate change is predicted to affect the phenology and distribution of these belowground mutualists, emphasizing the consequent effects on host plant floral traits, plant-pollinator interactions, and bee behavior. We find evidence that warming, advanced snowmelt, and drought are likely to cause phenological and distributional shifts in soil microbes, leading to diminished mutualistic interactions with plants and symbiont switching. Consequently, shifts in flowering phenology, smaller floral displays, and lower quality floral rewards are expected, increasing foraging time and energy demands for bees and altering their floral preferences. Such costs could translate into reduced fitness and novel selection pressures for bees and flowering plants in the short term. We highlight knowledge gaps and ways forward, urging studies on microbe dispersal and phenological cues, experiments that manipulate soil microbe-host plant interactions under simulated climate change conditions, and large-scale field studies across environmental gradients, all with the goal of understanding how climate change will affect soil microbe-plant-pollinator mutualisms.

New age constraints on the Late Cretaceous lower Williams Fork Formation, Coal Canyon, Colorado - Jordan T. Walker; Andres Aslan; Rex D. Cole; Michael T. Heizler (The Mountain Geologist, 2021)
The precise age of terrestrial sediments in the Late Cretaceous Williams Fork Formation of western Colorado is poorly constrained due to a paucity of radiometric data. Sanidine and zircon dating of a volcanic ash encased in coal (i.e., the Coal Canyon ash) within the Cameo-Wheeler coal zone of the lower Williams Fork Formation in Coal Canyon, Colorado provides an important new age constraint for the southwestern Piceance Basin. A 10-30 cm thick, light gray, clayey mudstone encased in coal was sampled for both zircon U-Pb and sanidine 40Ar/39Ar geochronology. The presence of numerous euhedral zircon crystals, a lenticular geometry, and a clayey texture suggest that the mudstone is a minimally reworked and slightly altered volcanic ash. Analysis of the euhedral zircon crystals (n=108) in the ash produced a statistically robust U-Pb date with 93 grains yielding a weighed mean age of 74.52 ±0.11 Ma (1σ analytical uncertainty). 40Ar/39Ar sanidine analyses yielded a younger weighted mean age of 73.10 ±0.12 Ma (1σ analytical uncertainty) based on 6 of the 36 grains analyzed. Our preferred age is given by the weighted mean age of the sanidine as it is based on higher precision analyses that can better discriminate older inherited grains that are likely included in the zircon mean-age calculation. Isotopic data for the Coal Canyon ash overlap in age with a K-Ar date of 72.5 ±5.1 Ma for a widespread Williams Fork Formation tonstein, known as the Yampa Bed, found in coal-bearing outcrops and mine workings throughout the northern Piceance and Sand Wash basins and Axial Basin Uplift. Based on the similarity in isotopic age, sedimentologic context and stratigraphic position, we suggest that the Coal Canyon ash and the regionally extensive Yampa Bed are coeval. Additionally, this correlation corroborates that the Cameo-Wheeler coal zone of the Williams Fork Formation in the southwestern Piceance Basin is correlative with the Middle coal zone of the Danforth Hills and Yampa regions. Lastly, this proposed correlation may suggest that the Coal Canyon ash, like the Yampa Bed, correlates with the Baculites reesidei ammonite zone, which is associated regionally with a bentonite dated to 72.94 ±0.45 Ma. Detrital sanidine geochronology of two lower Williams Fork sandstone units that overly the Coal Canyon ash did not produce grains younger than the ash and thus do not quantitatively improve the chronostratigraphy of these specific units. Lastly, the Coal Canyon ash date serves as a basis for future evaluations of the diachroneity of non-marine strata of the Williams Fork Formation.

Effect of elevation, season and accelerated snowmelt on biogeochemical processes during isolated conifer needle litter decomposition - Laura T. Leonard; E. L. Brodie; K. H. Williams; Jonathon O. Sharp (PeerJ, 2021)
Increased drought and temperatures associated with climate change have implications for ecosystem stress with risk for enhanced carbon release in sensitive biomes. Litter decomposition is a key component of biogeochemical cycling in terrestrial ecosystems, but questions remain regarding the local response of decomposition processes to climate change. This is particularly complex in mountain ecosystems where the variable nature of the slope, aspect, soil type, and snowmelt dynamics play a role. Hence, the goal of this study was to determine the role of elevation, soil type, seasonal shifts in soil moisture, and snowmelt timing on litter decomposition processes. Experimental plots containing replicate deployments of harvested lodgepole and spruce needle litter alongside needle-free controls were established in open meadows at three elevations ranging from 2,800-3,500 m in Crested Butte, Colorado. Soil biogeochemistry variables including gas flux, porewater chemistry, and microbial ecology were monitored over three climatically variable years that shifted from high monsoon rains to drought. Results indicated that elevation and soil type influenced baseline soil biogeochemical indicators; however, needle mass loss and chemical composition were consistent across the 700 m elevation gradient. Rates of gas flux were analogously consistent across a 300 m elevation gradient. The additional variable of early snowmelt by 2-3 weeks had little impact on needle chemistry, microbial composition and gas flux; however, it did result in increased dissolved organic carbon in lodgepole porewater collections suggesting a potential for aqueous export. In contrast to elevation, needle presence and seasonal variability of soil moisture and temperature both played significant roles in soil carbon fluxes. During a pronounced period of lower moisture and higher temperatures, bacterial community diversity increased across elevation with new members supplanting more dominant taxa. Microbial ecological resilience was demonstrated with a return to pre-drought structure and abundance after snowmelt rewetting the following year. These results show similar decomposition processes across a 700 m elevation gradient and reveal the sensitivity but resilience of soil microbial ecology to low moisture conditions.

