Utilizing sustainability criteria to evaluate river basin decision-making: the case of the Colorado River Basin - John Berggren (Regional Environmental Change, 2018)

Habitat preference of an herbivore shapes the habitat distribution of its host plant - N. M. Alexandre; Parris T Humphrey; A. D. Gloss; J. W. Lee; J. Frazier; H. A. Affeldt; Noah K Whiteman (Ecosphere 9, 2018)
Plant distributions can be limited by habitat-biased herbivory, but the proximate causes of such biases are rarely known. Distinguishing plant-centric from herbivore-centric mechanisms driving differential herbivory between habitats is difficult without experimental manipulation of both plants and herbivores. Here we tested alternative hypotheses driving habitat-biased herbivory in bittercress (Cardamine cordifolia), which is more abundant under shade of shrubs and trees (shade) than in nearby meadows (sun) where herbivory is intense from the specialist fly Scaptomyza nigrita. This system has served as a textbook example of habitat-biased herbivory driving a plant's distribution across an ecotone, but the proximate mechanisms underlying differential herbivory are still unclear. First, we found that higher S. nigrita herbivory in sun habitats contrasts sharply with their preference to attack plants from shade habitats in laboratory choice experiments. Second, S. nigrita strongly preferred leaves in simulated sun over simulated shade habitats, regardless of plant source habitat. Thus, herbivore preference for brighter, warmer habitats overrides their preference for more palatable shade plants. This promotes the sun-biased herbivore pressure that drives the distribution of bittercress into shade habitats.

Conditional Exploitation and Context-Dependent Fitness Consequences of Pollination Mutualisms - S. K. Richman (http://hdl.handle.net/10150/628436, 2018)
The aboveground primary productivity within each of four areas, differing in length of the snow-free season, was determined in a high subalpine (3380 m) herbaceous meadow in Colorado. Net productivity, minus losses to herbivores, ranged from 114 g -m™ - yr“ in the area with the shortest snow-free period, to maximum values of 192 g - m™?. yr“ in areas with snow-free periods of intermediate length. Caltha leptosepala and Senecio cras- sulus, the only dominant forb species com- mon to all four areas, showed differing pat- terns of productivity within and between areas. Domestic sheep may have removed up to 38% of the peak standing crop within the study area during 6 h of grazing. Variation in dominance-diversity curves among the four areas suggests that the effect of snow cover in controlling the length of the growing season may be less important than its influence on moisture availability in determining the over- all structure of this subalpine community.

Dispersal, Wing Morphology and Physiology relationships in Euphydryas Gillettii and implications for conservation - O. Shrestha (2018)
Dispersal is important for recolonization, migration and maintenance of local metapopulations and populations, in case of disruption in an animal's habitat. Morphology (wing loading and wing aspect ratio) and physiology (metabolic rates) are features that have been shown to explain dispersal processes in insects. However, there are no studies indicating the direct relationship between morphology and metabolic rates in association with dispersal. I studied Euphydryas gillettii butterflies at Rocky Mountain Biological Laboratory, Colorado to assess the link between wing morphology and metabolic rates and their influence on dispersal within different sites at RMBL. Individuals that dispersed to other sites had greater wing wear (an age estimate) and greater wing loading. The total flight distance increased with increasing residual resting metabolic rate (RMR), that is, RMR adjusted for body mass. Residual flight metabolic rate (FMR) and peak metabolic rates (PMR) were related to wing loading. Residual FMR was greater for greater wing loading. Residual PMR was also greater for greater wing loading, but only in females. Overall, greater wing wear, greater wing loading and greater RMR are indicative of better dispersal in E. gillettii, but these three morphological and physiological characteristics are not linked to each other. These findings regarding dispersal characteristics of E. gillettii butterflies can help inform conservation strategies prior to any reintroduction and translocation efforts. More species-specific dispersal studies underpinning an organism's dispersal mechanisms can minimize difficulties due to unpredicted dispersal reportedly faced by managers during the translocation-reintroduction processes. v

First reports of turtle tracks from the Williams Fork Formation (‘Mesaverde’ Group), Upper Cretaceous (Campanian) of western Colorado - Martin G. Lockley; J. E. Smith; M. Ryan King (Cretaceous Research, 2018)

Direct and indirect effects of episodic frost on plants growth and reproduction in subalpine wildflowers - Pardee G.; David W. Inouye; R. E. Irwin (Global Change Biology, 2018)

Examining the impact of pollen diet composition on bee development and lifespan - M. McAulay (2018)
Pollen is the sole protein source for most bees and the largest component of their larval diets.

Consistent shifts in pollinator-relevant floral coloration along a Rocky Mountain elevation gradient - M. Gray; M. J. Stansberry; J. S. Lynn; C. F. Williams; T. E. White; Kenneth D. Whitney (Journal of Ecology, 2018)

Microenvironment and functional-trait context dependence predict plant community dynamics - B. Blonder; R. E. Kapas; R. M. Dalton; Bente J. Graae; Jacob M. Heiling; Oystein H. (Journal of Ecology, 2018)
Abstract Predicting the structure and dynamics of communities is difficult. Approaches linking functional traits to niche boundaries, species co‐occurrence and demography are promising, but have so far had limited success. We hypothesized that predictability in community ecology could be improved by incorporating more accurate measures of fine‐scale environmental heterogeneity and the context‐dependent function of traits. We tested these hypotheses using long term whole‐community demography data from an alpine plant community in Colorado. Species distributions along microenvironmental gradients covaried with traits important for below‐ground processes. Positive associations between species distributions across life stages could not be explained by abiotic microenvironment alone, consistent with facilitative processes. Rates of growth, survival, fecundity and recruitment were predicted by the direct and interactive effects of trait, microenvironment, macroenvironment and neighbourhood axes. Synthesis . Context‐dependent interactions between multiple traits and microenvironmental axes are needed to predict fine‐scale community structure and dynamics.

Consequences of secondary nectar robbing for male components of plant reproduction - S. K. Richman; R. E. Irwin; Bosak J. T.; J. L. Bronstein (American Journal of Botany, 2018)
Premise of the StudyOrganisms engage in multiple species interactions simultaneously. While pollination studies generally focus on plants and pollinators exclusively, secondary robbing, a behavior that requires other species (primary robbers) to first create access holes in corollas, is common. It has been shown that secondary robbing can reduce plants' female fitness; however, we lack knowledge about its impact on male plant fitness.MethodsWe experimentally simulated primary and secondary robbing in the monocarpic perennial Ipomopsis aggregata (Polemoniaceae), quantifying indirect effects on pollinator‐mediated pollen (dye) donation. We also assessed whether continual nectar removal via the floral opening has similar effects on hummingbird‐pollinator behavior as continual secondary robbing through robber holes.Key ResultsWe found no significant indirect effects of secondary robbing on a component of Ipomopsis male fitness. Although robbing did reduce pollen (dye) donation due to avoidance of robbed plants by pollinating hummingbirds, pollen donation did not differ between the two robbing treatments. The effects of secondary robbing on hummingbird behavior resembled effects of chronic nectar removal by pollinators. Our results indicate that hummingbird pollinators may use a combination of cues, including cues given by the presence or absence of nectar, to make foraging decisions.ConclusionsCombined with prior research, this study suggests that secondary robbing is less costly to a component of male fitness than to female fitness in Ipomopsis, broadening our knowledge of the overall costs of mutualism exploitation to total plant fitness.

Selenium Distribution for Soils Derived from Mancos Shale in Gunnison and Uncompahgre River Basins, West-Central Colorado - Moustafa A. Elrashidi (Communications in Soil Science and Plant Analysis, 2018)
Selenium (Se) is an essential micronutrient for humans and animals and can be toxic when present in high concentrations in soil and water. Many soils in Gunnison and Uncompahgre River Basins in West-Central Colorado are formed from deposits derived mainly from weathered Mancos shale that have high concentration of Se and salts. Elevated concentrations of Se and salts were detected in streams and rivers in this area. The objectives were to determine the amount and distribution of different forms of Se and relationships with physical and chemical properties for soils derived from Se-rich Mancos shale. The information may help to improve land management practices and minimize the environmental impact on natural water resources. A total of 48 topsoil samples and soils from horizons in 9 pedons were investigated. The total and water-soluble Se and other elements as well as physical and chemical properties were determined in soils. The total Se ranged from 330 to 5,673 µg/kg with a mean of 2,224 µg/kg. The water-soluble Se ranged from a minimum of 4.95 µg/kg to a maximum of 2,415 µg/kg and a mean of 338 µg/kg. A highly significant correlation was detected between the total and water-soluble Se in soils. Both the total organic carbon (TOC) and CaCO3% had significant positive correlations with the total Se. A highly significant correlation was also found between the water-soluble Se and electric conductivity (EC), as well as with the water-soluble chloride, sulfate, nitrate, molybdenum, and sodium in soils. For the pedons tested, in general, both the total and water-soluble Se increased with depth. However, the water-soluble Se concentrations were greater in shallow than deep pedons where most Se was removed from soils with drainage water. It could be concluded that Se leaching from topsoils and that dissolving from Se-rich parent materials would be a major source of elevated Se concentrations in streams/rivers for the West-Central Colorado area. To minimize the impact on water quality, an appropriate land/water management practices should be followed to minimize Se leaching from soils derived from Mancos shale.

Transient LTRE analysis reveals the demographic and trait-mediated processes that buffer population growth - Adriana A. Maldonado-Chaparro; Daniel T. Blumstein; Kenneth B. Armitage; D. Z. Childs (Ecology Letters, 2018)
Adriana A. Maldonado- Temporal variation in environmental conditions affects population growth directly via its impact Chaparro,1,2,3* Daniel T. on vital rates, and indirectly through induced variation in demographic structure and phenotypic Blumstein,1,4 Kenneth B. Armitage5 trait distributions. We currently know very little about how these processes jointly mediate popu- and Dylan Z. Childs6* lation responses to their environment. To address this gap, we develop a general transient life table response experiment (LTRE) which partitions the contributions to population growth arising from variation in (1) survival and reproduction, (2) demographic structure, (3) trait values and (4) climatic drivers. We apply the LTRE to a population of yellow-bellied marmots (Marmota fla- viventer) to demonstrate the impact of demographic and trait-mediated processes. Our analysis provides a new perspective on demographic buffering, which may be a more subtle phenomena than is currently assumed. The new LTRE framework presents opportunities to improve our understanding of how trait variation influences population dynamics and adaptation in stochastic environments.

Evaluating Critical Thermal Tolerances of Solitary Bees - L. Naslund (2018)
Climate change is predicted to impact pollinators through both direct and indirect mechanisms: by altering physiological stress through warming temperatures and by changing species interactions through the altered phenology and abundance of food sources and competitors. While research has been done to evaluate the indirect mechanism of climate change on bees, less is known about the direct mechanism of thermal stress. To fill this gap, we measured the critical maxima (CTmax) of 20 distinct solitary bee taxa to 1) evaluate differences in CTmax among taxa, 2) identify the life history-traits that influence thermal tolerance, 3) determine how well CTmax predicts success in hotter-than-average years, as a proxy for conditions under long-term warming, and 4) evaluate if there is local adaptation of CTmax at different elevations within the same species. We found significant differences among taxa in average CTmax, driven primarily by Lasioglossum inconditum, Halictus virgatellus, Sphecodes sp., and Habropoda sp. which had significantly lower CTmax and Pseudopanurgus bakeri, Halictus rubicundus, Osmia spp. and Megachile spp. which had significantly higher CTmax than all additional species tested. In evaluating the traits related to differences in thermal tolerance, we found that only mass significantly predicted CTmax, with larger bees demonstrating higher CTmax. We found that CTmax predicted responses to a hotter-than-average year, indicating a relationship between thermal tolerance and fecundity effects. Finally, we found evidence for local adaptation in CTmax to elevation only in Hylaeus spp. and Megachile spp. Taken together, these results indicate a direct mechanism of climate change impact beyond alterations in the phenology and abundance of interacting species and indicate a species-specific response to warming based on both the breadth of thermal tolerance and local adaptation of populations.

Flannelmouth Sucker: The Ironhorse of the Colorado River Basin - C Nate Cathcart (Fisheries, 2018)

Determining the Effects of Climate-Induced Range Shifts on Caddisfly Population Dynamics - M. Hagaman (2018)
The geographic distribution of many freshwater insects is restricted in part by timing of snowmelt and the temperature of the water. Because of this, climate change is having a significant effect on the distribution of aquatic species around Gothic, Colorado. Scientists have documented that species typically found in lower elevation have begun to expand their range into higher alpine ponds. However, it is unknown how elevation will affect their population dynamics and rate of nutrient recycling. Caddisflies are a species of aquatic detritivores that are fundamental in providing nutrients to the ecosystem. Understanding how elevation affects caddisfly growth and population size is key to understanding how climate change will affect alpine communities globally. To have a better understanding of this concept, I studied 37 ponds ranging from 2,347 to 3,505 meters in elevation and looked at how elevation affected population density, adult body size, and adult emergence time of four species of caddisfly: Limnephilus externus, Limnephilus picturatus, Grammotaulius lorretae, and Asynarchus nigriculus. I took density samples of these species in each pond throughout the summer. Pupae were placed in emergence chambers, and adults were collected and measured. Elevation had a significant effect on the emergence time of Asynarchus. Elevation also positively affected Asynarchus density while it negatively affected Grammotaulius density. Pond type had a significant effect on Asynarchus thorax and abdomen weight at the Mexican Cut. This study was important because understanding how climate change affects foundational species may help us better understand its far-reaching effects on ecosystems.

Marmots do not consistently use their left eye to respond to an approaching threat but those that did fled sooner - Daniel T. Blumstein; A. Diaz; L. Yin (Current Zoology, 2018)
In many vertebrates, the brain's right hemisphere which is connected to the left visual field specializes in the processing of information about threats while the left hemisphere which is connected to the right visual field specializes in the processing of information about conspecifics. This is referred to as hemispheric lateralization. But individuals that are too predictable in their response to predators could have reduced survival and we may expect selection for somewhat unpredictable responses. We studied hemispheric lateralization in yellow-bellied marmots Marmota flaviventer, a social rodent that falls prey to a variety of terrestrial and aerial predators. We first asked if they have lateralized responses to a predatory threat. We then asked if the eye that they used to assess risk influenced their perceptions of risk. We recorded the direction marmots were initially looking and then walked toward them until they fled. We recorded the distance that they responded to our experimental approach by looking, the eye with which they looked at us, and the distance at which they fled (i.e., flight initiation distance; FID). We found that marmots had no eye preference with which they looked at an approaching threat. Furthermore, the population was not comprised of individuals that responded in consistent ways. However, we found that marmots that looked at the approaching person with their left eye had larger FIDs suggesting that risk assessment was influenced by the eye used to monitor the threat. These findings are consistent with selection to make prey less predictable for their predators, despite underlying lateralization.

Rocky Mountain Biological Lab. 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)

Ecological causes and consequences of flower color polymorphism in a self pollinating plant (Boechera stricta) - Priya Vaidya; Ansley McDurmon; Emily Mattoon; Michaela Keefe; L. Carley; Lee C-R; Robin Bingham; J. T. Anderson (New Phytologist, 2018)

Ammoniozippeite, a New Uranyl Sulfate Mineral from the Blue Lizard Mine, San Juan County, Utah, and the Burro Mine, San Miguel County, Colorado, USA - Anthony R. Kampf; Jakub Plášil; Travis A. Olds; Barbara P. Nash; Joe Marty (The Canadian Mineralogist, 2018)
Research Article| May 30, 2018 Ammoniozippeite, a New Uranyl Sulfate Mineral from the Blue Lizard Mine, San Juan County, Utah, and the Burro Mine, San Miguel County, Colorado, USA Anthony R. Kampf; Anthony R. Kampf § Mineral Sciences Department, Natural History Museum of Los Angeles County, 900 Exposition Boulevard, Los Angeles, California 90007, U.S.A. § Corresponding author e-mail address: akampf@nhm.org Search for other works by this author on: GSW Google Scholar Jakub Plášil; Jakub Plášil Institute of Physics ASCR, v.v.i., Na Slovance 1999/2, 18221 Prague 8, Czech Republic Search for other works by this author on: GSW Google Scholar Travis A. Olds; Travis A. Olds Department of Civil and Environmental Engineering and Earth Sciences, University of Notre Dame, Notre Dame, Indiana 46556, U.S.A. Search for other works by this author on: GSW Google Scholar Barbara P. Nash; Barbara P. Nash Department of Geology and Geophysics, University of Utah, Salt Lake City, Utah 84112, U.S.A. Search for other works by this author on: GSW Google Scholar Joe Marty Joe Marty 5199 E. Silver Oak Road, Salt Lake City, Utah 84108, U.S.A. Search for other works by this author on: GSW Google Scholar Author and Article Information Anthony R. Kampf § Mineral Sciences Department, Natural History Museum of Los Angeles County, 900 Exposition Boulevard, Los Angeles, California 90007, U.S.A. Jakub Plášil Institute of Physics ASCR, v.v.i., Na Slovance 1999/2, 18221 Prague 8, Czech Republic Travis A. Olds Department of Civil and Environmental Engineering and Earth Sciences, University of Notre Dame, Notre Dame, Indiana 46556, U.S.A. Barbara P. Nash Department of Geology and Geophysics, University of Utah, Salt Lake City, Utah 84112, U.S.A. Joe Marty 5199 E. Silver Oak Road, Salt Lake City, Utah 84108, U.S.A. § Corresponding author e-mail address: akampf@nhm.org Publisher: Mineralogical Association of Canada First Online: 25 May 2018 Online Issn: 1499-1276 Print Issn: 0008-4476 © 2018 Mineralogical Association of Canada The Canadian Mineralogist (2018) 56 (3): 235–245. https://doi.org/10.3749/canmin.1800002 Article history First Online: 25 May 2018 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Anthony R. Kampf, Jakub Plášil, Travis A. Olds, Barbara P. Nash, Joe Marty; Ammoniozippeite, a New Uranyl Sulfate Mineral from the Blue Lizard Mine, San Juan County, Utah, and the Burro Mine, San Miguel County, Colorado, USA. The Canadian Mineralogist 2018;; 56 (3): 235–245. doi: https://doi.org/10.3749/canmin.1800002 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyThe Canadian Mineralogist Search Advanced Search Abstract The new mineral ammoniozippeite (IMA2017-017), (NH4)2[(UO2)2(SO4)O2]·H2O, was found in both the Blue Lizard mine San Juan County, Utah, and the Burro mine, San Miguel County, Colorado, USA. At both mines, it occurs as a low-temperature, secondary phase. The mineral is yellow to yellowish orange with pale yellow streak and fluoresces dull green yellow under 405 nm laser light. Crystals are transparent and have vitreous luster. It is brittle, with Mohs hardness of about 2½, splintery fracture, and three cleavages: {010} and {001} perfect, {100} good. The calculated density for the ideal formula is 4.433 g/cm3. Crystals are acicular to bladed, elongate on [100], up to about 0.2 mm in length at the Blue Lizard, and up to 2 mm at the Burro. Ammoniozippeite is optically biaxial (+) with α = 1.678(2), β = 1.724(3), γ = 1.779(3) (white light); the measured 2V is 87.1(5)°; r < v dispersion is weak; the optical orientation is X = b, Y = c, Z = a; and pleochroism is X colorless, Y orange yellow, and Z yellow orange (X ≪ Y < Z). Electron microprobe analyses (WDS mode) provided the empirical formulae [(NH4)1.97Na0.03]Σ2.00(U1.00O2)2(S1.01O4)O2·H2O and [(NH4)1.99K0.06Na0.04]Σ2.09(U1.01O2)2(S0.97O4)O2·H2O for crystals from the Burro and Blue Lizard mines, respectively. The five strongest X-ray powder diffraction lines for Burro mine material are [dobs Å(I)(hkl)]: 7.17(100)(020), 3.580(21)(040), 3.489(42)(203), 3.138(63)(223), and 1.6966(18)(229,426). Ammoniozippeite is orthorhombic, Ccmb, a 8.7944(3), b 14.3296(7), c 17.1718(12) Å, V 2164.0(2) Å3, and Z = 8. The structure of ammoniozippeite (R1 = 0.0396 for 932 reflections with Io > 2σI) contains edge-sharing zig-zag chains of pentagonal bipyramids that are linked by sharing corners with SO4 groups, yielding a [(UO2)2(SO4)O2]2– sheet based on the zippeite-type topology. The interlayer region contains two NH4+ groups and one H2O group pfu, statistically distributed over three sites. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

The Effects of Declining Aspen Forest Health on Rocky Mountain Birds - J. D. Gerber (2018)

Climate Warming Drives Local Extinction: Evidence from Observation and Experimentation - A. M. Panetta; M. L. Stanton; J. Harte (ScienceAdvances, 2018)
Climate warming causes plant populations to crash by reducing fecundity and survival across multiple life stages.

Phenological shifts of native and invasive species under climate change: insights from the Boechera Lythrum model - R. I. Colautti; J. Agren; J. T. Anderson (Philosophical Transactions of the Royal Society B: Biological Sciences, 2017)

Snowmelt controls on concentration-discharge relationships and the balance of oxidative and acid-base weathering fluxes in an alpine catchment, East River, Colorado - M. J. Winnick; R. W. H. Carroll; K. H. Williams; R. M. Maxwell; Wenming Dong; Katharine Maher (Water Resources Research, 2017)

Examining Spatial Patterns of Exhumation in Colorado’s Elk Mountains During the Late Miocene Using Apatite (U-Th)/He Thermochronology - N. McCorkel (2017)
Spatial patterns of the magnitude and rate of exhumation occurring during the late

Differences in Evolutionary History and Ploidy Type Shape the Interactions of Populus tremuloides Michx. with Climate - B. T. Greer (2017)

Effects of Microclimate on the regeneration of Quaking Aspens, Populus tremuloides - Marco Castaneda (2017)
Populus tremuloides is a keystone species found throughout North America. P. tremuloides aids the regeneration of eco systems, however as climate changes, the health of P. tremuloides is changing. P. tremuloides populations are on the decline in the American southwest, and with time it could affect P. tremuloides populations in the Rocky Mountains of Colorado. In this Study the relationship between tree regeneration, tree death, soil temperature and soil moisture, a one hectare plot was tested to show if low soil moisture and higher soil temperatures were causing higher P. tremuloides mortality rates and low regeneration rates. The study resulted in no significance between dead trees and soil moisture and soil temperature. However, regenerating trees expressed a decline when soil temperature rises.

Does it stay or does it go: exploring seasonal influences on nutrients across topography in a Colorado mountain watershed - E. Ballor (2017)
Climate change is a current issue that impacts ecosystems and the natural processes within them. Through the variance of factors such as, temperature, precipitation and hydrology due to climate change key processes such as nutrient cycling are affected. This study focused on the movement of nitrogen in a Colorado mountain watershed. Through the measurement of various forms of nitrogen, i.e. nitrate and ammonium (NH4+ & NO3-) which are available to aid plant growth, found throughout the cycle and potential effects of climate change can be realized. Nitrogen amounts were compared with NDVI data, soil water content, near infrared photography and microclimate data to find any correlations that affect the nitrogen cycle and the amount of available nitrogen in the ecosystem. This study looked at a different way to view the Colorado mountain watershed. Over time NDVI values changed at both sites (Lower Montane and Lower Sub-Alpine). How NDVI changes over time varies and depends on the site specific conditions.

Comment on Cognition-mediated evolution of low-quality floral nectars. - G. H. Pyke; Nickolas M. Waser (Science, 2017)
Nachev et al (Reports, 6 January 2017, p. 75) present dilute nectar in bat-pollinated plants as "paradoxical" because bats prefer concentrated nectar, but paradox disappears with realistic assumptions about nectar evolution. We argue that they make unrealistic assumptions about the cognitive abilities of bat pollinators, invoke Weber's law inappropriately, and cannot predict observed nectar concentrations of bat flowers or negative correlations between pollinator body size and average concentration.

Pollinator traits and competitive context shape dynamic foraging behavior in bee communities - H. M. Briggs; B. J. Brosi (bioRxiv, 2017)

Does a foliar endophyte improve plant fitness under flooding? - A. Adams; Melanie R Kazenel; Jennifer A. Rudgers (Plant Ecology, 2017)
The novel hypothesis that endophyte symbiosis promotes host fitness under flooded conditions, contributing to niche differentiation between the two bluegrass species is investigated, demonstrating an overall benefit of fungal symbiosis in this system.

Native ant (Formica rufa, Formica fusca), Nicrophorus spp. interactions at small mammal carcass resources in the southern Rocky Mountains, Gunnison National Forest, Colorado. - A. Solis (2017)
Competition for carcass resources can be fierce with a broad range of taxa vying for control of the nutrient rich resource. Arthropod competition for carcasses is well studied. Flies, beetles, and ants are common carcass utilizers. The burying beetle (Nicrophorus spp). is an obligate carrion breeder who has developed many methods of securing carcasses. Ants are opportunistic scavengers who would utilize many resource made available to them, including carcasses. Competition between the two taxa is not well understood, but invasive species Solenopsis invicta and native species of Florida, Solenopsis geminata, have been shown to have significant effect on Nicrophorus reproductive success. The purpose of this study is to investigate if native ants of the higher latitude and elevation of southern Rocky Mountains, Gunnison National forest, Colorado, have the same negative effect on Nicrophorus sequestration of carcass resource for reproduction. The study found the native ant species Formica rufa and Formica fusca had no effect on the burial of carcasses by Nicrophorus. These findings support previously established evidence of decreased competition for carcasses in higher elevations and latitudes.

