Ecosystem Consequences of Soil Warming - J. Harte (2019)

Invasive plants and water availablity mediate outcomes of plant-pollinator interactions - W. Recart Gonzalez (2019)

A meta-analysis of 1,119 manipulative experiments on terrestrial carbon-cycling responses to global change - Jian Song; Shiqiang Wan; S. Piao; A. Knapp; Aimee T Classen; S. Vicca; P. Ciais; M. J. Hovenden; Sebastian Leuzinger; C. Beier; P. Kardol; J. Xia; et al. (Nature Ecology & Evolutiion, 2019)
There is an urgent need to explore the interactions among multiple global change drivers in underrepresented regions such as semi-arid ecosystems, forests in the tropics and subtropics, and Arctic tundra when forecasting future terrestrial carbon-climate feedback.

The individual and combined effects of snowmelt timing and frost exposure on the reproductive success of montane forbs - Pardee G.; Isaac O. Jensen; David W. Inouye; R. E. Irwin (Journal of Ecology, 2019)

Effects of avalanches on rodent populations - G. Sandoval (2019)
Ecologists are interested in studying the factors that affect the abundance of a species. Disturbances, such as avalanches, could affect the populations of small mammals. Live trapping has been a traditional method to study abundances of small mammals; however, it has some downsides. A new, non-invasive method of measuring small mammal abundance was tested in a study last year (2018), and proved to be a good indicator of abundance, but not identification of specific species. This new method is using hair tube traps. This year (2019), these hair tube traps were used to measure the effect of avalanches on small mammal populations. The results showed that avalanches had an effect on abundance at three of the four sites, and that these sites showed a recovery at both the avalanche and non-avalanche sites over the summer.

Exploring source water mixing and transient residence time distributions of outflow and evapotranspiration with an integrated hydrologic model and Lagrangian particle tracking approach - R. M. Maxwell; L. E. Condon; M. Danesh-Yazdi; L. A. Bearup (Ecohydrology, 2019)
Abstract Understanding the time water takes as it moves from rain or snowmelt through the terrestrial system to arrive as stream discharge, or evapotranspiration (ET) is an important hydrologic quantity. We develop a Lagrangian particle tracking method to capture transient residence times from source to either ET or outflow in an integrated hydrologic model. This method is parallel and efficiently captures time evolution of parcels of water in the model and tracks the source of water for hydrograph or ET separation. We demonstrate this model using hypothetical hillslope simulations driven by snow or rain dominated forcing and two different land cover types. We show that land cover and forcing both impact the outflow residence time distribution, which spans many years. We also introduce the idea of ET residence time distributions and show that while mean ET residence times are typically less than 1 year, land cover affects this quantity and simulated ET processes draw from much older wa

Low to Mid Elevational Resurvey of Bumble bee Distributions in Response to Climate Change - J. Hsu (2019)
In 1974, Graham Pyke conducted a study that examined Bombus spp. distributions along five transects around the Rocky Mountain Biological Laboratory area in Crested Butte, CO. The study was repeated in 2007 and within the intervening 33-year period, it showed that certain species of bumble bees had shifted higher in elevation due to climate change. The study has been repeated every five to seven years since 2007 with the most recent re-survey carried out in 2014. These studies are intended to use bumble bees as an ideal indicator of climate change due to their rapid life cycle. In 2019, I repeated the study using only low to mid-elevation sites to determine whether there was an increase or decrease in relative abundance compared to 2014. Data was collected by capturing bumble bees, identifying them in the field, and also taking photos of bumble bees in a clear cylindrical PVC tube to confirm field identifications. I also recorded the flower species the bumble bees were collected off of.

Foraging efficiency and size matching in a plant-pollinator communitiy: the importance of sugar content and tongue length - Saskia G.T. Klumpers; M. Stang; Peter G.L. Klinkhamer (Ecology letters, 2019)
A long-standing question in ecology is how species interactions are structured within communities. Although evolutionary theory predicts close size matching between floral nectar tube depth and pollinator proboscis length of interacting species, such size matching has seldom been shown and explained in multispecies assemblages. Here, we investigated the degree of size matching among Asteraceae and their pollinators and its relationship with foraging efficiency. The majority of pollinators, especially Hymenoptera, choose plant species on which they had high foraging efficiencies. When proboscides were shorter than nectar tubes, foraging efficiency rapidly decreased because of increased handling time. When proboscides were longer than nectar tubes, a decreased nectar reward rather than an increased handling time made shallow flowers more inefficient to visit. Altogether, this led to close size matching. Overall, our results show the importance of nectar reward and handling time as driver

Phenotypic plasticity of floral volatiles in response to increasing drought stress - Diane R. Campbell; Paula Sosenski; Robert A. Raguso (American Journal of Botany, 2019)

Carbon Dioxide Concentrations and Efflux from Permanent, Semi-Permanent, and Temporary Subalpine Ponds - A. G. DelVecchia; J. A. Balik; S. Campbell; B. W. Taylor; D. C. West; S. A. Wissinger (Wetlands, 2019)
Small ponds account for a disproportionately high percentage of carbon dioxide emissions relative to their small surface area. It is therefore crucial to understand carbon flow in these ponds to refine the current global carbon budget, especially because climate change is affecting pond hydrology. High elevation ponds in the Elk Mountains of western Colorado are drying more frequently as the timing of snowmelt advances. We compared CO2 concentrations and fluxes among ponds of different hydroperiods over diel sampling periods during the course of the 2017 open-water period. CO2 concentrations were significantly negatively correlated with pond depth and averaged 77.6 ± 24.5 μmol L−1 (mean ± S.E.) across all ponds and sampling events. Ponds were up to twenty times supersaturated in CO2 with respect to the atmosphere. Flux was highly variable within individual ponds but correlated with time of sampling and was highest at night. Flux averaged 19.7 ± 18.8 mg CO2 m−2 h−1 across all ponds and

Effects of Climate Change on Birds - David W. Inouye (2019)

Stable isotope compositions of precipitation from Gunnison, Colorado 2007–2016: implications for the climatology of a high-elevation valley - Suzanne B. Marchetti; Suzanne B. Marchetti (Heliyon, 2019)
Stable isotope ratios of precipitation are useful tracers of climatic and hydrological processes. To better understand the isotope hydro-climatology of a high-elevation Rocky Mountain valley we collected meteoric water samples from Gunnison, Colorado, USA and determined stable isotope values for 239 individual precipitation events over a nine year period. Annual precipitation in Gunnison is moderately bi-modal with significant winter snowfall and convective summer thunderstorms associated with the North American Monsoon. Stable isotope values of precipitation span a large range, with summer rains as high as δ2H = +19‰ and δ18O = +4.8‰ (relative to V-SMOW) and winter snowfall as low as δ2H = -286‰ and δ18O = -36.7‰. These data define a local meteoric water line for Gunnison of δ2H = 7.2 δ18O - 4.2. Monthly meteoric water lines have slopes similar to the Global Meteoric Water Line (∼8) for winter months and more evaporated

Feeding Preference and Growth Effects for Three Trichoptera Species - D. Hughes (2019)
Detritivores diets are very limited in key nutrients such as phosphorus, nitrogen, and fatty acids. This study looked at how detritivores caddisflies selected food based on nutrient quality. We set up controlled experiments to examine food preference and how that might affect overall growth. Our study found that there is the possibility for preference among different food types and that it could influence growth, but nothing has been confirmed. This study help us understand what types of nutrients were available in these aquatic systems.

Social transmission of a novel foraging trait in yellow-bellied marmots - A. W. Evans (2019)
Social transmission of novel behaviors can be an adaptive technique to rapidly and flexibly change responses to the surrounding environment. Although the dynamics of social transmission have been studied in highly social birds, primates, otters, and bats, we lack a solid understanding of the dynamics of social transmission in less social species, for which weaker social relationships may be less conducive for social transmission. To explore this knowledge gap, we tested a facultatively social species, yellow-bellied marmots (Marmota flaviventer), for presence of social transmission in a novel foraging task. We introduced a novel foraging behavior into a wild population with a 2-action puzzle box and studied the diffusion of this trait through the colonies’ social network with network-based diffusion analysis (NBDA). In two out of four successful diffusion we found that a social transmission model fit better than an asocial model. From this we infer that social transmission is condition

Identifying the Impact of Biotic Interactions on Meadow Species Distributions in Sagebrush and Bunchgrass Dominated Systems - S. LaRocca (2019)
Understanding drivers of species distributions is an important challenge for more accurately projecting ecological change under climate warming. Species distributions have often been modeled using solely environmental factors as predictors. However, there is much recent data supporting the hypothesis that biotic interactions strongly influence species distributions at both local and global scales. This study aims to provide data on how existing plant communities alter the realized ranges of other species. By comparing species distribution model (SDM) predictions with field observations, we analyzed the effects of two taxa of dominant plant cover, sagebrush and a Fescue bunchgrass, upon the distributions of \ 20 different herbaceous meadow species in a subalpine valley in western Colorado. This data will add to our understanding of how plant community dynamics interact with observed distributions across scales.

Plant chemical mediation of ant behavior - A. S. Nelson; N. C. Acosta; K. A. Mooney (Current Opinion in Insect Science, 2019)
Ants are ecologically dominant members of terrestrial communities. Ant foraging is often strongly associated with plants and depends upon associative learning of chemicals in the environment. As a result, plant chemicals can affect ant behaviors and, in so doing, have strong multi-trophic indirect effects. Plant chemicals mediate ant behaviors in the contexts of floral visitation, seed dispersal and predation, leaf cutting, interactions with ant-mutualist host plants, interactions with mutualist and prey insects in plant canopies, and plant predation of ants by carnivorous plants. Here, we review what is known about these differing contexts in which plant chemicals influence ant behavior, the mechanisms by which ants are affected by plant chemicals, and future directions within these topics.

Elevated temperatures alter an ant aphid mutualism - E. H. Mooney; B. Davidson; James H Den Uyl; M. L. Mullins; E. Medina; P. Nguyen; J. Owens (Entomologia Experimentalis et Applicata, 2019)

Global Climate Change-Induced Mutualism Breakdown Among Legumes and their Soil Synbionts - E. Paulson (2019)

Surveying historical patterns in vegetation change (1929-2019) in the upper East River Valley using RMBL's archival herbarium records - K. Alvarado (2019)
One of the ongoing challenges in studying the effects of global change on biodiversity is finding credible baseline data of prior conditions. The Rocky Mountain Biological Laboratory in Gothic, Colorado is located in a valley with a wide range of plant species and communities due to its diversity of microclimates, and sharp gradients of precipitation and elevation (ca. 8000 – 14000 feet ASL). There have been a number of studies conducted near Gothic documenting changes in plant community composition, population distributions and flowering phenology, but the herbarium has been little used by researchers as a source of historical plant distribution and phenology data. Herbarium data provide a novel tool to assist biologists when conducting floristic studies to trace vegetation distribution patterns and studies of long-term phenological change. With the data available in the RMBL’s online herbarium database, potential study sites can be located, and target species lists can be generated f

The Effects of Exclusion Bags and Open-Top Chambers on Pollinator Activity - C. Adamson (Student paper, 2019)
It’s common for scientists to apply experimental practices that have worked well in another study to their own studies without a complete consideration of how that manipulation may impact their system. Open-top warming chambers and pollinator exclusion bags are two such common experimental manipulations that scientists may employ with unintended side effects. This study aims to understand the potential side effects that the presence of open-top chambers (OTCs) and exclusion bags may have on the pollination of open flowers at the Rocky Mountain Biological Laboratory in Gothic, CO. Pollinator observations were conducted at three sites on two plant species (Delphinium nuttallianum and Potentilla pulcherrima). Treatment plots were manipulated either by placing an OTC around the plants or placing exclusion bags over 50-75% of the flowers per plant. Control plots were left unmanipulated during the observations. Bags did not significantly impact pollinator activity on open flowers on bagged p

The effect of 10 years of repeat lethal sampling on wild bee abundance - H. T. Benkoski (2019)
Insect pollinators serve vital roles in natural and agricultural systems. There is a lack of long-term data on wild bee populations in North America, so standardized sampling protocols have been developed to address this need. The purpose of this study was to determine the effect of 10 years of long-term, repeated lethal sampling through the use of aerial netting and pan traps on wild bee abundance. Several single-sample sites were sampled and compared to phenologically similar sites that had been repeatedly sampled for a decade. In this paper, we focus on the bumble bees only. We predicted to find no effect of repeated sampling on bumble bee abundance or diversity because they are not lethally sampled but, rather, identified in the field and released. We found no significant difference between the catch rate and species richness for bumble bees caught among single-sample and their paired repeated-sample sites. This suggests that the paired sites are suitably comparable, and allows us

The Effect of Predation on Ant-aphid Mutualism in Ligusticum porteri - E. Cruz (2019)
Predation and mutualism take up a large part of interactions within communities. These multi-trophic level interactions affect the makeup of the community. We explored how predation impacts the strength of mutualism between ants and aphids on the plant Ligusticum porteri. It has been a base assumption that ants mediate the effect of predation on aphids. We manipulated half of the plants by adding lygus bugs and measured ant density of each site. Through this study, it was discovered the presence of predators broke down the mutualism and disrupted it from forming (P < 0.0056). Ant density had no correlation to the efficiency of the mutualism forming or the strength of it (P = 0.360). Larger aphid colonies did attract more ants, and the larger the number of ants resulted in greater services for the aphids (P < 0.0056). Higher ant abundance resulted in a greater growth rate for aphid colonies. The predation impacts the mutualism potentially affecting aphid, ant and lygus abundance, as wel

Pollinator Community Compositions Across Four Subalpine Plant Species - V. DeLira (2019)
Studies have shown that there have been pollinator declines occurring worldwide (e.g., Beismiejer et al. 2006; Potts et al. 2010; Burkle et al. 2013; Goulson et al. 2015). It is important to understand plant-pollinator interactions as thoroughly as possible, including which species are interacting with each other, to understand the possible consequences that may follow these declines. which prompts a number of problems considering their importance in plant reproduction. The primary objective of this study was to explore the variation in pollinator visitation rates and community composition across four subalpine species that bloom sequentially throughout the summer growing season. This study was conducted at the Rocky Mountain Biological Laboratory (RMBL) located at Gothic, Colorado. Timed pollinator observations of various patches of four subalpine plant species, Delphinium nuttallianum, Hydrophyllum fendleri, Erigeron speciousus and Potentilla pulcherrima, throughout their flowering p

Quantifying Nectar Resources in Bumble Bee Visited Plants - G. Kirschke (2019)
Native bumble bees play key roles in their ecosystems as pollinators, but little is known about the quantity and quality of floral resources on which they depend in natural areas across a season. Additionally, how those resources might be affected by abiotic factors, many of which are being altered under climate change, is poorly understood. To address this knowledge gap, we quantified nectar resources for bumble bee visited plant species in subalpine meadows. Specifically, we (1) examined interspecific variation in nectar resources, (2) compared nectar resources across wet and dry meadow conditions, and (3) examined intraspecific variation in nectar resources between years. Nectar volume, sugar concentration, and sugar content (“nectar traits”) were variable across species, within species, and in response to both local and annual water availability. This research clarifies the relative contributions of plant species to the resource landscape available for bumble bees, and how this res

Investigating the relationship between plant morphology, density, and herbivory of Thlaspi - B. Laake (2019)
The mustard family Brassicaceae includes many crop species, model plant systems, and invasive species. Many of these species produce a class of secondary defense to deter herbivory with a class of chemicals called glucosinolates (Carlsson et. al, 2009; Keeler & Chew, 2008). Thlaspi arvense is a non-native member of the Brassicaceae family that produces these chemicals, yet it remains a target for herbivory. Studying the interaction of both T. arvense and herbivores assists in understanding the factors of what influences a continued arms race of defense and attack (Rodman and Chew, 1980; Lee et. al, 2009). We will investigate how these two factors react to a change of density and an elevational gradient by measuring herbivory at similar phenological stages in a common garden in the Gothic townsite and in randomized field plots at sites of varying elevation. By manipulating density and seed source in the common garden, environmental factors are stabilized, and herbivory selection factors

Ecological role of Limnephilus abbreviates in detritus dynamics - C. Leitz (2019)
Caddisflies are the dominant detritivores in ponds and wetlands in many high elevation freshwaters. By processing detritus, caddisflies mobilize nutrients and energy that are not used by primary consumers which can play an important role in secondary production and nutrient cycling. Thus, caddisflies are significant for these oligotrophic ecosystems because they are often oligotrophic and therefore limited by nutrients. Previous studies have shown detritus processing by caddisflies stimulates algal growth. Historical data shows that certain species of caddisflies are shifting their range to higher elevations due to increasing temperatures. Past experiments at the Rocky Mountain Biological Laboratory have quantified caddisfly diet, detritus breakdown rates, and influences on algal growth, and other measures for several species of caddisfly in this guild. However, data is missing for several species of caddisflies, including those recently expanding their range upslope. I used a microcos

Are Marmot Alarm Class Condition Dependent? - A. L. Nash (2019)
The production and structure of animal signals may be condition dependent and may provide more than one type of information to receivers. While alarm calls are not typically viewed as condition dependent, recent studies have suggested that their structure and possibly their propensity to be emitted depends on condition and state. We asked whether the propensity of yellow-bellied marmots (Marmota flaviventer) to emit calls is influenced by their immunological or parasite status, by quantifying both trap-elicited and natural calling rates as a function of their neutrophil to lymphocyte (NL) ratio, the presence of a blood borne trypanosome, and the presence of several intestinal parasites (Eimeria, Entamoeba, and Ascaris). We built linear mixed effects models to determine if the health measures we collected were associated with the probability of calling in a trap and with annual rates of wild alarm calling. Marmots infected with trypanosomes were marginally more likely to call when trapp

Does Aphis asclepiadis colony size mediate Formica rufa and Tapinoma sessile competition for mutualist aphids - N. Nguyen (2019)
Mutualisms are the species interaction in which both mutualist partners benefit from the relationship. Most mutualisms involve multiple interacting species and associating with multiple mutualist partners can be beneficial if they provide complementary benefits. Yet, mutualist species may also compete with each other for access to partners, which can alter the benefits the partner receives. Ant-aphid mutualism is a food-for-protection in which aphids produce honeydew to feed ants while ants provide aphids protection against predators. Previous studies of the aphid Aphis asclepiadis and two species of ants, Formica rufa and Tapinoma sessile, show that both ant species provide mutualistic services to aphids. However, aphid colonies tended by F. rufa are five-fold larger than colonies that tended by T. sessile, and the mechanisms driving this pattern are unclear. In this study, we tested whether aphid colonies tended by F. rufa are larger than those tended by T. sessile because (1) F. ruf

The impacts of long term warming on potential soil microbial activity across soil depth - F. K. Quan-Shau (2019)
Terrestrial soils store more carbon than exists in the atmosphere and all plant life combined. Thus, small changes in the amount of carbon stored in soil or released back to the atmosphere from soil can have large impacts on atmospheric carbon concentrations and climate change. As climate change progresses, warming temperatures are projected to increase soil microbial activity, leading to shifts in soil carbon accumulation and stabilization. Here, we sampled soils across the soil profile during the decommissioning of a 30-year warming experiment conducted in a subalpine meadow to understand the degree to which warming impacts carbon losses in both surface soils and soils deep within the soil profile.