Trade-off mitigation: a conceptual framework for understanding floral adaptation in multispecies interactions - K. Ohashi; A. Jurgens; J. D. Thomson (Biological Reviews, 2021)
ABSTRACTExplanations of floral adaptation to diverse pollinator faunas have often invoked visitor‐mediated trade‐offs in which no intermediate, generalized floral phenotype is optimal for pollination success, i.e. fitness valleys are created. In such cases, plant species are expected to specialize on particular groups of flower visitors. Contrary to this expectation, it is commonly observed that flowers interact with various groups of visitors, while at the same time maintaining distinct phenotypes among ecotypes, subspecies, or congeners. This apparent paradox may be due to a gap in our understanding of how visitor‐mediated trade‐offs could affect floral adaptation. Here we provide a conceptual framework for analysing visitor‐mediated trade‐offs with the hope of stimulating empirical and theoretical studies to fill this gap. We propose two types of visitor‐mediated trade‐offs to address negative correlations among fitness contributions of different visitors: visitor‐mediated phenotypic trade‐offs (phenotypic trade‐offs) and visitor‐mediated opportunity trade‐offs (opportunity trade‐offs).Phenotypic trade‐offsoccur when different groups of visitors impose conflicting selection pressures on a floral trait. By contrast,opportunity trade‐offsemerge only when some visitors’ actions (e.g. pollen collection) remove opportunities for fitness contribution by more beneficial visitors. Previous studies have observed disruptive selection due tophenotypic trade‐offsless often than expected. In addition to existing explanations, we propose that some flowers have achieved ‘adaptive generalization’ by evolving features to avoid or eliminate the fitness valleys thatphenotypic trade‐offstend to produce. The literature suggests a variety of pathways to such ‘trade‐off mitigation’. Trade‐off mitigation may also evolve as an adaptation toopportunity trade‐offs. We argue that active exclusion, or floral specialization, can be viewed as a trade‐off mitigation, occurring only when flowers cannot otherwise avoid strongopportunity trade‐offs. These considerations suggest that an evolutionary strategy for trade‐off mitigation is achieved often by acquiring novel combinations of traits. Thus, phenotypic diversification of flowers through convergent evolution of certain trait combinations may have been enhanced not only through adaptive specialization for particular visitors, but also through adaptive generalization for particular visitor communities. Explorations of how visitor‐mediated trade‐offs explain the recurrent patterns of floral phenotypes may help reconcile the long‐lasting controversy on the validity of pollination syndromes.

Climate and multiple dimensions of plant diversity regulate ecosystem carbon exchange along an elevational gradient - C. M. Prager; X. Jing; Jeremiah A Henning; Quentin D Read; P. Meidi; S. Lavorel; Nathan J. Sanders; M. K. Sundqvist; D. A. Wardle; Aimee T Classen (Ecosphere, 2021)
Abstract The impacts of warming on communities and ecosystems are predicted to be significant in mountain ecosystems because physiological processes, including rates of carbon (C) cycling, are often more temperature‐sensitive in colder environments. Plant biodiversity can also influence C exchange, yet few studies integrate how biotic and abiotic factors may directly or interactively impact ecosystem C flux. Here, we examine the link between simultaneous changes in multiple dimensions of plant diversity and peak growing season ecosystem C uptake across a climatic gradient in the Rocky Mountains, Colorado, USA. We found that taxonomic diversity (species richness), functional diversity (functional evenness), and phylogenetic diversity (mean pairwise distance) were significantly and positively related to peak growing season ecosystem C uptake (i.e., net ecosystem exchange) when considered independently. However, when abiotic and biotic factors were integrated in a structural equation model, only plant phylogenetic diversity was significantly related to C uptake. In addition, we found that actual evapotranspiration (AET—a measure that integrates precipitation and temperature) affected ecosystem C exchange indirectly via its impact on the three dimensions of plant diversity that we examined. These findings highlight complex relationships among key measures of biodiversity and ecosystem C uptake in a rapidly warming ecosystem, and the possible mechanisms that underlie relationships between biodiversity and ecosystem functioning. They also point to the need for integrating multiple dimensions of biodiversity into studies of community and ecosystem ecology.

Unraveling the ecological and evolutionary impacts of a plant invader on the pollination of a native plant - Wilnelia Recart; Diane R. Campbell (Biological Invasions doi 10.1007/s10530-021-02457-z, 2021)
The results show how the presence of an invasive plant and year-to-year variation in plant-pollinator interactions affect the pollination and components of pollinator-mediated selection in native plants.

Blocks X and Y - Andrew R. Boehm; R. B. Anderson (University Press of Colorado eBooks, 2021)
which, following Aldenderfer (2006), we define as locations at elevations greater than 2,500 meters above sea level (e.g.,

Block C - Brooke Morgan; Brian N. Andrews; David J. Meltzer (University Press of Colorado eBooks, 2021)
which, following Aldenderfer (2006), we define as locations at elevations greater than 2,500 meters above sea level (e.g.,

The sensory and cognitive ecology of nectar robbing - S. K. Richman; J. L. Barker; M. Baek; D. R. Papaj; R. E. Irwin; J. L. Bronstein (Frontiers in Ecology and Evolution, 2021)
Animals foraging from flowers must assess their environment and make critical decisions about which patches, plants, and flowers to exploit to obtain limiting resources. The cognitive ecology of plant-pollinator interactions explores not only the complex nature of pollinator foraging behavior and decision making, but also how cognition shapes pollination and plant fitness. Floral visitors sometimes depart from what we think of as typical pollinator behavior and instead exploit floral resources by robbing nectar (bypassing the floral opening and instead consuming nectar through holes or perforations made in floral tissue). The impacts of nectar robbing on plant fitness are well-studied; however, there is considerably less understanding, from the animal’s perspective, about the cognitive processes underlying nectar robbing. Examining nectar robbing from the standpoint of animal cognition is important for understanding the evolution of this behavior and its ecological and evolutionary consequences. In this review, we draw on central concepts of foraging ecology and animal cognition to consider nectar robbing behavior either when individuals use robbing as their only foraging strategy or when they switch between robbing and legitimate foraging. We discuss sensory and cognitive biases, learning, and the role of a variable environment in making decisions about robbing vs. foraging legitimately. We also discuss ways in which an understanding of the cognitive processes involved in nectar robbing can address questions about how plant-robber interactions affect patterns of natural selection and floral evolution. We conclude by highlighting future research directions on the sensory and cognitive ecology of nectar robbing.