The behavioral ecology of nectar robbing: why be tactic constant? - J. L. Bronstein; J. L. Barker; E. M. Lichtenberg; L. L. Richardson; R. E. Irwin (Current Opinion in Insect Science, 2017)
It is documented that even though individuals can switch foraging tactics, they often do not, and hypotheses of floral constancy are extended to understand when and why visitors exhibit tactic constancy and raise questions for future research.

Metabolism of toxic sugars by the bee gut symbiont Gilliamella apicola - H. Zheng; A. Nishida; W. K. Kwong; H. Koch; P. Engel; M. I. Steele; N. A. Moran (mBio, 2017)

Is Compensatory Growth Costly? - S. Heissenberger (2017)
1. Compensatory growth is well-studied and exhibited across a variety of taxa, including plants, invertebrates, and a variety of vertebrates. Compensatory mechanisms allow individuals to recover from adverse conditions, potentially enhancing survival and fitness. However, to compensate for a low body condition, individuals may allocate energetic resources to a few physiological functions, affecting the ability of other bodily functions to perform efficiently. Such costs associated with compensatory growth are shown in previous studies, and are expected to be strongest at early life stages. The allocation of resources to accelerate body growth may be traded-off against other essential physiological processes, such as bone growth, immunocompetence, and tissue repair. 2. We quantified short and long-term consequences of differential body growth rates in a wild population of yellow-bellied marmots, Marmota flaviventer, obligate hibernators with a short active season. We used mass measurements collected from 2002-2014 to calculate individual growth trajectories, and estimated annual survival from 688 females at distinct life stages (142 adults, 239 yearlings, 643 juveniles) distributed along a mild elevational gradient (165 m). We also estimated longevity utilizing 322 longitudinal mass measurements throughout the lifespan of 72 females. 3. We found that increased mass gain rate, coupled with the demands of a harsher higher- elevation environment, reduced annual survival in the young cohort. Older individuals with accelerated mass gain had higher survival, regardless of location in the elevational gradient. Collectively, we found that rapid mass gain had no effect on longevity. 2 4. Thus, while adults may benefit from accelerated mass gain, it may be that younger individuals pay a price. This cost in the younger cohort varies according to environmental conditions. Developing individuals face conflicting demands of structural vs. fat reserve growth, and one may be prioritized over the other in adverse conditions. Therefore, the benefits and costs of rapid growth are age and site- specific, and the costs are concentrated in young individuals in harsh environments. Furthermore, the costs of accelerated growth in this species may be exerted in the short-term, rather than paid later in life.

Detrending phenological time series improves climate-phenology analyses and reveals evidence of plasticity - Amy M. Iler; David W. Inouye; N. M. Schmidt; T. T. Hoye (Ecology, 2017)
AbstractTime series have played a critical role in documenting how phenology responds to climate change. However, regressing phenological responses against climatic predictors involves the risk of finding potentially spurious climate–phenology relationships simply because both variables also change across years. Detrending by year is a way to address this issue. Additionally, detrending isolates interannual variation in phenology and climate, so that detrended climate–phenology relationships can represent statistical evidence of phenotypic plasticity. Using two flowering phenology time series from Colorado, USA and Greenland, we detrend flowering date and two climate predictors known to be important in these ecosystems: temperature and snowmelt date. In Colorado, all climate–phenology relationships persist after detrending. In Greenland, 75% of the temperature–phenology relationships disappear after detrending (three of four species). At both sites, the relationships that persist after detrending suggest that plasticity is a major component of sensitivity of flowering phenology to climate. Finally, simulations that created different strengths of correlations among year, climate, and phenology provide broader support for our two empirical case studies. This study highlights the utility of detrending to determine whether phenology is related to a climate variable in observational data sets. Applying this as a best practice will increase our understanding of phenological responses to climatic variation and change.

The maintenance of flower colour polymorphism in self-pollinating Boechera stricta - Priya Vaidya (2017)
Pollinator-mediated selection cannot explain why flower colour polymorphisms exist in self-pollinating plants. There is a tight link between plant stress response and anthocyanin pigment production, which means that abiotic stress, such as UV radiation or drought, and biotic stress, such as herbivory or competition, can also affect flower colour selection indirectly. I used Boechera stricta to test whether environmental factors are responsible for flower colour polymorphism in self-pollinating plants, and evaluate 1) the biotic and abiotic correlates of flower colour variation, 2) the fitness consequences of this polymorphism, and 3) whether flower colour variation and ultimately pigment production are plastic traits. I sampled at Gothic, Colorado along an elevational range of approximately 2700m to 3400m, where I visited 11 locations and sampled from six 15m transects randomly per location. I measured plant growth and reproduction, along with abiotic and biotic factors that may correlate with flower colour. I also analyzed data from the long-term common garden experiment run by the Anderson lab to determine plasticity of flower colour. The observational data are still under analyses, but we have analyzed some of the common garden data and can conclude that 1) lower elevation plants are more likely to produce pink or purple flowers, and 2) pink or purple flowered plants have lower herbivore damage than white flowered plants. Water availability and natural enemies may play important roles in the first pattern because lower elevations generally show lower precipitation and a greater influence of biotic interactions. Plants with pigmented flowers may also induce greater herbivore-resistance compounds due to the shared biosynthetic pathway of anthocyanin and other flavonoids. This may present indirect selection on flower colour if herbivores influence chemical resistance traits in these plants. However, we will need to analyze the observational data to determine how these abiotic and biotic factors correlate with flower colour, and analyze heritability from the common garden.

Genetic basis of between-individual and within-individual variance of docility - J. G. A. Martin; E. Pirotta; M. B. Petelle; Daniel T. Blumstein (Journal of Evolutionary Biology, 2017)
AbstractBetween‐individual variation in phenotypes within a population is the basis of evolution. However, evolutionary and behavioural ecologists have mainly focused on estimating between‐individual variance in mean trait and neglected variation in within‐individual variance, or predictability of a trait. In fact, an important assumption of mixed‐effects models used to estimate between‐individual variance in mean traits is that within‐individual residual variance (predictability) is identical across individuals. Individual heterogeneity in the predictability of behaviours is a potentially important effect but rarely estimated and accounted for. We used 11 389 measures of docility behaviour from 1576 yellow‐bellied marmots (Marmota flaviventris) to estimate between‐individual variation in both mean docility and its predictability. We then implemented a double hierarchical animal model to decompose the variances of both mean trait and predictability into their environmental and genetic components. We found that individuals differed both in their docility and in their predictability of docility with a negative phenotypic covariance. We also found significant genetic variance for both mean docility and its predictability but no genetic covariance between the two. This analysis is one of the first to estimate the genetic basis of both mean trait and within‐individual variance in a wild population. Our results indicate that equal within‐individual variance should not be assumed. We demonstrate the evolutionary importance of the variation in the predictability of docility and illustrate potential bias in models ignoring variation in predictability. We conclude that the variability in the predictability of a trait should not be ignored, and present a coherent approach for its quantification.

Measuring occupation span at two stone circle sites in Larimer County, Colorado - Halston F.C. Meeker; LaBelle, Jason M.; Pante, Michael; Jacobi, Tobi (Digital Collections of Colorado (Colorado State University), 2017)
Stone circle sites are notorious for low artifact frequencies. This deters archaeological study because low artifact frequencies are thought to limit research potential. Two stone circle sites, Killdeer Canyon (5LR289) and T-W Diamond (5LR200) offer insight into short-term habitations, despite their low artifact frequencies. The two sites are located in northern Colorado, in the hogback zone along the Front Range of the Southern Rocky Mountains. The Colorado State University field school excavated the sites in 1982 and 1971 respectively. Artifacts from the interior of the features include lithic tools and debris, bone, and ceramics. This thesis examines each artifact class from excavated context as a proxy for understanding the length and number of occupations. Local and non-local chipped stone ratios, faunal procurement and processing strategies, and petrographic analysis are used to address how long and how many times each site was occupied. New radiocarbon dates show contemporaneity between rings at each site, dating Killdeer Canyon to the late A.D. 1600s and T-W Diamond to the late A.D. 1200s. These data demonstrate the ephemerality of the two sites but highlight potential differences in site use. While Killdeer Canyon likely represents a small group passing through an area, T-W Diamond could represent a larger group congregation, perhaps for hunting purposes. Furthermore, this thesis attests to the merit of using multiple lines of evidence to compensate for small sample sizes.

Consistently inconsistent drivers of patterns of microbial diversity and abundance at macroecological scales - J. N. Hendershot; Quentin D Read; Jeremiah A Henning; Nathan J. Sanders; Aimee T Classen (Ecology, 2017)
AbstractMacroecology seeks to understand broad‐scale patterns in the diversity and abundance of organisms, but macroecologists typically study aboveground macroorganisms. Belowground organisms regulate numerous ecosystem functions, yet we lack understanding of what drives their diversity. Here, we examine the controls on belowground diversity along latitudinal and elevational gradients. We performed a global meta‐analysis of 325 soil communities across 20 studies conducted along temperature and soil pH gradients. Belowground taxa, whether bacterial or fungal, observed along a given gradient of temperature or soil pH were equally likely to show a linear increase, linear decrease, humped pattern, trough‐shaped pattern, or no pattern in diversity along the gradient. Land‐use intensity weakly affected the diversity‐temperature relationship, but no other factor did so. Our study highlights disparities among diversity patterns of soil microbial communities. Belowground diversity may be controlled by the associated climatic and historical contexts of particular gradients, by factors not typically measured in community‐level studies, or by processes operating at scales that do not match the temporal and spatial scales under study. Because these organisms are responsible for a suite of key processes, understanding the drivers of their distribution and diversity is fundamental to understanding the functioning of ecosystems.

Structural evolution of the Hamilton Creek-Dry Creek anticline and its relationship to the southeast termination of Paradox Valley, SW Colorado, The - Elizabeth P. Wilson (Digital Collections of Colorado (Colorado State University), 2017)
The Pennsylvanian-Permian Paradox Basin is an asymmetrical basin on the Colorado Plateau (Figure 1.1) that has been studied for decades due to its unique geologic history and economic quantities of potash, petroleum, and minerals such as uranium, vanadium, radium, and copper. The basin has a complex tectonic history, made more difficult to interpret due to the large volume of Pennsylvanian-aged salt deposited in the northern part of the basin, now forming a series of salt walls. The basin has been interpreted as a foreland basin by Barbeau (2003), formed in response to loading by the Uncompahgre Uplift, which delineates the northeastern boundary of the basin. There is no definitive evidence, to date, of the tectonic influence of later tectonic events, namely the Late Cretaceous Laramide orogeny. Understanding the evolution of the salt walls and intervening strata within the basin will help identify indicators of tectonic regimes and influences throughout the basin history. The Paradox Basin contains the thickest contiguous salt deposit in continental North America (Hite, 1960), which makes it an important outcrop analog for subsurface salt systems around the world, including the Gulf of Mexico, North Sea, and south Atlantic Margin. Most of the work to date in the northern Paradox Basin has been conducted on the large-scale salt walls, such as Castle Valley, Salt Valley, and Moab Valley in Utah (Figure 1.1), but relatively little work has been done on the Colorado side of the basin to the southeast. Additionally, little work has been conducted on smaller-scale salt structure, such as Gibson dome, Lockhart anticline, and Rustler dome (Figure 1.1). Research must be conducted on these small-scale salt features to further academic and industrial understanding of the geology and evolution of this salt system because these features are more intact, less eroded, and, therefore, may contain better preserved evidence of the relationship between tectonic movement and reactivation, salt wall evolution, and halokinetic stratigraphy.

Effects of Didymosphenia germinata on American Dipper (Cinclus mexicanus) Territory Size - Richard G. Baker (2017)
The American dipper (Cinclus mexicanus) is a medium-sized passerine that forages predominantly in

Interaction rewiring and the rapid turnover of plant-pollinator networks - Paul J. CaraDonna; William K. Petry; Ross M. Brennan; James L. Cunningham; J. L. Bronstein; Nickolas M. Waser; Nathan J. Sanders (Ecology Letters, 2017)
Paul J. CaraDonna,1,2,3,4* Whether species interactions are static or change over time has wide-reaching ecological and evo- William K. Petry,1,5,6 lutionary consequences. However, species interaction networks are typically constructed from tem- Ross M. Brennan,1,7 porally aggregated interaction data, thereby implicitly assuming that interactions are fixed. This James L. Cunningham,1,2 approach has advanced our understanding of communities, but it obscures the timescale at which Judith L. Bronstein,2 interactions form (or dissolve) and the drivers and consequences of such dynamics. We address Nickolas M. Waser1 and this knowledge gap by quantifying the within-season turnover of plant–pollinator interactions Nathan J. Sanders1,3,8 from weekly censuses across 3 years in a subalpine ecosystem. Week-to-week turnover of interac- tions (1) was high, (2) followed a consistent seasonal progression in all years of study and (3) was dominated by interaction rewiring (the reassembly of interactions among species). Simulation models revealed that species’ phenologies and relative abundances constrained both total interac- tion turnover and rewiring. Our findings reveal the diversity of species interactions that may be missed when the temporal dynamics of networks are ignored.

Constraining the Timing of River Incision in the Upper Colorado Drainage Basin Using Apatite (U-Th)/He Thermochronology in the Elk Mountains, Western Colorado - C. Hiett (2017)
This study utilizes apatite (U-Th)/He, or AHe, to produce a vertical transect of cooling histories along the height of the partially exhumed Crystal Pluton in the Elk Mountains of west/central Colorado. These cooling histories are interpreted to reflect exhumation controlled by the incision of the Crystal River – a tributary of the Colorado River. A period of rapid exhumation is observed from 8 – 11 Ma, likely beginning earlier, that is consistent with previous AHe data taken from nearby exhumed plutons in the Elk and northern West Elk Mountains. This period of exhumation predates the incision of a low relief surface that developed in northwestern Colorado by ca. 10 Ma, and is therefore not believed to have been controlled by the incision of the Colorado River. A review of previously noted incision constraints suggests that post-10 Ma Colorado River incision has become more rapid in the last 1 – 3 Ma, suggesting that climate change, rather than epeirogenic uplift, is the major driver for recent river incision.

Assessing Plant Community Assembly Along an Elevational Gradient: A Functional Niche Hypervolume Approach - K. Hayashi (2017)
Niche-based processes, such as environmental filtering and niche differentiation, have been proposed to contribute to the assembly of ecological communities. While functional traits can be useful for testing hypotheses regarding niche-based community assembly, most studies utilizing functional traits to examine such hypotheses have focused on patterns of individual traits or of mean trait values. We tested for signatures of environmental filtering and niche differentiation on the assembly of subalpine meadow communities in the Rocky Mountains, Colorado, USA by constructing site-level and species-level trait space hypervolumes from field-collected functional trait data (foliage height, SLA, LDMC). We found a trend of increasing community trait space volume and decreasing community trait space density (species/volume) with increasing elevation. Species-level trait space, however, exhibited no relationship with elevation. Additionally, we found that pair-wise distances of species-level trait space hypervolume increases with elevation. Overall, contrary to conventional hypotheses regarding niche-based community assembly, our results support a pattern of larger community trait space at higher elevations and more “packed” trait space at lower elevations. Incorporation of additional communities, sites, and trait combinations into our study should yield further insights into the patterns observed here.

The Effects of Early Snow-melt on the Pollination and Seed Production of Delphinium nuttallianum - L. Gonzalez (2017)

Growth Tendencies in Didymosphenia geminata - J. Kast (2017)
Didymosphenia geminata cells, when secreting excessive exopolysaccharide stalks, can coalesce and form blooms that affect their local community. It is unknown what causes D. geminata cells to produce stalk, as not all D. geminata cells do produce stalk. Natural growth patterns and the potential for D. geminata cells to utilize a population dynamic such as quorum sensing to begin to produce stalk was tested through placement of microscope slides in Copper Creek and the East River (to observe undisturbed growth over time) and observations of stalk production based on compartmentalized D. geminata populations of different cell densities (8, 80, 800, and 8000 cells/cm2), to monitor how cell density affects stalk production. Statistical analyses found that stalk production (measured by the frequency of cells with stalks, or FSC) was significantly different due to differing cell densities, and that after a threshold of approximately 15 cells/cm2, the rate of change of FSC changed, indicating that cell density does affect stalk production.

Groundhog day is so silly. But as a groundhog scientist I love it anyway - Daniel T. Blumstein (2017)

States and transitions in aspen dominated ecosystems in western Colorado - Christopher Patrick King Dickey; Meiman, Paul; Fernandez-Gimenez, Maria; Melzer, Susan; Shepperd, Wayne (Digital Commons - USU (Utah State University), 2017)
In Colorado and the southwestern United States, quaking aspen (Populus tremuloides Michx.) is a species of high ecological, economic, and aesthetic importance. In response to the interests of several landowners and land managers in my study sites, this thesis describes my efforts to identify differences among aspen stand types in western Colorado and the ecological sites on which they occur; to describe aspen communities on different ecological sites based on species composition, functional traits, and drivers of change; and to synthesize this information in state-and-transition models (STM) applicable to specific ecological sites (ESs). In Chapter 2, I analyzed the results of aspen inventories and found that three of my four study sites contained aspen stands that are considered stable aspen subtypes. The fourth site contained stands representing a seral aspen type where conifer encroachment has occurred. I found higher frequencies and intensities of browsing in areas with isolated stands compared to areas with large continuous stands and in these areas there was evidence that browsing has affected juvenile aspen stem densities. Clear-felling on one site with large stable stands stimulated new stem growth, while prescribed burns on another site with smaller stable stands did not stimulate new stem growth. In Chapter 3, I classified sites based on soil and other abiotic site characteristics using partitioning around medoids (PAM). I then developed STMs for these sites using agglomerative hierarchical clustering analysis, indicator species analysis, permutational multivariate analysis of variance (PERMANOVA), non-metric multidimensional scaling (NMS), and the Random Forest algorithm to identify plant species associations and correlated abiotic factors and management treatments. Three of my STMs depict aspen and non-aspen dominated states associated with differences in abiotic site characteristics, and one STM depicts a single aspen dominated state. My investigation of aspen health and factors contributing to aspen mortality provides land managers in western Colorado with useful information for making informed decisions regarding aspen management. The STMs I have developed for these sites show which abiotic variables can be expected to be correlated with specific vegetation states and will inform future STM development for aspen-dominated systems. My findings suggest that the frequency and intensity of herbivory has played a major role in aspen survival at three of my four study sites. Future work is needed to develop more complete STMs for aspen-dominated systems in western Colorado.

Variation in bill morphology and pollen prevalence in the Broad-Tailed Hummingbird (Selasphorus platycercus) - T. J. Barnes (2017)
We found that the Broad-Tailed Hummingbird (Selasphorus platycercus) exhibits significant intraspecies variation across several morphological traits, including those important in foraging. However, the effects of these morphological variation on flower visitation is not well understood. To begin to understand the effects morphological variation on flower foraging, we quantified morphological variation across a total of 521 Broad-Tailed Hummingbirds across two summers at the Rocky Mountain Biological Laboratory. We also quantified prevalence of Ipomopsis spp. pollen in this population in order to test for a link between variation in bill morphology and variation in Ipomopsis visitation. We found that females are significantly larger in full gape, exposed culem, bill width, bill depth, mandible width than males. There was no difference in curvature of bill and wing chord between males and females. We found a significant and positive association between bill length in males and the presence of Ipomopsis spp. pollen in males and a negative association between curvature and Ipomopsis spp. presence in both males and females. Overall, our analysis suggests that the considerable variation in bill traits in the Broad-Tailed Hummingbird at RMBL may be functionally important. These patterns may mirror patterns across hummingbird species, which show tight linkages between bill length and curvature and morphological traits of nectar plants.

Consequences of Nectar Robbing in Colorado Wildflowers: Insect Variation and Nectar Sugar Concentration - D. Drouilhet (2017)
Nectar robbing is a process used by various insects to retrieve nectar from flowers that would otherwise be inaccessible. The community-level consequences of nectar robbing have not been widely studied, and the differences between primary and secondary robbing have been studied even less. Fitness costs to plants from nectar robbing have been documented, such as reductions in male and female components of plant reproduction, but there is room for additional experimentation. In this study, I examined the consequences of nectar robbing on insect visitation and nectar sugar concentration. This was accomplished through both manipulation and natural surveys in an attempt to observe any differences between flowers that had been robbed and those that had not. In general, I found no evidence to support that insects chose flowers based on the presence of nectar robbing in Ipomopsis aggregata, nor did I find evidence that sugar concentration in nectar differs depending on the size of robber holes. I found significantly more insects in robbed flowers than unrobbed flowers in Linaria vulgaris, but this data is not enough to prove preference. Due to this difference, further experimentation into L. vulgaris would help to clarify insect preference in this plant in robbed versus unrobbed flowers, and these results may provide better insight into the consequences and effects of nectar robbing.

Pond nutrient storage across permanence and temporal gradients - A. Long (2017)
Our goal was to understand how range shifts in detrivorous larval caddisflies could affect nutrient storage along a pond permanence gradient in the Mexican Cut Preserve (Gunnison County, Colorado). As part of a larger project quantifying other ecological impacts and interactions arising from the caddisfly range shift, this study focused on measuring nutrient distributions along the permanence gradient. First, through an observational study, we measured levels of nitrogen and phosphorus in the water column and took samples of benthic organic matter (BOM) and sedge for analysis at a later date. By sampling these nutrient compartments with respect to time and pond permanence, we will be better able to understand the magnitude and timing of nutrient storage in oligotrophic subalpine ponds. Second, we designed an experiment to quantify the effects of caddisflies on pond nutrient distribution. We created an in- situ cage experiment to compare the effects of two Limnephilid caddisfly species: L. externuns and L. picturatus. This allowed us to understand the nutrient cycling that caddisflies are responsible for within these ponds. This experiment also serves to contextualize our nutrient observations with respect to larval caddisfly activity and the ongoing research on caddisfly distributional shifts and nutrient excretion.

Dormancy rates in microbial communities across an elevational gradient - M. Manto (2017)
Despite the broad impacts microbial dormancy has on ecosystems and ecosystem models, dormancy as a response to climate-change-related environmental stressors is poorly understood. Dormancy is an essential bet-hedging strategy used by microbes to tolerate unfavorable conditions and increase overall community diversity. Accurate estimates of dormancy improve existing models of microbial systems. However, the ways in which climatic gradients shape the level of dormancy in soil bacterial and fungal communities remains unclear. Here, we performed a genomics-based, integrated field and laboratory study to evaluate the level of dormancy in bacterial and fungal communities across a natural climate gradient to test if dormancy in bacterial and fungal communities was related to changes in soil properties and climatic factors. To test this question, we examined microbial dormancy at five sites along an elevational gradient near Crested Butte, CO. Additionally, temporal changes over the growing season may shift dormancy patterns at a single site, leading us to collect weekly samples from a low and high elevation site to compare dormancy shifts among sites and temporal shifts within sites. Dormancy work is ongoing, however some preliminary evidence has shown that pH decreases from low to high elevation and increases over the growing season. A better grasp of microbial dormancy will improve our ability to model microbial communities and ecosystems, thus leading to a more thorough understanding of the effects climate change will have on microbial communities and the myriad of environmental processes that they support.

Climate Change Affects Boechera stricta Genotypes Through Local Maladaptation - A. Neild (2017)
As environments continue to change, plant communities will increasingly be pressured to adapt to their environment to maintain fitness levels. The most common release of climatic stressor result in range shifts and changes in phenology for plants. Boechera stricta, a perennial forb native to a range of elevations in the Rocky Mountains in the western United States, has been study species for adaptation responses from climate change. Already, it has been documented that local maladaptation has occurred for this wild mustard species. Low elevation species adapted B. stricta was recorded to do better along an entire elevation gradient than its locally adapted counterparts. This study inquires if, by manipulating snowfall to mimic historic levels, we can reverse the maladaptation in B. stricta, and see locally adapted mustards do better than either high or low adapted genotypes. We found that we were able to restore local adaptation of B. stricta for all sites in our snow addition treatment. In addition, we saw a continued shift in optimum source elevation to lower elevation genotypes. However, with notably high mortality rates among all gardens on all treatments, more than one climatic factor needs to be changed for there to be any lasting impact on these local adaptations.

Hibernation as a major determinant of life-history traits in marmots - Kenneth B. Armitage (Journal of Mammalogy, 2017)
During the downward trend of Quaternary global temperatures, crown-group marmots evolved to occupy harsh, seasonal environments at high latitudes and elevations. Marmots evolved hibernation and large body size, which allowed them to cope with a long, cold season with low, stressful ambient temperatures when food was unavailable. Harsh conditions during a short active season frequently cause reproductive failure and reproductive skipping in marmots. Seasonal phenology is controlled by a circannual rhythm that directs metabolic changes and fat accumulation for hibernation and reproduction. Metabolism and water balance in marmots are adapted to the low environmental temperatures of hibernation. Thus, marmots are subject to heat stress from solar radiation and high ambient temperatures during the active season. Energy conservation characterizes metabolism in marmots throughout the annual cycle: metabolic rates are lower than predicted from body size and decline during the active season, metabolism is actively suppressed to enter torpor, and most of the time during hibernation is spent at low metabolism in deep torpor. Young typically require 2 or more of the short active seasons to reach reproductive maturity and are retained at home, which leads to sociality based on kinship. Competition within the social group is expressed primarily as reproductive suppression, which delays the age of 1st reproduction that in turn strongly affects demography. Early snowmelt due to global warming may enable marmots to colonize new habitats or increase population growth. However, climate change most likely will diminish the ability of marmots to mobilize sufficient energy resources in a drier, warmer active season, which will reduce both survivorship and reproduction.