Niche breadth changes in response to environmental perturbation: the impact of early snowmelt on subalpine plant-pollinator specialization - E. Sharer (2019)
With global climate change, we observe phenological changes across all ecosystems. In the Colorado Rocky Mountains, warming is resulting in lower snowpack and earlier spring melt. Since plants use snow melt timing as a cue to start growing, climate change is implicated in accelerated bloom time and thus has the potential to cause a phenological mismatch between plants and their pollinators. To account for this mismatch, pollinators may change the plant species they interact with (i.e. their niche breadth) to account for the difference in timing of floral resources. This could include wholescale switching to a new resource, changing the number of species they visit, or instead could change the frequency of their visits to different plants. In this study, we investigated the impact of an environmental perturbation on plant-pollinator niche breadth, focusing on if and how niche breadth changes. We perturbed the system by inducing a phenological change by manipulating the timing of snowmel

Seasonal Progression of Algal Development and Quality in Streams that Vary in Timing of Springtime Peak Flow - Angela Wright; J. A. Balik; B. W. Taylor (2019)
Climate driven shifts in stream hydrology from early, rapid snowmelt may have implications for algae growing within high altitude montane streams. Peak flow scours the benthic layer and clears senesced algal growth and sediment, effectively priming the substrate for new algal growth following peak flow. An earlier peak flow allows for a longer season for algae to accrue biomass, but the implications for algal resource quality are unknown. Algae are crucial components of aquatic ecosystems because they are the basal food resource for animals, and algal nutrient uptake can dominate stream nutrient cycling. This study considers how variation in the timing of peak streamflow of different streams in the southern Rocky Mountains could impact the resource quality and development of algae. Algal samples from these streams were analyzed for biomass, chlorophyll-a, community composition, and percent phosphorous. Baetis bicaudatus, a grazing mayfly, was also sampled as they can selectively feed o

Immersive Co-production to Inform Ranch Management in Gunnison, Colorado, USA - Jacob S. Courkamp; Corrine N. Knapp; Bruce Allen (Rangelands, 2019)
On the Ground To be successful, producers must interpret environmental stimuli and respond with management actions that help match their production operations to the ecosystem services they depend on. Climate change, and the increased variability that will likely result, may lessen the relevance of historical rules of thumb and management heuristics by altering environmental conditions and giving rise to novel systems that feature more frequent and intense periods of stress. Sustaining livestock production in the face of climate change depends on the rapid production of knowledge to inform adaptation to novel systems. Involving producers in research is often discussed as a strategy to help accomplish this goal. We propose immersive co-production, wherein a student researcher is embedded within the production operations of a working ranch while studying and conducting research, as one method of quickly developing the knowledge resources necessary to sustain livestock production in the c

Does road dust have an effect on nectar production in pomopsis aggregata ? - D. Zuver (2019)
Road dust has potential impacts on plant metabolism and reproduction even in small amounts. Dust is everywhere and is increasing due to human influence, this has the potential to reduce overall plant pollination worldwide. Since dust is roughly the size of a grain of pollen, it might possibly clog the stigma of plants. It appears that there is already a correlation between road dust and flower life span as well as pollination success (Mary Price personal communication 2019; Waser et al. 2017). For these reasons it is an interesting question to determine whether road dust affects nectar production in Ipomopsis aggregata. In order to explore this question, we located 30 pairs of flowering I. aggregata plants. We simulated roadside dust levels with 5 puffs of sieved dust from a garden duster to one half of the plants, while the other half received a controlled 5 puffs of normal air from another garden duster. Treatment was assigned at random within each pair. Elongated flower buds on thes

Stridulation in Nicrophorus investigator as a Possible Means of Cooperation during Carcass Sequestration - O. Ortuno (2019)
Burying beetle stridulation has been observed and documented when caring for their young, as well as among agonistic beetles competing for carrion. Burying beetles in the genus Nicrophorus require a small carcass, typically 16-50 grams, in order to reproduce. Once located, the carcass is buried by the burying beetles, after which the beetles lay their eggs in the underground chamber and partake in biparental care. This study found that N. investigator pairs use stridulation during carcass sequestration when faced with an obstacle, but found no significant difference between the beetles’ use of stridulation and lack thereof in terms of their ability to move carrion.

The Gothic Muse and Meta-Gothic Moment: Afterword to Russian Gothic Forum - Caryl Emerson (Russian Literature, 2019)
Abstract The afterword offers an additional discussion related to the initial debate posed by the new developments in Russian Gothic as a special kind of literary genre. This article reviews, contextualizes and traces connections between the essays on Russian Gothic in this edition by Jeffrey Brooks, Kevin Platt, Mark Lipovetsky, and Dina Khapaeva.

Is the Recent Drought on the Colorado River the New Normal? - Joseph Barsugli; Martin Hoerling; Ben Livneh (Eos, 2019)
Understanding Historical Changes in the Flow of the Colorado River; Boulder, Colorado, 24–25 September 2018

The Risk of Curtailment under the Colorado River Compact - Anne Castle; Jacob A. Fleck (SSRN Electronic Journal, 2019)
Water supply in the Colorado River could drop so far in the next decade that the ability of the Upper Colorado River Basin states – Colorado, Utah, Wyoming, and New Mexico – to meet their legal obligations to downstream users in Nevada, Arizona, California, and Mexico would be in grave jeopardy. Legal institutions designed nearly a century ago are inadequate to address the significant risk of shortfall combined with uncertainty about whose water supplies would be cut, and by how much. This report indicates that declines in the Colorado River’s flow could force water curtailments in coming decades, posing a credible risk to Colorado communities and requiring serious consideration of insurance protection like demand management.

Mapping the range shifts of East River Valley caddisflies (Trichoptera) - K. Wirebach (2019)
Range shifts occur when all individuals of a species or population move from a previously- habitable area to a newly-habitable area in response to changing environmental conditions. Climate- induced range shifts are well-documented for certain regions, biomes, and taxa, but large knowledge gaps exist for the Western Hemisphere and for aquatic macroinvertebrates specifically. There is a need to understand how climate-induced range shifts of aquatic macroinvertebrates are occurring, especially for taxa which have marked effects on ecosystem functioning, such as detritus shredders. Thirty years of aquatic sampling at the Rocky Mountain Biological Laboratory have revealed that Trichoptera species seem to be shifting their ranges, but the details of this observation have not been quantified. My project aimed to map and describe the multidimensional ranges (and later, range shifts) of caddisflies in this region using survey data and GIS technology. I mapped the current ranges of twelve speci

Late Quaternary vertebrates from the Upper Gunnison Basin, Colorado, and small-mammal community resilience to climate change since the last glacial maximum - Steven D. Emslie; David J. Meltzer (Quaternary Research, 2019)
AbstractThe Upper Gunnison Basin (UGB), Colorado, is a montane region characterized by unusual physiography and topographic isolation. Excavations of three caves in the UGB provide one of the most diverse records of high-elevation late Quaternary vertebrates in North America. The localities, Haystack Cave (2450 m above sea level [m asl]), Cement Creek Cave (2860 m asl), and Signature Cave (3055 m asl), together provide a near-continuous record of vertebrate communities that extends from before the last glacial maximum to the present. These communities largely represent a sagebrush (Artemisiaspp.) steppe-tundra environment that prevailed throughout the UGB in the late Pleistocene. At least five taxa of extinct large mammals disappear from the UGB by the Early Holocene; one small mammal (the short-faced skunkBrachyprotomacf.B.brevimala) also became extinct. The fossil record further indicates that only four small extant mammals (Sorex preblei,Dicrostonyxsp.,Lemmiscus curtatus, andUrocite

Climate change, phenological shifts, and species interactions: Case studies in subalpine plant and migratory fish populations - R. M. Dalton (2019)
Climate Change, Phenological Shifts, and Species Interactions:

Intraspecific flower color variation along elevation gradients - A. T. Smith (2019)

The depredation of Mountain White-crowned Sparrow (Zonotrichia leucophyrys oriantha) nests by the golden-mantled ground squirrel (Callospermophilus lateralis) and long-tailed weasel (Mustela frenata) - Savannah Troy; Ross R. Conover (The Wilson J. of Ornithology, 2019)
The identities of avian nest predators remain unknown in many systems. The Mountain White-crowned Sparrow (Zonotrichia leucophrys oriantha) is a high-elevation ground-nesting passerine for which only 4 of 15 suspected nest predator species have been confirmed. In this short communication, we confirm 2 previously suspected but unverified nest predators of Z. l. oriantha that were video recorded during the 2016 and 2017 summer breeding seasons. These nest depredation events include a golden-mantled ground squirrel (Callospermophilus lateralis) in 2016 and a long-tailed weasel (Mustela frenata) in 2017. Both predators were recorded removing nestlings.

Does the seedbank reflect the composition of the metacommunity for alpine plants? - G. Belfry (2019)
Community ecology and dynamics are often only thought of in terms of the processes selection and speciation. Likewise, plants are often only considered in their immobile, germinated form. However, when it comes to plant community dynamics, seeds and the seedbank are often critical in predicting community change through the processes of drift, and dispersal. The goal of this study is to analyze the relationship between the soil seedbank and the spatial and composition patterns across an alpine plant community. Ultimately, this study found a significant correlation between local vegetation abundance and seed abundance in a given sample, meaning that vegetative community composition plays an important role in community assemblage. The exact mechanism by which seed aggregation by vegetation occurs remains unknown, however this is a subject of current study. The results also suggested possible topographical or meteorological dispersal interactions, which are the subject of planned future st

Spectacle in the meadows - David W. Inouye (Gunnison County Times, 2019)

Effects of pond permanence on avian behaviors - L. Braun (2019)
As global temperatures rise due to climate change, aquatic ecosystems, such as alpine ponds, become more at risk of drying earlier than normal. These changes in pond hydrology have the potential to alter not only the aquatic ecosystems, but also terrestrial and riparian ecosystems, through resource subsidies provided by the ponds. Vernal ponds (temporary ponds) are particularly vulnerable to these changes due to their size, therefore making the surrounding terrestrial ecosystems susceptible as well. Through observing avian behaviors around both permanent and temporary ponds, our study strived to gain insight on how terrestrial predators react to the change of aquatic hydrology. Our preliminary results indicate that avian predators spend more total time near semi-permanent ponds, but further inclusion of habitat variables, such as pond size, may change these results. Understanding the causes and effects of climate altered hydrology are important in building conservation strategies for a

Effect of blood parasites on incubation efficiency of Z. l. oriantha in the Colorado Rocky Mountains - C. McCuen (2019)
Haemoparasites are common in passerines and have known mild to detrimental effects on populations. It is important to understand how these effects influence nest incubation in females, as it could reflect future reproductive success of that species as vectors and transmission increase with climate change. We investigated how incubation temperatures varied in female mountain white-crowned sparrows in the presence and absence of haemoparasites to determine if these parasites are influencing efficiency. There was a trend showing that parasitized females showed more variance in nest temperature, but it was not significant. A larger sample is necessary to draw conclusions from this study.

How vulnerable are pollen-specialist solitary bees to temperature-mediated shifts in the timing of food availability? - G. Gauthier (2019)
Rising temperatures are advancing the seasonal timing of flowering and pollinator activity in

Effects of recreational trails on small mammal communities in north-central Gunnison County, Colorado - L. Macias (2019)
Human recreation can lead to changes in behavior and distribution patterns of wildlife populations. This project aims to (1) evaluate the effectiveness of the Hunt trap, a novel non- invasive technique used to estimate small mammal abundance (2) determine the distance from trails at which we see an effect on small mammal activity and (3) assess the impact of non- motorized recreational activities on rodent species abundance. We investigated these objectives at areas of high utilization using a non-invasive camera trap method at a series of locations throughout July and August 2019. Heavily used recreational trails did not show a significant impact on habitat utilization by several small mammal species. Nocturnal species including deer mice (Peromyscus maniculatus) activity was higher, however not significant, in proximity to trails. Diurnal rodents including golden-mantled ground squirrels (Callospermaphilus lateralis) and least chipmunks (Tamias minimus) did not exhibit a negative tra

Litter relocation behavior in two species of ground dwelling squirrels - J. R. Aliperti; D. H. Van Vuren; A. J. Rossi; Kenneth B. Armitage (Ethology, 2019)
Abstract Maternal investment in mammals may take many forms, including spatial relocation of offspring. Litter relocation behavior, in which a female moves her litter to a new location, has been reported for several species of carnivores and rodents but has received little study. We describe litter relocations during long‐term studies of two species of ground‐dwelling squirrels, yellow‐bellied marmots (YBM, Marmota flaviventer ) and golden‐mantled ground squirrels (GMGS, Callospermophilus lateralis ), to determine the distance and frequency of litter relocations and to explore possible explanations for litter relocation behavior. We observed 19 litters relocated by YBM mothers and 32 by GMGS mothers. Although YBM are much larger than GMGS, relocation distances for YBM (median = 46 m and range = 15–324 m) were not greater than those for GMGS (median = 79 m and range = 16–252 m), possibly because YBM home ranges in our study area were exceptionally small. Frequency of litter relocation w

Gene expression shifts in yellow-bellied marmots prior to natal dispersal - Tiffany Armenta; D. N. Cole; D. H. Geschwind; Daniel T. Blumstein; R. K. Wayne (Behavioral Ecology, 2019)
The causes and consequences of vertebrate natal dispersal have been studied extensively, yet little is known about the molecular mechanisms involved. We used RNA-seq to quantify transcriptomic gene expression in blood of wild yellow-bellied marmots (Marmota flaviventer) prior to dispersing from or remaining philopatric to their natal colony. We tested 3 predictions. First, we hypothesized dispersers and residents will differentially express genes and gene networks since dispersal is physiologically demanding. Second, we expected differentially expressed genes to be involved in metabolism, circadian processes, and immune function. Finally, in dispersing individuals, we predicted differentially expressed genes would change as a function of sampling date relative to dispersal date. We detected 150 differentially expressed genes, including genes that have critical roles in lipid metabolism and antigen defense. Gene network analysis revealed a module of 126 coexpressed genes associated with

Climate change shifts natural selection and the adaptive potential of the perennial forb Bochera stricta in the Rocky Mountians - Jordan B. Bemmels; J. T. Anderson (Evolution, 2019)
Heritable genetic variation is necessary for populations to evolve in response to anthropogenic climate change. However, antagonistic genetic correlations among traits may constrain the rate of adaptation, even if substantial genetic variation exists. We examine potential genetic responses to selection by comparing multivariate genetic variance-covariances of traits and fitness (multivariate Robertson-Price identities) across different environments in a reciprocal transplant experiment of the forb Boechera stricta in the Rocky Mountains. By transplanting populations into four common gardens arrayed along an elevational gradient, and exposing populations to control and snow removal treatments, we simulated future and current climates and snowmelt regimes. Genetic variation in flowering and germination phenology declined in plants moved downslope to warmer, drier sites, suggesting that these traits may have a limited ability to evolve under future climates. Simulated climate change via s

Two-year bee or not two-year bee? How voltinism is affected by temperature and season length in a high-elevation solitary bee - Jessica R. K. Forrest; Regan Cross; Paul J. CaraDonna (American Naturalist, 2019)
Organisms must often make developmental decisions without complete information about future conditions. This uncertainty-for example, about the duration of conditions favorable for growth-can favor bet-hedging strategies. Here, we investigated the causes of life cycle variation in Osmia iridis, a bee exhibiting a possible bet-hedging strategy with co-occurring 1- and 2-year life cycles. One-year bees reach adulthood quickly but die if they fail to complete pupation before winter; 2-year bees adopt a low-risk, low-reward strategy of postponing pupation until the second summer. We reared larval bees in incubators in various experimental conditions and found that warmer-but not longer-summers and early birthdates increased the frequency of 1-year life cycles. Using in situ temperature measurements and developmental trajectories of laboratory- and field-reared bees, we estimated degree-days required to reach adulthood in a single year. Local long-term (1950-2015) climate records reveal tha

Fungal colonization of plant roots is resistant to nitrogen addition and resilient to dominant species losses - Jeremiah A Henning; Quentin D Read; Nathan J. Sanders; Aimee T Classen (Ecosphere, 2019)
Abstract Global change drivers, such as nitrogen (N) deposition and non‐random species extinctions, may shift interactions among aboveground and belowground communities. However, tightly coupled interactions between aboveground and belowground organisms may buffer ecosystems to global change. Here, we test how four years of organic and inorganic N addition and removal of a dominant plant species, Festuca thurberi , independently and interactively influences fungal colonization patterns and performance in a co‐dominant plant species, Helianthella quinquenervis . Surprisingly, we found N addition and Festuca removal had no measurable effects on the colonization of arbuscular mycorrhizal fungi (AMF) and dark septate endophyte ( DSE ) or the performance of Helianthella seedlings grown with field‐collected inoculum in a companion greenhouse experiment. However, the proximity of Helianthella to Festuca predicted fungal colonization: DSE colonization decreased by 1% for each cm of distance He

Phenology as a process rather than an event: from individual reaction norms to community metrics - B. D. Inouye; J. Ehrlen; N. Underwood (Ecological Monographs doi 10.1002/ecm.1352, 2019)
Abstract Measures of the seasonal timing of biological events are key to addressing questions about how phenology evolves, modifies species interactions, and mediates biological responses to climate change. Phenology is often characterized in terms of discrete events, such as a date of first flowering or arrival of first migrants. We discuss how phenological events that are typically measured at the population or species level arise from distributions of phenological events across seasons, and from norms of reaction of these phenological events across environments. We argue that individual variation in phenological distributions and reaction norms has important implications for how we should collect, analyze, and interpret phenological information. Regarding phenology as a reaction norm rather than one year's specific values implies that selection acts on the phenologies that an individual expresses over its lifetime. To understand how climate change is likely to influence phenology, w

Lifetime Fitness, Sex-Specific Life History, and the Maintenance of a Polyphenism - A. C. R. Lackey; Michael P. Moore; J. Doyle; N. Gerlane; Ashley Hagan; Morgan Geile; Christopher Eden; H. H. Whiteman (The American Naturalist, 2019)
Polyphenisms-alternative morphs produced through plasticity-can reveal the evolutionary and ecological processes that initiate and maintain diversity within populations. We examined lifetime fitness consequences of two morphs in a polyphenic population of Arizona tiger salamanders using a 27-year data set with 1,317 adults and 6,862 captures across eight generations. Larval salamanders develop into either an aquatic paedomorph that retains larval traits and stays in its natal pond or a terrestrial metamorph that undergoes metamorphosis. To evaluate the adaptive significance of this polyphenism, we compared lifetime reproductive success of each morph and assessed how life-history strategies and spatiotemporal variation explained fitness. We found sex-specific differences in lifetime fitness between morphs. For males, paedomorphs had more reproductive opportunities than metamorphs when we accounted for the potential mating advantage of larger males. For females, in contrast, metamorphs h

Modeling transient soil moisture limitations on microbial carbon respiration - K. B. Liu; C. R. Lawrence; M. J. Winnick; H. T. Hsu; Katharine Maher; J. L. Druhan (Journal of Geophysical Research: Biogeosciences, 2019)
Abstract Soil microorganisms are known to survive periods of aridity and to recover rapidly after wetting events, with the ability to transition between a dormant state in dry conditions and an active state in wet conditions. Though this dynamic behavior has been previously incorporated into soil carbon respiration modeling frameworks, a direct comparison between this active‐dormant transition mechanism and a more simplified first‐order model has yet to be made. Here, we demonstrate the necessary extent of model complexity needed to reproduce transient carbon respiration rates obtained from a set of soil incubation experiments implemented over a range of soil depths and time intervals. Two approaches are tested, one uses simplified first‐order kinetics, whereas the other employs a transition between active and dormant biomass. The performance of each model is evaluated using an Akaike Information Criterion (AIC) based on the accuracy with which they reproduce an experimental dataset co

Context dependent biotic interactions control plant abundance across altitudinal environmental gradients - J. S. Lynn; Melanie R Kazenel; Stephanie N. Kivlin; Jennifer A. Rudgers (Ecography, 2019)
Climate change is causing species with non-overlapping ranges to come in contact, and a key challenge is to predict the consequences of such species re-shuffling. Experiments on plants have focused largely on novel competitive interactions; other species interactions, such as plant–microbe symbioses, while less studied, may also influence plant responses to climate change. In this greenhouse study, we evaluated interactions between soil microbes and alpine-restricted plant spe- cies, simulating a warming scenario in which low-elevation microbes migrate upslope into the distribution of alpine plants. We examined three alpine grasses from the Rocky Mountains, CO, USA (Poa alpina, Festuca brachyphylla, and Elymus scribneri). We used soil inocula from within (resident) or below (novel) the plants’ current elevation range and examined responses in plant biomass, plant traits, and fungal colonization of roots. Resident soil inocula from the species’ home range decreased biomass to a greater

Parasites Are Associated With Noisy Alarm Calls - K. Nouri; Daniel T. Blumstein (Front. Ecol. Evol., 2019)
Many animal signals used for mate choice assessment are condition dependent, but less is known about the condition dependence of other biologically important signals. We asked whether yellow-bellied marmot (Marmota flaviventer) alarm calls varied as a function of parasite infection and/or neutrophil:lymphocyte ratios (a measure of immunological challenge). We found that marmots infected with Eimeria, an intestinal parasite, had noisier calls. This is potentially because of an immunostimulating effect of Eimeria infection which may draw energy from nonvital functions. The results suggest calls potentially contain information about parasite status which could be used by receivers to estimate a caller’s condition. Future studies are required to determine whether infection influences caller reliability and how receivers respond to alarm calls from parasitized individuals.