Firmicutes and Bacteroidetes explain mass gain variation in an obligate hibernator - G. C. Johnson (bioRxiv, 2021)
Abstract Body condition is an important life history challenge that directly impacts individual fitness and is particularly important for hibernating animals, whose maintenance of adequate body fat and mass is essential for survival. It is well documented that symbiotic microorganisms play a vital role in animal physiology and behaviour. Recent work demonstrates that gut microbes are associated with fat accumulation and obesity; Firmicutes is consistently associated with obesity while Bacteroidetes is associated with leanness both in humans and other animals. The focus of most microbiome studies has been on human health or involved lab reared animals used as a model system. However, these microbes likely are important for individual fitness in wild populations and provide potential mechanistic insights into the adaptability and survival of wildlife. Here we test whether symbiotic microorganisms within the phyla of Firmicutes and Bacteroidetes are associated with summer mass gain in an exceptionally well-studied wild population of yellow-bellied marmots ( Marmota flaviventer ) by quantifying microbial abundance over five years of fecal samples (2015 – 2019) collected during their summer active season. Results show that marmots with higher mass gain rates have a greater abundance of Firmicutes . In contrast, higher abundance of Bacteroidetes was associated with lower mass gain rates, but only for marmots living in harsher environments. Similar patterns were found at the family level where Ruminococcaceae , a member of Firmicutes , was associated with higher mass gain rates, and Muribaculaceae , a member of Bacteroidetes , was associated with lower mass gain rates, and similarly in harsher environments. Although correlative, these results highlight the importance of symbiotic gut microbiota to mass gain in the wild, a trait associated with survival and fitness in many taxonomic groups.

Chemical Variation among Castes, Female Life Stages and Populations of the Facultative Eusocial Sweat Bee Halictus rubicundus (Hymenoptera: Halictidae) - I. Steitz; R. J. Paxton; S. Schulz; M. Ayasse (Journal of Chemical Ecology, 2021)
In eusocial insects, chemical communication is crucial for mediating many aspects of social activities, especially the regulation of reproduction. Though queen signals are known to decrease ovarian activation of workers in highly eusocial species, little is known about their evolution. In contrast, some primitively eusocial species are thought to control worker reproduction through physical aggression by the queen rather than via pheromones, suggesting the evolutionary establishment of chemical signals with more derived sociality. However, studies supporting this hypothesis are largely missing. Socially polymorphic halictid bees, such as Halictus rubicundus, with social and solitary populations in both Europe and North America, offer excellent opportunities to illuminate the evolution of caste-specific signals. Here we compared the chemical profiles of social and solitary populations from both continents and tested whether (i) population or social level affect chemical dissimilarity and whether (ii) caste-specific patterns reflect a conserved queen signal. Our results demonstrate unique odor profiles of European and North American populations, mainly due to different isomers of n-alkenes and macrocyclic lactones; chemical differences may be indicative of phylogeographic drift in odor profiles. We also found common compounds overproduced in queens compared to workers in both populations, indicating a potential conserved queen signal. However, North American populations have a lower caste-specific chemical dissimilarity than European populations which raises the question if both use different mechanisms of regulating reproductive division of labor. Therefore, our study gives new insights into the evolution of eusocial behavior and the role of chemical communication in the inhibition of reproduction.

Changes in hunting season regulations (1870s–2019) reduce harvest exposure on greater and Gunnison sage-grouse - Jonathan B. Dinkins; Courtney J. Duchardt; Jacob D. Hennig; Jeffrey L. Beck (PLOS ONE, 2021)
Hunter harvest is a potential factor contributing to population declines of sage-grouse (Centrocercus spp.). As a result, wildlife agencies throughout western North America have set increasingly more conservative harvest regulations over the past 25 years to reduce or eliminate hunter success and concomitant numbers of harvested greater (C.urophasianus) and Gunnison (C.minimus) sage-grouse. Sage-grouse hunting has varied widely over time and space, which has made a comprehensive summary of hunting management challenging. We compiled data on harvest regulations among 11 western U.S. states and 2 Canadian provinces from 1870–2019 to create a timeline representative of hunting regulations. We compared annual harvest boundaries and area-weighted average hunting regulations, 1995–2018, relative to administrative boundaries and areas of high probability of sage-grouse occupation. We also summarized estimated numbers of birds harvested and hunters afield, 1995–2018, across both species’ ranges. From 1995–2018, there was a 30% reduction in administrative harvest boundaries across the greater sage-grouse range compared to a 16.6% reduction in area open to harvest within 8 km from active leks. Temporary closures occurred in response to wildfires, disease outbreaks, low population numbers, and two research projects; whereas, permanent closures primarily occurred in small populations and areas on the periphery of the species distribution. Similarly, area-weighted possession limits and season length for greater sage-grouse decreased 52.6% and 61.0%, respectively, while season start date stayed relatively stable (mean start date ~259 [mid-September]). In contrast, hunting of the now federally-threatened Gunnison sage-grouse ended after 1999. While restrictions in harvest regulations were large in area, closures near areas of high greater sage-grouse occupancy were relatively smaller with the same trend for Gunnison sage-grouse until hunting ceased. For greater sage-grouse, most states reduced bag and possession limits and appeared to adhere to recommendations for later and shorter hunting seasons, reducing potential for additive mortality.