Concentration-discharge behavior as an indication of groundwater contribution in Copper Creek sub-catchment of the Upper East River Basin - M. Ruckhaus (2017)
Groundwater in high elevation watersheds is difficult to quantify, but remains a major component in the hydrologic budget for the western United States. Concentration-discharge (C-Q) data can provide a framework for characterizing groundwater flow in small alpine catchments by indicating fluid residence times and solute fluxes. Such factors heavily influence biochemical processes and mixing behaviors downstream. Complimenting field measurements, End Member Mixing Analysis (EMMA) was conducted to apply a statistical approach for identifying solutes. Most small catchments exhibit chemostatic behavior which is defined as nearly constant solute concentration with changing discharge rates (Maher, 2011) therefore, SF6 and N2/Ar samples were collected to estimate fluid residence time and recharge temperature. We investigated these relationships in the Copper Creek sub-catchment by analyzing solute concentrations of anions, cations, and dissolved organic and inorganic carbon coupled with discharge measurements to assess its groundwater and solute contributions to East River.

The importance of seasonal resource selection when managing a threatened species: targeting conservation actions within critical habitat designations for the Gunnison sage-grouse - Mindy B. Rice; Anthony D. Apa; Lief A. Wiechman (Wildlife Research, 2017)
Context The ability to identify priority habitat is critical for species of conservation concern. The designation of critical habitat under the US Endangered Species Act 1973 identifies areas occupied by the species that are important for conservation and may need special management or protection. However, relatively few species’ critical habitats designations incorporate habitat suitability models or seasonal specificity, even when that information exists. Gunnison sage-grouse (GUSG) have declined substantially from their historical range and were listed as threatened by the US Fish and Wildlife Service (USFWS) in November 2014. GUSG are distributed into eight isolated populations in Colorado and Utah, and one population, the Gunnison Basin (GB), has been the focus of much research. Aims To provide season-specific resource selection models to improve targeted conservation actions within the designated critical habitat in the GB. Methods We utilised radio-telemetry data from GUSG captured and monitored from 2004 to 2010. We were able to estimate resource selection models for the breeding (1 April–15 July) and summer (16 July–30 September) seasons in the GB using vegetation, topographical and anthropogenic variables. We compared the seasonal models with the existing critical habitat to investigate whether the more specific seasonal models helped identify priority habitat for GUSG. Key results The predictive surface for the breeding model indicated higher use of large areas of sagebrush, whereas the predictive surface for the summer model predicted use of more diverse habitats. The breeding and summer models (combined) matched the current critical habitat designation 68.5% of the time. We found that although the overall habitat was similar between the critical habitat designation and our combined models, the pattern and configuration of the habitat were very different. Conclusions These models highlight areas with favourable environmental variables and spatial juxtaposition to establish priority habitat within the critical habitat designated by USFWS. More seasonally specific resource selection models will assist in identifying specific areas within the critical habitat designation to concentrate habitat improvements, conservation and restoration within the GB. Implications This information can be used to provide insight into the patterns of seasonal habitat selection and can identify priority GUSG habitat to incorporate into critical habitat designation for targeted management actions.

Does bumble bee (Bombus spp.) diet breadth vary with differences in floral resource abundance? - V. Watson (2017)
In the Rocky Mountains of Colorado, changes in the availability of floral resources through the growing season may affect the ability of bumble bee colonies to successfully complete their life cycle and produce reproductive individuals in the season’s end. A way bees could potentially deal with this challenge is by broadening their diets —visiting a wider variety of flower species for pollen and nectar. I investigated the diet breadths of three bumble bee species in that region at the species and individual levels, asking whether bee diet breadths varied with floral resource abundance. I found that at both the species and individual level, bees’ diet breadth does not seem to vary with floral resource abundance. Bees may have another strategy for dealing with a lack of floral resources, or their diet breadth may be constrained by other factors such as competition.

A Presence-Only Species Distribution Model Comparison Predicting the Distribution of the Amphibian Chytrid Fungus (Batrachochytrium dendrobatidis) - M. L. Torres (2017)

Is Plant Fitness Proportional to Seed Set? An Experiment and a Spatial Model - Diane R. Campbell; Alison K. Brody; Mary V. Price; Nickolas M. Waser; George Aldridge (The American Naturalist, 2017)
Individual differences in fecundity often serve as proxies for differences in overall fitness, especially when it is difficult to track the fate of an individual's offspring to reproductive maturity. Using fecundity may be biased, however, if density-dependent interactions between siblings affect survival and reproduction of offspring from high- and low-fecundity parents differently. To test for such density-dependent effects in plants, we sowed seeds of the wildflower Ipomopsis aggregata (scarlet gilia) to mimic partially overlapping seed shadows of pairs of plants, one of which produced twice as many seeds. We tested for differences in offspring success using a genetic marker to track offspring to flowering multiple years later. Without density dependence, the high-fecundity parent should produce twice as many surviving offspring. We also developed a model that considered the geometry of seed shadows and assumed limited survivors so that the number of juvenile recruits is proportional to the area. Rather than a ratio of 2∶1 offspring success from high- versus low-fecundity parents, our model predicted a ratio of 1.42∶1, which would translate into weaker selection. Empirical ratios of juvenile offspring and of flowers produced conformed well to the model's prediction. Extending the model shows how spatial relationships of parents and seed dispersal patterns modify inferences about relative fitness based solely on fecundity.

Does Road Dust Affect Hylemya Oviposition in Scarlet Gilia (Ipomopsis aggregata)? - C. Rosas (2017)
A previous study conducted at RMBL has found that road dust affects wildflower pollination and reproduction, this study included Ipomopsis aggregata. In 19 of 20 independent tests wildflowers carried less pollen on their stigmas in dusty conditions, but their seed sets were not consistently affected. The study lists compensatory herbivory as a mechanism that could contribute to the inconsistent seed set, therefore for this study we will be looking at the pre-dispersal seed predator the Anthomyiid fly Hylemya spp. We studied whether road dust affects Hylemya oviposition. We found more Hylemya eggs in experimentally undusted than in dusted Ipomopsis aggregata plants, both on a per-flower and whole-plant basis. On average there were 4.3 eggs per undusted plant and 2.2 eggs per dusted plant. This study also compared the results of a similar 2016 study. In both years undusted plants had higher egg loads, but egg loads were overall higher in 2016. Overall, between both years, 11.43% of undusted elongated buds had an egg and 5.22% of dusted elongated buds had an egg with a significant difference.

Blooms of benthic diatoms in phosphorus-poor streams - M. L. Bothwell; B. W. Taylor (Frontiers in Ecology and the Environment, 2017)
During the past 50 years, freshwater ecologists have mostly attributed massive accumulations of algal biomass in lakes and rivers to high nutrient inputs. While researching the role that phosphorus (P) plays in increasing diatom biomass in rocky-bottomed rivers, I (MLB) was puzzled by the presence of thick mats (“blooms”) of the benthic diatom Didymosphenia geminata in low-nutrient rivers with no obvious evidence of a pollution source (Figure 1a). D geminata has long been associated with nutrient-poor conditions and is native to but historically rare in North America (Figure 1b). Beginning in the early 1990s, thick and visually unappealing mats of the diatoms appeared suddenly in streams that drained pristine watersheds, despite no obvious increase in pollution. The basic natural history of this species was unknown and the origin of the blooms remained an unsolved mystery for more than 20 years. (a) Didymosphenia geminata mat formation in North York Creek, a nutrient-poor stream in the Canadian Rocky Mountains (1600-m elevation). (b) A single specimen of D geminata was found in seven sediment cores taken 7 km WNW of Prince Rupert, British Columbia. The sediment layer in which this D geminata specimen was found dated to between 11,000 and 12,000 calendar years ago (Letham et al. 2016). U Silins B Letham After the species was introduced to New Zealand, D geminata blooms began to be observed there in 2004 (Kilroy 2004), but early evidence suggested that more was involved than a simple movement of cells into previously uninhabited areas. For instance, when transplanted into spring-fed creeks that were tributaries of rivers already infested with D geminata, the diatoms failed to flourish (Sutherland et al. 2007) even though nutrient levels, including P, were higher in the creeks than in the rivers. These creeks also appeared to be physically suitable habitats for the species. Because D geminata did not form blooms when P concentrations were high, it was hypothesized that a different chemical constituent of stream water was critical for bloom formation. A carefully conducted study was undertaken in New Zealand in search of a “silver bullet” in spring water that would prevent D geminata establishment and might be useful for controlling the blooms in other rivers. I designed a riverbank flume apparatus that would allow settled D geminata cells to be bathed in either river water or spring water without first having to be physically transplanted. Once D geminata cells had attached on the bottoms of all flumes exposed to river water, the source of water for some populations was gradually switched to the spring water. I assumed that the newly settled cells would perish, but something unexpected happened (Bothwell and Kilroy 2011). After being exposed to spring water for 8 days, 40% of D geminata cells were in late stages of cell division compared to only 10% of the cells with continued exposure to river water (Figure 2). D geminata cells seemed to thrive in spring water and a follow-up experiment confirmed that, when exposed to spring water, cell division rates were elevated because of the higher nutrient levels, especially dissolved P (Bothwell and Kilroy 2011). (a) A non-dividing D geminata cell; (b) D geminata undergoing cell division; (c) D geminata cell division complete, but new daughter cells remain attached in a “doublet” stage; (d) after division and separation, daughter cells remain attached to the same stalk until new stalks are produced by each cell. Under low light, cells can be “trapped” in this stage because high photosynthetic rates are needed for new stalk production. M Bothwell and G Meyer So, why would higher P concentrations have a positive impact on cell division but a negative impact on bloom development? This paradox was clarified by an additional observation – that D geminata populations with rapidly dividing cells tended to have much shorter stalks, which would adversely affect bloom development. Observations on the frequency of cellular division allowed us to explore the influence of P on D geminata growth and mat development in rivers. On the South Island of New Zealand, river surveys showed the counterintuitive, inverse relationship between low rates of D geminata cell division and the more extensive coverage and thickness of D geminata mats on river bottoms (Kilroy and Bothwell 2012). For mats to develop, D geminata's extracellular stalks – which are composed of polysaccharides (Hoagland et al. 1993) – need to elongate, but frequent cell division results in shorter stalks (Kilroy and Bothwell 2011) and a lower probability of benthic mat formation. By increasing the rates of cell division, high P concentrations appear to leave little time for stalks to grow longer and so mats fail to develop. The presence of D geminata blooms in nutrient-poor conditions challenges the long-held view of the relationship between limiting nutrients and algal production in freshwater ecosystems. The opposing effects of P availability on cell division versus non-cellular mat development suggest a strategy that is more reminiscent of terrestrial plants reallocating energy into tissues and structures (eg roots or shoots) needed to access limiting resources. Production of long extracellular stalks allows cells to have better access to nutrients in free-flowing water; this enhanced accessibility is one of the longstanding explanations for the adaptive significance of diatom stalk production (Hudon and Bourget 1981). The explanation for higher algal-derived carbon in a declining P regime is the shunting of carbon into non-P-containing stalks. Unlike algal “blooms” in the limnological lexicon, D geminata mat formation does not necessarily represent increased cellular biomass. An even greater paradox is that, because an excessive P supply results in the decline of mats (Kilroy and Larned 2016), the D geminata mats produced in response to low P must remain P-limited to continue to dominate benthic algal communities. A careful balance between P acquisition and allocation of growth to stalks is required for D geminata to remain the dominant algal taxon in a stream ecosystem. While lower P concentrations provide an explanation for why D geminata mats form, whether or not dissolved P in pristine streams worldwide is declining remains unknown (Taylor and Bothwell 2014). Surprisingly, studying the natural history of D geminata's cellular division has been the key to deciphering the larger-scale natural history of mat formation and the recent dominance of this organism when P concentrations are low. The experiments described here were a collaborative undertaking between Environment Canada's National Water Research Institute and New Zealand's National Institute of Water and Atmospheric Research.

Can individual variation in phenotypic plasticity enhance population viability? - Adriana A. Maldonado-Chaparro; D. W. Read; Daniel T. Blumstein (Ecological Modeling, 2017)
It is found that compensatory growth plays an important role in decreasing the probability of extinction under both less favorable colder and random climate scenarios and the importance of trade-offs in population dynamics.

Quantifying Whitewater Recreation Opportunities in Cataract Canyon of the Colorado River, Utah: Aggregating Acceptable Flows and Hydrologic Data to Identify Boatable Days - E. Stafford; N. Fey; J. J. Vaske (River Research and Applications, 2017)
AbstractThe structural norm approach was combined with the Potential for Conflict Index to define recreation streamflow needs for the Colorado River in Utah and Colorado. An online survey was completed by 128 commercial and non‐commercial boaters, who evaluated a range of flows for whitewater boating. For the Cataract Canyon reach, respondents rated the quality of their recreation experience of specific flows, describing the quality of boating opportunities across the full range of historical streamflows. Ranges for both acceptable and optimum flows were defined, as well as thresholds for unacceptable flows. These ranges were then evaluated against historical hydrologic records to quantify the timing, frequency, and duration of days when defined whitewater flows exist across different year types (i.e. average boatable days). Results indicated that on average, a total of 257 boatable days existed in dry years, and 353 total boatable days occurred in dry‐typical years. In wet and wet‐typical years, 362 and 365 total boatable days respectively, occurred on average. Results of the boatable days' analysis indicated that over the 23‐year period of record, whitewater boating opportunities occurred nearly every day of the year in all but the driest year types. Results from this study provide resource managers with information which can be used in the development of annual operating plans for the Colorado River Basin and help managers understand how changes in flow impact the quality of recreational opportunities. This application demonstrates the value of analysing boatable days on any river where recreation management is a priority. Copyright © 2016 John Wiley & Sons, Ltd.

The Colorado River Aqueduct - T.R. Witcher (Civil Engineering Magazine, 2017)
One of the greatest achievements in engineering the West, the 242 mi long Colorado River Aqueduct brought water to Southern California and paved the way for the region’s tremendous growth.

Evolution of Water Institutions in the Indus River Basin: Reflections from the Law of the Colorado River - Erum Sattar; Jason Anthony Robison; Daniel McCool (SSRN Electronic Journal, 2017)
Transboundary water institutions in the Indus River Basin can be fairly characterized as broken in key respects. International relations between India and Pakistan over the Indus Waters Treaty, as well as interprovincial relations within Pakistan over the 1991 Water Accord, speak to this sentiment. Stemming from research undertaken by the authors for the Harvard Water Federalism Project and the United States Agency for International Development (USAID), this Article seeks to spur the evolution of the Indus River Basin’s water institutions by offering a comparative perspective from North America’s most “institutionally encompassed” basin, the Colorado River Basin. Mindful of the importance of context for comparative water law and policy scholarship, the Article begins with overviews of the Colorado and Indus basins. In turn, the Article considers in greater detail major water-related challenges facing the latter basin, including climate change and overallocation. Against this backdrop, the Article ultimately turns to analysis and prescription. Examining a host of topics involving transboundary water allocation, conservation, and governance, the Article considers key institutions associated with these topics in the Colorado River Basin and reflects on how, if at all, they may serve as reference points for institutional evolution in the Indus Basin. Many of the proposals in the Article are expensive. But compared to military operations, they are quite modest in terms of expense and minimize the risk of loss of life and destruction of property. Still, the Article prioritizes solutions that maximize individual and local freedom to the greatest extent possible. This means relying upon voluntary market-based transfers that protect the vulnerable, favoring incentives rather than regulations, and creating a reward structure that includes benefits other than water.

Assessing the Presence of Supercooled Liquid Water and Stability Using Radiometer Data Collected during the 2015-2016 Winter Cloud Seeding Program in the Upper Gunnison River Basin, Colorado - Stephanie D. Beall; Don A. Griffith (The Journal of Weather Modification, 2017)
During the 2015-2016 Winter Cloud Seeding Program, a Radiometrics microwave radiometer was installed in the Upper Gunnison River Basin cloud seeding target area.  The main purpose of using this device was to provide the ability to measure temperature and liquid water in frequent vertical profiles of the atmosphere above the radiometer.  With observations of these two variables, the presence of supercooled liquid water can be identified. This information may be used in real-time to determine the “seedablity” of naturally occurring winter storms that impact the target area. Data may also be used in the post-analysis of these winter storms. For example, the radiometer data used in conjunction with the Rawindsonde Observation Program (RAOB), can be used to generate a vertical sounding of temperature dew point (no winds are observed from these radiometers). Such plots can be used to assess lower level atmospheric stability during storm periods that contain “supercooled” liquid water, which is the target of glaciogenic winter cloud seeding programs.   The ensuing analyses indicated that stability is present in the lower valley levels upwind of the target area during most winter storms but that these inversions have a negligible effect on seeding operations primarily due to the very shallow nature of these inversions. Radiometer data were also compared to a nearby ground-based icing meter to determine if there was any correlation between the two types of observations.

The Effect of Dominant Floral Resource Removal on Plant-Pollinator Interactions - R. Dickson (2017)
In order to understand the ecological and evolutionary significance of plant-pollinator mutualisms, it is critical to first comprehend the fluctuating and complex nature of plant- pollinator interactions. Specifically, it is important to realize how these interactions respond to changes in factors such as phenology, morphology, and abundance. To examine the effect of floral resource removal on plant-pollinator interactions, we removed a dominant floral resource, Helianthella quinquenervis (Asteraceae) from 10 plots. We paired each removal plot with a control plot and conducted paired plant- pollinator observations for 30 hours per week for 5 weeks. We then analyzed differences in pollinator visitation rates between control and removal plots using paired t-tests and linear mixed effects models. We found that overall pollinator visitation increases in response to resource availability. We also found that removal of H. quinquenervis facilitates the pollination of some plant species and competes for pollination with others.

Impact of intra-meander hyporheic flow on nitrogen cycling - Dipankar Dwivedi; Carl I. Steefel; Bhavna Arora; G. Bisht (Procedia Earth and Planetary Science, 2017)
Redox gradients within hyporheic zones significantly impact the biogeochemical cycling of carbon and nitrogen. To investigate the effect of these redox gradients on nitrogen transformation in the subsurface, we integrated a genome-informed complex reaction network into PFLOTRAN, which is an open source, massively parallel, three-dimensional, reactive flow and transport code. This study was conducted in the lower East River catchment in southwestern Colorado. The lower East River has multiple river meanders extending over a distance of 11 km in rolling to mountainous region of the East Taylor watershed. We carried out reactive flow and transport simulations within two stream meanders to describe the biogeochemical zonation that evolves due to upwelling of nutrient rich groundwater and downwelling of oxygen rich stream. The specific objectives were to examine (1) the effect of hyporheic flow on biogeochemical zonation and (2) how meanders affect local nitrogen fluxes and transformation. Simulation results demonstrate that hyporheic flow paths within intra-meander regions lead to lateral redox zonation, which significantly impact nitrogen export into the stream system. Also, meander-driven hyporheic flow paths enhance denitrification rates because of the extended hyporheic region.

Experimental species removals impact the architecture of pollination networks - B. J. Brosi; Kyle Niezgoda; H. M. Briggs (Biology Letters, 2017)
Mutualistic networks are key for the creation and maintenance of biodiversity, yet are threatened by global environmental change. Most simulation models assume that network structure remains static after species losses, despite theoretical and empirical reasons to expect dynamic responses. We assessed the effects of experimental single bumblebee species removals on the structure of entire flower visitation networks. We hypothesized that network structure would change following processes linking interspecific competition with dietary niche breadth. We found that single pollinator species losses impact pollination network structure: resource complementarity decreased, while resource overlap increased. Despite marginally increased connectance, fewer plant species were visited after species removals. These changes may have negative functional impacts, as complementarity is important for maintaining biodiversity–ecological functioning relationships and visitation of rare plant species is critical for maintaining diverse plant communities.

Floral Albedo as a Response Factor of Climate Change, A case study in Helianthella quinquenervis - A. Walwema (2017)
Because phenology and climate are linked, studying the consequences of shifting phenology can help scientists understand the systems that make up current climates and construct future ones. In the Rocky Mountains, climate change has led to earlier snowmelt, an event that triggers the start of the growing season. When Helianthella quinquenervis flowers early, the harsher abiotic conditions of the early growing season can damage the buds that would have otherwise flowered that year. We hypothesize that locations with a dense population of H. quinquenervis, like the population located in Maxfield Meadow, are now subject to drier conditions and increased water stress in years when H. quinquenervis flowers are frosted by the low night temperatures of the earlier growing season. In this study, Helianthella bud removal simulated the bud frosting effect. We hypothesized that the lack of H. quinquenervis changes the overall color of the meadow from yellow to green, decreasing the amount of light that the meadow can reflect, decreasing soil moisture and increasing plant water stress. We found that Helianthella flower petals reflect significantly more light than leaves, and this effect persists at the plot-level. The data show that the effect of reduced albedo on soil moisture is most likely to occur during sunny conditions. It also shows Helianthella removal did result in a trend supporting the initial hypothesis, with slightly increased water stress in the removals, although this effect was not significant. Helianthella was not blooming as densely as has in the past years, and effects of reduced albedo on soils and plants may be stronger when floral density is higher.

Factors Influencing Ungulate Barking Patterns of Populus tremuloides - D. Sapena (2017)

How does experimental warming effect the rate of herbivory and fungi on host grasses? - Shermila B. Villanueva (2017)
As there is an increase in greenhouse gasses, it is causing direct and indirect changes in plant interactions with herbivory and fungal pathogens. By imitating the increase in climate change through temperature, it is possible to observe the indirect effect it has on herbivory/fungal pathogens on their plant hosts. In collecting data on three grass species, it cannot be concluded that there is an effect of warming on herbivory/pathogen damage on plant hosts however there is a pattern seen in all species the different plots. The accumulation of herbivory/pathogens in warmed and controlled plots have significance at various time interval of different species. Weather could be affecting the herbivory and pathogens at different plots which can be a reason for the pattern across plots.

Do birds differentiate between white noise and deterministic chaos? - Daniel T. Blumstein; J. R. Whitaker; J. Kennen (Ethology, 2017)
AbstractNoisy, unpredictable sounds are often present in the vocalizations of fearful and stressed animals across many taxa. A variety of structural characteristics, called nonlinear acoustic phenomena, that include subharmonics, rapid frequency modulations, and deterministic chaos are responsible for the harsh sound quality of these vocalizations. Exposure to nonlinear sound can elicit increased arousal in birds and mammals. Past experiments have used white noise to test for effects of deterministic chaos on perceivers. However, deterministic chaos differs structurally from white noise (i.e., random signal with equal energy at all frequencies), and unlike white noise, may differ dramatically depending on how it is produced. In addition, the subtle structural variation of chaos may not be distinguishable in the environment due to the attenuation and degradation of sound over distance and different habitat types. We designed two experiments to clarify whether American robins (Turdus migratorius) and warbling vireos (Vireo gilvus) discriminate between white noise and deterministic chaos. We broadcast and re‐recorded white noise and two exemplars of deterministic chaos—one generated with a Chua oscillator and the other generated using a logistic equation—at 1, 10, 20, 30, 40, and 80 m across open and forested habitat and used spectrogram correlations to compare stimuli along this degradational gradient. We found that sounds degraded similarly in both habitats when compared to a reference distance of 1 m. Comparing pairs of stimuli across distances suggested that Chua chaos was more easily distinguishable from noise and logistic chaos. In addition, all stimuli became more distinctive over increased distance. The second experiment tested behavioral responses of robins and warbling vireos to control sounds of tropical kingbird (Quiscalus mexicanus), white noise, and two exemplars of deterministic chaos (Chua and logistic). Neither American robins nor warbling vireos responded differently to at least two types of deterministic chaos and white noise, validating previous playback studies that used white noise as a surrogate for deterministic chaos. Uniform responses to a variety of nonlinear features in these birds possibly reflect error management in alarm signal detection.

Skiing for science - Daniel T. Blumstein (Science, 2017)

The effect of maternal glucocorticoid levels on juvenile docility in yellow-bellied marmots - M. B. Petelle; B. N. Dang; Daniel T. Blumstein (Hormones and Behavior, 2017)
The results suggest that a mother's life history stage interacts with stress to influence offspring personality, a personality trait, and can have long lasting effects on an individual's docility throughout life.

Adaptation, assisted migration, and extinction in a warming world: Understanding the response of Androsace septentrionalis to climate change through climate manipulation and transplant experiments - A. M. Panetta (2017)

Modeling the population dynamics and community impacts of Ambystoma tigrinum: A case study of phenotype plasticity - M. L. McCarthy; Diana Wallace; H. H. Whiteman; E. T. Rheingold; Amy E. Dunham; O. Prosper; M. Chen; E. Hu-Wang (Mathematical Biosciences, 2017)

Biogeography of plant-associated fungal symbionts in mountain ecosystems: A meta-analysis - Stephanie N. Kivlin; J. S. Lynn; Melanie R Kazenel; K. K. Beals; Jennifer A. Rudgers (Diversity and Distributions, 2017)
AbstractAimPredicting the potential for climate change to disrupt host–microbe symbioses requires basic knowledge of the biogeography of these consortia. In plants, fungal symbionts can ameliorate the abiotic stressors that accompany climate warming and thus could influence plants under a changing climate. Forecasting future plant–microbe interactions first requires knowledge of current fungal symbiont distributions, which are poorly resolved relative to the distributions of plants.LocationWe used meta‐analysis to summarize the biogeographic distributions of plant‐fungal symbionts in mountain ecosystems worldwide, because these ecosystems are likely to be among the first to experience climate change‐induced range shifts.MethodsWe analysed 374 records from 53 publications to identify general trends, pinpoint areas in need of greater study and develop reporting guidelines to facilitate future syntheses.ResultsElevational patterns varied strongly among fungal and plant functional groups. Fungal diversity and abundance increased with altitude for the ectomycorrhizal fungi. However, arbuscular mycorrhizal fungi and localized foliar endophytes declined in either abundance or diversity with altitude. In shrubs, fungal abundance increased with elevation, but in C3 grasses, fungal abundance declined with elevation. Altitudinal patterns in fungal composition were stronger than gradients in fungal abundance or diversity, suggesting that species turnover contributes more to elevational gradients in fungal symbionts than does variation in abundance or richness. Plant functional groups were overrepresented by C3 grasses and trees, with surprisingly few data on sedges or shrubs, despite their ecological dominance in mountain ecosystems. Similarly, epichloae, ericoid mycorrhizal fungi and root endophytes were understudied relative to other fungal groups.Main ConclusionsMeta‐analysis revealed broad biogeographic patterns in plant‐fungal symbiont abundance, diversity and composition that inform predictions of future distributions.