Correlates of maternal glucocorticoid levels in a socially flexible rodent - G. M. Pinho; X. Ortiz Ross; A. Reese; Daniel T. Blumstein (Hormones and behavior, 2019)
While it is generally accepted that social isolation has detrimental effects on social species, little is known about the importance of social interactions in less social species-particularly for wild reproductive females. We studied socially-flexible yellow-bellied marmots (Marmota flaviventer) and asked whether features of the social environment are associated with maternal fecal glucocorticoid metabolite (FGM) concentrations. Since changes in maternal baseline glucocorticoids may have positive or negative consequences for offspring fitness, we were also interested in estimating their relationship with measures of reproductive success. We fitted generalized linear mixed effects models to a dataset including maternal FGM measurements, social network metrics, maternal/alloparental care, and pup FGM and survival. Agonistic interactions were positively associated with maternal FGM levels, while mothers that engaged in relatively more affiliative interactions had reduced FGM levels when l

Parasitism modifies the direct effects of warming on a hemiparasite and its host - Nicole E. Rafferty; L. Agnew; Paul D. Nabity (PLOS ONE, 2019)
Climate change is affecting interactions among species, including host-parasite interactions. The effects of warming are of particular interest for interactions in which parasite and host physiology are intertwined, such as those between parasitic plants and their hosts. However, little is known about how warming will affect plant parasitic interactions, hindering our ability to predict how host and parasite species will respond to climate change. Here, we test how warming affects aboveground and belowground biomass of a hemiparasitic species (Castilleja sulphurea) and its host (Bouteloua gracilis), asking whether the effects of warming depend on the interaction between these species. We also measured how warming affected the number of haustorial connections between parasite and host. We grew each species alone and together under ambient and warmed conditions. Hosts produced more belowground biomass under warming. However, host biomass was reduced when plants were grown with a hemipara

Pre- and post-ingestive defenses affect larval feeding on a lethal invasive host plant - Rachel A Steward; Larry Fisher; C. L. Boggs (Entomologia Experimentalis et Applicata, 2019)
Abstract Evolutionary traps arise when organisms use novel, low‐quality or even lethal resources based on previously reliable cues. Persistence of such maladaptive interactions depends not only on how individuals locate important resources, such as host plants, but also the mechanisms underlying poor performance. Pieris macdunnoughii (Remington) (Lepidoptera: Pieridae) lays eggs on a non‐native mustard, Thlaspi arvense (L.) (Brassicaceae), which is lethal to the larvae. We first tested whether larval feeding behavior was affected before (pre‐) ingestion or following (post‐) ingestion of leaf material, indicating activity of feeding deterrents, toxins, or both in this evolutionary trap. Neonates were less likely to start feeding and eventually fed more slowly on T. arvense than on the native host plant Cardamine cordifolia (Gray) (Brassicaceae) in both laboratory and field. Starvation was a primary cause of mortality, indicating the role of a feeding deterrent. Feeding did not differ be

Transitivity and structural balance in marmot social networks - T. W. Wey; F. Jordan; Daniel T. Blumstein (Behav Ecol Sociobiol, 2019)
Social relationships are composed of both positive (affiliative) and negative (agonistic) interactions, representing opposing effects. Social network theory predicts that positive relationships should be transitive; thus, the friend of a friend is more likely to be a friend. Further, when considering both positive and negative relationships jointly, structural balance theory predicts that certain configurations of positive and negative relationships in a triad are inherently less stable (unbalanced) and should tend to be eliminated. However, structural balance has been rarely examined in nonhuman social systems. We tested for transitivity and structural balance in social networks of socially flexible yellow-bellied marmots (Marmota flaviventer) and asked if group size, network density, or group composition affected the degree of structural balance. We found a consistent pattern of significant transitivity in positive interactions, some transitivity in negative interactions, and some ev

Distinct Source Water Chemistry Shapes Contrasting Concentration-Discharge Patterns - Wei Zhi; Langlang Li; Wenming Dong; W. Brown; J. Kaye; Carl I. Steefel; K. H. Williams (Water Resources Research, 2019)
AbstractUnderstanding concentration‐discharge (C‐Q) relationships are essential for predicting chemical weathering and biogeochemical cycling under changing climate and anthropogenic conditions. Contrasting C‐Q relationships have been observed widely, yet a mechanistic framework that can interpret diverse patterns remains elusive. This work hypothesizes that seemingly disparate C‐Q patterns are driven by switching dominance of end‐member source waters and their chemical contrasts arising from subsurface biogeochemical heterogeneity. We use data from Coal Creek, a high‐elevation mountainous catchment in Colorado, and a recently developed watershed reactive transport model (BioRT‐Flux‐PIHM). Sensitivity analysis and Monte‐Carlo simulations (500 cases) show that reaction kinetics and thermodynamics and distribution of source materials across depths govern the chemistry gradients of shallow soil water and deeper groundwater entering the stream. The alternating dominance of organic‐poor yet

Exploring mechanisms explaining coexistence patterns of Rhyacophila species (Trichoptera) in streams near the Rocky Mountain Biological Laboratory - A. Ruiz (2019)
Coexistence of closely related species can be explained by a number of biotic and abiotic factors. In Trichoptera (caddisflies), the patterns of coexistence of the species Rhyacophila in streams near the Rocky Mountain Biological Laboratory (RMBL) has been tracked for 43 years. This study is a continuation from previous student projects carried out in 2017 and 2018 to explore the mechanisms explaining patterns of coexistence of these caddisflies. In addition to coexistence patterns, data from previous studies include species preferences for streams of different altitude, size, water temperature, and the coverage of the nuisance diatom Didymosphenia geminata. The coverage of D. geminata varies among years (favored in low-flow years), and streams (favored in streams with lower levels of phosphorus). Previous studies considered those factors only at the scale of stream reaches, but microhabitat preferences within stream reaches by different species of Rhyacophila remain to be investigated

Snowmelt affects aphid (Aphis asclepladis) populations through soil moisture and host plant phenology - James H Den Uyl (2019)
Plant-insect interactions are ecologically important relationships that are greatly affected by climate change. Previous research concerning an aphid species (Aphis asclepiadis) and its host plant (Ligusticum porteri) has shown that aphid abundances correlate significantly with snowmelt date in the subalpine zone of the Rocky Mountains. The mechanisms underlying this phenomenon have not been previously identified. Our construction of a structural equational model identified soil moisture and plant phenology as two major pathways by which snowmelt indirectly affects aphids. By comparing aphid and host plant populations at different elevations and experimentally manipulating soil moisture we observed significant responses in aphid abundance, ant abundance, aphid predators, and some measures plant quality. While bottom-up processes may be playing a role in determining aphid abundances, top-down pressures appear to have much more control over this aphid dominated ecosystem. iii ACKNOWLEDGE

From grain to floodplain: Evaluating heterogeneity of floodplain hydrostratigraphy using sedimentology, geophysics, and remote sensing - H. F. Malenda (2019)
Floodplain stratigraphy, a major structural element of alluvial aquifers, is a fundamental component of floodplain heterogeneity, hydraulic conductivity, and connectivity. Watershed-scale hydrological models often simplify floodplains by modeling them as largely homogeneous, which inherently overlooks natural floodplain heterogeneity and anisotropy and their effects on hydrologic processes such as groundwater flow and transport and hyporheic exchange. This study, conducted in the East River Basin, Colorado, USA, combines point-, meander-, and floodplain-scale data to explore the importance of detailed field studies and physical representation of alluvial aquifers. We combine sediment core descriptions, hydraulic conductivity estimates from slug tests, ground-penetrating radar (GPR), historical maps of former channels, LiDAR- based elevation and Normalized Difference Vegetation Index data to infer 3-D fluvial stratigraphy. We compare and contrast stratigraphy of two meanders with dispar

The effects of climate change and biodiversity loss on mutualisms - A. S. Nelson (2019)
The abiotic environment drives species abundances and distributions both directly and indirectly through effects on multi-trophic species interactions. However, few studies have documented the individual and combined consequences of these direct and indirect effects. We studied an ant-tended aphid along an elevational gradient, where lower elevations were more arid. Hypotheses of stronger species interactions at lower elevations and a greater sensitivity of higher trophic levels to climate led us to predict increased top-down control of aphids by natural enemies (third trophic level) but even stronger protection from mutualist ants (fourth trophic level) with increasing aridity. As a result, we predicted that mutualism strength and aphid abundance would increase with aridity. We documented patterns of aphid abundance and tested for both the direct and multi-trophic indirect effects of aridity on aphid performance. To do so, we used both observational and manipulative methods across two

Stoichiometry and infectious disease: Linking chemical elements and parasitic interactions - A. J. Sanders (2019)
A growing body of work has shown that parasites’ growth and reproduction can be influenced by the food quality available to their hosts. Consumers, including parasites, require a balanced diet to grow. Unlike many consumers, however, parasites are beholden to the diet quality presented to them by their host, which is in turn a function of the host’s own diet. Here, we tested the hypothesis that the relationship between parasite reproduction and host diet quality is subject to a threshold elemental ratio: that there is a balanced host diet that confers maximum growth to the parasite. We present results from a laboratory experiment where we fed a wide range of experimental diets to Tubifex tubifex infected with Myxobolus cerebralis and observed a hump-shaped relationship between M. cerebralis spore production and T. tubifex diet stoichiometry, indicative of a threshold elemental ratio. Further we compared these results to M. cerebralis spore production by wild T. tubifex, and found that

Implications of global climate change on cow parsnip in Colorado: from flowering phenology to multitrophic interactions - B. Smith; Ode, Paul J.; Bjostad, Louis; Seshadri, Arathi (Digital Collections of Colorado (Colorado State University), 2019)
Plants play a central role in structuring nearly all terrestrial communities and providing ecosystem services. As ectothermic organisms, the synchronization of plant and insect life history events (phenology) are strongly dependent on temperature and precipitation, two of the major components of climate change. Plants can serve as indicator species for how climate change might alter community composition that in turn contributes to ecosystem and landscape stability. I investigated elevation as a proxy for climate change from ten spatially separate Colorado populations of cow parsnip Heracleum maximum Bartram (Apiaceae) in both 2017 and 2018. I studied, plant flowering phenology and plant trait measurements that attributed to plant fitness measures (seed production and weight). Additionally, I investigated floral visitors in association with flowering phenology and how the presence or absence of parsnip webworm Depressaria radiella Goeze (Lepidoptera: Depressariidae) impacted pollinator

The importance of interflow to groundwater recharge in a snowmelt-dominated headwater basin - R. W. H. Carroll; Jeffrey Deems; Richard Niswonger; Rina Schumer; K. H. Williams (Geophysical Research, 2019)
AbstractUnderstanding the sensitivity of groundwater generation to climate in a mountain system is complicated by the tight coupling of snow dynamics to vegetation and topography. To address these feedbacks, we combine light detection and ranging (LiDAR)‐derived snow observations with an integrated hydrologic model to quantify spatially and temporally distributed water fluxes across varying climate conditions in a Colorado River headwater basin. Results indicate that annual groundwater flow is an important and stable source of stream water. However, interflow decreases during drought as a function increased plant water use and the relative fraction of groundwater to streams increases. Seasonal snowmelt and vegetation water use regulate small recharge rates in the lower portions of the basin, but snowmelt transported via interflow from high mountain ridges toward convergent topographic zones defines preferential recharge in the upper subalpine. Recharge in this zone appears decoupled fr

Hyporheic Zone Microbiome Assembly Is Linked to Dynamic Water Mixing Patterns in Snowmelt-Dominated Headwater Catchments - C. M. Saup; S. R. Bryant; A. S. Nelson; K. D. Harris; Audrey Sawyer; J. N. Christensen; Malak M. Tfaily; K. H. Williams; Michael J. Wilkins (Journal of Geophysical Research: Biogeosciences, 2019)
Abstract Terrestrial and aquatic elemental cycles are tightly linked in upland fluvial networks. Biotic and abiotic mineral weathering, microbially mediated degradation of organic matter, and anthropogenic influences all result in the movement of solutes (e.g., carbon, metals, and nutrients) through these catchments, with implications for downstream water quality. Within the river channel, the region of hyporheic mixing represents a hot spot of microbial activity, exerting significant control over solute cycling. To investigate how snowmelt‐driven seasonal changes in river discharge affect microbial community assembly and carbon biogeochemistry, depth‐resolved pore water samples were recovered from multiple locations around a representative meander on the East River near Crested Butte, CO, USA. Vertical temperature sensor arrays were also installed in the streambed to enable seepage flux estimates. Snowmelt‐driven high river discharge led to an expanding zone of vertical hyporheic mixi

No evidence that gut microbiota impose a net cost on their butterfly host - A. Ravencraft; Nicole Kish; Kabir Peay; C. L. Boggs (Molecular Ecology, 2019)
Gut microbes are believed to play a critical role in most animal life, yet fitness effects and cost-benefit trade-offs incurred by the host are poorly understood. Unlike most hosts studied to date, butterflies largely acquire their nutrients from larval feeding, leaving relatively little opportunity for nutritive contributions by the adult's microbiota. This provides an opportunity to measure whether hosting gut microbiota comes at a net nutritional price. Because host and bacteria may compete for sugars, we hypothesized that gut flora would be nutritionally neutral to adult butterflies with plentiful food, but detrimental to semistarved hosts, especially when at high density. We held field-caught adult Speyeria mormonia under abundant or restricted food conditions. Because antibiotic treatments did not generate consistent variation in their gut microbiota, we used interindividual variability in bacterial loads and operational taxonomic unit abundances to examine correlations between h

Altitudinal gradients fail to predict fungal symbiont responses to warming - Melanie R Kazenel; Stephanie N. Kivlin; D. L. Taylor; J. S. Lynn; Jennifer A. Rudgers (Ecology, 2019)
AbstractClimate change is shifting altitudinal species ranges, with potential to disrupt species interactions. Altitudinal gradient studies and warming experiments can both increase understanding of climate effects on species interactions, but few studies have used both together to improve predictions. We examined whether plant–fungal symbioses responded similarly to altitude and 23 yr of experimental warming. Root‐ and leaf‐associated fungi, which can mediate plants’ climate sensitivity, responded divergently to elevation vs. warming. Fungal colonization, diversity, and composition varied with altitude, but climate variables were generally weak predictors; other factors such as host plant identity, plant community composition, or edaphic variables likely drive fungal altitudinal distributions. Manipulated warming altered fungal colonization, but not composition or diversity. Leaf symbionts were more sensitive to climate and experimental warming than root symbionts. Altitudinal pattern

Microbial communities across a hillslope-riparian transect shaped by proximity to the stream, groundwater table, and weathered bedrock - A. Lavy; D. G. McGrath; P. B. M. Carnevali; Jiamin Wan; Wenming Dong; Tetsu Tokunaga; B. C. Thomas; K. H. Williams; S. S. Hubbard; Jillian F. Banfield (Ecology and Evolution, 2019)
Abstract Watersheds are important suppliers of freshwater for human societies. Within mountainous watersheds, microbial communities impact water chemistry and element fluxes as water from precipitation events discharge through soils and underlying weathered rock, yet there is limited information regarding the structure and function of these communities. Within the East River, CO watershed, we conducted a depth‐resolved, hillslope to riparian zone transect study to identify factors that control how microorganisms are distributed and their functions. Metagenomic and geochemical analyses indicate that distance from the East River and proximity to groundwater and underlying weathered shale strongly impact microbial community structure and metabolic potential. Riparian zone microbial communities are compositionally distinct, from the phylum down to the species level, from all hillslope communities. Bacteria from phyla lacking isolated representatives consistently increase

Plant Identity Influences Foliar Fungal Symbionts More Than Elevation in the Colorado Rocky Mountains - Stephanie N. Kivlin; Melanie R Kazenel; J. S. Lynn; D. L. Taylor; Jennifer A. Rudgers (Microbial Ecology, 2019)
Despite colonizing nearly every plant on Earth, foliar fungal symbionts have received little attention in studies on the biogeog- raphy of host-associated microbes. Evidence from regional scale studies suggests that foliar fungal symbiont distributions are influenced both by plant hosts and environmental variation in climate and soil resources. However, previous surveys have focused on either one plant host across an environmental gradient or one gradient and multiple plant hosts, making it difficult to disentangle the influence of host identity from the influence of the environment on foliar endophyte communities. We used a culture-based approach to survey fungal symbiont composition in the leaves of nine C3 grass species along replicated elevation gradients in grasslands of the Colorado Rocky Mountains. In these ecosystems, the taxonomic richness and composition of foliar fungal symbionts were mostly structured by the taxonomic identity of the plant host rather than by variation in c

Reproductive losses due to climate change? Induced earlier flowering are not the primary threat to plant population viability in a perennial herb - Amy M. Iler; Aldo Compagnoni; David W. Inouye; J. H. Williams; Paul J. CaraDonna; A. M. Anderson; T. E. X. Miller (Journal of Ecology, 2019)
Abstract Despite a global footprint of shifts in flowering phenology in response to climate change, the reproductive consequences of these shifts are poorly understood. Furthermore, it is unknown whether altered flowering times affect plant population viability. We examine whether climate change‐induced earlier flowering has consequences for population persistence by incorporating reproductive losses from frost damage (a risk of early flowering) into population models of a subalpine sunflower (Helianthella quinquenervis). Using long‐term demographic data for three populations that span the species’ elevation range (8–15 years, depending on the population), we first examine how snowmelt date affects plant vital rates. To verify vital rate responses to snowmelt date experimentally, we manipulate snowmelt date with a snow removal experiment at one population. Finally, we construct stochastic population projection models and Life Table Response Experiments for each population. We find

Adaptive gene regulation in wild mammals exposed to high predator abundance - Tiffany Armenta; S. W. Cole; R. K. Wayne; Daniel T. Blumstein (Animal Behaviour, 2019)
Psychological stress induced by exposure to predators has complex effects on the behaviour and physiology of prey species. This includes potential influences on gene expression mediated via stress-responsive physiological pathways such as the sympathetic nervous system and hypothalamus–pituitary–adrenal (HPA) axis. Laboratory studies have documented diverse transcriptional effects of predator-induced fear, but genomic responses to predator exposure in the wild remain poorly understood. Here, we used RNA-sequencing to investigate the leukocyte transcriptome response to chronic predator pressure in a well-studied population of wild yellow-bellied marmots, Marmota flaviventer. We assessed the genomic response to this stressor in three ways by (1) identifying differentially expressed individual genes across the genome, (2) assessing whether differentially expressed genes were statistically over-represented by functional categories and (3) testing for transcription factor activity that may

Return flows from beaver ponds enhance floodplain-to-river metals exchange in alluvial mountain catchments - Martin Briggs; C. Wang; F. D. Day-Lewis; K. H. Williams; Wenming Dong; J. W. Lane (Science of the Total Environment, 2019)
River to floodplain hydrologic connectivity is strongly enhanced by beaver- (Castor canadensis) engineered channel water diversions. The hydroecological impacts are wide ranging and generally positive, however, the hydrogeochemical characteristics of beaver-induced flowpaths have not been thoroughly examined. Using a suite of complementary ground- and drone-based heat tracing and remote sensing methodology we characterized the physical template of beaver-induced floodplain exchange for two alluvial mountain streams near Crested Butte, Colorado, USA. A flowpath-oriented perspective to water quality sampling allowed characterization of the chemical evolution of channel water diverted through floodplain beaver ponds and ultimately back to the channel in 'beaver pond return flows'. Subsurface return flow seepages were universally suboxic, while ponds and surface return flows showed a range of oxygen concentration due to in-situ photosynthesis and atmospheric mixing. Median concentrations o

Volatile organic compounds as signals for pollinators and their consistency across years - L. Sharrett (2019)
Volatile organic compounds (VOCs) are emitted by every part of a plant and are believed to work as possible olfactory signals, drawing in pollinators and antagonists. This study was designed to address whether VOCs served as a signal to pollinators, indicating the size of the nectar reward. This part of the study focused on two populations of Ipomopsis aggregata plants. Another part of the 2019 study measured floral VOCs for six species in a dry meadow also studied in 2017 and 2018 to address the consistency of emission of VOCs across three years differing in environmental conditions including date of snowmelt. The total emission of volatiles by flowers of I. aggregata did not correlate detectably with the production of nectar. In the dry meadow experiment, the composition of volatile emissions changed significantly across the three years, particularly for Galium boreale in the late snowmelt year of 2019.