From Insects to Frogs, Egg–Juvenile Recruitment Can Have Persistent Effects on Population Sizes - B. J. Downes; B. L. Peckarsky; J. Lancaster; W. D. Bovill; M. Alp (Annual Review of Ecology, Evolution, and Systematics, 2021)
Understanding what regulates population sizes of organisms with complex life cycles is challenging because limits on population sizes can occur at any stage or transition. We extend a conceptual framework to explore whether numbers of successfully laid eggs determine densities of later stages in insects, fish, amphibians, and snails inhabiting marine, freshwater, or terrestrial habitats. Our review suggests novel hypotheses, which propose characteristics of species or environments that create spatial variation in egg densities and predict when such patterns are maintained throughout subsequent life-cycle stages. Existing data, although limited, suggest that persistent, strong associations between egg and subsequent juvenile densities are likely for species where suitable egg-laying habitat is in short supply. Those associations are weakened in some environments and for some species by density-dependent losses of eggs or hatchlings. Such cross-ecosystem comparisons are fundamental to generality in ecology but demand place-based understandings of species’ biology and natural history.

Folsom Point Diggings: The Johnson Site in the Foothills of Larimer County, Colorado - Jason M. LaBelle; Kelton A. Meyer; Raymond V. Sumner (PaleoAmerica, 2021)
The Johnson site is a Folsom occupation in Larimer County, Colorado. T. Russell Johnson discovered the site in 1935, which led to excavations by the Colorado Museum of Natural History in 1936 and later work in 1960 by the University of Wyoming. Little is known of the site due to limited reporting of the excavation and the Folsom assemblage. Our examination of the site collections gathered between 1935 and 1936 reveals an assemblage of 96 items, consisting of Folsom points, preforms, and channel flakes, as well as other tools including end scrapers, gravers, bifaces, and flake tools. Technological analysis of the Folsom points and byproducts of hunting-tool production suggests that site occupants fluted and finished points made from preforms of non-local materials, while additional tools and a few points were made from materials locally available in the Front Range foothills. As such, Johnson represents at minimum a hunting-weaponry-replacement locale.

Direct Observation of the Depth of Active Groundwater Circulation in an Alpine Watershed - Andrew H Manning; Lyndsay B Ball; R. B. Wanty; K. H. Williams (Water Resources Research, 2021)
AbstractThe depth of active groundwater circulation is a fundamental control on stream flows and chemistry in mountain watersheds, yet it remains challenging to characterize and is rarely well constrained. We collected hydraulic conductivity, hydraulic head, temperature, chemical, noble gas, and 3H/3He groundwater age data from discrete levels in two boreholes 46 and 81 m deep in an alpine watershed, in combination with chemical and age data from shallow groundwater discharge, to discern groundwater flow rates at different depths and directly observe active and inactive groundwater. Vertical head gradients are steep (average of 0.4) and thermal profiles are consistent with typical linear conductive continental geotherms. Groundwater deeper than ∼20 m is distinct from shallow groundwater and creek water in its chemistry, noble gas signature, and age (dominantly >65 years compared to <9 years). Together these results suggest low vertical groundwater flow velocities and a relatively shallow active circulation depth of ∼20 m. This hypothesis is tested with a simple 2‐D numerical fluid flow and heat transport model representing a hillslope transect through the two boreholes. The modeling indicates that the subhorizontally bedded sedimentary rocks underlying the basin are highly anisotropic with low vertical hydraulic conductivity, and at most ∼10% of bedrock recharge (equivalent to <2% of stream baseflow) flows below a depth of 20 m. The study demonstrates the considerable value of discrete‐depth hydrogeologic, chemical, and age data for determining active circulation depth, and illustrates an approach for maximizing the utility of individual boreholes drilled for mountain bedrock aquifer characterization.

Chemical Variation among Castes, Female Life Stages and Populations of the Facultative Eusocial Sweat Bee Halictus rubicundus (Hymenoptera: Halictidae) - I. Steitz; I. Steitz; R. J. Paxton; M. Ayasse; R. J. Paxton; S. Schulz; S. Schulz; M. Ayasse (Journal of Chemical Ecology, 2021)
In eusocial insects, chemical communication is crucial for mediating many aspects of social activities, especially the regulation of reproduction. Though queen signals are known to decrease ovarian activation of workers in highly eusocial species, little is known about their evolution. In contrast, some primitively eusocial species are thought to control worker reproduction through physical aggression by the queen rather than via pheromones, suggesting the evolutionary establishment of chemical signals with more derived sociality. However, studies supporting this hypothesis are largely missing. Socially polymorphic halictid bees, such as Halictus rubicundus, with social and solitary populations in both Europe and North America, offer excellent opportunities to illuminate the evolution of caste-specific signals. Here we compared the chemical profiles of social and solitary populations from both continents and tested whether (i) population or social level affect chemical dissimilarity and whether (ii) caste-specific patterns reflect a conserved queen signal. Our results demonstrate unique odor profiles of European and North American populations, mainly due to different isomers of n-alkenes and macrocyclic lactones; chemical differences may be indicative of phylogeographic drift in odor profiles. We also found common compounds overproduced in queens compared to workers in both populations, indicating a potential conserved queen signal. However, North American populations have a lower caste-specific chemical dissimilarity than European populations which raises the question if both use different mechanisms of regulating reproductive division of labor. Therefore, our study gives new insights into the evolution of eusocial behavior and the role of chemical communication in the inhibition of reproduction.