Identifying targets and agents of selection: Innovative methods to evaluate the processes that contribute to local adaptation - Susana M. Wadgymar; D. Lowry; Byron C.; Gould B.; Mactavish R.; J. T. Anderson (Method in Ecology and Evolution, 2017)
Summary Extensive empirical work has demonstrated local adaptation to discrete environments, yet few studies have elucidated the genetic and environment mechanisms that generate it. Here, we advocate for research that broadens our understanding of local adaptation beyond pattern and towards process. We discuss how studies of local adaptation can be designed to address two unresolved questions in evolutionary ecology: Does local adaptation result from fitness trade‐offs at individual loci across habitats? How do agents of selection interact to generate local adaptation to discrete contrasting habitats types and continuous environmental gradients? To inform future investigations of the genetic basis of local adaptation, we conducted a literature review of studies that mapped quantitative trait loci (QTL) for fitness in native field environments using reciprocal transplant experiments with hybrid mapping populations or Genome‐wide Association Study (GWAS) panels. We then reviewed the literature for field experiments that disentangle the contributions of various agents of selection to local adaptation. For each question, we suggest future lines of inquiry and discuss implications for climate change and agriculture research. (i) Studies in the native habitats of five biological systems revealed that local adaptation is more often caused by conditional neutrality than genetic trade‐offs at the level of the QTL. We consider the ramifications of this result and discuss knowledge gaps in our current understanding of the genetic basis of local adaptation. (ii) We uncovered only five studies that identified the agents of selection that contribute to local adaptation, and nearly all were conducted in discrete habitats rather than across the continuous environmental gradients that many species inhabit. We introduce a novel experimental framework for illuminating the processes underlying local adaptation. A holistic view of local adaptation is critical for predicting the responses of organisms to climate change, enhancing conservation efforts, and developing strategies to improve crop resilience to environmental stress. Experiments that manipulate agents of selection in native field environments using pedigreed populations or GWAS panels offer unique opportunities for detecting the genetic and environmental mechanisms that generate local adaptation.

Elevation alters ecosystem properties across temperate treelines globally - Jordan R. Mayor; Nathan J. Sanders; Aimee T Classen; R. D. Bardgett; J. C. Clement; A. Fajardo; S. Lavorel; M. K. Sundqvist; M. Bahn; C. Chisholm; E. Cieraad; Z. Gedelof; et al. (Nature, 2017)
Evaluated treeline ecotones in seven temperate regions of the world find that declining temperatures with increasing elevation did not affect tree leaf nutrient concentrations, but did reduce ground-layer community-weighted plant nitrogen, leading to the strong stoichiometric convergence of ground- layer plant community nitrogen to phosphorus ratios across all regions.

Distribution of native and nonnative ancestry in red foxes along an elevational gradient in central Colorado - C. Merson; M. J. Statham; J. E. Janecka; R. R. Lopez; N. J. Silvy; B. N. Sacks (Journal of Mammalogy, 2017)
The red foxes (Vulpes vulpes) indigenous to the mountains of the western United States are high-elevation specialists that could face range reduction due to climatic warming, as well as potential encroachment, loss of adaptive alleles, and displacement by introduced nonnative red foxes. We investigated the genetic integrity of the native Rocky Mountain red fox (V. v. macroura) in Colorado through analysis of the composition, distribution, and patterns of gene flow between native and nonnative red fox populations along an elevational gradient. The study area spanned the high plains around Denver in the east to the alpine zone of the Rocky Mountains adjacent to Gunnison and Crested Butte in the west. We used microsatellites and mitochondrial DNA (mtDNA) from Colorado foxes, along with previously published reference data from other native western and nonnative populations, to evaluate the distribution of native versus nonnative ancestry and its relationship to elevation, distance, and landscape type. Nonnative red fox ancestry predominated in Denver and low-lying areas, whereas native ancestry was most prevalent at high elevations. The genetic integrity of foxes at higher elevations (i.e., within the historical native range) was greater in terms of mtDNA than nuclear DNA, consistent with higher male-mediated gene flow. Nonnative admixture was most pronounced in human-altered landscapes. Our findings provide baseline data necessary to monitor future trends of these Rocky Mountain red fox populations and highlight the potential for similar threats to affect genetic integrity of endangered montane red fox subspecies along the Pacific Crest.

Aboveground resilience to species loss but belowground resistance to nitrogen addition in a montane plant community - Quentin D Read; Jeremiah A Henning; Aimee T Classen; Nathan J. Sanders (Journal of Plant Ecology, 2017)
Aims resembled those of the previously removed dominant species. Decades of empirical work have demonstrated how dominant plant Ecosystem productivity generally increased with N addition: soil species and nitrogen fertilization can influence the structure and carbon efflux was ~50% greater when either form of N was added, function of plant communities. More recent studies have examined while inorganic N addition increased aboveground biomass pro- the interplay between these factors, but few such studies use an duction by ~60% relative to controls. The increase in production explicit trait-based framework. In this study, we use an explicit trait- was mediated by increased average height, leaf mass:area ratio and based approach to identify potential mechanisms for community- leaf dry matter content in plant communities to which we added level responses and to test ecological niche theory. inorganic N. Contrary to our predictions, there were no interactive effects of N fertilization and dominant species loss on plant com-

Shifts in water availability mediate plant–pollinator interactions - M. K. Gallagher; Diane R. Campbell (New Phytologist, 2017)
SummaryAltered precipitation patterns associated with anthropogenic climate change are expected to have many effects on plants and insect pollinators, but it is unknown if effects on pollination are mediated by changes in water availability. We tested the hypothesis that impacts of climate on plant–pollinator interactions operate through changes in water availability, and specifically that such effects occur through alteration of floral attractants.We manipulated water availability in two naturally occurringMertensia ciliata(Boraginaceae) populations using water addition, water reduction and control plots and measured effects on vegetative and floral traits, pollinator visitation and seed set.While most floral trait values, including corolla size and nectar, increased linearly with increasing water availability, in this bumblebee‐pollinated species, pollinator visitation peaked at intermediate water levels. Visitation also peaked at an intermediate corolla length, while its relationship to corolla width varied across sites. Seed set, however, increased linearly with water.These results demonstrate the potential for changes in water availability to impact plant–pollinator interactions through pollinator responses to differences in floral attractants, and that the effects of water on pollinator visitation can be nonlinear. Plant responses to changes in resource availability may be an important mechanism by which climate change will affect species interactions.

Multitrophic interactions mediate theÂ effects ofÂ climate change onÂ herbivore abundance - Anthony T. Robinson; David W. Inouye; Jane E. Ogilvie; E. H. Mooney (Oecologia, 2017)
Observational and experimental results show the importance of multitrophic species interactions for predicting the effect of climate change on the abundances of herbivores.

Thermal evolution and exhumation history of the Uncompahgre Plateau (northeastern Colorado Plateau), based on apatite fission track and (U-Th)-He thermochronology and zircon U-Pb dating - Christian Rønnevik; Anna K. Ksienzyk; Haakon Fossen; Joachim Jacobs (Geosphere, 2017)
Over the past two decades, thermochronological studies have greatlyincreased our knowledge of the Cenozoic evolution of the Colorado Plateau(western United States). There has been particular interest in the southwesternpart of the plateau, leading to debate regarding the timing of uplift andfluvial incision along the Colorado River system. We here combine apatite fissiontrack (AFT) and apatite (U-Th)-He (AHe) analyses as well as zircon U-Pbdating to investigate the much less studied northeastern Colorado Plateau,particularly the Uncompahgre Plateau and the Unaweep Canyon, which has avery unusual drainage pattern in two opposite directions.We obtained 12 AFT ages from the Uncompahgre Plateau: 3 from the top ofthe basement of the plateau reveal Laramide ages (65–63 Ma), and 6 samplesfrom the Unaweep Canyon (35–27 Ma) and 3 from the northeastern plateaumargin (33–17 Ma) underwent complete thermal resetting in the late Eoceneto Oligocene. Thermal history modeling of top basement samples revealsLate Cretaceous heating to temperatures of at least 90 °C, implying sedimentaryburial to ~3 km, followed by cooling throughout the latest Cretaceous toEocene.However, AHe ages (38–31 Ma) indicate minor reheating to 40–80 °C forthese samples in the late Eocene to Oligocene.Zircons from the La Sal Mountains laccolith gave an Oligocene U-Pb crystallizationage of 29.1 ± 0.3 Ma. AFT ages from the laccolith range from 33 to27 Ma, confirming rapid cooling of this shallow subvolcanic intrusion. Thislate Eocene to Oligocene magmatism caused thermal resetting of most of theAFT (except top basement) and AHe ages from the Uncompahgre Plateau,even though samples were collected as much as 60 km away from the intrusion.Canyon samples also underwent an increase in cooling rates in the past5–10 m.y. This Miocene–Pliocene cooling event is interpreted as regional upliftof the Colorado Plateau associated with canyon incision.

Oxytocin experiments shed light on mechanisms shaping prosocial and antisocial behaviors in non-human mammals - Smith J.E.; M. B. Petelle; Jerome E.L.; H. Cristofari; Daniel T. Blumstein (Integrative and Comparative Biology, 2017)

Biotic and abiotic drivers of plant symbionts determine plant performance, the maintenance of diversity, and response to global change - Jeremiah A Henning (2017)
Interactions among organisms regulate the structure and function of ecosystems and the response of ecosystems to global change. The outcome of species interactions is shaped by the partners involved in the interaction and the climate contexts of the systems in which they reside. Global change is altering the distributions of organisms as well as the climate contexts of the systems they reside within, shifting the biotic and abiotic factors shaping species interactions. Thus, predicting the response of ecosystem structure and function to global change remains unresolved. For my dissertation, I explored how the interactions among plants and their mutualistic communities alter individual plant, community, and ecosystem function and how these interactions are shaped by changing biotic and abiotic factors. To do this, I combined a series of experiments and observations across scales, from detailed root-microbe experiments in laboratory mesocosms to coupled observations and experiments conducted along elevation gradients. Overall, my work provides mechanistic insights on how microbial community composition shapes the morphology and physiology of plant hosts, how plant community composition shapes the structure and function of microbial communities, and how abiotic and biotic contexts shape fungal endophyte assemblages at global scales. vi TABLE OF CONTENTS

A global test for phylogenetic signal in shifts in flowering time under climate change - Nicole E. Rafferty; Paul D. Nabity (Journal of Ecology, 2017)

Facilitated exploitation of pollination mutualisms: fitness consequences for plants - S. K. Richman; R. E. Irwin; C. J. Nelson; J. L. Bronstein (Journal of Ecology, 2017)

Technical Appendix: Legal Analysis - Shepherding Appropriated Water in Colorado for Colorado River Compact Security - Lawrence MacDonnell; Anne Castle (SSRN Electronic Journal, 2017)

Effects of road dust on the pollination and reproduction of wildflowers - Nickolas M. Waser; Mary V. Price; G. Casco; M. Diaz; Morales A-L; J. Solverson (International Journal of Plant Sciences, 2017)
Premise of research. Dust particles and pollen grains are similar in size. Dust deposition might therefore influence the pollination and reproduction of flowering plants. Little is known about such effects, however, despite more general interest in ecological effects of dust.Methodology. We used observational and experimental methods to explore whether dust generated by traffic on unpaved roads affects the amounts of pollen received and numbers of seeds produced by four species of native wildflowers in the western United States.Pivotal results. Flowers of Nuttall’s larkspur (Delphinium nuttallianum), scarlet gilia (Ipomopsis aggregata), Lewis flax (Linum lewisii), and sulphur paintbrush (Castilleja sulphurea) growing 1–2 m from a road received substantially more dust and less pollen than those growing 40–50 m away. We observed the same pattern when we transplanted individuals of the first two species into pots and placed pots near to compared with far from a road. Experimental “hand dusting” of scarlet gilia and Lewis flax plants also reduced stigma pollen loads to a degree that resembled the average effect of road proximity for those species. On the other hand, numbers of seeds per flower (“seed set”) did not vary consistently for any species as a function of road proximity or hand-dusting treatment.Conclusions. Several mechanisms might contribute to the different effects of dust on pollen loads and seed set. We discuss four possible mechanisms, which we refer to as pollen excess, pollen quality, resource limitation, and compensatory herbivory. These mechanisms suggest avenues for further study of dust, pollination, and plant reproduction with this and other systems.

Plant-Pollinator Interactions and Environmental Change: Effects of Experimental Changes in Phenology and Water Availability on a Montane Wildflower - M. K. Gallagher (2017)

A statistical estimator for determining the limits of contemporary and historic phenology - Pearse W.D.; C. C. Davis; David W. Inouye; R. B. Primack; Davis T.J. (Nature Ecology & Evolution, 2017)

Interactions between bee foraging and floral resource phenology shape bee populations and communities - Jane E. Ogilvie; J. R. K. Forrest (Current Opinion in Insect Science, 2017)
The interactions between floral resource phenology, bee foraging behaviour, and traits such as diet breadth, sociality, and body size are discussed and greater use of information contained in museum collections on bee phenologies and floral hosts is encouraged.

Social security: are socially connected individuals less vigilant? - R. Mady; Daniel T. Blumstein (Animal Behaviour, 2017)
Group size effects, whereby animals allocate less time to antipredator vigilance as a function of increasing group sizes are widely reported in many taxa, but group size is but one of many social attributes that could increase a individual’s sense of security. Indeed, meta-analyses suggest that group size only explains about 20% of the variation in vigilance, and studies have shown that social factors, such as dominance status, also influences perceived risk and time allocated to vigilance. Social network statistics quantify a variety of specific social attributes, some of which have been suggested to influence security. Using vigilance as an indicator of risk assessment, we tested the prediction that more socially connected female yellow-bellied marmots (Marmota flaviventris) allocate less time to vigilance while foraging compared to less socially connected individuals. We used a principle component analysis to reduce social attributes to three factors. After explaining variation accounted for by glucocorticoid levels, substrate, incline, and day of the year and, individuals in larger social groups allocated less time to vigilance while those in more cohesive social relationships allocated more time to vigilance. These somewhat contradictory results suggest that vigilance is multi-faceted and highlight the importance of using an attribute-based approach to explaining variation in vigilance. The attribute-based approach has allowed us, for the first time to show that social group size indeed reduces risk, and suggest that maintaining social relationships requires social vigilance. 2

Female kin density affects offspring sex ratio in an asocial mammal, the golden-mantled ground squirrell Callospermophilus lateralis - Caitlin P. Wells; D. H. Van Vuren (Animal Behaviour, 2017)

East River and East River #2 by Mitchell Johnson - Margaret R. Wentz (Mayo Clinic Proceedings, 2017)
Recognizing the contribution art has had in the Mayo Clinic environment since the original Mayo Clinic Building was finished in 1914, Mayo Clinic Proceedings features some of the numerous works of art displayed throughout the buildings and grounds on Mayo Clinic campuses.

Effects of Life History Traits in the Mountain White-Crowned Sparrow During Incubation - G. Shwahla (2017)
Reproductive success in passerines is dependent upon the fitness of the parents. Knowledge of how life history traits affect fitness is required to understand fitness and nest cycle relations. There was no significance between body mass and wing length and morning off bout frequency found. Blood parasite loads were not examined and therefore not included in data analysis. A larger sample size is needed to conclude any results from this study. Knowing how life history traits relate to fitness, and how fitness influences incubation is crucial in our understanding of Z. I. oriantha population dynamics.

Neighborhood Influence on Plant Interactions with Seed-Eating Flies and Pollinating Bees - E. Zuniga (2017)

Foraging strategy predicts foraging economy in a facultative secondary nectar robber - S. K. Richman; R. E. Irwin; J. L. Bronstein (Oikos, 2017)
In mutualistic interactions, the decision whether to cooperate or cheat depends on the relative costs and benefits of each strategy. In pollination mutualisms, secondary nectar robbing is a facultative behavior employed by a diverse array of nectar‐feeding organisms, and is thought to be a form of cheating. Primary robbers create holes in floral tissue through which they feed on nectar, whereas secondary robbers, which often lack chewing mouthparts, feed on nectar through existing holes. Because primary robbers make nectar more readily available to secondary robbers, primary robbers facilitate the behaviors of secondary robbers. However, the net effect of facilitation on secondary robber fitness has not been empirically tested: it is unknown whether the benefit secondary robbers receive is strong enough to overcome the cost of competing with primary robbers for a shared resource. We conducted foraging experiments using the bumble bee Bombus bifarius , which can alternatively forage ‘legitimately’ (from the floral opening) or secondary‐rob. We measured the relative foraging efficiencies (handling time per flower, flowers visited per minute, proportion of foraging bout spent consuming nectar) of these alternative behaviors, and tested whether the frequency of primary robbing and nectar standing crop in primary‐robbed flowers of Linaria vulgaris (Plantaginaceae) affected foraging efficiency. Surprisingly, there was no effect of primary robbing frequency on the foraging efficiency of secondary‐robbing B. bifarius . Instead, foraging strategy was a major predictor of foraging efficiency, with legitimate foraging being significantly more efficient than secondary robbing. Legitimate foraging was the more common strategy used by B. bifarius in our study; however, it is rarely used by B. bifarius foraging on L. vulgaris in nature, despite indications that it is more efficient. Our results suggest the need for deeper investigations into why bees adopt secondary robbing as a foraging strategy, specifically, the environmental contexts that promote the behavior.

Methods in Stream Ecology, Volume 1: Ecosystem Structure - B. L. Peckarsky; G. A. Lamberti (2017)

Zen Ecology and the origin of scientific ideas - Nickolas M. Waser; Mary V. Price (American Society of Naturalists, 2017)

Phenological responses to multiple environmental drivers under climate change: insights from a long-term observational study and a manipulative field experiment - Susana M. Wadgymar; Jane E. Ogilvie; David W. Inouye; A. E. Weis; J. T. Anderson (2017)
Abstract Climate change has induced pronounced shifts in the reproductive phenology of plants, with the timing of first flowering advancing in most species. Indeed, population persistence may be threatened by the inability to track climate change phenologically. Nevertheless, substantial variation exists in biological responses to climate change across taxa. Here, we explore the consequences of climate change for flowering phenology by integrating data from a long-term observational study and a manipulative experiment under contemporary conditions. Dissecting the environmental factors that influence phenological change will illuminate why interspecific variation exists in responses to climate change. We examine a 43-year record of first flowering for six species in subalpine meadows of Colorado in conjunction with a 3-year snow manipulation experiment on the perennial mustard Boechera stricta from the same site. We analyze shifts in the onset of flowering in relation to environmental drivers known to influence phenology: the timing of snowmelt, the accumulation of growing degree days, and photoperiod. At our study site, climate change is reducing snowpack and advancing the timing of spring snowmelt. We found that variation in phenological responses to climate change depended on the sequence in which species flowered, with early-flowering species flowering faster, at a lower heat sum, and under increasingly disparate photoperiods in comparison to species that flower later in the season. Furthermore, climate change is outpacing phenological change for all species. Early snow removal treatments confirm that the timing of snowmelt governs observed trends in flowering phenology of B. stricta and that climate change can reduce the probability of flowering, thereby depressing fitness. Shorter-term studies would not have captured the trends that we document in our observational and experimental datasets. Accurate predictions of the biological responses to climate change require a thorough understanding of the specific environmental factors driving shifts in phenology.

Phenology and Phenotypic Variation of Thlaspi arvense Along an Elevational Gradient - A. Glasser (2017)
Thlaspi arvense, a non-native plant in the Brassicaceae family, was first introduced to the Gunnison valley of Colorado in the 1800s (Chew 1975). Long-term studies done at the Rocky Mountain Biological Laboratory suggest the presence of T. arvense has negative impacts on the fitness of native Pieris butterflies (Nakajima et. al 2013, Chew 1975). It may also negatively impact native plants in its introduced range; a closely related invasive mustard found in Northeast North America, Alliaria petiolata, is known to impede growth of native plants by reducing mycorrhizal colonization of plant roots through production of antifungal glucosinolates similar to those produced by T. arvense (Wolfe et. al 2008, Chumala and Suchy 2003). Current research is investigating the capacity of T. arvense to disrupt plant-mycorrhizal associations of surrounding native plants where it grows (Stinson lab unpub.). Thlaspi arvense shows a high degree of phenotypic plasticity for traits such as branching, fruit number and height, which may increase its competitiveness (Best and McIntyre 1974). In order to determine where T. arvense will spread and potentially dominate as climate changes, we measured phenology, specifically timing of seed set, and phenotypic variation of adaptive traits along an elevational gradient. At nine sites, we assessed phenology and phenotypic traits for a subpopulation of plants within consistent 1m2 plots. While there was no significant relationship between change in phenology and elevation, there were significant relationships between phenotypic traits and elevation, with high elevation sites favoring shorter plants with fewer fruits and branches. Low elevation sites had denser populations of plants than medium and high elevation sites, and tended to have plants with more fruits and branches. Many factors that could impact trait plasticity of T. arvense vary predictably along the elevational gradient, including temperature, soil moisture and nitrogen availability (McCain and Grytnes 2010). Knowing that conditions at low elevations favor reproductive success of T. arvense, as climate changes and high elevation climates increasingly resemble current low elevation climates, T. arvense may be able to increase its range and persist at higher elevations.

Water and irrigation : Colorado Agriculture Bibliography - Allison V. Level; Sierra Standish (Digital Collections of Colorado (Colorado State University), 2017)
The records in this bibliography may cover several subject areas and are listed alphabetically by author.

Intraspecific variation in traits reduces ability of trait-based models to predict community structure - Quentin D Read; Jeremiah A Henning; Nathan J. Sanders (Journal of Vegetation Science, 2017)
AbstractQuestionsIs it possible to predict the composition of local plant assemblages? Trait‐based approaches have offered some promise, especially in cases where deterministic processes such as environmental filtering and niche differentiation shape communities. In this study, we asked how much intraspecific variation contributes to trait distributions within and among plant communities, and whether trait distributions resulting from environmental filtering and niche differentiation can predict accurately the relative species abundances of montane plant species in local communities.LocationWest Elk Mountains, Colorado, USA.MethodsWe collected functional trait, species composition and environmental data from 14 sites along a broad climate gradient in Colorado, USA, ranging in elevation from 2480 to 3560 m. We partitioned the variation within and among sites into intraspecific and interspecific components, and compared the results to values from a recent global meta‐analysis, which examined intraspecific trait variability patterns. We also used these data to parameterize statistical models that have been shown to reproduce patterns associated with the processes of environmental filtering and niche differentiation. We fit two models to the data, one assuming that niche differentiation is invariant among sites, and another assuming that niche differentiation varies among sites.ResultsWe found that the trait‐based models were worse at predicting species relative abundances in local communities than a null model assuming equal abundances of all species. One plausible explanation for the poor performance of the models is that intraspecific variation in functional traits, which in our system was higher than the global averages documented in the meta‐analysis, swamped the effects of interspecific variation in functional traits along the climatic gradient. In particular, almost all variation in root traits was within rather than among species, even among sites.ConclusionOur results suggest that a greater focus be placed on measuring intraspecific trait variability and determining its consequences for community assembly and ecosystem properties.

Integrating viability and fecundity selection to illuminate the adaptive nature of genetic clines - Susana M. Wadgymar; S. Caroline Daws; J. T. Anderson (Evolution Letters, 2017)
AbstractGenetically based trait variation across environmental gradients can reflect adaptation to local environments. However, natural populations that appear well-adapted often exhibit directional, not stabilizing, selection on ecologically relevant traits. Temporal variation in the direction of selection could lead to stabilizing selection across multiple episodes of selection, which might be overlooked in short-term studies that evaluate relationships of traits and fitness under only one set of conditions. Furthermore, nonrandom mortality prior to trait expression can bias inferences about trait evolution if viability selection opposes fecundity selection. Here, we leveraged fitness and trait data to test whether phenotypic clines are genetically based and adaptive, whether temporal variation in climate imposes stabilizing selection, and whether viability selection acts on adult phenotypes. We monitored transplants of the subalpine perennial forb, Boechera stricta (Brassicaceae), in common gardens at two elevations over 2–3 years that differed in drought intensity. We quantified viability, and fecundity fitness components for four heritable traits: specific leaf area, integrated water-use efficiency, height at first flower, and flowering phenology. Our results indicate that genetic clines are maintained by selection, but their expression is context dependent, as they do not emerge in all environments. Moreover, selection varied spatially and temporally. Stabilizing selection was most pronounced when we integrated data across years. Finally, viability selection prior to trait expression targeted adult phenotypes (age and size at flowering). Indeed, viability selection for delayed flowering opposed fecundity selection for accelerated flowering; this result demonstrates that neglecting to account for viability selection could lead to inaccurate conclusions that populations are maladapted. Our results suggest that reconciling clinal trait variation with selection requires data collected across multiple spatial scales, time frames, and life-history stages.