Pollen and vegetative secondary chemistry of three pollen-rewarding lupines - Jacob M. Heiling; Daniel Cook; Stephen T. Lee; R. E. Irwin (American Journal of Botany, 2019)
Our results are consistent with the hypothesis that, in these pollen-rewarding species, pollen secondary chemistry may reflect the need to attract and reward pollinators more than the need to defend pollen from herbivory.

Social security: less socially connected marmots produce noisier alarm calls - H. Fuong; Daniel T. Blumstein (Animal Behaviour, 2019)
The nonlinearity and fear hypothesis predicts that the structure of alarm vocalizations will be influenced by the signaller's internal state. Specifically, stressed or otherwise more aroused individuals will produce alarm calls that are relatively more nonlinear (i.e. they sound noisier). The position of an individual in a social network can influence an individual's sense of security. More centrally located individuals may feel more secure and thus we might expect that they would produce noisier calls. Building on previous research about the influence of social relationships on an individual's sense of security, we asked whether social network position explained variation in the noisiness (quantified as Wiener entropy) and goodness of pitch of alarm calls produced by trapped yellow-bellied marmots, Marmota flaviventer. More socially isolated individuals, characterized by lower instrength, produced alarm calls with higher entropy and higher goodness of pitch. These isolated individuals

Early snowmelt projected to cause population decline in a subalpine plant - Diane R. Campbell (PNAS, 2019)
How climate change influences the dynamics of plant populations is not well understood, as few plant studies have measured responses of vital rates to climatic variables and modeled the impact on population growth. The present study used 25 y of demographic data to analyze how survival, growth, and fecundity respond to date of spring snowmelt for a subalpine plant. Fecundity was estimated by seed production (over 15 y) and also divided into flower number, fruit set, seeds per fruit, and escape from seed predation. Despite no apparent effects on flower number, plants produced more seeds in years with later snowmelt. Survival and probability of flowering were reduced by early snowmelt in the previous year. Based on demographic models, earlier snowmelt with warming is expected to lead to negative population growth, driven especially by changes in seedling establishment and seed production. These results provide a rare example of how climate change is expected to influence the dynamics of

Mixed support for state maintaining risky personality traits in yellow-bellied marmots - M. B. Petelle; J. G. A. Martin; Daniel T. Blumstein (Animal Behaviour, 2019)
In a variety of taxa, individuals behave in consistently different ways. However, there are relatively few studies that empirically test the potential mechanisms underlying the causes and maintenance of these personality differences. Several hypotheses for the causes and maintenance of risky personality traits have been suggested but all have received mixed support. Both the pace-of-life hypothesis and state-dependent safety hypothesis propose that differences in internal state cause and maintain personality traits. Formally, the pace-of-life hypothesis states that differences in life-history traits including productivity (growth) and residual reproductive value (age) create initial differences in individual behaviour that is later maintained by positive feedback, while the state-dependent safety hypothesis suggests that body condition (mass) is responsible for causing and maintaining behavioural differences. We tested and evaluated whether either of these two hypotheses explained the

Elevational cline in herbivore abundance driven by a monotonic increase in trophic level sensitivity to aridity - A. S. Nelson; Cole T. Symanski; Matthew J. Hecking; K. A. Mooney (Journal of Animal Ecology, 2019)
The abiotic environment drives species abundances and distributions both directly and indirectly through effects on multi-trophic species interactions. However, few studies have documented the individual and combined consequences of these direct and indirect effects. We studied an ant-tended aphid along an elevational gradient, where lower elevations were more arid. Hypotheses of stronger species interactions at lower elevations and a greater sensitivity of higher trophic levels to climate led us to predict increased top-down control of aphids by natural enemies (third trophic level) but even stronger protection from mutualist ants (fourth trophic level) with increasing aridity. As a result, we predicted that mutualism strength and aphid abundance would increase with aridity. We documented patterns of aphid abundance and tested for both the direct and multi-trophic indirect effects of aridity on aphid performance. To do so, we used both observational and manipulative methods across two

Abiotic and biotic factors influencing western United States coniferous forests - Bradley M. Lalande; Stewart, Jane; Stromberger, Mary; Tinkham, Wade; Trivedi, Pankaj (Digital Collections of Colorado (Colorado State University), 2019)
In the next decade, climate models suggest that global temperatures will continue to rise. In the western United States, increases in temperatures and changes in precipitation patterns will escalate the risk of drought conditions. These potentially warmer, drier conditions could induce physiological changes within trees, subsequently increasing stress on coniferous forests that are adapted to cool, wet environments. The abiotic stress accompanied by drought conditions can predispose susceptible hosts to biotic stress of insect and disease populations. In particular, high elevation subalpine fir (Abies lasiocarpa) have encountered higher than average mortality rates throughout the western United States in association with abiotic and biotic agents. Chapter 2 of this thesis investigated the potential drivers of subalpine fir mortality and determined how climatic factors and site and stand characteristics influenced the presence of mortality and biotic agents. The objectives were to ident

Progressive sensitivity of trophic levels to warming underlies an elevational gradient in ant–aphid mutualism strength - A. S. Nelson; J. R. Pratt; J. R. Pratt; R. J. Smith; Cole T. Symanski; Cathrine Prenot; K. A. Mooney (Oikos, 2019)
Although species interactions are often proposed to be stronger at lower latitudes and elevations, few studies have evaluated the mechanisms driving such patterns. In this study, we assessed whether, and by which mechanisms, abiotic changes associated with elevation altered the outcome of an ant–aphid protection mutualism. To do so, we characterized the multi‐trophic interactions among the ant Formica podzolica , the aphid Aphis varians , and aphid natural enemies occurring on the plant Chamerion angustifolium within replicate high and low elevation valleys. Low (versus high) elevation sites had longer summers (snowmelt 13 days earlier) and were on average 1.1°C warmer and 41% drier throughout the year. At low elevations, individual ant colonies consumed approximately double the volume of carbohydrate baits, likely due to a higher foraging tempo, and possibly due to a greater demand for sugar‐ versus protein‐rich resources (as indicated by stable isotope analysis). Wild aphid colonies

Sensitivity analysis of hydraulic conductivity and Manning’s n parameters lead to new method to scale effective hydraulic conductivity across model resolutions. - R. M. Maxwell; L. M. Foster (Hydrological Processes, 2019)
Hydrological modeling is an important tool for research, policy, and management, but uncertainty remains about parameters transferability from field observations made at small scale to models at the catchment scale and larger. This uncertainty compels the need to develop parameter relationships that are translatable across scale. In this study we compare the changes to modeled processes as resolution is coarsened from 100m to 1km in a topographically-complex, 255km2 Colorado River headwater catchment. We conducted a sensitivity analysis for hydraulic conductivity (K) and Manning’s n parameters across 4 orders of magnitude. Results showed that K acts as a moderator between surface and subsurface contributions to streamflow, while n moderates the duration of high intensity, infiltration-excess flow. The parametric sensitivity analysis informed development of a new method to scale effective hydraulic conductivity across modeling resolutions in order to compensate for the loss of topograph

The Personhood of the Therapist: Effect on Systems - Virginia Satir (2019)
EDITOR’S NOTE. In the following excerpts from the beginning of Virginia Satir’s first Process Community (Avanta Process Community I, Crested Butte, Colorado, August 1981), and some of her writings, we can see the reason for this theme on personhood. It was Virginia’s conviction that therapy actually revolves around personhood-the use of the essential self of the therapist for change in couples, the model for couples to learn to engage, authentic self to authentic self.

Streamflow partitioning and transit time distribution in snow-dominated basins as a function of climate - Z. Fang; R. W. H. Carroll; Rina Schumer; C. Harman; D. Wilusz; K. H. Williams (Journal of Hydrology, 2019)
Abstract Snowmelt is the principal control on the timing and magnitude of water flow through mountainous watersheds. The effects of precipitation type and quantity on storage and hydrologic connectivity in mountainous systems were explored by combining the observed stable isotope δ18O in rain, snow, snowmelt, and streamflow with numerically simulated hydrologic boundary fluxes and inverse techniques applied to transient travel time distributions (TTD) using StorAge Selection (SAS) functions. Hydrologic simulations of the East River (ER, 85 km2), a snow-dominated Colorado River headwater basin, for water years 2006–2017 were used to test a diverse set of snow accumulation scenarios. During the snowmelt period, the ER released younger water during high storage periods across seasonal and annual timescales (an “inverse storage effect”). Additionally, more young water was released from storage during wet years than during dry years. However, wet years also appeared to increase hydrologic c

From Grain to Floodplain: Evaluating heterogeneity of floodplain hydrostatigraphy using sedimentology, geophysics, and remote sensing. - H. F. Malenda; Nicholas Sutfin; G. Guryan; Sophie Stauffer; J. C. Rowland; K. H. Williams; K. Singha (Earth Surface Processes and Landforms, 2019)
AbstractStratigraphy is a fundamental component of floodplain heterogeneity and hydraulic conductivity and connectivity of alluvial aquifers, which affect hydrologic processes such as groundwater flow and hyporheic exchange. Watershed‐scale hydrological models commonly simplify the sedimentology and stratigraphy of floodplains, neglecting natural floodplain heterogeneity and anisotropy. This study, conducted in the upper reach of the East River in the East River Basin, Colorado, USA, combines point‐, meander‐, and floodplain‐scale data to determine key features of alluvial aquifers important for estimating hydrologic processes. We compare stratigraphy of two meanders with disparate geometries to explore floodplain heterogeneity and connectivity controls on flow and transport. Meander shape, orientation, and internal stratigraphy affected residence time estimates of laterally exchanged hyporheic water. Although the two meanders share a sediment source, vegetation, and climate, their div

Soil microbes that may accompany climate warming increase alpine plant production - J. S. Lynn; D. A. Duarte; Jennifer A. Rudgers (Oecologia, 2019)
Climate change is causing species with non-overlapping ranges to come in contact, and a key challenge is to predict the consequences of such species re-shuffling. Experiments on plants have focused largely on novel competitive interactions; other species interactions, such as plant–microbe symbioses, while less studied, may also influence plant responses to climate change. In this greenhouse study, we evaluated interactions between soil microbes and alpine-restricted plant spe- cies, simulating a warming scenario in which low-elevation microbes migrate upslope into the distribution of alpine plants. We examined three alpine grasses from the Rocky Mountains, CO, USA (Poa alpina, Festuca brachyphylla, and Elymus scribneri). We used soil inocula from within (resident) or below (novel) the plants’ current elevation range and examined responses in plant biomass, plant traits, and fungal colonization of roots. Resident soil inocula from the species’ home range decreased biomass to a greater

The impact of climate change on Rocky Mountain plant communities: Differences in floral trait along an elevational gradient of transplanted communities - L. DuFresne (2019)
Alpine climates are seemingly adverse environments for plants. These habitats directly impact plants via pollinator scarcity and abiotic factors like extreme temperatures and precipitation that influence resource allocation. As a result, elevational gradients are natural laboratories that can be used to examine how climate shapes plant form, function, and diversity. The aim of this project is to assess the effects of temperature and snowmelt date on the floral traits and reproductive phenology of experimental transplanted communities along an elevational gradient. Traits measured in this study were flower length, diameter, petal length, and height of the highest flower; phenology stages recorded were bud, flower, withered petals, and fruiting. Data collection occurred along three subalpine meadow sites off of Washington Gulch Road in Crested Butte, CO, each of which contains transplanted turfs from higher/lower on the mountain as well as both transplanted and untouched control plots. C

Predator and prey species have opposing responses to recreational trail use - A. Escamilla (2019)
While many ecological studies have investigated the impacts of recreation and trails on wildlife, we lack an understanding of how wildlife respond to recreational trails that exhibit seasonally dynamic levels of human activity. We used camera traps to assess changes in the presence of mammals along a recreational trail before and during the summer tourism season in Crested Butte, CO. We used linear mixed-effects regression models to explain variation in the ungulate and carnivore detection rates as a function of whether the cameras were on or off a trail, on an established versus proposed trail, and how these interacted with the presence of dogs, humans, and for ungulates, carnivores. We controlled for the potentially confounding effects of distance from trailhead and controlled for detectability by quantifying the proportion of each camera’s detection area that was covered with trees using ArcMap. We found that deer and elk detection rates were higher in July and in the current trail

The Direct and Interactive Effects of Warming and Species Interaction on Plant Functional Traits - K. Rand (2019)
Global climate change is a threat that continues to affect nearly every ecosystem on the planet through warmer temperatures, changes in precipitation patterns, and many other manifestations of a warmer world. Warming directly and indirectly affects plants and ecosystem functioning. In the natural world, both the direct and indirect effects of warming impact plant communities and the ecosystem functions simultaneously. Here, we conducted an experiment to determine how the direct and indirect effects of warming impacts plant functional traits in an alpine ecosystem. We leveraged an existing warming experiment in the Upper Gunnison Valley Basin in Colorado, USA. The ongoing 6-year study elevates plot temperatures using open-top warming chambers and manipulates species composition by removing the dominant plant species at a high and low elevation to evaluate the direct and indirect effects of warming on ecosystem structure and function. We sampled plant species from within the plots to ans

Observing pollinator trait variation in relation to niche breadth in seasons of high and low precipitation - B. Davis (2019)
Interactions between plants and pollinators are complex and a change to one can cause a significant impact on the other. Environmental perturbations like drought can alter plant- pollinator systems, changing the relative abundance of flower species, shifting species distribution, and decreasing floral resources. As a result of these drought-induced changes, pollinators, particularly insect pollinators, may be forced to change their foraging behavior. Pollinators’ foraging behavior is greatly defined by their niche breadth, which is the set of flower species that they can and will visit. A niche breadth is influenced by multiple factors such as the phenology of flowers, geography, and both the morphology of flowers and pollinators. Pollination events are more likely to occur if the morphological traits of the pollinator and the flower “match” in such a way as to make the interaction most efficient and beneficial for both partners: the pollinator needs to be able to reach nectar and the

Effects of weather and floral density on foraging activity of cavity nesting bees ( Osmia spp.) - I. Rivera; Jessica R. K. Forrest; Lydia H. Wong (2019)
Thermoregulation is an important factor for bee flight which ultimately contributes to an individual’s ability to forage and produce offspring. Rising temperatures could benefit insects by increasing their efficiency in reproduction and provisioning. However, warming could negatively impact floral resources, thereby indirectly affecting foraging and reproductive success in specialist bees negatively. In this study I investigated the effects of weather variation and floral density on individual foraging rate in subalpine populations of the solitary bee species ​Osmia iridis and Osmia coloradensis​ on individual foraging rate. I examined how temperature, percent cloud coverage and floral density affected the foraging rates and provisioning efficiency. Foraging rate did not increase with rising temperatures nor with increased floral densities. However, increased cloud coverage did decrease the foraging rates of bees, as expected. The results suggest that temperature, cloud coverage, and h

Impacts of the invasive species Linaria vulgaris on soil ecology and native plant biodiversity - F. Shirley (2019)
Invasive species are a major threat to biodiversity. Invasive plant species can alter ecosystems by outcompeting natives, lowering biodiversity, and change soil ecology. Additionally, invasive species can be costly to manage. Linaria vulgaris, a non-native noxious weed from Europe and Asia, was used as a study organism to better understand how invasive plant species impact biodiversity and soil ecology. I hypothesized that Linaria vulgaris would lower native plant biodiversity and increase litter and total nitrogen levels in invaded areas. However, there was no significant difference found between plots with L. vulgaris present or absent or with plots where L. vulgaris has been experimentally pulled for 19 years. Additionally, I hypothesized that the soil ecology was negatively affecting L. vulgaris growth. However, a potted-plant experiment found no significant difference in the growth of L. vulgaris between soils where it was locally abundant vs. declining. Taken together, these resu

Trap behavior of Zonotrichia leucophrys oriantha at different elevations in the West Elk Mountains, Colorado - E. Wieser (2019)
High-alpine ecosystems are particularly vulnerable to climate change. Thus, many ecosystem patterns are shifting due to warming temperatures, extreme weather events, and seasonal changes. This becomes an issue for birds that breed and live in high-elevation environments, as they may not be able to co-adapt quick enough to rapid shifts in mountain conditions and habitat. Zonotrichia leucophrys oriantha or the Mountain White-Crowned Sparrow (henceforth called: oriantha) is a native, migratory species that resides in Gunnison County, CO, USA. Oriantha can serve as a model species because it lives and breeds across an elevational range, allowing for life-history differences in the population to be observed. Our hypothesis states that if there are variations in life-history traits along an elevational gradient, than trap-behavior will also show variation. Within this study, our aim was to determine whether there were differences in oriantha behavior across elevation by gauging the level of

Seasonal manganese transport in the hyporheic zone of a snowmelt-dominated river (East River, Colorado) - S. R. Bryant (2019)
Manganese (Mn) plays a critical role in river water quality since Mn-oxides serve as

Pollinator mediated reproductive consequences of altered co-flowering under climate change depend on abiotic context - M. Faust (2019)
Pollinator mediated reproductive consequences of altered co-flowering under climate change depend on abiotic context