A hybrid data-model approach to map soil thickness in mountain hillslopes - Qina Yan; Haruko M. Wainwright; Baptiste Dafflon; Sebastian Uhlemann; Carl I. Steefel; Nicola Falco; J. Kwang; S. S. Hubbard (Earth Surface Dynamics, 2021)
Abstract. Soil thickness plays a central role in the interactions between vegetation, soils, and topography, where it controls the retention and release of water, carbon, nitrogen, and metals. However, mapping soil thickness, here defined as the mobile regolith layer, at high spatial resolution remains challenging. Here, we develop a hybrid model that combines a process-based model and empirical relationships to estimate the spatial heterogeneity of soil thickness with fine spatial resolution (0.5 m). We apply this model to two aspects of hillslopes (southwest- and northeast-facing, respectively) in the East River watershed in Colorado. Two independent measurement methods – auger and cone penetrometer – are used to sample soil thickness at 78 locations to calibrate the local value of unconstrained parameters within the hybrid model. Sensitivity analysis using the hybrid model reveals that the diffusion coefficient used in hillslope diffusion modeling has the largest sensitivity among all input parameters. In addition, our results from both sampling and modeling show that, in general, the northeast-facing hillslope has a deeper soil layer than the southwest-facing hillslope. By comparing the soil thickness estimated between a machine-learning approach and this hybrid model, the hybrid model provides higher accuracy and requires less sampling data. Modeling results further reveal that the southwest-facing hillslope has a slightly faster surface soil erosion rate and soil production rate than the northeast-facing hillslope, which suggests that the relatively less dense vegetation cover and drier surface soils on the southwest-facing slopes influence soil properties. With seven parameters in total for calibration, this hybrid model can provide a realistic soil thickness map with a relatively small amount of sampling dataset comparing to machine-learning approach. Integrating process-based modeling and statistical analysis not only provides a thorough understanding of the fundamental mechanisms for soil thickness prediction but also integrates the strengths of both statistical approaches and process-based modeling approaches.

Air - John Harner (University Press of Colorado eBooks, 2021)

Liberty - John Harner (University Press of Colorado eBooks, 2021)

Analysis of the Potential for Events Similar to the Deadly West Salt Creek Landslide, Grand Mesa Area, Colorado - Omid Arabnia; Paul Michael Santi; Edward Emmens; Emily Sparks (SSRN Electronic Journal, 2021)

The benefits of being dominant: Health correlates of male social rank and age in a marmot - K. Uchida; R. Ng; S. A. Vydro; J. E. Smith; Daniel T. Blumstein (Current Zoology, 2021)
The benefits of dominance may not come without costs, particularly for males. For example, the “immunocompetence handicap hypothesis” states that males with enhanced mating success allocate resources to enhance reproductive output at a cost to their current health, whereas the “resource quality hypothesis” predicts that high-ranking males may benefit from increased reproduction and good health. While the predictions from each have been well tested in captive animals and in a variety of highly social primates, fewer studies have been carried out in free-living, facultatively social animals. Using adult male yellow-bellied marmots (Marmota flaviventer), we evaluated predictions of these hypotheses by examining the relationship between social rank and two health indicators--fecal corticosterone metabolite (FCM) levels, and neutrophil/lymphocyte (N/L) ratios--after accounting for variation explained by age, body mass, and seasonality. We found that higher-ranking males tended to have a lower N/L ratio (reflecting good health) than lower-ranking individuals, whereas FCM levels were not significantly related to rank. In addition, heavier male marmots had lower N/L ratios, while body mass was not associated with FCM levels. We also found that older adult males had lower FCM levels (reflecting less physiological stress) but higher N/L ratios than younger adults. Finally, we found that FCM levels decreased as the active season progressed and FCM levels were associated with the time of the day. Overall, our results suggest that socially-dominant male marmots enjoyed better, not worse health in terms of lower N/L ratios. Key words: immunocompetence handicap hypothesis, life history trade-offs, N/L ratio, physiological stress, resource quality hypothesis

Sources of Controversy in the Law of the Colorado River: An Upper Basin View - Lawrence MacDonnell (SSRN Electronic Journal, 2021)

Habituation or sensitization? Long-term responses of yellow-bellied marmots to human disturbance - K. Uchida; Daniel T. Blumstein (Behavioral Ecology, 2021)
Abstract Continuous exposure to humans causes wildlife to either habituate or sensitize. Although increased tolerance may play an important role in coexistence with humans, the mechanisms and fitness outcomes of long-term changes of tolerance are not fully understood because only a few studies have assessed individual- and population-level responses over many years. We developed a novel predictive framework to study habituation and sensitization to humans and applied it to yellow-bellied marmots (Marmota flaviventer) in areas of high and low human disturbance. We focused on two antipredator behaviors—time allocation to vigilance during foraging to quantify baseline vigilance levels and flight initiation distance (FID)—to quantify subsequent responsiveness to threat. We used the rate of body mass gain during the active season as a fitness outcome. Assessing 15 years’ population and individual-level responses to human disturbances, marmots in highly disturbed colonies allocated more time to vigilance, but this did not change over time. FID decreased on average when they were approached more and also tended to decrease in highly disturbed colonies and over 15 years. Yet, there was individuality in FIDs; marmots that fled at greater distances became sensitized with repeated approaches. Additionally, the marmots in highly disturbed colonies gained less body mass over time compared to conspecifics in less disturbed colonies. These results suggested that, although marmots habituated to humans, long-term human disturbance has negative fitness consequences. Our framework should help wildlife managers evaluate the comprehensive impact of human activities on wildlife.

Are vigilance and flight initiation distance correlated in yellow-bellied marmots? - I. DeVito (2021)
Behavioral syndromes are widespread and can have important ecological consequences, since correlations between distinct behaviors shape how animals can respond to changing pressures and can limit behavioral plasticity. Various antipredator behaviors have been identified within behavioral syndromes in many species, and therefore studying the structure of potential behavioral syndromes is important for understanding an animal’s overall behavioral response to predators. This study focused on two antipredator behaviors in yellow-bellied marmots (Marmota flaviventer): time allocation to vigilance during foraging, which represents an individual’s baseline level of wariness, and flight initiation distance (FID), which quantifies the flightiness of an animal in response to a predator. We estimated the correlation between these traits by fitting bivariate model on data collected over 18 years and found a modest correlation between vigilance and FID at the individual level.