Selection for early reproduction in the solitary bee Hoplitis fulgida - Lydia H. Wong (2017)
Reproductive timing is an important determinant of offspring success which ultimately contributes to an individual’s overall fitness. In seasonal environments with short growing seasons, organisms must time reproductive activity so that offspring experience relatively high levels of resource abundance but also have enough time to undergo sufficient ontogenetic development to successfully overwinter. The timing of other life-history events that necessarily precede reproduction such as gonadal maturation, migration, and emergence from diapause may place further constraints on reproductive timing. We investigated the effects of reproductive timing in subalpine populations of the solitary bee Hoplitis fulgida on individual reproductive output and offspring success. Specifically, we examined how timing of nesting in H. fulgida affected both individual reproductive output (given by nest construction rate and total number of brood cells constructed per nest), and offspring success (using larval development as a proxy). We also conducted surveys of H. fulgida floral hosts to determine temporal patterns of resource abundance. Nest construction rate significantly declined over the course of the season but was only explained by the day of the year and was not associated with floral resource abundance in our models. Similarly, the total number of brood cells per nest decreased seasonally but was only explained by the day on which the nest was initiated and not by floral resource abundance. Both results seemed to suggest that H. fulgida individuals are under directional selection for early reproduction; however, the selective pressures that are driving these trends have yet to be investigated.

Interannual bumble bee abundance is driven by indirect climate effects on floral resource phenology - Jane E. Ogilvie; Sean R. Griffin; Z. J. Gezon; David W. Inouye; N. Underwood; David W. Inouye; R. E. Irwin (Ecology Letters, 2017)
Jane E. Ogilvie,1,2* Climate change can influence consumer populations both directly, by affecting survival and repro- Sean R. Griffin,1,3 duction, and indirectly, by altering resources. However, little is known about the relative impor- Zachariah J. Gezon,1,4,5 tance of direct and indirect effects, particularly for species important to ecosystem functioning, Brian D. Inouye,1,2 like pollinators. We used structural equation modelling to test the importance of direct and indi- Nora Underwood,1,2 rect (via floral resources) climate effects on the interannual abundance of three subalpine bumble David W. Inouye1,6 and bee species. In addition, we used long-term data to examine how climate and floral resources have Rebecca E. Irwin1,3 changed over time. Over 8 years, bee abundances were driven primarily by the indirect effects of climate on the temporal distribution of floral resources. Over 43 years, aspects of floral phenology changed in ways that indicate species-specific effects on bees. Our study suggests that climate- driven alterations in floral resource phenology can play a critical role in governing bee population responses to global change.

Plant-pollinator interactions under climate change: the use of spatial and temporal transplants - E. M. Morton; Nicole E. Rafferty (Applications in Plant Sciences, 2017)
Climate change is affecting both the timing of life history events and the spatial distributions of many species, including plants and pollinators. Shifts in phenology and range affect not only individual plant and pollinator species but also interactions among them, with possible negative consequences for both parties due to unfavorable abiotic conditions or mismatches caused by differences in shift magnitude or direction. Ultimately, population extinctions and reductions in pollination services could occur as a result of these climate change–induced shifts, or plants and pollinators could be buffered by plastic or genetic responses or novel interactions. Either scenario will likely involve altered selection pressures, making an understanding of plasticity and local adaptation in space and time especially important. In this review, we discuss two methods for studying plant–pollinator interactions under climate change: spatial and temporal transplants, both of which offer insight into whether plants and pollinators will be able to adapt to novel conditions. We discuss the advantages and limitations of each method and the future possibilities for this area of study. We advocate for consideration of how joint shifts in both dimensions might affect plant–pollinator interactions and point to key insights that can be gained with experimental transplants.

A Comparative Analysis of Saxicolous Lichen Diversity and Cover along an Elevation Gradient on Talus Slopes in Gunnison National Forest to Infer Possible Climate Change Effects - M. Rada (2017)
Climate change in Colorado has already increased temperatures by 2 ℉ and is predicted to continue to rise. Precipitation during winter months is predicted to increase, while projected precipitation for the spring, summer and fall is still uncertain. It is important to understand how saxicolous lichen communities (those growing on or in rock) will respond to climate change as they are primary successors and many other organisms rely on their ecological services. Saxicolous lichen communities are important primary successors of barren talus rock slopes, slowly eroding rock and creating habitats for micro and eventually macro plant communities. Some other roles of lichens include; nutrient deposition, nesting material, habitat for microscopic organisms, erode rock, and forage for reindeer (Pegau 1968, Nash et al. 1995, Crossman et al. 2001, Winchester et al. 2008). Lichen communities are expected to change in species diversity, distribution and cover along an elevational gradient and with varying aspect differences. Climate warming and changes in precipitation patterns may lead to a shift in community diversity and cover, and ultimately ecosystem function. The diversity and cover of saxicolous lichens were measured along an elevational gradient on talus slopes in Gunnison National Forest, Colorado. Six sites and a total of 180 transects were analyzed for abundance and cover of lichen thalli and bare rock using the image processing program ImageJ. Talus slopes with varying aspects and elevations had significantly different compositions of lichen species. Diversity and abundance of lichens decreased with elevation and on drier south-facing slopes. This has potential negative implications for the persistence of lichen communities that colonize harsh environments already experiencing extreme conditions. It is important to look at how these lichen communities are structured to predict how they might respond to a rapidly changing climate, as many biological models do not represent these communities. This study pursued how lichen cover and diversity will change over time as climate change progresses.

Young inversion with multiple linked QTLs under selection in a hybrid zone - C. R. Lee; B. Wang; Julius Mojica; T. Mandakova; T. Mitchell-Olds (Nature Ecology and Evolution, 2017)
AbstractFixed chromosomal inversions can reduce gene flow and promote speciation in two ways: by suppressing recombination and by carrying locally favoured alleles at multiple loci. However, it is unknown whether favoured mutations slowly accumulate on older inversions or if young inversions spread because they capture pre-existing adaptive quantitative trait loci (QTLs). By genetic mapping, chromosome painting and genome sequencing, we have identified a major inversion controlling ecologically important traits inBoechera stricta. The inversion arose since the last glaciation and subsequently reached local high frequency in a hybrid speciation zone. Furthermore, the inversion shows signs of positive directional selection. To test whether the inversion could have captured existing, linked QTLs, we crossed standard, collinear haplotypes from the hybrid zone and found multiple linked phenology QTLs within the inversion region. These findings provide the first direct evidence that linked, locally adapted QTLs may be captured by young inversions during incipient speciation.

Roderick Nash 1939– - Gregory Graves (2017)
Roderick Nash was one of many young, talented scholars attracted to the university's majestic setting on the Pacific Coast just west of Santa Barbara. As Nash developed courses in American environmental history, fate stepped in when oil from a drilling pipe rupture on an offshore platform bubbled 70,000 barrels of crude into the ocean and onto the beaches of Santa Barbara. Nash's interest in environmental history and intellectual history led to an array of books, articles, and other publications. Presently, Nash spends extensive time cruising his tugboat, Forever Green, in the Gulf of California, the central coast of California, and the inland passages to British Columbia and Alaska, while also skiing one hundred days a year near his winter home in Crested Butte, Colorado. Nash has told the story of attitudes toward wilderness, and has also expanded that concept to capture the dynamics of modern environmentalism.

Effects of global change on insect pollinators: multiple drivers lead to novel communities - Nicole E. Rafferty (Current Opinion in Insect Science, 2017)
Global change drivers, in particular climate change, exotic species introduction, and habitat alteration, affect insect pollinators in numerous ways. In response, insect pollinators show shifts in range and phenology, interactions with plants and other taxa are altered, and in some cases pollination services have diminished. Recent studies show some pollinators are tracking climate change by moving latitudinally and elevationally, while others are not. Shifts in insect pollinator phenology generally keep pace with advances in flowering, although there are exceptions. Recent data demonstrate competition between exotic and native bees, along with rapid positive effects of exotic plant removal on pollinator richness. Genetic analyses tie bee fitness to habitat quality. Across drivers, novel communities are a common outcome that deserves more study.

Lateralized Function Without Lateralization - A. Diaz (2017)
In many vertebrates, the right hemisphere/left visual field is used to process information about threats while the left hemisphere/right visual field is used to process information about conspecifics. This is referred to as hemispheric lateralization. But prey that are too predictable in their response to predators could have reduced survival. We studied hemispheric lateralization in yellow-bellied marmots (Marmota flaviventer), a social rodent that falls prey to a variety of terrestrial and aerial predators. We first asked if they have lateralized responses to a predatory threat. We then asked if the eye that they used to assess risk influenced their perceptions of risk. We recorded the direction marmots were initially looking and then walked towards them at 0.5 m/s. We recorded the distance that they responded to our experimental approach by looking, the eye with which they looked at us, and the distance at which they fled (i.e., flight initiation distance; FID). We found that marmots had no eye preference with which they looked at an approaching threat. Furthermore, the population was not comprised of individuals that responded in consistent ways. However, we found that marmots who looked at the approaching person with their left eye had larger FIDs suggesting that risk assessment was influenced by they eye with which they used when assessing risk. These findings are consistent with selection to make prey less predictable for their predators, despite lateralized function.

Does environmental heterogeneity drive functional trait variation? A test in montane and alpine meadows - Jordan Stark; Rebecca Lehman; Lake Crawford; Brian J. Enquist; B. Blonder (Oikos, 2017)
While community‐weighted means of plant traits have been linked to mean environmental conditions at large scales, the drivers of trait variation within communities are not well understood. Local environmental heterogeneity (such as microclimate variability), in addition to mean environmental conditions, may decrease the strength of environmental filtering and explain why communities support different amounts of trait variation. Here, we assess two hypotheses: first, that more heterogeneous local environments and second, that less extreme environments, should support a broader range of plant strategies and thus higher trait variation. We quantified drivers of trait variation across a range of environmental conditions and spatial scales ranging from sub‐meter to tens of kilometers in montane and alpine plant communities. We found that, within communities, both environmental heterogeneity and environmental means are drivers of trait variation. However, the importance of each environmental factor varied depending on the trait. Our results indicate that larger‐scale trait–climate linkages that hold across communities also apply at small spatial scales, suggesting that microclimate variation within communities is a key driver of community functional diversity. Microclimatic variation provides a potential mechanism for helping to maintain diversity in local communities and also suggests that small‐scale environmental heterogeneity should be measured as a better predictor of functional diversity.

Carbon Dioxide Efflux and Storage in Small, Drying Alpine Ponds - S. Campbell (2017)
Climate change is expected to influence the drying regimes of small ponds, impacting their carbon cycling capabilities and potentially inducing unprecedented pond drying that could lead to higher greenhouse gas efflux rates. Small ponds are already known to release disproportionately high amounts of carbon dioxide and methane. Riverine, lake and large pond systems have all received increasing attention, both for their vulnerability to climate change and their ability to exacerbate it. Yet the role of small ponds, especially alpine ponds, has remained understudied. The goal of our work was to quantify aqueous CO2 concentrations in small alpine ponds in northwestern Colorado and to explore the drivers of these concentrations. Additionally, we linked these concentrations to drying patterns and the unique characteristics of ponds with different permanence traits. We found that these ponds had smaller concentrations than comparable small ponds at temperate latitudes, and more closely resembled concentrations in boreal ponds. Our study ponds had aqueous CO2 concentrations ranging from 33.6 to 77.6 μmol/L, as compared to measurements as high as 360 μmol/L in Connecticut ponds. We found that permanence traits had no significant relationship with CO2 concentrations early in the season, and that dissolved oxygen was not a good predictor of these concentrations. Further work will be conducted into investigating CO2 concentration drivers. Our work impacts understanding of the global carbon budget with respect to the role of small ponds.

Impacts of Historical Hydroperiod on Bird Predation of Emergent Aquatic Insects - K. H. Williams (2017)
As global climate changes ephemeral freshwater systems face changes in historical hydroperiod with a shift towards shorter wet periods. Vernal ponds are one such type of lentic ephemeral system; in general they are relatively small and shallow, which causes them to dry in late spring or early summer. Their size allows vernal ponds to have a close connection with the terrestrial environment adjacent to them, and changes in their hydroperiod could have effects on both the species, which inhabit the ponds. Emergent aquatic insects are an important food source for terrestrial birds and shifts in hydroperiod may affect the availability of this resource. The present study investigates how birds in the Mexican Cut Nature Preserve interact with ponds of different hydroperiods. There were a greater number of bird observations at permanent ponds than at temporary ponds (Linear mixed effects model, p<0.001, F = 68.82). Permanent ponds are more diverse and consistent systems, which may attract birds to them. More research is required to understand how birds interact with aquatic systems to better aid in conservation efforts in the future.

Assessing the Role of Oxbow Deposits in Carbon and Nitrogen Dynamics within Alpine Watersheds - Z. Birnholz (2017)
Despite their abundance, floodplains are poorly understood components of the global carbon cycle that are not well represented in Earth system models. The hydrology of floodplains was thought to be the major factor in controlling the chemical state and microbial activity within their sediments and groundwater. This paper seeks to characterize the impact of changing water levels on carbon and nitrogen cycling within alpine floodplains. This study took place in a meander in the East River floodplain in Central Colorado, where the summer drawdown causes a rapid decline in the floodplain’s groundwater. Although carbon and nitrogen data have not been received at the time of writing, reduced iron was found to increase throughout the meander over time even as groundwater levels fell, with an unexpected peak in the center of the meander. This peak suggests that there is also a peak in metabolized organic carbon in the same location, which tends to drive the reduction of iron. We expect that ammonium (reduced nitrogen) will follow the same trend as reduced iron, while nitrate should follow the opposite trend, as nitrogen and iron are both redox-active. Dissolved oxygen was low in the center of the meander but occurred in higher concentrations along the riverbanks. Plants in the floodplain, which can oxygenate the subsurface via their roots, may be the cause of the oxicity of the downstream edge of the meander. Overall, it is clear that there are other major controls on floodplain chemical cycling beyond hydrology.

Metabolic Partitioning across Individuals in Ecological Communities - J. Harte; A. Rominger; E. Newman (Global Ecology and Biogeography, 2017)
AbstractThe mechanistic origin and shape of body‐size distributions within communities are of considerable interest in ecology. A recently proposed light‐limitation model provides a good fit to the distribution of tree sizes in a tropical forest plot. The maximum entropy theory of ecology (METE) also predicts size distributions, but without explicit mechanistic assumptions, and thus its predictions should hold in ecosystems generally, regardless of whether they are light limited. A comparison of the form and success of the predictions of the model and the theory can provide insight into the role that mechanisms play in shaping patterns in macroecology. The prediction by the METE of the size distribution of organisms is remarkably similar in form to that of the model: power‐law behaviour in the size range where the light‐limitation model predicts a power law, and exponential behaviour in the size range where the model predicts an exponential tail. The METE prediction matches data widely, including data in ecosystems where light is not limiting. We show examples for three disparate communities: trees in a tropical forest plot; herbaceous plants in a treeless subalpine meadow; and island arthropods. We conclude that the success of METE's predicted form across systems, including those that are clearly not light limited, enriches our capacity to predict patterns in macroecology without making explicit mechanistic assumptions and provides a unified framework that can capture ubiquitous features of those patterns across diverse ecosystems governed by a variety of mechanisms.

The ability of ants to associatively learn based on olfactory chemical cues produced by plants. - K. Sentner (2017)
Associatively learning is commonly observed throughout the natural world in many interactions between species and their environment. We know ants utilize environmental cues in their foraging patterns to locate and recruit to food, but little is known about their ability to associatively learn to forage using these cues. Associative learning in ants has been tested in laboratory settings but the experiment has never been replicated in the field. It is also unknown to what extent the ants learn on certain environmental cues including olfactory cues. After allowing ants to forage and recruit to baits associated with scents produced by plants associated with sugar rich resources (either Ligusticum porteri or Helianthella quinquenervis), we found that additional baits with the same scent were significantly more likely to be discovered than those with the other scent (30-40% more likely to be discovered), although there was no significant difference in how quickly the baits were discovered or the number of ants that recruited to the bait. Furthermore, significantly more ants recruited to the baits if the first bait smelled like Ligusticum porteri as opposed to Helianthella quinquenervis (23% more likely). This result indicates that ants detect plant scents when foraging for sugar rich resources and subsequently forage more frequently for resources on those same plant species. This learned association could increase the capability of ants to forage successfully and increase the fitness of ant colonies.

Direct benefits and indirect costs of warm temperatures for high-elevation populations of a solitary bee - J. R. K. Forrest; S. P. M. Chisholm (Ecology, 2017)
AbstractWarm temperatures are required for insect flight. Consequently, warming could benefit many high‐latitude and high‐altitude insects by increasing opportunities for foraging or oviposition. However, warming can also alter species interactions, including interactions with natural enemies, making the net effect of rising temperatures on population growth rate difficult to predict. We investigated the temperature‐dependence of nesting activity and lifetime reproductive output over 3 yr in subalpine populations of a pollen‐specialist bee, Osmia iridis. Rates of nest provisioning increased with ambient temperatures and with availability of floral resources, as expected. However, warmer conditions did not increase lifetime reproductive output. Lifetime offspring production was best explained by rates of brood parasitism (by the wasp Sapyga), which increased with temperature. Direct observations of bee and parasite activity suggest that although activity of both species is favored by warmer temperatures, bees can be active at lower ambient temperatures, while wasps are active only at higher temperatures. Thus, direct benefits to the bees of warmer temperatures were nullified by indirect costs associated with increased parasite activity. To date, most studies of climate‐change effects on pollinators have focused on changing interactions between pollinators and their floral host‐plants (i.e., bottom‐up processes). Our results suggest that natural enemies (i.e., top‐down forces) can play a key role in pollinator population regulation and should not be overlooked in forecasts of pollinator responses to climate change.

Confounding effects of spatial variation on shifts in phenology - C. W. de Keyzer; Nicole E. Rafferty; David W. Inouye; J. D. Thomson (Global Change Biology, 2017)
Shifts in the timing of life history events have become an important source of information about how organisms are responding to climate change. Phenological data have generally been treated as purely temporal, with scant attention to the inherent spatial aspects of such data. However, phenological data are tied to a specific location, and considera- tions of sampling design, both over space and through time, can critically affect the patterns that emerge. Focusing on flowering phenology, we describe how purely spatial shifts, such as adding new study plots, or the colonization of a study plot by a new species, can masquerade as temporal shifts. Such shifts can look like responses to climate change but are not. Furthermore, the same aggregate phenological curves can be composed of individuals with either very different or very similar phenologies. We conclude with a set of recommendations to avoid ambiguities arising from the spatiotemporal duality of phenological data.

Social Security: social relationship strength and connectedness influence how marmots respond to alarm calls - Daniel T. Blumstein; H. Fuong; E. L. Palmer (Behavioral Ecology and Sociobiology, 2017)
Yellow-bellied marmots are studied to suggest a new way that social relationships can be beneficial: they increase perceptions of security and this ultimately may facilitate foraging and illustrate an effect of social relationships on predation risk assessment.

Can yellow-bellied marmots (Marmota flaviventer) learn foraging innovations? - M. Standen (2017)
Innovation is widespread in animals and may help them modify their behavior to changes in the environment. A common method to determine whether a species possesses innovative abilities is to present them with a novel foraging problem and then to explain the traits that may predict success. Individuals differ in their innovative propensity and factors that have been linked to such differences include age, sex, rank, and personality. Yellow-belied marmots (Marmota flaviventer) are 3-5 kg ground dwelling squirrels that live in female kin groups at predictable locations, making them an ideal subject of an innovation study. Here we asked whether yellow- bellied marmots can learn foraging innovations and how the factors of age, sex, and sociality affect an individual’s innovative propensity. We presented individuals with a two-action puzzle box and began by determining who was able to solve it, and who was not. We used logistic regression to study characteristics associated with success and our preliminary data suggest that the social group to which an individual belongs to was an important predictor of innovative success. To determine whether innovative success illustrated learning, we asked whether marmots’ latency to open the box declined over repeated exposures. We also asked whether the diversity of behaviors used to open the box decreased with successive experience. Surprisingly, we found no evidence that marmots learned to open the box either faster or more efficiently with more experience. In order to better study innovation, larger sample sizes will be needed. In addition, future studies will ask whether innovation can be socially transmitted through marmot groups.

Species Co-occurrence Patterns and Mechanisms for Rhyacophila in High-Altitude Streams - B. Sparrow (2017)
Currently, due to global warming, we are seeing large range shifts in many different species across the world. As these species shift they are encountering new species and new environments. The way that a species interacts with these new species and environments will determine its ability to expand its range, preventing extinction by being successful in this new environment. Rhyacophila is a genus of caddisflies, which belong to a group of terrestrial insects that complete their aquatic larval stage in cold, fast-flowing and highly oxygenated freshwater streams. Previous research has shown that the distribution and abundance of species in this genus vary greatly across streams in the Upper East River Basin in Gunnison, Colorado. In this study we wanted to determine if there were any species co-occurrence patterns that we could identify that would explain the distribution of these species. We also wanted to test potential mechanisms such as species interactions and environmental variables to see if they would explain these distribution patterns. We did find both positive and negative association patterns between various species. Rhyacophila alberta seemed to be negatively associated with Rhyacophila brunnea and weakly positively associated with Rhyacophila hyalinata. Both Rhyacophila alberta and Rhyacophila brunnea seem to have environmental preferences that were opposite of each other and Rhyacophila hyalinata seemed to fall somewhere in the middle of the spectrum. Using an experiment we tested whether or not predation and growth rates of Rhyacophila alberta were affected by the presence of species it commonly co-existed with compared to species it rarely co- occurred with. We did find effects on both predation rate and growth rate depending on treatment. However, predation rate did not predict growth rate. This experiment shows that species distributions can be influenced by both interspecific and intraspecific species interactions and environmental factors.

Effects of Climate Changes on Ecologically Important Bees and Flowers - H. Rocha (2017)
Climate warming affects the phenology, abundance and distributions of plants and pollinators. Despite this, there is still limited knowledge on how temperature affects plant- pollinator mutualisms. The ongoing project with Dr. Rebecca E. Irwin in collaboration with David Inouye has been gathering data at the Rocky Mountain Biological Laboratory (Colorado, USA). We are studying bee phenology and abundance, and flower phenology and abundance, and how those relationships have been changing over time as they are impacted by climate change. We have used historical data from 2009 - 2016 to determine if the increase in temperature causes phenological mismatches. Our results showed that flowers are reacting to temperature changes and may be blooming earlier, leaving a bee pollinator without food resources. Thus, bees are altering their flower visitations over the years and how flower abundance at any given site has been changing as well.

Effect of Road Dust Deposition on the Floral Lifespan of Scarlet gilia, Ipomopsis aggregata - D. Lopez (2017)
The Rocky Mountains are one of the world’s most diverse areas in all of Western United States. Like most wonders of the world, the Rocky Mountains are also subjected to unpaved roads, and these roads often produce fine particulates of dirt that are able to rise into the air with ease. In this study, we investigate how these dust particulates influence the life span of flowers. The plant used in this study was the sub montane perennial Scarlet gilia, Ipomopsis aggregata. We unveil how road dust particulates may be the mechanism that could explain of lower pollen loads on Scarlet gilia near unpaved roads. When exposed to the dusty treatment, the stigma on the flowers remain receptive only a fraction of the time as those that are undusted. This evidence supports the idea that road dust reduces the amount of time the stigma is receptive to pollen, which would explain the low pollen loads of Scarlet gilia near unpaved roads.

Diversification of Type VI Secretion System Toxins Reveals Ancient Antagonism among Bee Gut Microbes - M. I. Steele; W. K. Kwong; M. Whiteley; N. A. Moran (mBio, 2017)
ABSTRACT Microbial communities are shaped by interactions among their constituent members. Some Gram-negative bacteria employ type VI secretion systems (T6SSs) to inject protein toxins into neighboring cells. These interactions have been theorized to affect the composition of host-associated microbiomes, but the role of T6SSs in the evolution of gut communities is not well understood. We report the discovery of two T6SSs and numerous T6SS-associated Rhs toxins within the gut bacteria of honey bees and bumble bees. We sequenced the genomes of 28 strains of Snodgrassella alvi , a characteristic bee gut microbe, and found tremendous variability in their Rhs toxin complements: altogether, these strains appear to encode hundreds of unique toxins. Some toxins are shared with Gilliamella apicola , a coresident gut symbiont, implicating horizontal gene transfer as a source of toxin diversity in the bee gut. We use data from a transposon mutagenesis screen to identify toxins with antibacterial function in the bee gut and validate the function and specificity of a subset of these toxin and immunity genes in Escherichia coli . Using transcriptome sequencing, we demonstrate that S. alvi T6SSs and associated toxins are upregulated in the gut environment. We find that S. alvi Rhs loci have a conserved architecture, consistent with the C-terminal displacement model of toxin diversification, with Rhs toxins, toxin fragments, and cognate immunity genes that are expressed and confer strong fitness effects in vivo . Our findings of T6SS activity and Rhs toxin diversity suggest that T6SS-mediated competition may be an important driver of coevolution within the bee gut microbiota. IMPORTANCE The structure and composition of host-associated bacterial communities are of broad interest, because these communities affect host health. Bees have a simple, conserved gut microbiota, which provides an opportunity to explore interactions between species that have coevolved within their host over millions of years. This study examined the role of type VI secretion systems (T6SSs)—protein complexes used to deliver toxic proteins into bacterial competitors—within the bee gut microbiota. We identified two T6SSs and diverse T6SS-associated toxins in bacterial strains from bees. Expression of these genes is increased in bacteria in the bee gut, and toxin and immunity genes demonstrate antibacterial and protective functions, respectively, when expressed in Escherichia coli . Our results suggest that coevolution among bacterial species in the bee gut has favored toxin diversification and maintenance of T6SS machinery, and demonstrate the importance of antagonistic interactions within host-associated microbial communities.