The function of floral orientation in bluebells: interactions with pollinators and rain in two species of Mertensia (Boraginaceae) - S. Y. Lin; J. R. K. Forrest (Journal of Plant Ecology, 2019)
Aims Important Findings Pollinators are traditionally considered to be the primary agent of Mertensia brevistyla had a significantly more upright floral orienta- selection on floral traits. However, floral traits may also be under tion than M. fusiformis, and seed set was highest in upright M. bre- selection from abiotic agents (e.g. rain), which makes considering vistyla and in horizontal/pendant M. fusiformis stems, supporting an the relative importance of pollinators and abiotic selective agents adaptive function (via female fitness) of the interspecific difference on floral traits essential. The functional significance of floral orien- in orientation. However, floral visitor assemblages did not differ tation is often ascribed to pollinator attraction, but orientation can significantly between the two species; visitors did not exhibit sig- also protect reproductive structures from rain. Therefore, a study nificant preference for either orientation; and pollinator-mediated that incor

Análisis geomorfológico y paleoambiental de la depresión tectónica de Ullum-Zonda, Provincia de San Juan - Pablo Blanc (Conicet, 2019)
El objetivo de la presente tesis doctoral es evaluar la evolución geomorfológica del valle de Ullum-Zonda y las condiciones paleoambientales que prevalecieron en esta depresión durante el Cuaternario tardío. Para ello, se efectuó un análisis geomorfológico, morfotectónico y neotectónico de este valle y de dos grandes cuencas fluviales asociadas que forman parte de la misma depresión tectónica: las cuencas de los ríos de La Travesía y La Ciénaga. Se realizó, además, un análisis litofacial y geocronológico en diversos afloramientos de la Formación Valentín, con el fin de determinar el ambiente sedimentario en que se formó esta unidad. El valle de Ullum-Zonda, situado en la Precordillera de los Andes Centrales de Argentina es una depresión tectónica ubicada en el sector centro-sur de la Provincia de San Juan, en la República Argentina, a unos 20 km al oeste de la ciudad capital de San Juan. Constituye una depresión intermontana de fondo plano, elongada en sentido norte-sur con una extensi

Adaptation and diversification of bluebells Mertensia spp., Boranginaceae - S. Y. Lin (2019)
Flowering phenology marks the transition from vegetative growth to reproduction and exposes plants to seasonally varying selective environments during flowering. Life-history trade- offs between time and size at reproduction suggest that early-flowering species should generally be smaller than late-flowering species. Furthermore, consistent seasonal variation in environmental conditions may generate seasonally varying selection on morphological traits (such as vegetative size and floral traits), potentially causing correlations between morphological traits and flowering phenology. Similarly, trait correlations may be driven by multiple traits responding in parallel to environmental gradients; for example, low air temperature and high wind velocity in high-altitude habitats might favour smaller species that also flower rapidly after snowmelt. To assess interspecific correlations between flowering phenology and other traits, I focused on 12 species of Mertensia (Boraginaceae) that have s

Floral reward strategies, visitor behavior, and plant reproductive outcomes - Jacob M. Heiling (2019)
Many plants that bear hidden or recessed floral nectar experience nectar robbing, the removal of nectar by a floral visitor through holes pierced in the corolla. Although robbing can reduce plant reproductive success, many studies fail to find such effects. We outline three mechanistic hypotheses that can explain when interactions between plants and nectar-robbers should be commensal rather than antagonistic: the non-discrimination (pollinators do not avoid robbed flowers), visitor prevalence (robber visitation is rare relative to pollinator visitation), and pollen saturation (stigmas receive sufficient pollen to fertilize all ovules with one or very few pollinator visits) hypotheses. We then explore these mechanisms in the North American subalpine, bumble bee-pollinated and nectar-robbed plant Corydalis caseana (Fumariaceae). We first confirmed that the effects of nectar robbing on female reproductive success were neutral in C. caseana. We then tested the three mechanisms underlying t

King of the hill? How biotic interactions affect biogeographical pattern and species responses to climate change - J. S. Lynn (2019)
As climate has warmed, many species have moved up mountains as physiological limits to their distributions have ameliorated. These distribution shifts are creating novel communities, begging the question: What happens to species at the tops of mountains as potential antagonists encroach upwards? Theory predicts that upward migrations will cause range contractions for high-elevation species because of novel interactions with encroaching antagonists. My dissertation work is one of the most comprehensive tests of this question to date, using a combination of ecological niche modeling (ENM), experiments, and demographic and trait-based modeling approaches. I created novel ENMs that suggest context-dependency of biotic interactions, where predictions of biotic interactions change from positive to negative over environmental gradients, is common over elevation gradients. Additionally, ENMs suggested the current focus on plant-plant interactions in niche modeling targets the most important bi

The persistent maladaptation of Pieris macdunnoughii: Constraints on adaptation to an evolutionary trap - Rachel A Steward (2019)
Evolutionary traps arise when organisms use novel, low-quality or even lethal resources based on previously reliable cues. Persistence of such maladaptive interactions depends not only on how individuals locate important resources, such as host plants, but also the mechanisms underlying poor performance. Pieris macdunnoughii (Remington) (Lepidoptera: Pieridae) lays eggs on a non-native mustard, Thlaspi arvense (L.) (Brassicaceae), which is lethal to its larvae. However, in the 150 years since T. arvense invaded this butterfly continues to recognize and oviposit on the invasive mustard. I evaluated two possible constraints on the evolution of decreased preference within an invaded population. First, an evolutionary response to selection may be constrained by low heritable genetic variation for preference. Second, evolutionary traps are expected to persist when overlapping cue sets (cue similarity) link decreased preference for the novel, unsuitable plant with decreased preference for th

Predicting sedimentary bedrock subsurface weathering fronts and weathering rates - Jiamin Wan; Tetsu Tokunaga; K. H. Williams; Wenming Dong; W. Brown; A. N. Henderson; Alexander W. Newman; S. S. Hubbard (Scientific Reports, 2019)
AbstractAlthough bedrock weathering strongly influences water quality and global carbon and nitrogen budgets, the weathering depths and rates within subsurface are not well understood nor predictable. Determination of both porewater chemistry and subsurface water flow are needed in order to develop more complete understanding and obtain weathering rates. In a long-term field study, we applied a multiphase approach along a mountainous watershed hillslope transect underlain by marine shale. Here we report three findings. First, the deepest extent of the water table determines the weathering front, and the range of annually water table oscillations determines the thickness of the weathering zone. Below the lowest water table, permanently water-saturated bedrock remains reducing, preventing deeper pyrite oxidation. Secondly, carbonate minerals and potentially rock organic matter share the same weathering front depth with pyrite, contrary to models where weathering fronts are stratified. Th

Challenges in Building an End-to-End System for Acquisition, Management, and Integration of Diverse Data From Sensor Networks in Watersheds: Lessons From a Mountainous Community Observatory in East River, Colorado - Charuleka Varadharajan; Deb Agarwal; W. Brown; Madison Burrus; R. W. H. Carroll; D. S. Christianson; Baptiste Dafflon; Dipankar Dwivedi; Brian J. Enquist; Boris Faybishenko; A. N. Henderson; A. N. Henderson; et al. (IEEE Access, 2019)
The U.S. Department of Energy's Watershed Function Scientific Focus Area (SFA), centered in the East River, Colorado, generates diverse datasets including hydrological, geological, geochemical, geophysical, ecological, microbiological and remote sensing data. The project has deployed extensive field infrastructure involving hundreds of sensors that measure highly diverse phenomena (e.g. stream and groundwater hydrology, water quality, soil moisture, weather) across the watershed. Data from the sensor network are telemetered and automatically ingested into a queryable database. The data are subsequently quality checked, integrated with the United States Geological Survey's stream monitoring network using a custom data integration broker, and published to a portal with interactive visualizations. The resulting data products are used in a variety of scientific modeling and analytical efforts. This paper describes the SFA's end-to-end infrastructure and services that support the generation

Mayflies avoid sweets: fish skin mucus amino sugars stimulate predator avoidance behaviour of Baetis larvae - A. Landeira-Dabarca; M. Alvarez; B. L. Peckarsky (Animal Behaviour, 2019)
Nonconsumptive effects of predators can have knock-on effects on prey fitness, life history and population dynamics. However, the origin of cues stimulating predator avoidance behaviour and the mechanisms underlying prey responses need further investigation. Previous studies revealed that nonconsumptive effects of predatory fish on Baetis mayfly larvae are mediated by water-borne chemical cues released from fish mucus. However, there are conflicting results regarding the nature of these cues and the specific role of the activity of fish mucus-dwelling bacteria in stimulating predator avoidance by prey. To address those conflicting results, we investigated whether bacteria dwelling in fish mucus and/or chemical components present in fish mucus are responsible for the predator avoidance response by Baetis mayflies to salmonids. Results of five bioassays conducted in microcosms revealed that to stimulate Baetis predator avoidance behaviour: (1) bacteria do not need to be present in salmon

Assessment of Spatiotemporal Variability of Evapotranspiration and Its Governing Factors in a Mountainous Watershed - Anh Phuong Tran; J. Rungee; Boris Faybishenko; Baptiste Dafflon; S. S. Hubbard (Water, 2019)
Evapotranspiration (ET) is a key component of the water balance, which influences hydrometeorology, water resources, carbon and other biogeochemical cycles, and ecosystem diversity. This study aims to investigate the spatio-temporal variations of ET at the East River watershed in Colorado and analyze the factors that control these variations. ET was acquired using the community land model (CLM) simulations and was compared with the values estimated using Fu’s equation and a watershed-scale water balance equation. The simulation results showed that 55% of annual precipitation in the East River is lost to ET, in which 75% of the ET comes from the summer months (May to September). We also found that the contribution of transpiration to the total ET was \ 50%, which is much larger than that of soil evaporation (32%) and canopy evaporation (18%). Spatial analysis indicated that the ET is greater at elevations of 2950–3200 m and lower along the river valley (<2750 m) and at the high elevat

Depth- and time-resolved distributions of snowmelt-driven hillslope subsurface flow and transport and their contributions to surface waters. - Tetsu Tokunaga; Jiamin Wan; K. H. Williams; W. Brown; A. N. Henderson; Yeonju Kim; Markus Bill; R. W. H. Carroll; Wenming Dong; Benjamin Gilbert; Boris Faybishenko; S. S. Hubbard (Water Resources Research, 2019)
AbstractMajor components of hydrologic and elemental cycles reside underground, where their complex dynamics and linkages to surface waters are obscure. We delineated seasonal subsurface flow and transport dynamics along a hillslope in the Rocky Mountains (USA), where precipitation occurs primarily as winter snow and drainage discharges into the East River, a tributary of the Gunnison River. Hydraulic and geochemical measurements down to 10 m below ground surface supported application of transmissivity feedback of snowmelt to describe subsurface flow and transport through three zones: soil, weathering shale, and saturated fractured shale. Groundwater flow is predicted to depths of at least 176 m, although a shallower limit exists if hillslope‐scale hydraulic conductivities are higher than our local measurements. Snowmelt during the high snowpack water year 2017 sustained flow along the weathering zone and downslope within the soil, while negligible downslope flow occurred along the soi

Water in the West : perspectives from an Upper Basin tributary of the Colorado River - Tait James Andersen (BIBSYS Brage (BIBSYS (Norway)), 2018)
This thesis explores two institutional frameworks utilized in the governance of water in the Southwest of the United States through how they deliver, or fail to deliver, complex equity. These are (1) the legal framework and (2) cooperative agreements. This is done through a case study in the Roaring Fork River watershed, a major Upper Basin tributary to the Colorado River, by evaluating how stakeholders and different values of water are recognized and included in decision-making arenas. Stakeholders in the watershed can be positioned into three main groups: (1) agriculturalists, (2) municipalities and (3) environmentalists and recreationalists. I argue that neither institutional framework currently delivers complex equity and that achieving such equity will require changes in the legal framework because cooperative agreements do not tackle the core issues of property rights and compensation and thus, cannot effectively operate outside the legal framework.

Using ecological stoichiometry to understand and predict infectious diseases - A. J. Sanders; B. W. Taylor (Oikos, 2018)
A key characteristic of host–parasite interactions is the theft of host nutrients by the parasite, yet we lack a general framework for understanding and predicting the interplay of host and parasite nutrition that applies across biological levels of organization. The elemental nutrients (C, N, P, Fe, etc.), and ecological stoichiometry provide a framework for understanding host–parasite interactions and their relation to ecosystem functioning. Here we use the ecological stoichiometry framework to develop hypotheses and predictions regarding the relationship between elemental nutrients and host–parasite interactions. We predict that a suite of host and parasite traits, stoichiometric homeostasis, host diet stoichiometry, and biogeochemical cycling are related to disease dynamics, host immunity and resistance, and bacterial growth form determination. We show that ecological stoichiometry is capable of expanding our understanding of host–parasite interactions, and complementing other appr

Why are some plant-nectar robber interactions commensalisms? - Jacob M. Heiling; Trevor Ledbetter; S. K. Richman; Heather Ellison; J. L. Bronstein; R. E. Irwin (Oikos, 2018)
Many plants that bear hidden or recessed floral nectar experience nectar robbing, the removal of nectar by a floral visitor through holes pierced in the corolla. Although robbing can reduce plant reproductive success, many studies fail to find such effects. We outline three mechanistic hypotheses that can explain when interactions between plants and nectar‐robbers should be commensal rather than antagonistic: the non‐discrimination (pollinators do not avoid robbed flowers), visitor prevalence (robber visitation is rare relative to pollinator visitation), and pollen saturation (stigmas receive sufficient pollen to fertilize all ovules with one or very few pollinator visits) hypotheses. We then explore these mechanisms in the North American subalpine, bumble bee‐pollinated and nectar‐robbed plant Corydalis caseana (Fumariaceae). We first confirmed that the effects of nectar robbing on female reproductive success were neutral in

High interspecific variation in nutrient excretion within a guild of closely related caddisfly species - J. A. Balik; B. W. Taylor; Washko S. E.; S. A. Wissinger (Ecosphere, 2018)
AbstractUnderstanding the amount of variation in functional traits between closely related species within guilds is critical for understanding links between community composition and ecosystem processes. Nutrient excretion is an important link between animals and their environments, and aquatic invertebrate communities can supply a considerable proportion of ecosystem nutrient demand via excretion. We quantified nitrogen (N) and phosphorus (P) excretion rates of 10 species of larval caddisflies that inhabit high‐elevation ponds and wetlands to determine the magnitude of variation in nutrient excretion within this guild. We found considerable interspecific variation in biomass‐specific excretion of nitrogen (eightfold differences), phosphorus (sevenfold differences), and the stoichiometric N:P ratios (fivefold differences). Through a meta‐analysis, we compared the variation within this guild to the variation found in other family‐level species assemblages to determine the overall range

Age, state, environment and season dependence of senescence in body mass - Svenja B. Kroeger; Daniel T. Blumstein; Kenneth B. Armitage; Jane M. Reid; J. G. A. Martin (Ecology and Evolution, 2018)
AbstractSenescence is a highly variable process that comprises both age‐dependent and state‐dependent components and can be greatly affected by environmental conditions. However, few studies have quantified the magnitude of age‐dependent and state‐dependent senescence in key life‐history traits across individuals inhabiting different spatially structured and seasonal environments. We used longitudinal data from wild female yellow‐bellied marmots (Marmota flaviventer), living in two adjacent environments that differ in elevation and associated phenology, to quantify how age and individual state, measured as “time to death,” affect body mass senescence in different environments. Further, we quantified how patterns of senescence differed between two biologically distinct seasons, spring, and late summer. Body mass senescence had an age‐dependent component, expressed as a decrease in mass in old age. Overall, estimated age‐dependent senescence was greater in females living in the more favo

Factors Controlling Seasonal Groundwater and Solute Flux from Snow-Dominated Basins - R. W. H. Carroll; L. A. Bearup; W. Brown; Wenming Dong; Markus Bill; K. H. Williams (Hydrological Processes, 2018)
AbstractCritical zone influences on hydrologic partitioning, subsurface flow paths and reactions along these flow paths dictate the timing and magnitude of groundwater and solute flux to streams. To isolate first‐order controls on seasonal streamflow generation within highly heterogeneous, snow‐dominated basins of the Colorado River, we employ a multivariate statistical approach of end‐member mixing analysis using a suite of daily chemical and isotopic observations. Mixing models are developed across 11 nested basins (0.4 to 85 km2) spanning a gradient of climatological, physical, and geological characteristics. Hydrograph separation using rain, snow, and groundwater as end‐members indicates that seasonal contributions of groundwater to streams is significant. Mean annual groundwater flux ranges from 12% to 33% whereas maximum groundwater contributions of 17% to 50% occur during baseflow. The direct relationship between snow water equivalent and groundwater flux to streams is scale dep

Short-term, low-level nitrogen deposition dampens a trophic cascade between bears and plants - J. B. Grinath (Ecology and Evolution, 2018)
AbstractHuman activities have substantially increased atmospheric nitrogen (N) deposition in ecosystems worldwide, often leading to higher plant quality for herbivores and greater herbivory. Predators frequently suppress herbivores and indirectly benefit plants via “trophic cascades”, and the strength of these interactions can also depend on N availability. However, the evidence for N deposition effects on cascades primarily comes from studies of high‐level N deposition. Most terrestrial ecosystems currently receive elevated, but low‐level N deposition, and it is unclear whether this subtle N enrichment has any effect on cascades. Here, I asked whether low‐level N deposition alters a trophic cascade from black bears to plants in Colorado. In this ecological network, bears indirectly benefit plants by consuming ants and suppressing positive effects of ants on herbivores. Using a three year N enrichment experiment, I assessed changes in this cascade by measuring plant and arthropod respo

A molecular investigation of soil organic carbon composition across a subalpine catchment - H. T. Hsu; C. R. Lawrence; M. J. Winnick; John R. Bargar; Katharine Maher (Soil Systems, 2018)
The dynamics of soil organic carbon (SOC) storage and turnover are a critical component of the global carbon cycle. Mechanistic models seeking to represent these complex dynamics require detailed SOC compositions, which are currently difficult to characterize quantitatively. Here, we address this challenge by using a novel approach that combines Fourier transform infrared spectroscopy (FT-IR) and bulk carbon X-ray absorption spectroscopy (XAS) to determine the abundance of SOC functional groups, using elemental analysis (EA) to constrain the total amount of SOC. We used this SOC functional group abundance (SOC-fga) method to compare variability in SOC compositions as a function of depth across a subalpine watershed (East River, Colorado, USA) and found a large degree of variability in SOC functional group abundances between sites at different elevations. Soils at a lower elevation are predominantly composed of polysaccharides, while soils at a higher elevation have more substantial por

The East River, Colorado, Watershed: A mountainous community testbed for improving predictive understanding of multiscale hydrological-biogeochemical dynamics - S. S. Hubbard; K. H. Williams; Deb Agarwal; Jillian F. Banfield; Harry Beller; Nicholas J. Bouskill; E. L. Brodie; R. W. H. Carroll; Baptiste Dafflon; Dipankar Dwivedi; Nicola Falco; Boris Faybishenko; et al. (Vadose Zone Journal, 2018)
Core Ideas Development of a 300‐km 2 mountainous headwater testbed began in 2016 in the East River. The testbed can be used to explore how watershed changes impact downgradient water availability and quality. System‐of‐system, scale‐adaptive approaches can potentially improve watershed dynamics simulation. We have new approaches to monitor and simulate water partitioning and system responses. The East River watershed has been developed as a “community” testbed. Extreme weather, fires, and land use and climate change are significantly reshaping interactions within watersheds throughout the world. Although hydrological–biogeochemical interactions within watersheds can impact many services valued by society, uncertainty associated with predicting hydrology‐driven biogeochemical watershed dynamics remains high. With an aim to reduce this uncertainty, an approximately 300‐km 2 mountainous headwater observatory has been developed at the East River, CO, watershed of the Upper Colorado River B

Plant dominance in a subalpine montane meadow: biotic vs. abiotic controls of subordinate diversity within and across sites - E. LaPlante; L.A. Souza (PeerJ, 2018)
Background. Understanding the underlying factors that determine the relative abun- dance of plant species is critical to predict both biodiversity and ecosystem function. Biotic and abiotic factors can shape the distribution and the relative abundance of species across natural communities, greatly influencing local biodiversity.