Seasonal habitat suitability models for a threatened species: the Gunnison sage-grouse - Anthony D. Apa; Kevin Aagaard; Mindy B. Rice; Evan Phillips; Daniel J. Neubaum; Nathan Seward; Julie R. Stiver; Scott Wait (Wildlife Research, 2021)
Abstract Context The Gunnison sage-grouse (Centrocercus minimus) has experienced range-wide declines and has been listed as Threatened by the USA Fish and Wildlife Service to receive protections under the USA Endangered Species Act. A draft Recovery Plan was recently completed. No seasonal habitat models have been developed for the small isolated populations. Aims To develop a habitat suitability model that was collaboratively developed between modellers and conservation practitioners to predict the probability of use by Gunnison sage-grouse during the breeding and summer seasons in designated occupied critical habitat, and extrapolate to adjacent designated unoccupied critical habitat. Methods We captured, marked and tracked Gunnison sage-grouse in nine different studies spanning 25 years. We used a suite of biotic, abiotic and vegetation local-level and population-scale covariates in a use-available resource selection function to develop models that predict the probability of use by Gunnison sage-grouse. Key results We used 9140 Gunnison sage-grouse locations from 406 individual birds to develop nine resource selection models for occupied habitat and extrapolated model predictions to adjacent unoccupied critical habitat in five small isolated Gunnison sage-grouse populations. A majority of our models validated well. Conclusions We report the first two-season resource use-based habitat suitability models for five of six small isolated Gunnison sage-grouse populations. Because of the unique habitat use by Gunnison sage-grouse in each population, we recommend that resource managers strategically target management actions in individual populations and avoid ‘one-size-fits-all’ habitat management prescriptions. Implications Our models will assist managers in the identification of seasonal habitats within populations to target management actions for Gunnison sage-grouse recovery.

Nectar addition changes pollinator behavior but not plant reproduction in pollen rewarding Lupinus argenteus - Jacob M. Heiling; J. L. Bronstein; R. E. Irwin (American Journal of Botany, 2021)
The addition of nectar to pollen-rewarding plants resulted in modest increases in per-flower pollinator visit duration and pollen transfer, but had no effect on reproduction because, at the place and time the experiment was conducted, plants were not pollen-limited. These results suggest that a pollen-only reward strategy may allow plants that are visited by pollen foragers to minimize some costs of reproduction by eliminating investment in other rewards, such as nectar, without compromising female plant fitness.

Topographic Map Analysis of the North Platte River-South Platte River Drainage Divide Area, Western Larimer County, Colorado, USA Eric Clausen - Eric Clausen (Earth Science Research, 2021)
The United States Supreme Court settled legal disputes concerning four different Larimer County (Colorado) locations where water is moved by gravity across the high elevation North Platte-South Platte River drainage divide, which begins as a triple drainage divide with the Colorado River at Thunder Mountain (on the east-west continental divide and near Colorado River headwaters) and proceeds in roughly a north and northeast direction across deep mountain passes and other low points (divide crossings) first as the Michigan River (in the North Platte watershed)-Cache la Poudre River (in the South Platte watershed) drainage divide and then as the Laramie River (in the North Platte watershed)-Cache la Poudre River drainage divide. The mountain passes and nearby valley and drainage route orientations and other unusual erosional features can be explained if enormous and prolonged volumes of south-oriented water moved along today’s north-oriented North Platte and Laramie River alignments into what must have been a rising mountain region to reach south-oriented Colorado River headwaters. Mountain uplift in time forced a flow reversal in the Laramie River valley while flow continued in a south direction along the North Platte River alignment only to be forced to flow around the Medicine Bow Mountains south end and then to flow northward in the Laramie River valley and later to be captured by headward erosion of the east-oriented Cache la Poudre River-Joe Wright Creek valley (aided by a steeper gradient and less resistant bedrock). Continued uplift next reversed flow on the North Platte River alignment to create drainage routes seen today. While explaining Larimer County North Platte-South Platte drainage divide area topographic map drainage system and erosional landform evidence this interpretation requires a completely different Cenozoic history than the geologic history geologists usually describe.

Yampa River-Colorado River Drainage Divide Origin Determined from Topographic Map Evidence, Southern Routt County, Colorado, USA - Eric Clausen (Open Journal of Geology, 2021)
Detailed topographic map evidence and a new Cenozoic geologic and glacial history paradigm are used to determine the previously unexplained Yampa River-Colorado River drainage divide origin. The Yampa River now flows in a north direction away from the Colorado River (between the Park Range to the east and the Flat Tops region to the west) before turning in a west direction to reach the Unita Mountains where it joins the south-oriented Green River, which eventually joins the southwest-oriented Colorado River. Topographic maps show the Yampa-Colorado River drainage divide is asymmetric with steeper slopes leading to the Colorado River, barbed (south-oriented) tributaries leading to north-oriented Yampa River headwaters (especially near the Yampa River turn to the west), and evidence of a large north-to-south oriented diverging and converging channel complex that preceded present-day drainage routes. Map evidence is interpreted to mean massive south-oriented floods flowed through what are now north-oriented Yampa River headwaters valleys and that headward erosion of a deep west-oriented valley beheaded and reversed those south-oriented flood flow channels to create the north-oriented Yampa River headwaters and the Egeria Park area Yampa-Colorado River drainage divide seen today. Large south-oriented floods leading to the Colorado River (while regional uplift was occurring) are inconsistent with accepted Cenozoic geologic and glacial history paradigm predictions, but are predicted by a newly proposed Cenozoic geologic and glacial history paradigm in which a thick continental ice sheet created a deep “hole” by eroding underlying bedrock and also by causing crustal warping that raised the present-day northern Colorado east-west continental divide as immense south-oriented meltwater floods flowed across it.