40 years of progress in pollination biology, and what it means for citizen scientists - Nickolas M. Waser; Mary V. Price (Aquilegia: Newsletter of the Colorado Native Plant Society, 2017)

Reservoir trends and exploration potential of the El Vado Sandstone Member of the Mancos Shale, northwestern New Mexico - Tiffany Setare Hedayati (Texas ScholarWorks (Texas Digital Library), 2017)
The El Vado Sandstone Member (late Coniacian) of the Mancos Shale is considered by many to be an important unconventional hydrocarbon resource target (Ridgley, 2001) in the San Juan Basin located in northwestern New Mexico. The shelf sandstones of the El Vado were deposited along the western margin of the Western Interior Cretaceous Seaway. The El Vado is part of a transgressive-regressive wedge of rock that overlies a large, older transgressive wedge which contains the Tocito Sandstone (the largest oil producer in the basin). Despite its productivity in parts of the basin, the nature, origin, and distribution of the El Vado Sandstone is poorly understood. Using well logs and core, the subsurface has been mapped to illustrate the distribution of the El Vado Sandstone across its extent in the San Juan Basin. The El Vado is reflected in logs as a thick (~ 120 foot) interval of low gamma ray and high resistivity. The gamma ray log character reflects highly laminated sand-to-silts interbedded with shales. A total of 13 cross sections were constructed based on the high density of well log control. Isopach maps were then generated for the entire interval and individual cycles of the El Vado. Regional net sand and net-to-gross maps, determined from 104 digitized well logs, highlight the regional distribution of sand content. Two regions in the basin were examined in outcrop, the northeast and the southeast. In the northern outcrops, the El Vado consists of five cycles of similar thickness (~ 4 m each) separated by marine shales with cycles becoming progressively sandier upward. To the south, the El Vado Sandstone appears to transition from a shelf deposited sandstone into a lower shoreface sandstone. Examining the El Vado Sandstone in the subsurface and in outcrops helped the author to improve the understanding of the nature and distribution of the sands throughout the basin.

Factors that affect territory size in Mountain White-Crowned Sparrows (Zonotrichia leucophrys oriantha) - R. LaRitz (2017)
Male songbirds sing on the edge of their territory to warn away competing males. The mountain white-crowned sparrow (Zonotrichia leucophrys oriantha) prefers to sing on the edge of willows and spruce trees. High quality territory is determined by the availability of food, water and shelter. Meanwhile, lower quality territory lacks these key resources and reduce the chances of the holding male’s breeding success. I hypothesized that perimeter and area of a territory are directly correlated to elevation. However, due to unexpected restrictions in sample size, my analysis was strictly descriptive. For this study, I walked through the willows and recorded the GPS coordinates of the singing spots of each male. The median total territory area was 4047.2 meters squared and a total territory perimeter of 83.2 meters squared. I constructed four GIS maps which allowed the visualization of the variety of territory shapes.

Conflict of interest? Investigating the costs and benefits of herbivore defense using the model plant Boechera stricta - J. Poole (2017)
Boechera stricta, a native forb common to the Rocky Mountain range in western North America, is a model species at the forefront of genetics and ecology. Over millennia, in response to herbivory, plants have developed secondary metabolite defensive compounds to deter wide ranges of herbivores. Glucosinolates represent one such type of compound produced by Brassicaceous plants. However glucosinolates may act as cues for oviposition for specialist herbivores and thus may lead to a conflict of interest for their host plant. This study focused on whether contrasting glucosinolate chemical profiles confer costs or benefits to overall fitness in relation to defense against specialist herbivores. I combined field observations from two separate studies to infer whether glucosinolate chemical profile influences specialist oviposition and feeding behavior, and if this behavior may result in selection for plant chemistry, thus influencing phenotypic diversity in defensive strategy. Overall, I found that there was no significant response in specialist oviposition or abundance based on chemical profile. However, in natural populations of B. stricta, plants on which Euchloe ausonides were present had significantly higher levels of herbivore damage to fruits than plants on which the specialist was absent. These results indicate that plants that attract specialist herbivores suffer a reproductive disadvantage, but that host plant chemical profile does not appear to influence that attraction. Factors influencing specialist herbivore oviposition, presence/absence, and abundance remain unknown.

A cost of being amicable in a hibernating marmot. - Wei Jenny Yang; Adriana A. Maldonado-Chaparro; Daniel T. Blumstein (Behavioral Ecology, 2017)

Social capital and socio-cultural sustainability: mountain resort tourism and the community of Steamboat Springs - Natalie Ooi (Figshare, 2017)
Mountain resort tourism, in particular ski tourism, has brought about significant change to many alpine communities within North America. Providing an alternative to past industries such as ranching, agriculture, mining, and logging, tourism has been heralded by some as a panacea for the revitalisation of what are largely declining economic bases, whilst others have described it as a destructive force that has brought about many economic, environmental, and socio-cultural concerns. Although significant recognition exists within the academic literature regarding the various economic and environmental impacts resulting from mountain resort tourism, there appears to be a lack of detailed and targeted examination of its socio-cultural sustainability. My research addresses this gap within the mountain resort tourism literature by focusing on this often overlooked dimension of sustainability. This is achieved through using social capital as a conceptual lens to examine the networks, norms, and resources that form a part of our everyday socialisation. While social capital has been widely adopted within sociology, its use in exploring tourism phenomena has thus far been limited. This is despite its ability to highlight the various sociological processes and interactions that occur within tourism-dependent communities and how they have been affected by tourism development. Adopting an ethnographic case study design, I immersed myself within the community of Steamboat Springs, Colorado, living and participating in the daily activities of community members for ten months spanning the winter and summer tourism seasons. During this time, I undertook 53 qualitative interviews with a range of community members from various interest areas to help illuminate many of the socio-cultural issues faced as a result of mountain resort tourism. I accompanied these with participant observation of both special events and day-to-day activities, which were recorded in a field work journal. This was alongside photographs that were captured to provide a complementary visual record of my observations and experiences, as well as the analysis of relevant documentation in the form of council and county reports and plans, the local newspaper, local websites, and magazines. Overall, my research identified mountain resort tourism as having brought about a wide range of impacts that have affected the social capital components of networks, norms, and resources in numerous ways. These effects include the strengthening of community bonding networks, the reinforcement of social norms, and the mobilisation of shared resources through collective action; all of which highlight the existence of such positive aspects of socio-cultural sustainability as a sense of community, democratic community participation, collaboration, and empowerment. At the same time, mountain resort tourism was found to have contributed to such negative social capital outcomes as the social exclusion and isolation of newcomers and other marginalised groups within the community, the creation of anti-social norms in response to its many impacts, resource inequities both within Steamboat Springs and between the surrounding communities, and a growing sense of powerlessness. These outcomes appear reflective of the socio-culturally unsustainable nature of mountain resort tourism as they can be seen as negatively affecting quality of life, a sense of community ownership and attachment, the ability and willingness of many community members to democratically and equitably participate, and the likelihood of inter-community collaboration, whilst also exacerbating socio-economic class distinctions. This raises a number of socio-cultural concerns for the community of Steamboat Springs in regards to the long-term sustainability of mountain resort tourism. In particular, my research highlights the importance of more effective tourism governance, with the community needing to address such issues as future community ownership, democratic and equitable community representation, increased government transparency, and the development of intra- and inter-community bridging networks in order for the socio-cultural sustainability of mountain resort tourism to be achieved. At the same time, the potential for social capital to act as a heuristic device to guide the examination of the socio-cultural sustainability of tourism can also be noted. This is because of its ability to go beyond the identification of mountain resort tourism impacts to explore how individuals, groups, and organisations within tourism-dependent communities have responded to tourism development and its effects on their everyday lives, thereby providing a more holistic understanding of tourism sustainability within a mountain resort community context.

Variability in the effectiveness of Penstemon strictus pollinators and the role that water availability plays - A. Morse (2017)
Plant-pollinator interactions play a vital role in the functioning and stability of our ecosystems. Without pollination, angiosperms would not be able to set seed and reproduce, and most organisms would lose their primary source of nutrients and resources. Owing to the fact that pollination services are becoming increasingly threatened by anthropogenic impacts, a thorough understanding of the factors that influence the success of pollen transfer is important, relevant, and timely. In this study, we evaluate how water availability influences pollinator effectiveness. Pollinator effectiveness is defined as the amount of conspecific pollen deposited on the stigma in a single pollinator visit. Many researchers have compared and assessed pollinator effectiveness, while others have investigated how water availability influences floral and vegetative traits, but few have studied the relationship between environmental factors and conspecific pollen deposition. Using a water manipulation experiment on 80 paired Penstemon strictus plants growing in Crested Butte, Colorado, we were able to show that different types of pollinators vary in their behavior, handling time, and effectiveness. Our water treatment did not exert a significant effect on any of the floral or vegetative traits that we measured, so the pathway by which we predicted water availability to operate on pollinator performance was irrelevant. In our analysis of pollinator behavior, handling time and effectiveness, we therefore have not factored in water treatment or soil moisture (yet). With respect to pollinator effectiveness, we did not find a significant correlation between handling time and conspecific pollen deposition for any of the pollinators. We did, however, find a significant relationship between behavior and conspecific pollen deposition. Buzz pollination or sonication, a particular pollen foraging behavior employed by Bombus bifarius, yielded the greatest amount of pollen received by the stigma. Based on these findings, we suggest that behavior in conjunction with physical traits of pollinator species and genera, such as size, hairiness, and pollen-bearing structures, exert the largest influence on pollinator effectiveness.

The Role of Castilleja spp. In Plant and Mycorrhizae Communities Within Various Climates - M. McKibben (2017)
Hemiparasites such as those in the genus Castilleja have important effects on the plant communities they are found in. For example, hemiparasitic plants may reduce the abundance of dominant plant species, opening niche space for sub- ordinates. This effect may be driven by direct parasitism of Castilleja on dominant hosts species or maybe mediated through indirect interactions as Castilleja compete with root-associated fungal communities, like arbuscular mycorrhizal fungi and dark septate endophytes, for host carbon. Here we explored how Castilleja affects plant diversity, richness, and community composition, and how Castilleja influenced the relationship between dominant plants in the community and their root-associated fungal communities. Overall, we found that the presence of Castilleja increased plant diversity 9%, increased species richness 11%, without influencing plant community composition. Additionally, we found that Castilleja affected dominant plant interactions with mycorrhizal fungi, leading to an 18% reduction in arbuscular mycorrhizal fungal colonization within dominant root tissues.

Nano-scale Petrophysical Studies of The Gothic Shale Interval in the Paradox Basin, Colorado, U.S.A. - Marvin L Dunbar (UTA ResearchCommons (University of Texas Arlington), 2017)
Hydrocarbon production from shale has become a main energy source for the United States. Consequently, an increased knowledge of the petrophysical properties of shale such as porosity, permeability, tortuosity, and fluid-rock interactions (e.g., contact angle, imbibition) will improve production efficiency. Because of their minute size (nanoscale), the knowledge of pore structure (i.e., pore geometry and connectivity) has proven difficult to understand. Analyzing the pore size distribution and pore connectivity of Gothic Shale from selected locations in the Montezuma County of Colorado will lead to recommendations for greater oil production efficiency, fostering innovation into a thriving, environmentally safe, oil and gas industry. \nThis study investigated the pore structure and fluid interaction of Gothic Shale to understand the movement of hydrocarbon molecules in unconventional shale reservoirs, specifically focusing on the nano-scale pore geometry and connectivity of the organic matter and minerals, which are affected by maturity and mineralogy. In order to achieve this, a total of 10 core samples collected from four wells (A for 9-21 Antelope; KF for 1-4 Kissinger Federal; NF for 1-4 Norton Federal; UM for 44-34 Ute Mountain) received tests for organic carbon, pyrolysis, x-ray diffraction, contact angle, mercury injection capillary pressure, and fluid imbibition. \nPyrolysis results showed samples contained a percent carbonate from 42 – 69% with one outlier, sample UM8741, having a percent carbonate of 34%. TOC content varies within the dataset, containing values from 0.74 – 2.14. Tmax values ranged from 445 – 529⁰C corresponding with a vitrinite reflectance range from 0.92 – 1.79. Most samples are classified as a type of carbonate mudstone (i.e. mixed or silica-rich) and are dominated by either calcite or dolomite minerals. Samples NF5913 and UM8741 deviated from the other samples and contained a majority of quartz, these samples were classified as a mixed mudstone. \nDependent upon the availability of sample size, contact angle and core plug porosity /permeability were conducted for selected samples. MICP results show that many of the samples have porosity that fell within 0.5-1.0%. The dataset had an average porosity of 0.593% with the lowest porosity, 0.224%, found in the NF5915 (5915 ft of 1-4 Norton Federal) sample, and the highest, 0.951%, in sample NF5871, both of which are calcite dominated carbonate mudstones. Most samples had pore types that were dominated by either micro-fractures, particularly 1-10 micrometer sized pores, or inter-clay platelet pores (2.8-5 nm sized pore-throats). Furthermore, no correlation was found between pore size distribution and mineralogy or maturity. Permeability values reached 1.378 mD for sample A5989; however, this was an exception. The average value of the dataset was 0.541 mD. \nContact angle results show both API brine and 10% IPA are good wetting fluids, however 10% IPA typically displays better wettability. For most samples, n-decane imbibition showed higher slopes for pore connectivity in the rock matrix, indicating that the pore system has a better connection to oil wetting fluids, the only exceptions being KF5898 and A5985. Correlations between mineralogy (clay, carbonates, quartz) and pore connectivity are found, and discussed in further detail.

Colorado State University reports : Colorado Agriculture Bibliography - Allison V. Level; Sierra Standish (Digital Collections of Colorado (Colorado State University), 2017)
The records in this bibliography may cover several subject areas and are listed alphabetically by author.

Variation in Undisturbed Plant and Animal Populations and Its Implications for Studies of Recovering Ecosystems - David W. Inouye (2017)
Variation in population sizes of indicator species on an annual scale is much more likely to be of significance for most studies of ecosystem recovery. This broader time scale encompasses the regularly occurring seasonal climatic cycles and the corresponding variation in population dynamics of most plants and animals. Variation toward the long-term end of the temporal continuum is certainly significant on an evolutionary time scale, but can probably be safely ignored with regard to the recovery of damaged ecosystems. In this chapter, the author presents the analyses of two sets of data: a Christmas bird count of Passer domesticus (house sparrow) from 1947 to 1984 in Wichita, Kansas, and counts of the number of flowers of Helianthella quinquenervis (aspen sunflower) from 1974 to 1985 at the Rocky Mountain Biological Laboratory. Both of these data sets are perhaps representative of the types of census data that might be collected by researchers monitoring the status of recovering ecosystems.

Do the differing pollen foraging strategies of Megachile sp. and Bombus spp. result in differing pollen removal and deposition rates in Lupinus bakeri? - D. Jacobsmeyer (2017)
Mutualistic interactions between flowering plants and bees are a pairwise interaction, but exist in a network of similar interactions (Bronstein, 2001). The outcomes of these interactions differ, for example, the costs and benefits for flowering plants caused by floral visitors (Bronstein, 2001). Lupinus bakeri is a pollen-rewarding plant species that controls the amount of pollen removed by each floral visitor (Gori 1989; Harder 1990a). The bee genera Bombus spp. and Megachile sp. remove pollen differently from Lupinus bakeri, perhaps affecting the reproductive success of the plant differently. We assessed whether pollen removal and deposition rates are different for each bee genus through a interview stick based observational study. More Bombus spp. visited Lupinus bakeri than Megachile sp., but we did not detect a statistically significant difference in removal and deposition rates between bee taxa.

To the Rockies and back: studying marmots in Colorado - Svenja B. Kroeger (Mammal News, 2017)

Determinants of multiple paternity in a fluctuating population of ground squirrels - Caitlin P. Wells; K. M. Tomalty; C. H. Floyd; M. B. McElreath; B. May; D. H. Van Vuren (Behav Ecol Sociobiol, 2017)
It is found that the frequency of multiple paternity in golden-mantled ground squirrels varied considerably from year to year, that density of female kin interacted with male density to influence multiple paternity, and that older and heavier females tended to be less likely to produce multiply-sired litters.

Genetic basis of plant-insect interactions: insect recruitment to Boechera stricta - L. Macias (2017)
Mutualistic interactions are ubiquitous in nature. These type of interactions generally provide benefits to interacting species. Insects and plants are commonly involved in diverse forms of mutualism, however little is known if genetic variation among plants allows for a positive symbiosis with arthropods. In this study, we investigated whether plant traits in Boechera stricta (Brassicaceae) play a role in arthropod recruitment, and if so, whether the genetic basis of the plant contribute to this interaction. We also addressed whether visitation by ants and other insects minimized herbivory. We established a common garden experiment in which insect visitation to B. stricta was observed. We assessed insect visitation and herbivory on >400 known genotypes, as well as other plant traits. Within plant characteristics (number of flowers and fruits), plant height had a predominantly positive effect on the abundance of arthropods. Overall, plant height led to higher insect visitation, but the abundance of ants and other insects had no effect on herbivory due low insect observations and insufficient statistical power. Furthermore, we found a significance in the genetic basis of ant recruitment. These results indicate ant visitation can be influenced by plant traits, yet further studies are needed to determine what specific genes underlie in these traits.

The energetic and carbon economic origins of leaf thermoregulation - S. T. Michaletz; M. D. Weiser; N. G. McDowell; J. Zhou; M. Kaspari; B. R. Helliker; Brian J. Enquist (Nature Plants, 2016)
The theory, parameterized with global averaged leaf traits and microclimate, predicts a moderate level of leaf thermoregulation across a broad air temperature gradient, and predicts that net carbon assimilation can be maximized by means of a trade-off between leaf thermal stability and photosynthetic stability.

A PIT tagging technique for Ambystomatid salamanders - H. H. Whiteman; J. Doyle; J. Earl; C. B. Aubee; R. Brown; S. Thomason; T. Schoborg (Herpetological Review, 2016)

The effect of demographic correlations on the stochastic population dynamics of perennial plants - Aldo Compagnoni; Andrew J. Bibian; Brad M. Ochocki; Haldre S. Rogers; Emily L. Schultz; Michelle E. Sneck; Bret D. Elderd; Amy M. Iler; David W. Inouye; Hans Jacquemyn; T. E. X. Miller (Ecological Monographs, 2016)
AbstractUnderstanding the influence of environmental variability on population dynamics is a fundamental goal of ecology. Theory suggests that, for populations in variable environments, temporal correlations between demographic vital rates (e.g., growth, survival, reproduction) can increase (if positive) or decrease (if negative) the variability of year‐to‐year population growth. Because this variability generally decreases long‐term population viability, vital rate correlations may importantly affect population dynamics in stochastic environments. Despite long‐standing theoretical interest, it is unclear whether vital rate correlations are common in nature, whether their directions are predominantly negative or positive, and whether they are of sufficient magnitude to warrant broad consideration in studies of stochastic population dynamics. We used long‐term demographic data for three perennial plant species, hierarchical Bayesian parameterization of population projection models, and stochastic simulations to address the following questions: (1) What are the sign, magnitude, and uncertainty of temporal correlations between vital rates? (2) How do specific pairwise correlations affect the year‐to‐year variability of population growth? (3) Does the net effect of all vital rate correlations increase or decrease year‐to‐year variability? (4) What is the net effect of vital rate correlations on the long‐term stochastic population growth rate (λs)? We found only four moderate to strong correlations, both positive and negative in sign, across all species and vital rate pairs; otherwise, correlations were generally weak in magnitude and variable in sign. The net effect of vital rate correlations ranged from a slight decrease to an increase in the year‐to‐year variability of population growth, with average changes in variance ranging from −1% to +22%. However, vital rate correlations caused virtually no change in the estimates of λs(mean effects ranging from −0.01% to +0.17%). Therefore, the proportional changes in the variance of population growth caused by demographic correlations were too small on an absolute scale to importantly affect population growth and viability. We conclude that, in our three focal populations and perhaps more generally, vital rate correlations have little effect on stochastic population dynamics. This may be good news for population ecologists, because estimating vital rate correlations and incorporating them into population models can be data intensive and technically challenging.

Sex ratio and reproductive success along elevational gradients of gynodioecious populations of Geranium richardsonii - S. Antecon (2016)
We studied the sex-ratio and reproductive success of gynodioecious populations of Geranium richardsonii along elevational gradients near Gothic, Colorado. Gynodioecious means that the species produces hermaphrodite and female plants. The hermaphrodites have male (anthers and pollen) and female (ovules and seeds) functioning parts, while females produce non- functional anthers. Genetic and ecological factors are known to influence sex ratio and reproductive success of gynodioecious species (Alonso, 2005). We hypothesized low female frequency at high elevations because wetter, cooler environmental conditions would favor the hermaphrodites, which have higher resource demands, but also have higher individual relative fitness compared to females. Also, we expected hermaphrodites to have larger pollen receipt compared to females due to self-pollination and allocation of resources to pollinator attraction (flower size), when pollinators are limiting. We measured the sex ratio of 31 populations and compared 4 of our populations with data collected in 1997. Reproductive success was assessed for 10 out the 31 populations spanning an elevation range from 9400-11500 feet, by counting stigma pollen loads on hermaphrodite and female flowers. There was a significant negative correlation between the proportion of females in populations and elevation. However, there was no significant relationship between elevation and hermaphrodite or female pollination success. Relative female pollination success declined somewhat as population sex ratio increased, as predicted, but this relationship was not significant in the populations studied. Therefore, pollination success does not appear to be the main reason driving the increase in hermaphrodite frequency in higher elevation populations. Sex ratio has not changed over the past 20 years in four populations studied near Gothic, suggesting that individuals may the long-lived, or that selection maintains constant sex ratios over time.

Influence of Parasitism on Consumer Driven Nutrient Recycling by Aquatic Insects - M. Ealy (2016)
Parasites have only recently gained the attention they deserve in studies involving their role in ecosystems. Using ecological stoichiometry will allow parasite roles to be established. I attempted to establish parasite effects on hosts by measuring the excretion Nitrogen:Phosphorus of infected Megarcys signata, infected Baetis bicaudatus, and their parasite free counterparts. I had hypothesized that the excretion N:P of infected hosts would be greater than the excretion N:P of parasite free hosts. However, the data is proving that the excretion N:P does not shift for Megarcys signata of increasing infection level. The shift in excretion occurs from parasite free to parasitized; the N:P’s of excretion significantly differ. The Megarcys signata mass specific excretion rates of ammonium(N) and phosphate(P) do increase, but N increased at nearly twice the rate of P. My interpretation of these results is that the change in excretion is not because of a functional change in the Megarcys, but simply because of the addition of mites to the overall organism excretion equation. The increase of N and P excretion reflects the low body N:P of the water mite parasites. The mass specific excretion of phosphorous and nitrogen from Baetis bicaudatus were not found to be significantly different as the increased. Since nitrogen and phosphorus excretion did not change, this implies that the N:P of excretion did not change. The difference between the effects of mites and Mermithids is proposed to be because of their location and how they feed on the host.

How do Plant Traits Affect Thermoregulation? - Sabastian Escobar (2016)
Plants are known to regulate their leaf temperature, undergoing limited homeothermy. This may advantageous as it allows plants to utilize important photosynthetic and respiratory enzymes. We studied which traits affect a plant’s ability to regulate their temperature across highly variable air temperatures, helping build better models to predict which species will have a higher performance across different environmental gradients with a changing climate. Using a thermal camera, we took diurnal videos for seven separate sites over a 1,401 meter elevation gradient. After the diurnal measurements, we took trait measurements that include: leaf area, leaf height, stomatal conductance, and wet and dry mass. Using MATLAB, we cross-referenced thermal images with visible images to find individual leaves in a given plot. We determined which traits were responsible for the greatest deviation in the leaf’s temperature from ambient air temperature. The traits responsible for how quickly a plant can regulate its temperature can be found by finding the derivatives of air temperature versus time and the leaf temperature versus time functions and comparing them.

Larval feeding behavior and leaf components that affect the survival of Pieris macdunnoughii on the invasive mustard Thlaspi arvense - Larry Fisher (2016)
Pieris macdunnoughii, a butterfly native to the Rock Mountains in Colorado, is a specialist on mustard plants. An invasive mustard, Thlaspi arvense, introduced approximately 100 years ago creates an evolutionary trap for P. macdunnoughii due to the chemical signals that encourage ovipositioning, but it does not support larval development. Such interactions suggest larvae will develop means to successfully feed on T. arvense. First instar feeding behavior on T. arvense was compared to behavior on native host plants, Cardamine cordifolia and Descurainia incana. In laboratory trials, larvae were given T. arvense or C. cordifolia and photographed in two hour intervals for gut content. The results show that larvae fill their guts soon after encountering C. cordifolia, but for T. arvense larvae eat only small amounts of leaves and hardly fill their guts, exhibiting deterrent properties. Similar patterns of herbivory were observed in field trials where larvae were placed on either T. arvense or C. cordifolia, though larvae in the lab filled their guts more than those in the field. In a feeding assay with sinigrin, a glucosinolate believed to be the precursor in a metabolic pathway that produces hydrogen cyanide, 50μmol of sinigrin per gram of leaf mass were added to T. arvense, C. cordifolia, and D. incana leaves and fed to larvae along with control leaves painted with water. The results suggest larvae perform best on D. incana despite added sinigrin and sinigrin has deterrent effects for all species and increases larval death.