Costs and benefits of alternative food handling tactics help explain facultative exploitation of pollination mutualisms - E. M. Lichtenberg; R. E. Irwin; J. L. Bronstein (Ecological Society of America, 2018)
AbstractMany mutualisms are taken advantage of by organisms that take rewards from their partners but provide no benefit in return. In the absence of traits that limit exploitation, facultative exploiters (partners that can either exploit or cooperate) are widely predicted by mutualism theory to choose an exploitative strategy, potentially threatening mutualism stability. However, it is unknown whether facultative exploiters choose to exploit, and, if so, make this choice because it is the most beneficial strategy for them. We explored these questions in a subalpine plant‐insect community in which individuals of several bumble bee species visit flowers both “legitimately” (entering via the flower opening, picking up and depositing pollen, and hence behaving mutualistically) and via nectar robbing (creating holes through corollas or using an existing hole, bypassing stigmas and anthers). We applied foraging theory to (1) quantify handling costs, benefits and foraging efficiencies incurr

Chemotypic variation in oshá (Ligusticum porteri) in Colorado, USA - B. Smith; L. Lowe; J. Owens; E. H. Mooney (J Appl. Res. Med. Aromat. Plants, 2018)
Abstract Ligusticum porteri (osha) is an important wild-harvested medicinal plant. Populations of this plant occur in meadows and forest understories in the subalpine and montane zones of the Rocky Mountains. We examined variation in the bioactive compounds of 44 methanolic extracts of L. porteri roots harvested from eleven populations in Colorado, USA during 2012 and 2015. Populations were found in two distinct regions of Colorado, the Front Range and Western Slope. We also classified population light environment as either meadow or understory based on the mean percent of full-sun photosynthetically active radiation above plants. We used high performance liquid chromatography (HPLC) to quantify variation in five secondary metabolites: Z-ligustilide, trans-ferulic acid, (Z/E)-3-butylidenephthalide, isovanillin and elemicin. Variation between sampling years was found for trans-ferulic acid, elemicin and (E)-3-butylidenephthalide. Root extracts from the Front Range had more than double t

Multiple models and experiments underscore large uncertainty in soil carbon dynamics - B. N. Sulman; J. Moore; R. Abramoff; C. Averill; Stephanie N. Kivlin; Gates, Timothy K.; B. Sridhar; M. D. Hartman; G. Wang; W. R. Wieder; M. A. Bradford; Y. Luo; et al. (Biogeochemistry, 2018)
Soils contain more carbon than plants or the atmosphere, and sensitivities of soil organic carbon (SOC) stocks to changing climate and plant productivity are a major uncertainty in global carbon cycle projections. Despite a consensus that microbial degradation and mineral stabilization processes control SOC cycling, no systematic synthesis of long-term warming and litter addition experiments has been used to test process-based microbe-mineral SOC models. We explored SOC responses to warming and increased carbon inputs using a synthesis of 147 field manipulation experiments and five SOC models with different representations of microbial and mineral processes. Model projections diverged but encompassed a similar range of variability as the experimental results. Experimental measurements were insufficient to eliminate or validate individual model outcomes. While all models projected that CO2 efflux would increase and SOC stocks would decline under warming, nearly one-third of experiments

Assessing science training programs: Structured undergraduate research programs make a difference - A. E. Wilson; J. L. Pollock; Ian Billick; C. Domingo; E. G. Fernandez-Figueroa; E. S. Nagy; T. D. Steury; A. P. Summers (BioScience, 2018)
Training in science, technology, engineering, and mathematics (STEM) is a top priority for driving economic growth and maintaining technological competitiveness. We propose that exposure to a rigorous research program as an undergraduate leads to success in a research STEM career. We compared the scientific outcomes of 88 participants from five National Science Foundation Research Experiences for Undergraduates (REU) Site programs with demographically similar applicants to assess the impact that formal, organized, and funded undergraduate summer research experiences have on participants. Our study demonstrates that REU participants are more likely to pursue a PhD program and generate significantly more valued products, including presentations, publications, and awards, when compared with applicants. We believe that key components of the program include funding for personal and professional needs; access to diverse intellectual, analytical, and field resources; and the presence of other

Role of animal detritivores in the breakdown of emergent plant detrius in temporary ponds - S. A. Wissinger; M. E. Perchik; A. J. Klemmer (Freshwater Science, 2018)

Across Caste Variation of Proboscis Length and Within Caste Phenotype Matching of Subalpine Bumble Bees (Bombus spp.) - T. J. Barnes (2018)
Bumble bees (​Bombus ​spp.) are eusocial insects that typically consist of three castes, with each caste emerging and foraging at different times. Bumble bee queens and workers differ morphologically in several measurable traits, but morphological variation within species and within caste has not been well characterized. For the purposes of this study traits that are functionally significant are of particular interest, such as the length of the bumble bee’s proboscis, which bees use to extract nectar from flowers. Variation in the length of the bumble bee’s proboscis may affect their foraging behavior, and may inform what flowers they prefer to, or are capable of, feeding on. Variation of the length of the proboscis of five species of subalpine bumble bees was observed using 150 specimens of each species, comparing between species and between caste within those species. This study found that the queens of five of the five species have significantly longer proboscis than workers. Coroll

Effects of abiotic and biotic stress on plant fitness and herbivore defense in Boechera stricta - A. Carter (2018)
Abiotic and biotic factors influence plant fitness by altering the physical environment and resource availability. According to the stress gradient hypothesis, increasing physical stress in an environment increases positive plant-plant interactions and decreases negative interspecies interactions. I investigated how variance in abiotic stress modifies interactions between the wildflower Boechera stricta and its heterospecific plant neighbors. I also tested how heterospecific neighbor density may affect insect herbivory due to associational defenses. I conducted a common garden experiment where the density of neighbor vegetation naturally varied across microsites and rainout shelters were used to manipulate soil moisture. I collected data on B. stricta survival, fecundity, and insect herbivory under these varying combinations of drought and neighbor density. I also performed a potted plant experiment with B. stricta to isolate the relationship between neighbor vegetation density, herbiv

Rocky Mountain Biological Laboratory, Gothic CO Ecology of Place: Making Ecology and Evolutionary Biology Spatially Explicit - Ian Billick; Ian K Breckheimer; David W. Inouye; K. H. Williams; J. S. Lynn; J. Reithel (Mountain Views, 2018)

The Relationship between Soil Properties and Variation in the Morphology and Phenology of non-native mustard plant Thlaspi arvense in Subalpine Meadows - N. Djuric (2018)
The ability of soil to retain moisture can significantly impact the severity of droughts on plants. Deep, loamy soils retain moisture from snow melt into the dry season more efficiently than shallow, sandy soils that lose water to runoff and percolation. Soil depth and texture are thus significant in determining how plants respond to climatic challenges. Similarly, soil composition can impact the number of leaves, branching behaviour, and stem height of plants.Overall, there are many factors impacting the growth of plants and how they respond to challenges. Thlaspi arvense, an invasive mustard, has demonstrated success in diverse microhabitats in the subalpine meadows of Gunnison County. To determine what qualities of a microhabitat favour the growth of T. arvense, edaphic properties including moisture, pH, conductivity, organic content, and soil type were investigated. Distance from the road (as a proxy for disturbance) and elevation were also considered. These environmental character

Can Variation of Insect Populations Affect Mountain White-crowned Sparrow Daily Nest Survival? - A. Emerson (2018)
Mountain white-crowned sparrows’ (Zonotrichia leucophrys oriantha; hereafter MWCS) diet fluctuates across seasons given their changing nutrient requirements across life stages and environment. Insect population densities may influence the daily nest survival of MWCS who depend upon these organisms as food because the transition from egg to adult occurs in less than one year. Insect population fluctuation is influenced by temperature (˚C) and precipitation (cm), which were also examined in this nest survival study. Our objective was to determine nest success relative to insect prey availability with corresponding abiotic shifts. Nest data was collected in the upper East River Valley, Colorado, over a period of seven years (2005, 2007, 2008, and 2014-2017). We calculated daily nest survival using a time-sensitive, hierarchical modeling procedure in program MARK to determine the effects of insect population density (Diptera and Lepidoptera), weather, nest stage (incubation or nestling), c

Comparing Plant-Pollinator Network Structure between Drought and Non-Drought Years - A. Fife (2018)
Network analyses can be used to examine multi-species interactions and have been applied to many ecological interactions such as food webs, antagonistic relationships such as plant- herbivory, and mutualistic relationships. A particular focus has been on plant-pollinator interactions given their importance in driving terrestrial ecosystem functions. These networks can be structured with various attributes, which have been measured with network indices to describe the interactions. The indices of interest for this study are connectance, diversity of interactions, generality, vulnerability, nestedness, and specialization. Natural perturbations, such as drought or climate change, have the potential to alter the structure of these networks. We compared network structure between 2017, a year with normal precipitation and 2018, a year with extreme drought conditions in East River Valley in western Colorado, USA. Phenological mismatch and the decrease in relative abundances as a result of dro

Nutrient excretion rates of common aquatic taxa in high elevation ponds at the Mexican Cut - E. Jameson (2018)
Nutrient cycling is crucial for proper functioning of aquatic ecosystems. Animals play an integral part of this process, especially in nutrient poor ecosystems such as the high elevation ponds at the Mexican Cut Nature Preserve. Nutrients such as nitrogen (N) and phosphorus (P) are both limiting nutrients, and animal excretion increases the availability of these nutrients. We measured the excretion rates of common aquatic macroinvertebrates and the demand for nutrients in these pond ecosystems. We found excretion rates in aquatic macroinvertebrate taxa varied over several orders of magnitude for both nitrogen and phosphorus. It appeared that smaller taxa had higher mass-specific excretion rates, but we did not test these differences statistically. We compared nutrient demand between permanent and semi-permanent pond types, but did not observe any significant difference between the two. The macroinvertebrate community contributed significantly to pond N and P demand. Phosphorus contribu

More social female yellow-bellied marmots have enhanced summer survival - A. Montero (2018)
For many animals, group living is an effective strategy to mitigate predation risk and ensure survival. However, in yellow-bellied marmots (Marmota flaviventer), increased sociality is associated with lower female reproductive success, decreased female longevity, and increased over-winter mortality for both males and females which raises questions about the adaptive value of sociality in this facultatively social mammal. Here we used social network analysis to ask questions about the relationship between specific attributes of sociality and summer survival, which is almost always attributable to predation. Yearling females have enhanced survival when they have stronger social relationships and are more central in their network. Adult female survival is not associated with social network traits, but females are more likely to survive the summer if they live in larger groups. Male survival is not associated with either social network trait variation or variation in group size. These find

Effect of blood parasites on secondary sexual characteristics and morphology in mountain white-crowned sparrows - E. Newman (2018)
Blood parasites affect numerous species of birds across the world and can cause serious population declines. Haemosporidian blood parasites in Mountain White-crowned Sparrows (Zonotrichia leucophrys oriantha) are known to affect certain behavioral and morphological characteristics of hosts, including dominance-related characters like song. Blood parasites cause a host of symptoms, including anemia, reduced aerobic capacity, and increased metabolic demand. This study investigates the presence of various blood parasites and their influence upon crown-stripe width in males, a secondary sexual characteristic. According to the Hamilton-Zuk hypothesis, secondary sexual characteristics should be reduced in parasitized males and their breeding success consequently lowered. Birds were captured and processed at the Rocky Mountain Biological Laboratory, and for each bird a blood smear was taken as well as body measurements like tarsus, tail, and wing length. The presence of blood parasites Plasmo

Local adaption in Boechera stricta in the context of climate change - G. Steinmetz (2018)
This study examines whether climate change alters patterns of local adaptation in Boechera stricta (Brassicaceae). A common garden experiment was established in sites around the Rocky Mountain Biological Laboratory in Colorado. In the fall of 2017, Dr. Jill Anderson and her lab planted seeds from a broad elevational gradient into four common gardens in four treatments: a control (contemporary climate change condition), snow removal (a climate change simulation), snow addition (historical condition) and snow addition and supplemental water (another historical condition). In the growing season of 2018, we recorded data on three key early life history fitness components germination success, probability of survival of seedlings, and time until mortality for seedlings. As low elevation populations are exposed to hot and dry conditions, we predicted that low elevation maternal families would have greater fitness in treatments simulating ongoing climate change, whereas local adaptation would

The effect of surrounding bloom color on pan trap success in sampling Rocky Mountain bees - M. Turnley (2018)
On a global scale, bees are important pollinators but face declining populations. In order to monitor the health of bee populations and communities, accurate sampling methods are needed. One common sampling protocol utilizes a combination of pan-trapping and sweep netting. While pan- trapping has its benefits in removing observation bias, there is limited information on how surrounding flower color impacts the success of similarly colored pan traps. We analyzed a long- term data set from the Rocky Mountains (Colorado, USA) to gain a better understanding of the degree to which flower color biases pan trap success. Bees were sampled in 16 sites every two weeks over a nine-year period. Calculating the proportions of bees caught in certain colored pan traps as well as the proportions of certain colored flowers available allowed us to model the relationship between the two factors. We found that similarly colored surrounding bloom color had a small but statistically significant impact on pa

Are ants botanists?: Ant associative learning of plant volatiles - G. Zapata (2018)
Ants are important members of most terrestrial ecosystems, and often forage in plant canopies where they occasionally participate in mutualisms with either the plants, or aphids that live on the plants. To participate in these mutualisms, the ants must first find them, and it is not clear how ants do this while foraging in the field. It is known that while ants forage in plant canopies they encounter many plant volatiles. There is also some laboratory evidence of associative learning in ants. This leads to the hypothesis that the ants may be learning to recognize the scents of plants that host resources, and preferentially forage on similar smelling plants. In this study we explore whether ants exhibit an association between the scent of a plant, and a honey reward, and whether this is dependent on the local plant density, and thus scent density, in the surrounding area. The two plants used in the study were Helianthella quinquenervis. an ant mutualist, and Ligusticum porteri a host fo

Host-parasite ecology of Baetis bicaudatus mayflies and Gasteromermis sp. nematodes in high-altitude streams - K. J. Cromwell (2018)
Parasite-induced changes to host dispersal potentially influence the distribution of parasites and infection risk for hosts. Gasteromermis is a castrating endoparasitic nematode that infects both males and female mayflies (Baetis bicaudatus) but feminizes male hosts and manipulates them to disperse parasites to aquatic habitats via a mimicry of female oviposition behavior. In a stream network with high spatial heterogeneity in parasitism we used surveys and a large-scale field manipulation to 1) evaluate parasite effects on host dispersal capacity and site selection, and 2) test whether experimentally increasing host oviposition habitat would increase immigration of parasitized hosts, with subsequent increases in parasite recruitment and prevalence in the next generation. Initially assuming that manipulation benefits the parasite by increasing host encounters around oviposition sites, we predicted the parasite would not affect host dispersal capacity or site selection, and that more pa

Effects of Climate Change on Plants, Pollinators and Their Interactions - Pardee G. (2018)
1. Changes from historic weather patterns have affected the phenology of many organisms worldwide. Altered phenology can introduce organisms to novel abiotic conditions during growth and modify species interactions, both of which could drive changes in reproduction. 2. We explored how climate change can alter plant reproduction using an experiment in which we manipulated the individual and combined effects of snowmelt timing and frost exposure, as well as pollination and measured subsequent effects on phenology, peak flower density, frost damage, pollinator visitation, and reproduction of four subalpine wildflowers. The four plants included species flowering in spring to mid-summer. 11 3. The phenology of all four species significantly advanced and the bloom duration was longer in the plots from which we removed snow, but with species-specific responses to snow removal and frost exposure in terms of frost damage, flower production, pollinator visitation, and reproduction. The two early

Disintegration of the leaf economic spectrum within and across Quaking aspen (Populus tremuloides) genotypes - Rieksta J. (2018)
1. The leaf economic spectrum (LES) describes consistent and strong correlations among plant functional traits in a multidimensional trait space, which reflects fast or slow rate of return on carbon investment in leaves. These relationships between LES functional traits are strong at global scales and consistent across species and biomes. However, there is evidence that the LES relationships may be weak or absent at smaller scales due to different factors affecting traits locally. 2. Here we quantify: (1) the intraspecific functional trait variation within a model clonal species, Populus tremuloides; (2) how important is microclimate in determining intraspecific trait variation; (3) whether and how much trait-trait, trait-environment relationships in this species are consistent with global interspecific LES patterns; (4) how trait – trait and trait – environment relationships change with ploidy level. We collected leaf functional traits from 15 aspen clones using a hierarchical samplin

Rural-to-Urban Water Transfers: Measuring Direct Foregone Benefits of Irrigation Water under Uncertain Water Supplies - R. G. Taylor; Robert A. Young (2018)
Irrigation water from a southeastern Colorado county has been sold to distant municipalities. The county's junior water right delivered limited and uncertain water supplies which were used on relatively poor soils. The ability of water markets to allocate water to the highest-valued use was addressed by assessing the direct foregone benefits of the transfer using deterministic and discrete stochastic sequential (DSSP) programming models. Crop mix predicted by the DSSP followed observed regional patterns. The DSSP was thus used to derive regional water demand from which foregone value was estimated. Direct regional foregone agricultural benefits were relatively low—due to uncertain water supplies and unproductive soils—indicating the market selected a low-valued supply for transfer.

Invasion and restoration of western rivers dominated by Tamarix spp. - Raymond H. Johnson; Steven W. Carothers; Deborah M. Finch; Kenneth J. Kingsley; John T. Stanley (2018)
Fifty years ago, riparian habitats were not recognized for their extensive and critical contributions to wildlife and the ecosystem function of watersheds. This changed as riparian values were identified and documented, and the science of riparian ecology developed steadily. Papers in this volume range from the more mesic northwestern United States to the arid Southwest and Mexico. More than two dozen authors-most with decades of experience-review the origins of riparian science in the western United States, document what is currently known about riparian ecosystems, and project future needs. Topics are widespread and include: interactions with fire, climate change, and declining water; impacts from exotic species; unintended consequences of biological control; the role of small mammals; watershed response to beavers; watershed and riparian changes; changes below large dams; water birds of the Colorado River Delta; and terrestrial vertebrates of mesquite bosques. Appendices and referen

Landscape, Science, and Social Reproduction - Laura Alice Watt (2018)
This chapter discusses the arc of Carolyn Merchant’s direct and indirect influences on work, particularly now forming a bridge between completed landscape history of Point Reyes National Seashore here in northern California, and developing a new focus on the history of the Rocky Mountain Biological Laboratory in Colorado. Wilderness designation in large portions of the surrounding Grand Mesa, Uncompahgre, and Gunnison National Forests and the Black Canyon of the Gunnison National Park have increasingly bureaucratized the landscape, requiring permits for research projects where the ecologists once had fairly free rein. From studying how ideas of preservation become inscribed on working landscapes, to investigating the ways in which field science shapes and is shaped by the landscape around it, the author continue to find inspiration and insight from Merchant’s scholarship.