Concentration-Discharge Relationships of Dissolved Rhenium in Alpine Catchments Reveal Its Use as a Tracer of Oxidative Weathering - R. G. Hilton; J. M. Turowski; M. J. Winnick; M. Dellinger; Patrick Schleppi; K. H. Williams; C. R. Lawrence; Katharine Maher; M. West; A. Hayton (Water Resources Research, 2021)
Abstract Oxidative weathering of sedimentary rocks plays an important role in the global carbon cycle. Rhenium (Re) has been proposed as a tracer of rock organic carbon (OC petro ) oxidation. However, the sources of Re and its mobilization by hydrological processes remain poorly constrained. Here, we examine dissolved Re as a function of water discharge, using samples collected from three alpine catchments that drain sedimentary rocks in Switzerland (Erlenbach and Vogelbach) and Colorado, USA (East River). The Swiss catchments reveal a higher dissolved Re flux in the catchment with higher erosion rates, but have similar [Re]/[Na + ] and [Re]/[SO 4 2− ] ratios, which indicate a dominance of Re from OC petro . Despite differences in rock type and hydro‐climatic setting, the three catchments have a positive correlation between river water [Re]/[Na + ] and [Re]/[SO 4 2− ] and water discharge. We propose that this reflects preferential routing of Re from a near‐surface, oxidative weathering zone. The observations support the use of Re as a proxy to trace rock‐organic carbon oxidation, and suggest it may be a hydrological tracer of vadose zone processes. We apply the Re proxy and estimate CO 2 release by OC petro oxidation of 5.7 +6.6 / −2.0 tC km −2 yr −1 for the Erlenbach. The overall weathering intensity was ∼40%, meaning that the corresponding export of unweathered OC petro in river sediments is large, and the findings call for more measurements of OC petro oxidation in mountains and rivers as they cross floodplains.

The effects of drought on subalpine floral community diversity - S. Dewey (2021)
Global climate change is a threat to ecosystems globally. In subalpine environments, one of the

Selection of floral traits by pollinators and seed predators during sequential life history stages - Diane R. Campbell; Mascha Bischoff; Robert A. Raguso; H. M. Briggs; Paula Sosenski (American Naturalist, 2021)
AbstractOrganismal traits often influence fitness via interactions with multiple species. That selection is not necessarily predictable from pairwise interactions, such as when interactions occur during different life cycle stages. Theoretically, directional selection during two sequential episodes (e.g., pollination and seed survival) can generate quadratic or correlational selection for a set of traits that passes both selective filters. We compared strength of selection during pollination versus seed predation in the field and tested whether interactions with multiple species give rise to nonlinear selection on floral traits. We planted common gardens with seeds of two species of Ipomopsis and hybrids at sites where pollination was primarily by hummingbirds or also included hawk moths. We examined selection on six floral traits, including corolla width, sepal width, color, nectar, and two scent compounds. Female fitness (seeds) was broken down into fitness during (1) pollination (seeds initiated) and (2) seed predation (proportion of seeds escaping fly predation). All traits showed evidence of selection. Directional and quadratic selection were stronger during seed initiation than during seed predation. Correlational selection occurred mostly during seed initiation rather than arising from combining species interactions at two points in the life cycle. These results underscore how multispecies interactions can combine to exert selection on trait combinations.

Balancing the needs of consumers and producers for scientific data collections - Deb Agarwal; J. Damerow; Charuleka Varadharajan; D. S. Christianson; Gilberto Pastorello; Y. Cheah; Lavanya Ramakrishnan (Ecological Informatics, 2021)
Recent emphasis and requirements for open data publication have led to significant increases in data availability in the Earth sciences, which is critical to long-tail data integration. Currently, data are often published in a repository with an identifier and citation, similar to those for papers. Subsequent publications that use the data are expected to provide a citation in the reference section of the paper. However, the format of the data citation is still evolving, particularly with regards to citing dynamic data, subsets, and collections of data. Considering the motivations of both data producers and consumers, the most pressing need is to create user-friendly solutions that provide credit for data producers and enable accurate citation of data, particularly integrated data. Providing easy-to-use data citations is a critical foundation that is required to address the socio-technical challenges around data integration. Studies that integrate data from dozens or hundreds of datasets must often include data citations in supplementary material due to page limits. However, citations in the supplementary material are not indexed, making it difficult to track citations and thus giving credit to the data producer. In this paper, we discuss our experiences and the challenges we have encountered with current citation guidance. We also review the relative merits of the currently available mechanisms designed to enable compact citation of collections of data, such as data collections, data papers, and dynamic data citations. We consider these options for three data producer scenarios: a domain-specific data collection, a data repository, and a large-scale, multidisciplinary project. We posit that a new mechanism is also needed to enable citation of multiple datasets and credit to data producers.

Larval Feeding Ability on a Drought-Stressed Invasive Plant - K. Asselin (2021)
Native species are threatened by the introduction of non-native and invasive organisms.

Effects of soil moisture and temperature on plant palatability and herbivore plant preference - S. Pittman (2021)
Climate change is predicted to lead to increased water and temperature stress for plants. Reduced soil moisture and higher temperatures have the potential to impact plant growth, development, and survival. Changes in plant physiology due to climate change may also impact insect herbivores. Herbivores influence plant community composition and plant distribution, so changes in herbivore feeding with climate change could alter plant communities. To better understand the potential impacts of climate change on plant-insect interactions, this study investigates the combined and separate effects of soil moisture and increased temperature on leaf palatability and herbivore plant preference. Four treatment types, ambient precipitation + ambient temperature, watered + ambient temperature, ambient precipitation + warmed, and watered + warmed, were established in the field in plots containing five common plants growing near Gothic, Colorado, Erigeron speciosus, Helianthella quinquenervis, Potentilla pulcherrima, Heliomeris multiflora, and Lupinus bakeri. Plants were warmed with open topped chambers and watered twice a week. Multi-choice feeding tests with the generalist herbivore Melanoplus borealis were conducted to assess plant palatability and herbivore preference in different treatments. In single species trials, fewer Helianthella quinquenervis leaves were eaten from warmed plots than ambient temperature plots and fewer Heliomeris multiflora leaves were eaten from watered plots than ambient rainfall plots. In multiple species trials more Helianthella quinquenervis was eaten than Lupinus bakeri and Potentilla pulcherrima and more Heliomeris multiflora was eaten than Potentilla pulcherrima in heated only treatments. More Erigeron speciosus was eaten than Lupinus bakeri, and Potentilla pulcherrima and more Heliomeris multiflora was eaten than Potentilla pulcherrima in watered only treatments. Changes in herbivore preferences in treatments that reflect possible future climate scenarios suggest that shifts in herbivory could reshape plant communities in the coming decades.