The Changing Floral Color Landscape Across an Alpine Elevation Gradient - M. Gray (2016)
Flowers at high elevation must deal with less than ideal conditions, both abiotic and biotic. A limiting biotic factor plants must cope with at high elevations is pollinator limitation. With increasing elevation, insect groups such as Hymenoptera decrease with abundance whereas the abundance of Dipteran as a group remains the same. Thus, there is a shift in the dominant pollinator guild with increasing elevation: bees are predominant at lower elevations and with increasing elevation flies predominate. With this pollinator shift there could be a corresponding shift in floral color composition of communities with increasing elevation. Using spectral analysis we found that with increasing elevation there is a significant decrease in violet and blue- flowered species and a significant increase in green, yellow, orange and red flowered species. In our initial analysis of both bee and vision space we have evidence that pollinators may be able to distinguish these changes in floral color composition in communities of different elevations.

Assessing pollinators’ contribution to the reproductive success of Mertensia ciliata - A. Hacker (2016)
Shifting flowering phenologies as a result of climate change have the potential to disrupt plant-pollinator interactions through changes in temporal overlap of flowering and pollinator activity, decreasing plant fitness. Understanding current plant-pollinator interactions is key to predicting how plant fitness might be affected by such changes. The impact of temporal mismatch of flowering and pollinator activity on plant fitness should depend on how much each pollinator species contributes to a plant’s reproductive success. Using seed set to determine effectiveness, this study investigates the differences in the pollinator effectiveness of visitors of Mertensia ciliata (Boraginaceae). We conducted single pollinator visit observations and obtained average seed set per flower for each type of M. ciliata visitor. Bumble bees and muscid flies were the two primary visitors to M. ciliata. We found that bumble bees had a higher visitation rate than muscid flies and that bumble bee single visits resulted in a higher seed set per flower than muscid fly single visits. We concluded that bumble bees were more effective pollinators for M. ciliata than muscid flies. To continue elucidating plant-pollinator interactions, future research should incorporate visitation rate with pollinator effectiveness to determine pollinator importance and consider how pollinator effectiveness and importance might be impacted by climate change.

Impacts of early snow removal and frost on the reproductive success of Delphinium nuttallianum - Isaac O. Jensen (2016)
Anthropogenic climate change is causing increases in global average temperature, changes in seasonality, and altered precipitation patterns which are linked to upslope range shifts, population declines, and phenological changes. This study examines the impacts of climate induced changes in snowmelt date and episodic frost on the reproductive success of a subalpine forb species, Delphinium nuttallianum, in the Rocky Mountains of south-central Colorado, USA. D. nuttallianum plants were exposed to early or natural snowmelt, reduced or natural frost, and natural pollination and supplemental pollen treatments and reproductive success was measured in order to explore the effects of climate change on plant reproductive fitness. While plant density within a plot and pollinator visitation rate was significantly higher in early snowmelt treatments, there was no significant difference between any of the climate change related treatments in reproductive fitness, indicating that snow melt, frost exposure, and supplemental pollination did not significantly impact the reproductive success of D. nuttallianum in 2016. However, this may partially be due to dry conditions which caused many plants to abort a substantial portion of flowers and fruits, diluting the effects of climate-related variables. These data indicate that while plants that bloom earlier might be at an advantage for attracting pollinators, further research is need to elucidate the effects of climate change on the reproductive fitness of Delphinium nuttallianum and other subalpine forbs.

Social security: Are socially connected individuals less vigilant? - R. Mady (2016)
Group size effects, whereby animals allocate less time to antipredator vigilance as a function of increasing group sizes are widely reported in many taxa, but group size is but one of many social attributes that could increase a individual’s sense of security. Indeed, meta-analyses suggest that group size only explains about 20% of the variation in vigilance, and studies have shown that social factors, such as dominance status, also influences perceived risk and time allocated to vigilance. Social network statistics quantify a variety of specific social attributes, some of which have been suggested to influence security. Using vigilance as an indicator of risk assessment, we tested the prediction that more socially connected female yellow-bellied marmots (Marmota flaviventris) allocate less time to vigilance while foraging compared to less socially connected individuals. We used a principle component analysis to reduce social attributes to three factors. After explaining variation accounted for by glucocorticoid levels, substrate, incline, and day of the year and, individuals in larger social groups allocated less time to vigilance while those in more cohesive social relationships allocated more time to vigilance. These somewhat contradictory results suggest that vigilance is multi-faceted and highlight the importance of using an attribute-based approach to explaining variation in vigilance. The attribute-based approach has allowed us, for the first time to show that social group size indeed reduces risk, and suggest that maintaining social relationships requires social vigilance. 2

The Effects of Nest-Site Selection and Microclimate on Nest Survival in Sparrows of High Elevation - L. Michael (2016)
Nest-site selection is important in the determination of nest success in several bird species (Holway 1991, Wells and Fuhlendorf 2005). Birds that nest in high elevation breeding sites are under greater environmental stress, making it even more crucial for individuals to choose nest microclimates that buffer the nest and offspring from extreme weather events and provide stable conditions for the young (Bears et al. 2009). The Microclimate Selection Hypothesis predicts that females should choose nesting sites that best protect them and their offspring from severe or unpredictable weather events, such as extreme temperatures or high wind (With and Webb 1993, Wells and Fuhlendorf 2005). The relationship between nest-site characteristics, nest microclimate, and nest survival was examined in Mountain White-crowned Sparrows (Zonotrichia leucophrys oriantha) and the Lincoln’s Sparrows (Melospiza lincolnii) in three subalpine meadow sites in Gothic, CO. There were no significant differences between the nest-site characteristics of nests with a more stable microclimate and nests with a less stable microclimate, though the two groups did have significantly different microclimates. Overhead nest concealment and distance to the nearest road had a positive effect on daily nest survival but none of the nest characteristics had a significant positive or negative effect on the model.

Testing for nutrient limitation of algal biomass across elevational and permanence gradients in high elevation ponds near the Rocky Mountain Biological Lab - C. Parisek (2016)
We investigated nutrient limitation in high elevation ponds in the Gothic, Colorado, USA area and whether it varied with elevation and/or degree of permanence. Nitrogen (N) and phosphorus (P) are often the key limiting nutrients in aquatic systems that regulate algal biomass (Pick & Lean 1987; Heo & Kim 1995). Rock weathering is the primary way phosphorus enters a system. As in many location, the bedrock at subalpine and alpine ponds such as those at Mexican Cut are have little or no phosphorus, and I therefore predicted that this element would limit algal growth. In contrast, at montane elevations (e.g., Kettle Ponds below the Rocky Mountain Biological Lab (RMBL)) ponds should have a greater phosphorus supply from surface and subsurface water flow, and therefore be more likely to be nitrogen or nitrogen-phosphorus co-limited. We found a significant difference in algal biomass between elevational and permanence gradients, as well as in their interactions. However, even within the same permanence gradient nutrient limitation between the ponds varied. On average, permanent ponds showed no nutrient limitation, while semi-permanent and temporary ponds had lower mean chlorophyll a in the nutrient-addition treatments compared with the control. We believe that high control treatments may be due to extensive grazing on algae growing on nutrient addition treatments, or that the presence of the nutrients actually inhibited algal growth. Studying nutrient limitation is important in understanding the basics of this system, as well as providing useful preliminary data in understanding how this system might change as species migrate up-slope with globally warming temperatures, thereby altering the ecosystem structure currently in place.

Habitat patch use, density, and territoriality of American Red Squirrels (Tamiasciurus hudsonicus) in the southwestern Rocky Mountains, Colorado - E. Peterson-Trujillo (2016)
American Red Squirrels (Tamiasciurus hudsonicus) inhabit patches of conifer trees, relying upon the cones for food. They stockpile cones in middens, which are large piles of cones at the base of trees, and exhibit territorial behavior (alarm and warning calls) to protect their midden from squirrels and other mammals. Midden presence is an indicator of squirrel presence and can be used to predict squirrel population sizes within a patch of conifers, because each squirrel relies on the stockpile of cones in their middens to survive the winter. Previous studies have shown that Red Squirrels select conifer tree patches to occupy based on size, shape, and quality of tree availability. I investigated three questions related to the relationship between habitat patches and squirrel presence: 1) Is there a minimum patch size that squirrels will occupy? 2) Does squirrel density vary with patch size? 3) Does squirrel territoriality vary with patch shape or squirrel density? I searched nineteen patches of conifers of a range of sizes for middens, and observed 11 patches to note individual territorial behavior. I found that: 1) the smallest patch that a squirrel will occupy is 0.75 hectares in area, 2) more abandoned middens were found in smaller patches, indicating higher transience for squirrel occupation, 3) midden density did not vary with tree density or patch size. For the study on patch shape, I found fewer active middens in strip shaped patches, where there were also fewer territorial calls during observation periods, possibly explained by fewer neighbors and fewer territorial boundaries.

Effects of phenological stage and temperature on Ligusticum porteri’s volatiles and trophic interactions - Anthony T. Robinson (2016)
Volatile organic compounds (VOCs) are emitted by plants as signals to other organisms and are interrelated with atmospheric chemistry and climate change. Typically, phenology advances and temperature increases with climate change. How floral volatiles of Ligustigum porteri influences its multitrophic interactions and changes with increased temperature is unknown. We investigated how elevated temperature and phenological stage affects both the volatiles released by host plants and the performance of intraguild Miridae predators and their competitor/prey, aphid Aphis helianthi. Throughout the study we monitored phenological stage and insects present on L. porteri. Open top warming chambers (OTC) increased the temperature surrounding the plants by 0.81°C on average and were removed after 23 days for the advanced phenology treatment group, though no significant phenological advancement occurred (p=0.682). The OTC remained on plants for the advanced phenology plus increased temperature treatment group. Silicon tubing (ST) captured floral volatiles, and was analyzed by thermal desorption coupled to gas chromatography mass spectrometry (TD-GC-MS) to quantify volatiles released. Ten aphids from existing colonies were placed onto test of suitable condition. Miridae abundance was correlated to phenological stage and the amount of photosynthetically active radiation (PAR) (p=2.782 e-11) and found to drive plant damage (p=0.02716). The ability for aphids to colonize host plants was related to the amount of plant damage. Thus, Miridae populations seem to indirectly negatively impacting aphid performance, even though elevated temperatures typically increase aphid abundance. The volatile profile is expected to correlate with phenological stage, which may explain Miridae abundance patters. Additionally, the defense volatiles may play a role in why aphid ability to colonize host plants. As temperature increases and phenology advances with the changing climate, the biotic interactions associated with phenology may be stronger than direct effects of temperature

Effects of Helianthella quinquenervis Extrafloral Nectaries on Ant Abundance and Community Structure - J. Schurkman (2016)
The beneficial effects of ants to myrmecophilous species is well established, but there is little empirical evidence demonstrating the benefits of such interactions for ants. The intent of this experiment was to determine how ants are affected by their interaction with the Aspen sunflower (Helianthella quinquenervis). Ants forage on Aspen sunflower extra floral nectaries (EFN) as a carbohydrate source. Twenty 7 m diameter plots were established in a field site (Maxfield Meadow) located at the Rocky Mountain Biological Laboratory in Gothic Colorado. Half of the plots had EFN removed, the others did not. Through pitfall traps it was found that four groups of ants occupy the meadow, Tapinoma sessile, Myrmicinae, Formica fusca, and Formica rufa. By doing visual surveys of plant stems, it was found that Formica fusca and Tapinoma sessile are the predominant taxa foraging on EFN. Forager and colony abundance was not affected by EFN removal based upon pitfall trapping and examination of artificial nesting structures (bricks), respectively. However ants within the EFN removal plots recruited to (marginally significant) and consumed significantly more 20% sugar solution baits than do the ants within the control plots. These findings gave evidence that ants do not necessarily depend on EFN from Aspen sunflowers as a carbohydrate source, however, they utilize the carbohydrate source as much as possible, and most likely receive less carbohydrates when they are deprived of EFN.

Pollen thieving and pollen limitation in gynodioecious Polemonium foliosissimum (Polemoniaceae) - B. Smith (2016)
The limitation of pollen available to pollinators and visitors alike may potentially direct pollinator visitation choice as well as the plant’s ability to provide pollen rewards, nectar rewards, and plant defense mechanisms. Such trade-offs exist in Polemonium foliosissimum A. Gray (Polemoniaceae) a gynodioecious perennial plant in that we tested the hypothesis that pollen limitation would correlate to differences in stigma pollen deposition and plant fitness between females and hermaphrodites within a population sampled off of Kebler Pass Road near Crested Butte, CO (38.86301,-107.12087). As theory dictates that females must either produce more seeds, seeds of higher quality, or render themselves less attractive to herbivores and pre- dispersal seed predators to compensate for loss of male fitness in order to persist in gynodioecious populations (Burd 1994). The role of trade-offs effectively can alter plants’ choices of resource allocation between attracting pollinators and limiting harm from enemies. As such this balance has been investigated for herbivores, florivores, and pre-dispersal seed predators such as Hylemya (Delia) sp. (Diptera: Anthomyiidae), yet there has been insufficient attention in regards to these trade-offs in response to pollen thieves. Pollen thieving muscid flies (Diptera: Muscidae) consume protein-rich pollen with little to no direct pollination. Within hermaphroditic and female P. foliosissimum hermaphroditic advantages of offering protein-rich pollen and male siring capabilities are essentially lost to pollen thieves. This therefore allots females representative equal fitness amongst the gynodioecious population and can potentially warrant correlation with differences in fitness via seed-set quality and quantity between P. foliosissimum. Nevertheless, throughout the manipulation of pollen neighborhoods by removing half of the available pollen from Polemonium in ten 2m 2 plots we saw significant differences in pollen deposition between hermaphroditic and female flowers (p<0.001), but not between manipulation treatments, as denoted as “pre-treatment” and “post- treatment” (p=0.3892) Pollinator visitation rate as well substantiated that pollinators and pollen thieving muscid flies on average spend 95% more time upon hermaphroditic flowers as compared to female flowers (p<0.001). Yet, pollinators and enemies significantly visit more hermaphrodites than females on average (p<0.001), but do not significantly discriminate between number of flowers visited between hermaphrodites and females (p=0.0539) as analyzed in a One-way ANOVA using JMP.

Combattere lo sprawl con il trasporto pubblico: il Transit-Oriented Development in Colorado - Gabriele Manella (Archivio istituzionale della ricerca (Alma Mater Studiorum Università di Bologna), 2016)
Secondo l’U.S. Census Bureau, il 50% della popolazione degli Stati Uniti viveva in aree suburbane nel 2000. Stando ai dati del censimento 2010, questa quota è ulteriormente cresciuta, passando al 58%. Un aumento enorme, se pensiamo che negli anni ’20 del xx secolo questa quota era attorno al 15%. Nonostante segnali di controtendenza in alcune zone, la suburbanizzazione resta quindi una realtà profondamente radicata negli Stati Uniti. La dimensione di quanto è successo ci viene confermata dai dati sulla metratura media delle abitazioni suburbane: se nel 1950 era di 95 metri quadrati, nel 2000 arriva a 235, quasi due volte e mezzo.
\nQuesti dati evidenziano l’immenso urban flight avvenuto negli Stati Uniti, un esodo dai centri delle città verso il suburbano che è stato spiegato con tanti fattori diversi. In questo contributo, però, non intendo concentrarmi su questo esodo, quanto su alcune esperienze significative sorte per frenarlo e possibilmente invertire la tendenza. Una di queste è il Transit-Oriented Development, attraverso cui si prova a ripensare lo sviluppo urbano in modo più compatto, attorno alle direttrici del trasporto pubblico.
\nIl contributo considera l’implementazione di questa strategia nel Colorado, concentrandosi su quanto avvenuto nella regione della capitale Denver. Anche in altre zone del Colorado sono state intraprese politiche analoghe, ad esempio nella città di Boulder e nell’area della Roaring Fork Valley. Il caso di Denver, tuttavia è il più articolato e quello che ha dato risultati più interessanti.
\nIl contributo che propongo si basa sulla ricerca bibliografica e lo studio di rapporti e documenti, nonché su un soggiorno di ricerca che ho svolto presso la University of Denver. Quest’ultimo mi ha permesso di osservare direttamente la città e i suoi cambiamenti riguardo il trasporto pubblico.

Temporal ecology of a subalpine ecosystem: Plant communities, plant-pollinator interactions, & climate change. - Paul J. CaraDonna (2016)
Ecological systems are inherently dynamic, and a primary way in which they are dynamic is through time. Individual organisms, populations, communities, species interactions, and ecosystem functions all follow a temporal progression from the past, to the present, and into the future. This temporal progression can occur over the course of minutes, hours, days, weeks, months, years, decades, or various other timescales. In this sense, temporal dynamics are an intrinsic property of all biological systems. In fact, one of the most prominent signals of recent global climate change is the significant change in the timing of biological events for a diversity of organisms. In light of this widespread pattern, there is a renewed interest in understanding the multifaceted importance of time in ecology. In this dissertation, I investigate the temporal ecology of a subalpine ecosystem, specifically focusing on flowering plant communities and plant-pollinator interactions. I examine the temporal dynamics of this system over multiple decades in response to ongoing climate change as well as over shorter time scales within a growing season. Using a 39-year record of flowering phenology, I show that species-specific shifts in the timing of flowering in response to climate change can substantially reshape a subalpine plant community over this time period. Community phylogenetic analyses reveal that these changes are largely independent of evolutionary history. Using a laboratory experiment, I show that the timing of an important harsh abiotic event – low temperatures that cause frost damage to plants – can differentially affect flowering plant species, with implications for plant demography, community structure, and interactions with pollinators. Finally, I show that plant- pollinator interactions exhibit substantial within-season temporal turnover, and that this temporal flexibility of plant-pollinator interactions from one week to the next is consistent and predictable 8 across years. Taken together, this dissertation provides a multifaceted investigation of the temporal ecology of plant communities and plant-pollinator interactions, revealing the important consequences of ecological timing at short-term and longer-term scales. 9

A framework for assessing feasibility of Transit-Oriented Development (TOD) project sites - Avi Sharma; Strong, Kelly C.; Ozbek, Mehmet E.; Francis, James (Digital Collections of Colorado (Colorado State University), 2016)
After the Second World War, America saw a decline in ridership on transit systems which eventually resulted in the dismantling and abandonment of many rail systems. The primary mode of public transportation shifted from transit to buses, which used the same streets and competed with the same infrastructure capacity as automobiles. For this reason, bus systems also started to fail when people realized that if they have to wait for the traffic, they might as well do it in their own automobile, which provides higher flexibility of timing and route (Ditmar, Belzer and Autler, 2004). This shift, in effect, resulted in more congestion. To counter the problem of congestion resulting from modern urbanization, society developed the idea of Transit-Oriented Development (TOD). TOD (or similar concepts like transit village, transit-friendly design, and transit-supportive development) is a type of development designed in a fashion that encourages the use of public transit and the creation of pedestrian-friendly environments (TCRP, 2002). This thesis answers the following fundamental questions: How can a transit agency choose among alternative TOD locations within a transit network and what is the importance of each factor? This includes development of a framework which can be used by different transit agencies by incorporating their factors and weights using multiple-criteria decision-making (MCDM) tool called Analytic Hierarchy Process (AHP). The thesis also presents the implementation of this framework for Regional Transportation District (RTD) and Roaring Fork Transportation Authority (RFTA).

Individual variation in plant traits drives species interactions, ecosystem functioning, and responses to global change. - Quentin D Read (2016)
Ecologists have long sought to understand the processes that lead to the riotous diversity in communities of organisms that inhabit disparate climates and landscapes. Such a diversity of traits leads to a diversity of interactions among species in natural communities, which in turn generates a diversity of potential responses to ongoing global change. In this dissertation, I do three things: I explore the forces that structure plant communities and the ecosystem functions that they mediate, I describe patterns of variation among communities, species, and individual organisms across environmental contexts, and I disentangle the direct effects of global change from the indirect, cascading effects that result from disruptions of species interactions. I accomplish these goals through the synthesis of global data, the development of statistical and mathematical models, and the manipulation of global change drivers in field experiments. In the first chapter, I present a globe-spanning meta-analysis of plant functional trait patterns along elevational gradients. This meta-analysis shows that the plant traits that drive ecosystem function follow predictable trends with elevation due to climate filtering, and that much of this variation is at the level of the individual organism. In the second chapter, I present simulated data sets and illustrative experimental case studies that quantify how important individual-level variation is for explaining patterns in nature. In the third chapter, I present results from intensive plant sampling across a wide range of mountain environments; even in these harsh environments where only the hardiest species can survive, individual-level variation is so high that it makes predictions based on species identity nearly impossible. The fourth and fifth chapters consist of experimental evidence that ongoing human-caused global change is affecting montane plant communities, that species interactions mediate many of these effects, and that variation in the abiotic environment causes variation in both species interactions and in global change response. I demonstrate this through an experiment that combines nitrogen fertilization with removal of a dominant plant species in a montane meadow, and an experiment replicated at low and high elevations crossing dominant species removal with simulation of global warming. iv

Observed forest sensitivity to climate implies large changes in 21st century North American forest growth - Noah D. Charney; Flurin Babst; Benjamin Poulter; Sydne Record; Valerie M. Trouet; David Frank; Brian J. Enquist; Margaret E. K. Evans (Ecology Letters, 2016)
AbstractPredicting long‐term trends in forest growth requires accurate characterisation of how the relationship between forest productivity and climatic stress varies across climatic regimes. Using a network of over two million tree‐ring observations spanning North America and a space‐for‐time substitution methodology, we forecast climate impacts on future forest growth. We explored differing scenarios of increased water‐use efficiency (WUE) due to CO2‐fertilisation, which we simulated as increased effective precipitation. In our forecasts: (1) climate change negatively impacted forest growth rates in the interior west and positively impacted forest growth along the western, southeastern and northeastern coasts; (2) shifting climate sensitivities offset positive effects of warming on high‐latitude forests, leaving no evidence for continued ‘boreal greening’; and (3) it took a 72% WUE enhancement to compensate for continentally averaged growth declines under RCP 8.5. Our results highlight the importance of locally adapted forest management strategies to handle regional differences in growth responses to climate change.

Effects of larval dietary restriction on body morphology, with implications for flight and life history - C. L. Boggs; K. Niitepold (Entomologia Experimentalis et Applicata, 2016)
AbstractMany morphological traits of adult insects show a plastic response to larval environmental conditions. Past studies of Lepidoptera, other than on irruptive species, focused on species with specific ecologies or life histories. These studies must be interpreted in the context of past selection associated with those specializations. Here, we examined the effects on adult morphology of quantitative dietary restriction in the late last instar of Speyeria mormonia Edwards (Lepidoptera: Nymphalidae: Heliconiini). This univoltine species lives in open populations in montane meadows. Adults fed ad libitum as larvae on Viola sororia Willd. (Violaceae) were larger than those fed a restricted diet, for wet and dry body mass, dry mass of head, thorax, or abdomen, and forewing length. Females were larger than males for all but head mass. However, both males and individuals fed a restricted diet had a heavier head and thorax as a proportion of total mass, indicating conservation of visual or other sensory functions and flight. Females maintained a higher relative investment of mass in abdomens, indicating conservation of mass allocation to reproduction. Wing loading was greater in females and for individuals fed ad libitum. The sex*treatment interaction was also significant. The difference in wing loading between individuals fed ad libitum and those on a restricted diet were greater for females than for males. The allometric relationship between dry mass and wing area in both sexes was significantly less than isometric. Thus, allometry did not explain the effect of dietary restriction on wing loading. In contrast, wing aspect ratio was invariant. In combination with earlier studies, these results suggest that mass allocation in support of flight occurs generally under larval nutritional stress. Flight supports both reproduction and feeding. Our work thus highlights the need to include resource acquisition in studies of life history and fitness under nutritional stress.

Delving deeper: Questioning the decline of long-tongued bumble bees, long-tubed flowers and their mutualisms with climate change - C. W. de Keyzer; S. R. Colla; C. F. Kent; Nicole E. Rafferty; L. L. Richardson; J. D. Thomson (Journal of Pollination Ecology, 2016)
Miller-Struttmann et al. (2015) suggest that, in a North American alpine ecosystem, reduced flower abundance due to climate change has driven the evolution of shorter tongues in two bumble bee species. We accept the evidence that tongue length has decreased, but are unconvinced by the adaptive explanation offered. It posits foraging responses and competitive relationships not seen in other studies and interprets phenotypic change as evidence of evolutionary adaptation. By oversimplifying a complex phenomenon, it may exaggerate the potential for bees to quickly adapt to environmental changes.

The fingerprints of global climate change on insect populations - C. L. Boggs (Current Opinion in Insect Science, 2016)
Synthesizing papers from the last two years, generalizations about the fingerprints of climate change on insects' population dynamics and phenology are examined to show that knowledge of effects ofClimate change is still biased by organism and geographic region, and to some extent by scale of climate parameter.