The Bureau of land management Kerber Creek restoration project - Romana M. Sutton (Digital Collections of Colorado (Colorado State University), 2018)
From May to December, 2009, I worked as an intern for the Bureau of Land Management in Saguache, Colorado, primarily on the Kerber Creek Restoration Project.Mining during late the 1800s to mid 1900s resulted in mine waste deposits along the creek.These wastes had detrimental effects on the creek and riparian zone.The goal of the Kerber Creek Restoration Project is to improve conditions in Kerber Creek and the surrounding watershed.During my internship with the Bureau of Land Management I monitored water quality, evaluated aquatic invertebrate abundance and composition, assessed fishery abundance and diversity, determined upland vegetation Cover Frequency Index, and collected preliminary stream channel morphological data.Working closely with Steve Sanchez, Natural Resources Specialist, on the project from May-December 2009 taught me

Facies reconstruction and detrital zircon geochronology of the Ingleside/Casper Formation - Kajal Nair; Egenhoff, Sven; Singleton, John; Rocca, Monique (Digital Collections of Colorado (Colorado State University), 2018)
Mixed siliciclastic-carbonate deposits of the Ingleside/Casper Formation in northern Colorado and southeastern Wyoming developed along the flanks of the Ancestral Front Range during the Late Paleozoic. This study establishes a sedimentological model for the Ingleside/Casper Formation along with using detrital zircon data to identify siliciclastic sediment sources for Late Paleozoic deposits in two Ancestral Rocky Mountain basins along the Ancestral Front Range and Uncompahgre Highlands. The stratigraphic successions of the Ingleside/Casper Formation display a diverse suite of carbonate and siliciclastic lithofacies in close lateral and vertical association with each other. The six different siliciclastic facies and their subfacies identified in this study include: (1) cross-bedded sandstone (tabular cross-bedded sandstone and trough cross-bedded sandstone), (2) horizontally-bedded sandstone, (3) massive sandstone, (4) conglomeratic sandstone, (5) ripple-laminated sandstone (asymmetric

Developmental and social constraints on early reproduction in an asocial ground squirrel - Caitlin P. Wells; D. H. Van Vuren (Journal of Zoology, 2018)
AbstractFor short‐lived species, selection for early reproduction should be strong, yet females often delay their first reproductive bout. Delay in age of first reproduction due to developmental constraints, such as food availability, or social constraints, such as the inhibitory presence of breeding adults, has been documented for social mammals, but effects on asocial species are less well known. We evaluated the influence of developmental and social factors on early reproduction in a short‐lived, asocial species, the golden‐mantled ground squirrel (Callospermophilus lateralis). We found that females who reproduced as yearlings had been weaned earlier in their natal summer and experienced early snow melt during their yearling spring, suggesting the importance of access to high‐quality food at critical stages. Females were more likely to reproduce as yearlings when there were more adult males present during the breeding season, possibly because exposure to males accelerates reproducti

Effects of Light Availability on Aspen Understory Species - Marco Castaneda (2018)
Trembling aspen (Populus tremuloides) is a keystone species found throughout North America. P. tremuloides is a successional species which aids the regeneration of ecosystems after disturbance. However, climate change is altering aspen forest dynamics. Aspen forest die- off in the American Southwest is predicted to increase in the next few years as temperatures and drought increase. As forests change, so does their understory. Forest die-off will affect the understory plant communities, which play crucial role on regional biodiversity. In this study, the effect of aspen canopy light transparency was measured to find its impact on species richness and abundance of aspen understory shrub, grass and forbs in the Gunnison National Forest (Colorado). The hypothesis is that aspen understory forbs will decrease in richness and abundance, aspen understory shrub and grass species will increase in richness and abundance with increasing canopy light availability in the form of LAI. Aspen overstor

Nesting aggregation as a predictor of brood parasitism in mason bees (Osmia spp.) - A. Groulx; J. R. K. Forrest (Ecological Entemology, 2018)

Spatial patterns and climate relationships of major plant traits in the New World differ between woody and herbaceous species - I. Simova; C. Violle; J. C. Svenning; J. Kattge; K. Engemann; B. Sandel; R. K. Peet; S. K. Wiser; B. Blonder; B. J. McGill; B. Boyle; N. Morueta-Holme; et al. (Journal of Biogeography, 2018)

A model for leaf temperature decoupling from air temperature - B. Blonder; S. T. Michaletz (Agricultural and Forest Meteorology, 2018)
Abstract Leaf temperature (Tleaf) influences rates of respiration, photosynthesis, and transpiration. The local slope of the relationship between Tleaf and Tair, β, describes leaf thermal responses. A range of values have been observed, with β β = 1 indicating poikilothermy where Tleaf tracks Tair, and β >1 indicating megathermy where Tleaf increasingly exceeds Tair. However, theory for variation in β has not been developed. Here we derive an equation for β that predicts how it varies with multiple trait and microenvironment variables. The approach also predicts how maintenance of Tleaf away from lethally high values may help explain regulation of stomatal conductance (gS). The work delineates contexts in which each class of leaf thermal response is expected and develops concepts for predicting leaf responses to thermally extreme environments.

Traditional plant functional groups explain variation in economic but not size related traits across the tundra biome - H. Thomas; I. H. Myers-Smith; A. D. Bjorkman; S. C. Elmendorf; Johannes H. C. Cornelissen; Brieanne Forbes; B. Blonder (Global ecology and biogeography, 2018)

Heritable plant phenotypes track light and herbivory levels at fine spatial scales - Parris T Humphrey; A. D. Gloss; J. Frazier; A. C. Nelson-Dittrich; S. Faries; Noah K Whiteman (Oecologia, 2018)
Organismal phenotypes often co-vary with environmental variables across broad geographic ranges. Less is known about the extent to which phenotypes match local conditions when multiple biotic and abiotic stressors vary at fine spatial scales. Bittercress (Brassicaceae: Cardamine cordifolia), a perennial forb, grows across a microgeographic mosaic of two contrasting herbivory regimes: high herbivory in meadows (sun habitats) and low herbivory in deeply shaded forest understories (shade habitats). We tested for local phenotypic differentiation in plant size, leaf morphology, and anti-herbivore defense (realized resistance and defensive chemicals, i.e., glucosinolates) across this habitat mosaic through reciprocal transplant–common garden experiments with clonally propagated rhizomes. We found habitat-specific divergence in morphological and defen- sive phenotypes that manifested as contrasting responses to growth in shade common gardens: weak petiole elongation and attenuated defenses in

Efficient hydrogeological characterization of remote stream corridors using drones - Martin Briggs; Cian Dawson; C. L. Holmquist-Johnson; K. H. Williams; J. W. Lane (Hydrological Processes. doi 10.1002/hyp.13332, 2018)
Data S1 Supporting Information Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

The Effect of Climate Change on Plant Communities in the Rocky Mountains: How floral traits differ along an elevational gradient and in reciprocally transplanted communities - M. Lundin (2018)
Alpine zones are characterized by climatic conditions that can vary over short vertical distances. Therefore, elevational gradients have been used to study how changes in climate can influence plant form, function, and diversity. In my study, I examined floral traits in native communities along an elevational gradient as well as in a novel experimental set of transplant communities to understand how shifts in temperature and elevation influence floral traits. I measured flower diameter, flower radius, flower length, height of the highest flower and number of flowers (count) at a variety of sites in Washington Gulch. At three different experimental transplant sites, I sampled each transplanted and control plot. I also sampled at long-term research sites of Dr. Brian Enquist and Department of Energy (DOE) sites in the vicinity of Crested Butte, Colorado. I predicted that flower diameter, flower radius, flower length and height of the highest flower will increase at higher elevations beca

Strong social relationships are associated with decreased longevity in a facultatively social mammal - Daniel T. Blumstein; D. M. Williams; Alexandra N. Lim; Svenja B. Kroeger; J. G. A. Martin (Proc. R. Soc. B, 2018)
Humans in strong social relationships are more likely to live longer because social relationships may buffer stressors and thus have protective effects. However, a shortcoming of human studies is that they often rely on self-reporting of these relationships. By contrast, observational studies of non-human animals permit detailed analyses of the specific nature of social relationships. Thus, discoveries that some social animals live longer and healthier lives if they are involved in social grooming, forage together or have more affiliative associates emphasizes the potential importance of social relationships on health and longevity. Previous studies have focused on the impact of social metrics on longevity in obligately social species. However, if sociality indeed has a key role in longevity, we might expect that affiliative relationships should also influence longevity in less social species. We focused on socially flexible yellow-bellied marmots (Marmota flaviventer) and asked

The impacts of early snowmelt and summer precipitation on the physiology and leaf morphology of Ipomopsis aggregata - Jocelyn Navarro (2018)
Climate change is occurring, and the effects will be visible all over the planet. In a subalpine ecosystem, earlier snowmelt and changes in summer precipitation are predicted to occur due to an increase in air temperature. During the summertime, this variation may lead to changes in traits, a process known as phenotypic plasticity. In plants, these plastic changes could occur in morphological traits or physiological traits. This study aimed to find the impact of an earlier snowmelt as well as variation in summer precipitation on traits in ​Ipomopsis aggregata​, a subalpine herb. In this study, we manipulated the snowmelt date and summer precipitation and measured three traits, photosynthetic water-use efficiency, specific leaf area, and trichome density, to determine if the environmental constraints are impacting the plant’s physiology and leaf morphology. Plants that had experienced less precipitation had a higher photosynthetic water-use efficiency, but still had lower photosynthetic

The Where of Mineral Names: Creedite, Colorado Fluorspar Company Mine, Wagon Wheel Gap, Mineral County, Colorado - Mark Ivan Jacobson (Rocks & Minerals, 2018)
CREEDITE, Ca3Al2(SO4)(OH)2F8·2H2O, is a calcium aluminium sulfate fluoro-hydroxide. It forms colorless to white to purple, monoclinic prismatic crystals, frequently in acicular radiating sprays of ...

Women, Crime and Justice: Balancing the Scales E. Gunnison, F.P. Bernat and L. Goodstein. Chichester: Wiley (2017) 306pp. £75.50hb ISBN 9781118793466 - Gillian McNaull (The Howard Journal of Crime and Justice, 2018)
Women, Crime and Justice is an expansive teaching tool, focused on the position of women in the criminal justice system, as victims, offenders, and professional agents working within it. In addition, Gunnison, Bernat and Goodstein consider how the law impacts upon distinctly gendered issues, with women as the focus of legal social control. The textbook is accompanied by a series of online resources, accessible via the ‘instructor companion site’ of the publishers, which includes essay questions, quiz questions and PowerPoint slides for each of the book's eleven chapters. For students, the online resources feature additional engagement activities, reading and media suggestions, as well as chapter outlines and a glossary. Each chapter of the book commences with student learning outcomes, incorporates case studies and ‘special legal issues’, and closes with student activities and discussion questions. Chapter 1, ‘Foundations for understanding women and crime’, locates issues of women, cri

Polyploidy influences plant-environment interactions in quaking aspen (Populus tremuloides Michx.) - B. T. Greer; C. Still; G. L. Cullinan; J. R. Brooks; F. C. Meinzer (Tree Physiology, 2018)

Do socio-cultural traits and other demographics affect outdoor recreation constraints? The case for Mesa County, Colorado - Nathan Perry; T. Timothy Casey; Steven Ross Murray (Journal of Kinesiology & Wellness, 2018)
Physical activity from outdoor recreational pursuits is well known to be beneficial and has been encouraged by the US Surgeon General. Specific constraints, often reflected in sociocultural issues, can be impediments to individuals participating in outdoor recreational activities. Data were collected in conjunction with the Bureau of Land Management and the Mesa County Health Department in Colorado via surveys involving 580 residents of Mesa County regarding access to outdoor recreation. Ordinal logistic regression was used to test whether ten different constraints to outdoor recreation were important to the respondents, given their age, sex, education, race/ethnicity, native language, and residential density. The results indicated that the probability of experiencing outdoor constraints increased with lower education, Hispanic ethnicity, native Spanish speaking, and young age. A second model, albeit with fewer respondents, was tested to include income. The results of the second

Comparing detritus breakdown rates with and without detritivores in subalpine ponds with different hydroperiods - G. OMalley (2018)
It is widely accepted that in stream systems, detritivores accelerate the breakdown of detritus that has been “conditioned” by microbial decomposers. By accelerating the breakdown of dead plant material, detritivores release nutrients and smaller food particles that are used by downstream plants and animals, respectively . Standing-water ecologists have often assumed animal detritivores play a similar role in ponds and wetlands, but there are few published studies investigating the contribution of animal detritivores to the overall breakdown of detritus in standing water systems. In this study, I compared detrital breakdown rates with and without invertebrate detritivores in nine subalpine ponds that differ in hydroperiod (permanent, semi-permanent, and temporary) at the Mexican Cut in the East River Valley in the Colorado Rockies. The biomass dominant detritivores in these systems are cased caddisflies (Trichoptera: Limnephilidae). I placed 14 containers with 5g of sedge into 3 perman

An integrative study of marmot responses to ecotourism - J. Nelson (2018)
Human disturbance in the form of ecotourism alters behavior many species and may impact fitness but few studies take an integrative approach to quantify impact in various ways to test for variation in physiological, behavioral, and consequential life history and demographic traits. We extended a previous study on antipredator behavior for yellow-bellied marmots (Marmota flaviventer) by controlling for natural predation and by splitting the data by marmot age group. In addition, we tested the assumption between altered behavior and a decreased fitness by analyzing different physiological traits. Using the same 2009 disturbance data of vehicles, hikers, bicycles, and dogs as the previous study, we analyzed the relationship between the different types of disturbance with the variables of stress, mass gain, summer survival, and annual survival from that same year. We fit models to each age class for each type of disturbance for each variable. We found that, across all variables, juvenile m

Effects of Ant Presence on Nicrophorus investigator’s Reproductive Success - O. Ortuno (2018)
Burying beetles require carrion in order to successfully reproduce and they compete with vertebrate scavengers, other burying beetles, ants, flies, fungi, and microbes for this ephemeral resource. Burying beetles have mechanisms to combat competition from fly eggs, fungi, and microbes, but interactions between ants and beetles have not been extensively studied, and are not yet well understood. Interactions between the ant species Tapinoma sessile and the burying beetle Nicrophorus investigator may yield a diffuse mutualistic relationship involving the predation of undesired dipteran eggs from the carrion. This study found fly presence reduced successful carcass sequestration by Nicrophorus investigator, with fly presence at the carcass leading to the beetle’s complete failure to bury. Ants (T. sessile, Formica fusca, Formica rufa, Myrmicinae subfamily) were found to have a conditional interaction with flies, for their presences in tandem increased beetle burial success, while pure ant

The Effects of Climate-Driven Changes in Co-flowering between Linum lewisii and Potentilla pulcherrima on Pollinator Services - J. Robledo (2018)
Anthropogenic climate change is affecting many ecosystems. Changes in the melting of snowpack have altered flowering phenology in subalpine meadows. The subalpine meadows at the Rocky Mountain Biological Laboratory in Gothic, Colorado are experiencing shifts in co-flowering patterns. Two flowers, Linum lewisii and Potentilla pulcherrima, which had significant historical co-flowering overlap are now having 25% less overlap. The consequences of this shift are not well known and could be having an effect on plant-pollinator interactions. Although L. lewisii is self-compatible, outcrossing results in higher fruit and seed production. This means that pollinator services are important to L. lewisii, as it requires pollination to reproduce more effectively. This decrease in overlap may mean that there is less competition for pollinator services between these two species. This short-term study looked at pollinator visitation rates and pollen deposition on L. lewisii by applying different treat

Plant functional trait change across a warming tundra biome - A. D. Bjorkman; I. H. Myers-Smith; S. C. Elmendorf; S. Normand; N. Ruger; P. S. A. Beck; A. Blach-Overgaard; D. Blok; Johannes H. C. Cornelissen; Brieanne Forbes; D. Georges; B. Blonder (Nature, 2018)
Biome-wide relationships between temperature, moisture and seven key plant functional traits across the tundra and over time show that community height increased with warming across all sites, whereas other traits lagged behind predicted rates of change.

Transgenerational and within-generation plasticity in response to climate change: insights from a manipulative field experiment across an elevational gradient - Susana M. Wadgymar; Rachel M. MacTavish; J. T. Anderson (Am. Nat., 2018)
Parental environmental effects-or transgenerational plasticity-can influence an individual's phenotype or fitness yet remain underexplored in the context of global change. Using the perennial self-pollinating plant Boechera stricta, we explored the effects of climate change on transgenerational and within-generation plasticity in dormancy, germination, growth, and survival. We first conducted a snow removal experiment in the field, in which we transplanted 16 families of known origin into three common gardens at different elevations and exposed half of the siblings to contemporary snow dynamics and half to early snow removal. We planted the offspring of these individuals in a factorial manipulation of temperature and water level in the growth chamber and reciprocally transplanted them across all parental environments in the field. The growth chamber experiment revealed that the effects of transgenerational plasticity persist in traits expressed after establishment, even when accounting

Impacts of drought gradient on pollen limitation in flowers in dry subalpine meadows - D. MacArthur-Waltz (2018)

Comparing Longworth live traps to hair tubes for describing small mammal communities - G. Sandoval (2018)
Ecologists are always interested in studying populations of a certain area. There are many reasons for this, but two reasons include to see the change in distribution over time and because it can help tell about interactions between species. A traditional way of studying small mammal populations that has been commonly used is live trapping. As useful as it has been, live trapping does have some downfalls. It requires handling animals and is time restrictive. An alternate method of collecting small mammal population data has been explored and was tested in this experiment. My results demonstrated that abundance data from hair-tube traps was significantly positively correlated with traditional live-trap mark recapture population estimates. However, hair identification was difficult, so live trapping is still necessary to identify the species.

Investigation of Inbreeding Depression in Boechera stricta Fitness - K. Schepke (2018)
Maintaining high levels of self-fertilization within a population increases homozygosity, exposes deleterious alleles, and may cause inbreeding depression. Yet, many species of flowering plants have evolved to self-fertilize a majority of the time. Often, self-fertilization is favored over outcrossing when small populations experience harsh or stressful environments. Self-compatibility may evolve after a founder event or when natural selection favors high reproductive assurance, such as when there is limited pollinator activity. When this occurs, selfing syndrome, the reduction of petal size and pollen production, may follow. Conversely, natural selection may remove deleterious alleles from highly self-fertilizing plants, allowing for combinations of locally-adapted alleles to arise. As a result some species may show no evidence of inbreeding depression, and in fact may have decreased fitness due to loss of locally co-adapted allele combinations following outcrossing. In ​Boechera stri

What abiotic and biotic factors predict the shapes of plant diversity-productivity relationships? - F. Vila-Terrad (2018)
Anthropogenic influence over biodiversity has altered ecosystem functions. One important ecosystem function related to diversity is productivity. Plant richness has long been considered for determining productivity. Despite the importance of the relationships between diversity and productivity, their shapes are debated and what determines variation in shapes is not well understood. We examined diversity-productivity relationships from local to landscape scales in a mountain ecosystem. We first asked: what is the shape of the richness and productivity relationship at the landscape? We compared fits of linear and Michaelis-Menten models to richness predictions of productivity. Also, we evaluated whether the humped-back model of productivity and diversity applies in the system. Second, we asked: what abiotic and biotic factors predict the shapes of richness- productivity relationships within sites? We collected plant community composition data including richness and plant cover of each sp

Behavioral correlates of innovation success in facultatively social marmots (Marmota flaviventer) - C. A. Wu (2018)
Innovation has transformed ecology and evolution, and understanding behaviors that lead to innovation success can have profound implications and applications in animal populations and human society. In past research, persistence, behavioral selectivity, and neophobia have influenced an individual’s ability to innovate, however the traits that lead to innovation success are not well understood. Exploring these subjects in the socially flexible yellow-bellied marmot can disentangle these factors and reveal which one, if any, influences innovation success. To test innovation correlates in marmots, we will present them with a two-action puzzle box from which they can obtain a food reward, and video their interactions with the box. These videos will be scored for individual behaviors, and the interactions of innovation success, behavioral interactions with the box, and social metrics will be examined. We predict that high degrees of persistence, behavioral selectivity, and neophilia will co

Cumulative reproductive costs on current reproduction in a wild polytocous mammal - K. D. Kroeger; Daniel T. Blumstein; Kenneth B. Armitage; Jane M. Reid; J. G. A. Martin (Ecology and Evolution, 2018)
The cumulative cost of reproduction hypothesis predicts that reproductive costs accumulate over an individual's reproductive life span. While short-term costs have been extensively explored, the prevalence of cumulative long-term costs and the circumstances under which such costs occur alongside or instead of short-term costs, are far from clear. Indeed, few studies have simultaneously tested for both short-term and cumulative long-term reproductive costs in natural populations. Even in mammals, comparatively little is known about cumulative effects of previous reproduction, especially in species with high variation in offspring numbers, where costs could vary among successful reproductive events. Here, we quantify effects of previous short-term and cumulative long-term reproduction on current reproduction probability and litter size in wild female yellow-bellied marmots (Marmota flaviventer) and test how these effects vary with age and between two contrasting environments. We p

Clines in traits compared over two decades in a plant hybrid zone - Diane R. Campbell; A. Faidiga; G. Trujillo (Annals of Botany, 2018)
The increase in corolla length provides a rare example of a match between predicted and observed evolution of a plant trait in natural populations. The clinal properties are consistent with the hypothesis that habitat-mediated divergent selection on vegetative traits and pollinator-mediated selection on floral traits both maintain species differences across the hybrid zone.