How does incorporating microclimate data into ecological niche models change our estimates of the climatic niche of vascular plant species? - A. Wells (2021)

A deep learning hybrid predictive modeling (HPM) approach for estimating evapotranspiration and ecosystem respiration - Jiancong Chen; Baptiste Dafflon; Anh Phuong Tran; Nicola Falco; S. S. Hubbard (Hydrology and Earth Systems Science, 2021)
Abstract. Climate change is reshaping vulnerable ecosystems, leading to uncertain effects on ecosystem dynamics, including evapotranspiration (ET) and ecosystem respiration (Reco). However, accurate estimation of ET and Reco still remains challenging at sparsely monitored watersheds, where data and field instrumentation are limited. In this study, we developed a hybrid predictive modeling approach (HPM) that integrates eddy covariance measurements, physically based model simulation results, meteorological forcings, and remote-sensing datasets to estimate ET and Reco in high space–time resolution. HPM relies on a deep learning algorithm and long short-term memory (LSTM) and requires only air temperature, precipitation, radiation, normalized difference vegetation index (NDVI), and soil temperature (when available) as input variables. We tested and validated HPM estimation results in different climate regions and developed four use cases to demonstrate the applicability and variability of HPM at various FLUXNET sites and Rocky Mountain SNOTEL sites in Western North America. To test the limitations and performance of the HPM approach in mountainous watersheds, an expanded use case focused on the East River Watershed, Colorado, USA. The results indicate HPM is capable of identifying complicated interactions among meteorological forcings, ET, and Reco variables, as well as providing reliable estimation of ET and Reco across relevant spatiotemporal scales, even in challenging mountainous systems. The study documents that HPM increases our capability to estimate ET and Reco and enhances process understanding at sparsely monitored watersheds.

Characterizing the role of phosphorus availability and periphytic algae in the food choice and performance of detritivorous caddisflies (Trichoptera:Limnephilidae) - L. M. Demi; D. Hughes; B. W. Taylor (Freshwater Science, 2021)

Experimental test of the ability of plants to regulate their temperatures under climate change: Using transplanted communities, thermal imaging, and arcGIS across an elevation gradient - S. Buchholtz (2021)
The question of thermoregulation in plants is increasingly important in a rapidly changing climate. Plants have long been considered poikilotherms, where internal temperatures are decided by the external environment. However, observations show that plants have some ability to thermoregulate. If plants are heterotherms, then they have the potential to be more resilient to the warming climate. This project seeks to examine thermoregulation through technology, specifically FLIR imagery. At three different sites in Washington Gulch, plants were moved to examine the effects of a warmer or cooler environment. This project will use thermal imagery on those transplants in order to study how the temperature of plant communities change when moved to a new climate.

Nowcasting the distribution of Valeriana edulis using climate driven population models - M. Zeh (2021)
Climate change poses a unique problem for sessile species because individuals are unable to move to track their optimal habitat. Instead, population turnover governed by population processes must occur in order for the species distribution to change. Current methods to predict current and future species distributions are limited in that they are based on presence vs. absence data and use only currently observable climate regimes that may not reflect novel future climates. The first step towards improving our framework for predicting future species distributions is to develop a mechanistic model of species performance that uses contemporary data to predict the current spatial distribution of a specific species, then validate the model against field observations. Here we develop a Demographic Distribution Model (DDM) for Valeriana edulis, a long-lived species with a broad climatic niche, that uses an Integral Projection Model (IPM) to predict the individual- and population-level impacts of climate drivers (snowmelt timing and growing season temperature and precipitation) on population growth and fate. The complex interactions of the differing effects of the climate drivers were found to impact the vital rates of individual plants, which resulted in a range of predicted population growth rates across a landscape with varying climatic conditions. This proved to be an important tool for creating informed predictions about how species distributions respond to dynamically changing climate variables.

Hidden Processes During Seasonal Isolation of a High-Altitude Watershed - Jessica Buser-Young; L. L. Lapham; Andrew Thurber; K. H. Williams; Fredrick Colwell (Frontiers in Earth Science, 2021)
Biogeochemical processes capable of altering global carbon systems occur frequently in Earth’s Critical Zone–the area spanning from vegetation canopy to saturated bedrock–yet many of these phenomena are difficult to detect. Observation of these processes is limited by the seasonal inaccessibility of remote ecosystems, such as those in mountainous, snow- and ice-dominated areas. This isolation leads to a distinct gap in biogeochemical knowledge that ultimately affects the accuracy and confidence with which these ecosystems can be computationally modeled for the purpose of projecting change under different climate scenarios. To examine a high-altitude, headwater ecosystem’s role in methanogenesis, sulfate reduction, and groundwater-surface water exchange, water samples were continuously collected from the river and hyporheic zones (HZ) during winter isolation in the East River (ER), CO watershed. Measurements of continuously collected ER surface water revealed up to 50 μM levels of dissolved methane in July through September, while samples from 12 cm deep in the hyporheic zone at the same location showed a spring to early summer peak in methane with a strong biogenic signature (<65 μM, δ13C-CH4, −60.76‰) before declining. Continuously collected δ 18 O-H 2 O and δ 2 H-H 2 O isotopes from the water column exhibited similar patterns to discrete measurements, while samples 12 cm deep in the hyporheic zone experienced distinct fluctuations in δ 18 O-H 2 O, alluding to significant groundwater interactions. Continuously collected microbial communities in the river in the late fall and early winter revealed diverse populations that reflect the taxonomic composition of ecologically similar river systems, including taxa indicative of methane cycling in this system. These measurements captured several biogeochemical components of the high-altitude watershed in response to seasonality, strengthening our understanding of these systems during the winter months.