White-Crowned Sparrow respond to the alarm calls of local species but do not discriminate among them - K. Ziska (2018)
Eavesdropping is recognizing and gleaning information from a communication intended for someone else. Eavesdropping on alarm calls can benefit eavesdroppers by decreasing the time they spend allocated to vigilance, giving them more time for other behaviors such as foraging. Although there have been many studies done on eavesdropping on heterospecifics among birds, there have been few studies on migratory birds and their ability to learn heterospecifics alarm calls of local species in their breeding ranges. We conducted a playback on white-crowned sparrows (Zonotrichia leucophrys oriantha) using alarm calls from Lincoln’s sparrows (Melospiza lincolnii), yellow-bellied marmots (Marmota flaviventris), gray jays (Catharus minimus), American robins (Turdus migratorius), and white-crowned sparrows to try and understand if they listened to these acoustically variant alarm calls and gained any different information from each of them. We found that while sparrows responded to all playbacks, the

How does road dust influence Ipomopsis pollination? - N. Centeno Armenta (2018)
Premise of research. Road dust affects the quantity of pollen received by Ipomopsis aggregata flowers, with dusty flowers receiving less pollen than undusty flowers. One possibility is that hummingbird pollinators visit dusty flowers less and deliver less pollen. This could happen if dusty flowers produce less nectar. Methodology. I collected a total of ninety-one I. aggregata flowers from experimentally dusted and non-dusted plants in Maxfield Meadow. The flowers had been enclosed in drinking straws for twenty-four hours beginning when they were elongated buds. I measured the nectar quantity (mg of sugar), flower length (mm) and nectar concentration. In addition to nectar measurement, a total of eight censuses were done every three days to count the total number of flowers per plant produced over the 2018 flowering season Pivotal results. Dusted I. aggregata flowers were shorter than undusted flowers and produced less nectar. These two findings may be related since flower size and nec

Building up Biogeography: Pattern to Process - F. K. Pearse; A. M. Barbosa; S. A. Fritz; S. A. Keith; L. J. Harmon; J. Harte (Journal of Biogeography, 2018)
Abstract Linking pattern to process across spatial and temporal scales has been a key goal of the field of biogeography. In January 2017, the 8th biennial conference of the International Biogeography Society sponsored a symposium on Building up biogeography—process to pattern that aimed to review progress towards this goal. Here we present a summary of the symposium, in which we identified promising areas of current research and suggested future research directions. We focus on (1) emerging types of data such as behavioural observations and ancient DNA , (2) how to better incorporate historical data (such as fossils) to move beyond what we term “footprint measures” of past dynamics and (3) the role that novel modelling approaches (e.g. maximum entropy theory of ecology and approximate Bayesian computation) and conceptual frameworks can play in the unification of disciplines. We suggest that the gaps separating pattern and process are shrinking, and that we can better bridge these aspec

50 years of mountain passes: A perspective on Dan Janzen's classic article - K. S. Sheldon; R. B. Huey; M. Kaspari; Nathan J. Sanders (American Naturalist, 2018)

Atypical flowers can be as profitable as typical hummingbird flowers - Nickolas M. Waser; Paul J. CaraDonna; Mary V. Price (The American Naturalist, 2018)
In western North America, hummingbirds can be observed systematically visiting flowers that lack the typical reddish color, tubular morphology, and dilute nectar of "hummingbird flowers." Curious about this behavior, we asked whether these atypical flowers are energetically profitable for hummingbirds. Our field measurements of nectar content and hummingbird foraging speeds, taken over four decades at multiple localities, show that atypical flowers can be as profitable as typical ones and suggest that the profit can support 24-h metabolic requirements of the birds. Thus, atypical flowers may contribute to successful migration of hummingbirds, enhance their population densities, and allow them to occupy areas seemingly depauperate in suitable resources. These results illustrate what can be gained by attending to the unexpected.

Evolution of hydrothermal fluids from the deep porphyry environment to the shallow epithermal environment, The - Subaru Tsuruoka (Digital Collections of Colorado (Colorado State University), 2018)
The current understanding of magmatic-hydrothermal processes resulting in the formation of porphyry and epithermal deposits is based on case studies that focused on deposits such as Santa Rita porphyry copper deposit in New Mexico, the Refugio porphyry gold deposit in Chile, and the Summitville high-sulfidation epithermal deposit in Colorado. The present study re-examines these classical study sites to constrain the physical nature of the mineralizing hydrothermal fluids and to test recent models suggesting that metal transport can occur in the vapor phase. Careful petrographic investigations involving a combination of microanalytical techniques were performed to unravel paragenetic relationships in the three deposits. Based on fluid inclusion research on quartz closely associated with mineralization, it is shown that ore formation at Santa Rita occurred from a near-critical single-phase hydrothermal fluid under hydrostatic conditions. Observed fluid inclusion assemblages have saliniti

New Players on the Colorado River — the Tribes - Lawrence MacDonnell (SSRN Electronic Journal, 2018)

Pocket gopher (Thomomys talpoides) soil disturbance peaks at mid-elevation and is associated with air temperature, forb cover, and plant diversity - J. S. Lynn; Samuel Canfield; Ross R. Conover; Jeremy Keene; Jennifer A. Rudgers (Arctic, Antarctic, and Alpine Research, 2018)
Burrowing mammals can be ecosystem engineers by increasing soil aeration and erosion and altering the structure of plant communities. Studies that characterize the constraints on the distributions of fossorial mammal disturbances to soil can help predict changes in ecosystem engineering under future climates. We quantified the density of soil disturbances caused by Thomomys talpoides (northern pocket gopher) over replicate elevation gradients spanning 2,700–4,000 m a.s.l. in the Upper Gunnison Basin, Colorado, USA. As a conceptual framework for predicting biogeographic variation in soil disturbance, we used the abundant center hypothesis (ACH), which proposes that species abundance declines monotonically away from the most abundant location in its distribution, with the assumption that ecosystem engineering scales with gopher abundance. We also evaluated the relative importance of abiotic and biotic variables as correlates of soil disturbance. Gopher disturbance peaked at mid elevation

Contact Metamorphism of the Mancos Shale: Impacts on Solute Release and Weatherability in the East River Valley, Gothic, CO - B. C. Sams (2018)
Alteration of rocks by contact metamorphism directly impacts rock pore structure and mineralogy, potentially decreasing weathering susceptibility and altering water residence times and release rates of aqueous solutes. Mountainous catchments, which can often be metamorphosed, are important for water and solute supply. Changes in the underlying lithology of a catchment can therefore directly impact water quality and solute release rates, imparting watershed scale changes in flow regimes and rate of flow within hydrologic systems. Here we aim to quantify differences in solute release rates from Mancos shale samples as a function of degree of metamorphism. Variable contact metamorphism of Mancos shale bedrock in the East River provides a natural test bed to investigate the role of underlying geology on weathering susceptibility, solute release rates and changing river chemistry in metamorphosed and unmetamorphosed sections of the Mancos shale. To analyze the relationship between rate of s

Changes of dispersal ability in an isolated population - C. Bacon (2018)
Dispersal is a core mechanism in the maintenance of metapopulations. It maintains genetic diversity by connecting subpopulations and generates new populations to replace those that die out. However, as populations become more isolated, as occurs in habitat fragmentation, dispersal becomes more difficult. This should lead to selective pressure against dispersive individuals, causing a reduction in dispersal traits. Over time, this can lead to variation in dispersal traits among populations. We examine this idea using an extreme case of isolation in Euphydryas gillettii, a population that has remained completely isolated for forty years. By comparing this population to a baseline established using multiple populations in the native range of the species, we found that the isolated population showed characteristics indicative of relatively low dispersal. iv

Shepherding Compact Security Water in the Upper Colorado River Basin - Lawrence MacDonnell; Anne Castle (SSRN Electronic Journal, 2018)

Nesting Preferences of Osmia Bees in the Rocky Mountains - A. Gander (2018)
Osmia is a genus of solitary, cavity-nesting bees which will readily nest in artificial nest- blocks. Nest-blocks (or “trap-nests”) have long been used to study cavity-nesting bees and have recently been popularized for conserving bees in urban and agricultural systems. What attributes of the nest-block, its placement, and its proximal environment are attractive to Osmia? At each of several existing sites with nest-blocks already set up in the Rocky Mountains, CO, I measured the orientation and height of each nest-block; the health, circumference, and color of each tree with a nest-block; and the internal temperature of each nest-block. Osmia preferred warmer nest-blocks and blocks on larger trees, but there was no observed effect of any other variable on the number of nesting Osmia iridis. Future research should focus on measuring internal nest temperature for longer periods of time and placing nest-blocks on a wider variety of tree circumferences.

Influence of Metal Contamination and Sediment Deposition on Benthic Invertebrate Colonization at the North Fork Clear Creek Superfund Site, Colorado, USA - Brittanie L. Dabney; William H. Clements; Jacob L. Williamson; James F. Ranville (Environmental Science & Technology, 2018)
Assessing benthic invertebrate community responses to multiple stressors is necessary to improve the success of restoration and biomonitoring projects. Results of mesocosm and field experiments were integrated to predict how benthic macroinvertebrate communities would recover following the removal of acid mine drainage from the North Fork of Clear Creek (NFCC), a U.S. EPA Superfund site in Colorado, USA. We transferred reference and metal-contaminated sediment to an upstream reference site where colonization by benthic macroinvertebrates was measured over 30 days. Additionally, a mesocosm experiment was performed to test the hypothesis that patches of metal-contaminated substrate impede recolonization downstream. Abundance in all treatments increased over time during field experiments; however, colonization was slower in treatments with metal-contaminated fine sediment. Community assemblages in treatments with metal-contaminated fine substrate were significantly different from other tr

Effects of spatial patterning of co-flowering plant species on pollination quantity and purity - J. D. Thompson; H. F. Fung; Jane E. Ogilvie (Annals of Botany, 2018)

Climate Warming Drives Local Extinction in a Subalpine Meadow - A. M. Panetta; M. L. Stanton; J. Harte (Mountain Views, 2018)

Comparing the level of human disturbance in 2009 and 2018 at yellow-bellied marmot (Marmota flaviventer) colonies - E. Foli (2018)
Natural areas and the animal communities within them are inevitably affected by human disturbance. Human disturbance can occur through tourism, ecotourism, and simply human presence. The effect of a human on an animal can be detrimental, and has even been shown to cause increases of stress response, result in animals spending less time foraging and taking care of young and more time foraging, and influence development of habituation, or decreased sensitivity, to human presence (Frid & Dill, 2002; Maréchal et al., 2016, Knapp et al., 2013). In order to understand any effects human disturbance may have on yellow-bellied marmot colonies (Marmota flaviventer), human disturbance must first be documented. In 2009, a study documented the level of human disturbance occurring within 300m of five marmot colonies along the East River Valley in the form of light and heavy vehicles, bicycles, dogs, and pedestrians. By revisiting those methods of disturbance documentation, we produced a dataset meas

Geochemical exports to river from the intra-meander hyporheic zone under transient hydrologic conditions: East River Mountainous Watershed, Colorado - Dipankar Dwivedi; Carl I. Steefel; Bhavna Arora; Michelle Newcomer; J. D. Moulton; Baptiste Dafflon; Boris Faybishenko; P. M. Fox; P. Nico; Nick Spycher; R. W. H. Carroll; K. H. Williams (Water Resources Research, 2018)
AbstractTo understand how redox processes influence carbon, nitrogen, and iron cycling within the intrameander hyporheic zone, we developed a biotic and abiotic reaction network and incorporated it into the reactive transport simulator PFLOTRAN. Two‐dimensional reactive flow and transport simulations were performed (1) to evaluate how transient hydrological conditions control the lateral redox zonation within an intrameander region of the East River in Colorado and (2) to quantify the impact of a single meander on subsurface exports of carbon and other geochemical species to the river. The meander's overall contribution to the river was quantified by integrating geochemical outfluxes along the outside of the meander bend. The model was able to capture the field‐observed trends of dissolved oxygen, nitrate, iron, pH, and total inorganic carbon along a 2‐D transect. Consistent with field observations, simulated dissolved oxygen and nitrate decreased along the intrameander flow paths whil

Art/Science collaborations: new explorations of ecological systems, values, and their feedbacks - Ellison A. M.; LeRoy C.J.; Landsbergen K. J.; Bosanquet E.; Borden D. B.; Paul J. CaraDonna; Cheney K.; Crystal-Ornelas R.; Dwire, Kathleen A.; L. Goralnik; E. Irons; B. G. Merkle; et al. (Ecological Society of America, 2018)

An Analysis of the Emergency Fire Response to the Colorado 2012 Waldo Canyon and 2013 Black Forest Fires - Gregory S. Marzolf; Ronald M. Sega (Journal of Homeland Security and Emergency Management, 2018)
Abstract This research hypothesizes that changes in command and control along with increased levels of trust and training led to a stronger response in Colorado’s 2013 Black Forest fire than that of the 2012 Waldo Canyon fire. Because the fires were categorized as the worst in the region’s history, and because they occurred in very close succession, in roughly the same area, involving many of the same responders, the fires provide valuable insights into how the response system adapted, or failed to adapt, to overcome key events under both scenarios. The study found that the ability to tailor command and control and supporting response structures to a particular event instead of using traditional rigid frameworks were instrumental to a more effective response. The study goes on to suggest that even though the Black Forest fire was met with an improved response, a systems approach is needed to better accommodate increasingly complex future events.

Relationships between CO2, thermodynamic limits on silicate weathering, and the strength of the silicate weathering feedback - M. J. Winnick; Katharine Maher (Earth and Planetary Science Letters, 2018)

Are Hylemya avoiding dusted Ipomopsis aggregata for good reason? - C. Rosas (2018)
Waser et al. (2016) found that road dust consistently reduces the pollen received by Ipomopsis aggregata flowers but does not consistently reduce seed set. Over three years we tested the hypothesis that the reason undusted plants do not have higher seed sets is that more of their fruits are eaten by larvae of Hylemya sp. (Anthomyiidae), a predispersal seed predator. In all three years, Hylemya indeed oviposited on a greater fraction of the flowers of undusted than dusted plants, though the overall oviposition rate varied among years. In 2017 and 2018 we also compared the fates of Hylemya eggs laid on dusted and undusted flowers to determine whether the flies were choosing undusted plants because their eggs are more successful there. In 2017, 33.42% of eggs laid on dusted flowers and 55% of eggs laid on undusted flowers successfully hatched into a larva. In 2018, the success rate was 48.6% and 21.8% on dusted and undusted flowers, respectively. We conclude that Hylemya oviposition prefe

Characterizing nectar content in wet and dry subalpine meadows during an extreme summer drought - A. Murphy (2018)
Pollinating bees visit flowers in order to forage for nectar and pollen, their major sources of nutrition. The plant communities that a bee interacts with vary across time and space, as different flower species dominate different habitats. One key driver of the spatial variation in plant communities is soil moisture, which creates distinct wet and dry habitats in the subalpine meadows around the Rocky Mountain Biological Laboratory (RMBL). These different flower species provide different nutritional rewards for visiting bees by producing varying amounts of sugar. Relatedly, flower species have differential responses to drought, and the very dry summer of 2018 represented a significant water challenge to flowering plants. We found that over the course of the season, wet and dry meadows contained the same amount of nectar sugar, based on the 13 species we measured. At certain time points, however, dry meadows contained more nectar owing to higher flower abundances. As expected, we also f

First-order controls of soil and leaf moisture - Samuel Pierce (2018)

Mix and Match: Transplanting symbiotic fungal partners across elevational gradients to gauge responses in migrating Elymus hosts - Kirk C. Anderson (2018)
Within the next century, ecosystems are projected to experience climate warming, with strong effects in mountain systems. Warming can alter species distributions, with documented upward migrations along elevation gradients. Species interactions may be important factors that promote species establishment during climate-induced migration. For plants, fungal interactions could help or hamper establishment, but little research has addressed this issue in mountain ecosystems. As plants move up-slope, they may bring fungal symbionts with them, encounter novel fungal consortia, or have the roles of their symbionts change. To investigate fungal symbionts during upward migration, I performed a field study that transplanted a low-elevation restricted grass species (Elymus elymoides) and broadly distributed grass species (E. trachycaulus) into low- and high-elevation sites. At each site, I imposed three soil treatments: sterile soil, fungal spores added from low-elevation sites, or fungal spores

Synchronization of speed, sound and iridescent color in a hummingbird aerial courtship dive - B. G. Hogan; M. C. Stoddard (Nature Communications, 2018)
Many animal signals are complex, often combining multimodal components with dynamic motion. To understand the function and evolution of these displays, it is vital to appreciate their spatiotemporal organization. Male broad-tailed hummingbirds (Selasphorus platycercus) perform dramatic U-shaped courtship dives over females, appearing to combine rapid movement and dive-specific mechanical noises with visual signals from their iridescent gorgets. To understand how motion, sound and color interact in these spectacular displays, we obtained video and audio recordings of dives performed by wild hummingbirds. We then applied a multi-angle imaging technique to estimate how a female would perceive the male's iridescent gorget throughout the dive. We show that the key physical, acoustic and visual aspects of the dive are remarkably synchronized-all occurring within 300 milliseconds. Our results highlight the critical importance of accounting for motion and orientation when investigating animal

Spatial and Temporal Patterns of Coexistence in Closely Related Rhyacophila (Trichoptera) Species - J. Yang (2018)
Environmental change affects the survival, interaction and co-existence of species within an ecosystem. We studied multiple species of Rhyacophila, a primitive genus of caddisfly that, in its larval state, lives at the bottom of cold, oxygen rich and fast flowing streams. Previous research has shown that six species, four of which are common, occur in the high montane, subalpine and alpine streams of the Upper East River Basin in the Gunnison National Forest. The goals of this study are: 1) to document the patterns of co-existence of different Rhyacophila species over space by sampling the same streams previously surveyed and to conduct species co- occurrence analyses to determine if there are any positive or negative associations between pairs of species; 2) to measure various environmental factors to obtain descriptive data about the typical niches of different species, which enabled us to generate hypotheses about potential causes of species co-occurrences; and 3) to conduct both se