Selenium Biofortification and Phytoremediation Phytotechnologies: A Review - Michela Schiavon; Elizabeth A. H. Pilon‐Smits (Journal of Environmental Quality, 2016)
The element selenium (Se) is both essential and toxic for most life forms, with a narrow margin between deficiency and toxicity. Phytotechnologies using plants and their associated microbes can address both of these problems. To prevent Se toxicity due to excess environmental Se, plants may be used to phytoremediate Se from soil or water. To alleviate Se deficiency in humans or livestock, crops may be biofortified with Se. These two technologies may also be combined: Se‐enriched plant material from phytoremediation could be used as green fertilizer or as fortified food. Plants may also be used to “mine” Se from seleniferous soils. The efficiency of Se phytoremediation and biofortification may be further optimized. Research in the past decades has provided a wealth of knowledge regarding the mechanisms by which plants take up, metabolize, accumulate, and volatilize Se and the role plant‐associated microbes play in these processes. Furthermore, ecological studies have revealed important effects of plant Se on interactions with herbivores, detrivores, pollinators, neighboring vegetation, and the plant microbiome. All this knowledge can be exploited in phytotechnology programs to optimize plant Se accumulation, transformation, volatilization, and/or tolerance via plant breeding, genetic engineering, and tailored agronomic practices. Core Ideas Plants may be used to clean up excess selenium from the environment. Plants may be used to provide dietary selenium in selenium‐deficient areas. Plants may be used to mine Se from seleniferous soil.

Assessing the Role of State and Local Public Health in Outreach and Enrollment for Expanded Coverage: A Case Study on Eagle, Garfield, and Pitkin Counties, Colorado - Malcolm Williams; Laurie T. Martin; Nazleen Bharmal; Christian Lopez; Courtney Armstrong; Kate Heyer (RAND Corporation eBooks, 2016)
Part of a series highlighting innovative models and best practices for leveraging local health departments' involvement in Patient Protection and Affordable Care Act outreach and enrollment, this report is a case study on three Colorado counties that captures nuanced differences in how health departments support these efforts, identifies facilitators and barriers to these approaches, and develop lessons learned from these activities.

Accounting for the nested nature of genetic variation across levels of organization improves our understanding of biodiversity and community ecology - Quentin D Read; S. M. Hoban; M. B. Eppinga; J. A. Schweitzer; J. K. Bailey (Oikos, 2016)
Recent work has demonstrated that the presence or abundance of specific genotypes, populations, species

Site fidelity by bees drives pollination facilitation in sequentially blooming plant species - Jane E. Ogilvie; J. D. Thomson (Ecology, 2016)
AbstractPlant species can influence the pollination and reproductive success of coflowering neighbors that share pollinators. Because some individual pollinators habitually forage in particular areas, it is also possible that plant species could influence the pollination of neighbors that bloom later. When flowers of a preferred forage plant decline in an area, site‐fidelity may cause individual flower feeders to stay in an area and switch plant species rather than search for preferred plants in a new location. A newly blooming plant species may quickly inherit a set of visitors from a prior plant species, and therefore experience higher pollination success than it would in an area where the first species never bloomed. To test this, we manipulated the placement and timing of two plant species, Delphinium barbeyi and later‐blooming Gentiana parryi. We recorded the responses of individually marked bumble bee pollinators. About 63% of marked individuals returned repeatedly to the same areas to forage on Delphinium. When Delphinium was experimentally taken out of bloom, most of those site‐faithful individuals (78%) stayed and switched to Gentiana. Consequently, Gentiana flowers received more visits in areas where Delphinium had previously flowered, compared to areas where Delphinium was still flowering or never occurred. Gentiana stigmas received more pollen in areas where Delphinium disappeared than where it never bloomed, indicating that Delphinium increases the pollination of Gentiana when they are separated in time. Overall, we show that individual bumble bees are often site‐faithful, causing one plant species to increase the pollination of another even when separated in time, which is a novel mechanism of pollination facilitation.

Who pays? Intra- versus inter-generational costs of reproduction - J. Moore; Caitlin P. Wells; D. H. Van Vuren; M. K. Oli (Ecosphere, 2016)
AbstractReproduction is thought to be costly for female mammals due to high energetic costs associated with pregnancy and lactation. Such costs of reproduction can be particularly high for younger females, who are less experienced and smaller than fully grown adults, and can manifest themselves within (intra‐individual or intra‐generational trade‐offs) or between (inter‐generational trade‐offs) generations. Using lifetime survival and reproductive histories of 416 female golden‐mantled ground squirrels (Callospermophilus lateralis) in Colorado, USA, we tested for the evidence of intra‐ and inter‐generational trade‐offs between age of first reproduction and fitness and its components. Females who waited to begin reproduction lived longer but they did not experience a greater number of lifetime reproductive events, did not produce larger litters, nor did they have higher lifetime reproductive success than those females who attained reproductive maturity earlier. However, delaying age of first reproduction substantially reduced individual fitness, quantified as the dominant eigenvalue of the population projection matrix, suggesting that fitness benefits of earlier maturity exceeded associated costs. Females born to mothers who delayed age of first reproduction had a higher probability of surviving to reproduce at least once during their lifetimes. Thus, in our study system, daughters pay for their mothers’ reproductive decisions, suggesting that some costs of reproduction can transcend a generation. Studies testing for costs of reproduction on survival or reproductive output within a short timeframe or those focusing within a generation may fail to detect inter‐generational trade‐offs.

Sex-specific responses to climate change in plants alter population sex ratios and performance. - William K. Petry; Judith D. Soule; Amy M. Iler; Ana Chicas-Mosier; David W. Inouye; T. E. X. Miller; K. A. Mooney (Science, 2016)
Changing sex ratiosClimate-warming temperatures might be expected to affect the sex ratio of species if sex determination is temperature-dependent. Petryet al.show that indirect climate effects could also alter sex ratios in species in which sex is genetically determined and damage reproductive fitness (see the Perspective by Etterson and Mazer). Over four decades, sex ratios in populations of a dioecious alpine plant have shifted toward females as a result of the different water needs of the male and female plants. The lack of males has reduced the reproductive success and fitness of the females. Similar subtle differences between sexes in environmental sensitivities could eventually lead to population declines.Science, this issue p.69; see also p.32

EPISODIC UPLIFT OF THE ROCKY MOUNTAINS: EVIDENCE FROM U-PB DETRITAL ZIRCON GEOCHRONOLOGY AND LOW-TEMPERATURE THERMOCHRONOLOGY WITH A CHAPTER ON USING MOBILE TECHNOLOGY FOR GEOSCIENCE EDUCATION - Maria Magdalena Sandoval Donahue (UNM’s Digital Repository (University of New Mexico), 2016)
The timing and processes of development of the high topography and high relief of the southern Rocky Mountains of Wyoming, Colorado and New Mexico has been controversial for over a hundred years. The Mesozoic and Paleozoic rocks in the region formed a 3-4 km thick sub-horizontal stratigraphy that resided at elevations of zero to minus 4 km at the end of the Cretaceous. These units have been differentially uplifted/subsided and are presently at elevations of -10 to 4 km elevations, and have been eroded from above the core of many Precambrian basement cored uplifts exposed in > 4 km peaks. This study applies several different methodologies towards understanding the timing and relative importance of the events that uplifted and shaped the Rocky Mountains. These studies include incision studies (Chapter 1), detrital zircon analysis of Cenozoic fluvial deposits resting on the Rocky Mountain Erosion Surface (Chapter 2), and low temperature apatite fission track (AFT) and U-Th/He (AHe) low temperature thermochronology to look at differential cooling histories across the Rockies (Chapter 3). Chapter 4 investigates a project in which I designed and deployed a mobile device application for enhancing the traditional geoscience field education and research experience. Incision studies (Chapter 1) investigated the timing and rate of incision of the Black Canyon of the Gunnison by the Gunnison River. Canyon geometry is shaped by a headward-migrating knickzone presently located within the Painted Wall section of the Black Canyon. Average bedrock incision rates over the last 0.64 Ma surrounding the knickpoint vary from 150 m/Ma (downstream), to 400-550 m/Ma (within), to 90-95 m/Ma (upstream), suggesting it is a transient feature. Lava Creek B ash constrains strath terraces along a paleo-profile of the river. Within the paleo-Bostwick River tributary, we determine an incision rate of 400-550 m/Ma, reflecting incision at 2-3 times regional incision rates. We interpret this to be incision response to a headward-migrating wave of transient incision, potentially initiated by downstream base level fall during abandonment of Unaweep Canyon at about 1 Ma. Rate extrapolation indicates that the ~700 m depth of Black Canyon has been eroded since 1.3 – 1.75 Ma. The Black Canyon knickpoint overlies a strong gradient between low velocity mantle under the Colorado Rockies and higher velocity mantle of the Colorado Plateau. We interpret drainage reorganization and transient incision of both the Gunnison and upper Colorado River systems to be responding to mantle-driven epeirogenic uplift of the southern Rockies in the last 10 Ma. This study (Chapter 2) investigates the timing of erosion and deposition of several fragmented and little-understood conglomerate and sedimentary units, which are then used to better understand the timing of formation of the enigmatic Rocky Mountain Erosion Surface. Detrital zircon studies reclassify the Telluride Conglomerate and Blanco Basin Formation as being of Oligocene age, with maximum depositional ages of 30±3 Ma. This requires new understanding of the uplift of the San Juan Mountain regions, as we interpret these units to be the conglomeratic/sedimentary response to pre-volcanic epeirogenic doming and unroofing. This study also expands into New Mexico to investigate the depositional timing of the Paleocene-Eocene age McDermott, Galisteo and Baca Formations, and the Oligocene-age El Rito Formation and Ritito Conglomerate; each of these units rests upon the diachronous Rocky Mountain Erosion Surface and grades upward into volcanic deposits; these units are interpreted to be a sedimentary record of the multi-stage uplift of the Rocky Mountains. At each age, these units record the repeated process of doming and unroofing of basement rocks accompanying magmatism, deposition of thin gravel-sand sheets above regional unconformities, deposition of voluminous volcaniclastic aprons. This study suggests that relief has increased through time as the Rocky Mountain headwater regions of the fluvial systems that deposited progressively younger units of this study have gained in absolute elevation, while the ultimate base levels have remained the same or very similar. The third study (Chapter 3) moves to larger scales of both time and space in order to investigate uplift and exhumation histories on the regional scale. This study included a literature review and compilation of all published low-temperature thermochronology data (apatite fission track and apatite (U-Th)/He) (AHe) for the southern Rocky Mountain region and adds new apatite (U-Th)/He data on selected conglomeratic/sedimentary units to both add richness to the data base and to attempt to better constrain Oligocene burial histories. This study reinforces interpretations of a multi-stage uplift history to the Rocky Mountains by identifying regional episodes of rapid cooling that was driven by regional exhumation and differential uplift. Laramide cooling is investigated in compiled AFT and AHe data and age-elevation transects across the region. We notice spatial preservation of Laramide ages in Rocky Mountain thrust uplifts and elevation differences between the base of the Laramide-age AFT partial annealing zone, reinforcing models suggesting that Laramide cooling was driven by thrust uplifts that have not been reheated since uplift. New AHe data show that the Oligocene fluvial deposits were covered by ~1 km of volcaniclastic debris that likely extended westward onto the Colorado Plateau, refining understanding of the geometry and extent of the San Juan volcaniclastic apron. A delay of ~10 Ma between Oligocene magmatism and regional cooling through the 110-50ºC (AFT-AHe system) implies that post-Oligocene denudation was driven by erosional denudation following Oligocene surface uplift. Case studies highlight the semi-steady cooling of Oligocene plutons from ~30-15 Ma, followed by a potential ~20-10 Ma acceleration in cooling perhaps due to local faulting and/or uplift associated with Rio Grande rifting. Post-10 Ma cooling in areas not associated with the Rio Grande rift is compatible with models that incorporate regional integration of the Colorado River and Rio Grande to cause differential incision and localized rapid cooling. The fourth study highlights a project called Field Play. Our current human interaction with these landscapes is also of importance. The communication of science and education of Rockies both academic and public populations is of great importance as we have unprecedented access to information and rapidly evolving digital technologies. This project utilizes mobile technologies (smartphones, tablets) to augment the field experience. The goal of this project is to create a personalized, scalable and interactive educational learning environment which facilitates user exploration and access to robust geologic information. This project was featured in the New Mexico Geological Society's 2014 Fall Field Conference, as well as being used in my own teaching of introductory environmental science classes. This project is ongoing.

Assessing best management practices for the remediation of selenium in surface water in an irrigated agricultural river valley: sampling, modeling, and multi-criteria decision analysis - Brent E. Heesemann; Gates, Timothy K.; Bailey, Ryan T.; Hoag, Dana L. (Digital Collections of Colorado (Colorado State University), 2016)
The ecological impacts of selenium have been studied for decades and regulatory standards established in an effort to mitigate them. Agricultural activities in regions with high levels of alluvial selenium can lead to in-stream levels that far exceed regulatory limits. Agricultural best management practices (BMPs) are being considered to reduce in-stream selenium concentrations, but exploring the potential effectiveness of these BMPs can only be done after gaining an understanding of the in-stream processes that govern the speciation and transport of selenium in response to loading from irrigation return flows. This study uses extensive field data enhanced by numerical modeling to achieve this. In-stream water and sediment selenium samples, collected over a period of eight years in a region of Colorado’s Lower Arkansas River Valley, were analyzed. A sensitivity analysis (SA) was performed on a two part steady-state water quality / solute transport numerical model capable of simulating in-stream selenium processes. The combination of field data and SA was then used to calibrate an unsteady flow version of the model representative of the region to which it was applied. Dissolved and precipitated selenium species concentrations were accurately predicted by the calibrated model. Model simulations indicated that reduced fertilization is the BMP most effective at reducing in-stream SeO4 and NO3 concentrations out of the four BMPs examined. Reduced irrigation, land fallowing, and canal sealing indicated increases in in-stream SeO4 concentrations, likely caused by a concentration of SeO4 in the adjacent aquifer. Model results also indicated that the tributaries are impacted more by surface runoff as compared to lateral groundwater flows, while the opposite is true for the River. Although reasonable results were obtained from the model, further investigation into the computational processes and calibrated parameter values is required as part of future work. This study also examines the socio-economic feasibility of various BMPs, through the issuing survey to stakeholders in the study region and its evaluation using analytic hierarchy process multi-criteria decision analysis (MCDA). Reduced irrigation was determined to be the most feasible BMP based on the MCDA, with stakeholders showing a clear preference for economic concerns and placing a higher importance on salinity over SeO4 or NO3 concentrations. With model results indicating the effectiveness of various BMPs, and MCDA survey results providing insight into which of the BMPs are most likely to be accepted by stakeholders, it was possible to assess which BMPs are most appropriate for implementation in this study region. In considering both the results from the modeling study and the MCDA, it was determined that reduced fertilization is likely the single best BMP. To date there have been few if any studies utilizing both field data, numerical modeling, and MCDA to so comprehensively describe in-stream selenium processes and the future prospects for selenium remediation in an agricultural region in the western United States.

Pollinator specialization: from the individual to the community - B. J. Brosi (New Phytologist, 2016)
Most spermatophytes need conspecific pollen in order to produce seed. This need for specialization seems to conflict with the generalized nature of most plant–pollinator interactions. Specialization and generalization are dynamic – not fixed – and exist simultaneously in multiple states at different levels of biological hierarchy. Over the short term, specialization ensures conspecific pollen transfer, whereas over the long term, generalization improves system‐level robustness. The balance between specialization and generalization at different scales is critical for different kinds of ecological functioning and is an important factor in plant speciation and the evolution of plant mating systems. Community context, including diversity and interaction network structure at different levels of aggregation, is a key driver of specialization dynamics. Contents Summary 1190 I. Introduction 1190 II. Simultaneous specialization and generalization in pollination interactions 1191 III. The role of community context 1191 IV. Evolutionary considerations 1193 V. Conclusion 1193 Acknowledgements 1194 References 1194

Aversion and attraction to harmful plant secondary compounds jointly shape the foraging ecology of a specialist herbivore - Parris T Humphrey; A. D. Gloss; N. M. Alexandre; Martha M Villalobos; S. C. Groen; M. Fremgen; L. N. Meihls; G. Jander; Noah K Whiteman (Ecology and Evolution, 2016)
AbstractMost herbivorous insect species are restricted to a narrow taxonomic range of host plant species. Herbivore species that feed on mustard plants and their relatives in the Brassicales have evolved highly efficient detoxification mechanisms that actually prevent toxic mustard oils from forming in the bodies of the animals. However, these mechanisms likely were not present during the initial stages of specialization on mustard plants ~100 million years ago. The herbivorous fly Scaptomyza nigrita (Drosophilidae) is a specialist on a single mustard species, bittercress (Cardamine cordifolia; Brassicaceae) and is in a fly lineage that evolved to feed on mustards only in the past 10–20 million years. In contrast to many mustard specialists, S. nigrita does not prevent formation of toxic breakdown products (mustard oils) arising from glucosinolates (GLS), the primary defensive compounds in mustard plants. Therefore, it is an appealing model for dissecting the early stages of host specialization. Because mustard oils actually form in the bodies of S. nigrita, we hypothesized that in lieu of a specialized detoxification mechanism, S. nigrita may mitigate exposure to high GLS levels within plant tissues using behavioral avoidance. Here, we report that jasmonic acid (JA) treatment increased GLS biosynthesis in bittercress, repelled adult female flies, and reduced larval growth. S. nigrita larval damage also induced foliar GLS, especially in apical leaves, which correspondingly displayed the least S. nigrita damage in controlled feeding trials and field surveys. Paradoxically, flies preferred to feed and oviposit on GLS‐producing Arabidopsis thaliana despite larvae performing worse in these plants versus non‐GLS‐producing mutants. GLS may be feeding cues for S. nigrita despite their deterrent and defensive properties, which underscores the diverse relationship a mustard specialist has with its host when lacking a specialized means of mustard oil detoxification.

Caddisfly behavioral responses to drying cues in temporary ponds: Implications for effects of climate change - J. O. Lund; S. A. Wissinger; B. L. Peckarsky (Freshwater Science, 2016)
Aquatic organisms that live at high latitudes and elevations are especially vulnerable to climate-change-induced alterations in snowpack, snowmelt, and evaporation rates, all of which affect basin filling and drying dates. Extraordinarily early drying events in shallow ponds and wetlands at our study sites prompted us to conduct 2 mesocosm experiments to document how proximate cues of drying modify agonistic behaviors among larvae of the caddisfly, Asynarchus nigriculus. Larvae are mainly detritivores but can be extremely aggressive and engage in mob cannibalism, perhaps to obtain a dietary supplement that hastens escape from drying basins. In one experiment, we manipulated caddisfly density to simulate the effects of crowding during pond drying. In a 2nd experiment, we reduced water levels and manipulated a protein supplement that mimics the dietary benefits of cannibalism. We quantified the effects of those manipulations on aggressive behaviors that are precursors to cannibalism and on development time to pupation. Frequency and duration of agonistic encounters increased as a function of larval density and, independent of density, were higher in drying than nondrying treatments, especially in the absence of a protein supplement. Pupation occurred earlier in high- than low-density treatments and earlier with than without a protein supplement. In contrast, the timing of pupation was not accelerated in drying compared with nondrying treatments, which might reflect the extreme diel temperature fluctuations in drying ponds, hence suboptimal growth conditions. Our findings provide evidence that declining water levels and crowding serve as cues that enable caddisflies to adjust behavior and development in the face of habitat drying. Early drying events observed in recent years may exceed the limits of this flexibility and portend the demise of populations in temporary habitats that historically supported this species.

Morphological and physiological determinants of local adaptation to climate in Rocky Mountain butterflies - H. J. MacLean; J. K. Higgins; L. B. Buckley; J. G. Kingsolver (Conservation Physiology, 2016)
Flight is a central determinant of fitness in butterflies and other insects, but it is restricted to a limited range of body temperatures. To achieve these body temperatures, butterflies use a combination of morphological, behavioural and physiological mechanisms. Here, we used common garden (without direct solar radiation) and reciprocal transplant (full solar radiation) experiments in the field to determine the thermal sensitivity of flight initiation for two species of Colias butterflies along an elevation gradient in the southwestern Rocky Mountains. The mean body temperature for flight initiation in the field was lower (24-26°C) than indicated by previous studies (28-30°C) in these species. There were small but significant differences in thermal sensitivity of flight initiation between species; high-elevation Colias meadii initiated flight at a lower mean body temperature than lower-elevation Colias eriphyle. Morphological differences (in wing melanin and thoracic setae) drive body temperature differences between species and contributed strongly to differences in the time and probability of flight and air temperatures at flight initiation. Our results suggest that differences both in thermal sensitivity (15% contribution) and in morphology (85% contribution) contribute to the differences in flight initiation between the two species in the field. Understanding these differences, which influence flight performance and fitness, aids in forecasting responses to climate change.

A model of inter-cohort cannibalism and paedomorphosis in Arizona tiger salamanders, Ambystoma tigrinum nebulosum - M. L. McCarthy; H. H. Whiteman (International Journal of Biomathematics, 2016)
Cannibalism is widespread in size-structured populations. If cannibals and victims are in different life stages, dominant cohorts of cannibals can regulate recruitment. Arizona Tiger Salamanders, Ambystoma tigrinum nebulosum, exhibit facultative paedomorphosis in which salamander larvae either metamorphose into terrestrial adults or become sexually mature while still in their larval form. Although many salamanders exhibit cannibalism of larvae, the Arizona Tiger Salamander also exhibits cannibalism of young by the aquatic adults. We formulate a differential equations model of this system under the assumption that the terrestrial adults do not impact the system beyond their contribution to the birth of young larvae. We establish non-negativity, boundedness and persistence of the salamander population under certain assumptions. We consider the equilibrium states of the system in the presence or absence of a birth contribution from the terrestrial or metamorph adults. Constant per capita paedomorphosis leads to asymptotically stable equilibria. The per capita paedomorphosis rate of the larvae must be density dependent in order for periodic solutions to exist. Furthermore, the stage transition rate must be sufficiently decreasing in order to guarantee the existence of an unstable equilibrium. Periodic solutions are only possible in the presence of a unique nontrivial unstable equilibrium. Our results conform to previous theory on paedomorphosis which suggests general applicability of our results to similar systems.

Strain diversity and host specificity in a specialized gut symbiont of honeybees and bumblebees - J. E. Powell; N. Ratneyeke; N. A. Moran (Molecular Ecology, 2016)
AbstractHost‐restricted lineages of gut bacteria often include many closely related strains, but this fine‐scale diversity is rarely investigated. The specialized gut symbiont Snodgrassella alvi has codiversified with honeybees (Apis mellifera) and bumblebees (Bombus) for millions of years. Snodgrassella alvi strains are nearly identical for 16S rRNA gene sequences but have distinct gene repertoires potentially affecting host biology and community interactions. We examined S. alvi strain diversity within and between hosts using deep sequencing both of a single‐copy coding gene (minD) and of the V4 region of the 16S rRNA gene. We sampled workers from domestic and feral A. mellifera colonies and wild‐caught Bombus representing 14 species. Conventional analyses of community profiles, based on the V4 region of the 16S rRNA gene, failed to expose most strain variation. In contrast, the minD analysis revealed extensive strain variation within and between host species and individuals. Snodgrassella alvi strain diversity is significantly higher in A. mellifera than in Bombus, supporting the hypothesis that colony founding by swarms of workers enables retention of more diversity than colony founding by a single queen. Most Bombus individuals (72%) are dominated by a single S. alvi strain, whereas most A. mellifera (86%) possess multiple strains. No S. alvi strains are shared between A. mellifera and Bombus, indicating some host specificity. Among Bombus‐restricted strains, some are restricted to a single host species or subgenus, while others occur in multiple subgenera. Findings demonstrate that strains diversify both within and between host species and can be highly specific or relatively generalized in their host associations.

Contrasting the hydrologic response due to land cover and climate change in a mountain headwaters system - C. E. Pribulick; L. M. Foster; L. A. Bearup; A. K. Navarre-Sitchler; K. H. Williams; R. W. H. Carroll; R. M. Maxwell (Ecohydrology, 2016)
Land cover change due to drought and insect-‐induced tree mortality or altered vegetation succession is one of the many consequences of anthropogenic climate change. While the hydrologic response to land cover change and increases in temperature have been explored independently, few studies have compared these two impacts in a systematic manner. These changes are particularly important in snow-‐dominated, headwaters systems that provide streamflow for continental river systems. Here we study the hydrologic impacts of both vegetation change and climate warming along three transects in a mountain headwaters watershed using an integrated hydrologic model. Results show that while impacts due to warming generally outweigh those resulting from vegetation change, the inherent variability within the transects provides varying degrees of response. The combination of both vegetation change and warming results in greater changes to streamflow amount and timing than either impact individually, indicating a nonlinear response from these systems to multiple perturbations. The complexity of response underscores the need to integrate observational data and the challenge of deciphering hydrologic impacts from proxy studies. Cite as: Pribulick, C.E., Foster, L.M., Bearup, L.A., Navarre-‐Sitchler, A.K., Williams, K.H., Carroll, R.W.H, and Maxwell, R.M. Contrasting the hydrologic response due to land cover and climate change in a mountain headwaters system. Ecohydrology, in press, 2016.

Effects of experimental warming on herbivory and fungal pathogen load on subalpine grasses - Ian W. McCowen (2016)
Rising global temperatures are predicted to alter community dynamics by shifting species ranges and altering biotic interactions. Herbivory is expected to increase with prolonged growing seasons and heightened animal metabolic rates; pathogen damage may increase as well. Thus, we investigated whether damage by herbivores and pathogens on subalpine grass species would increase with warming. We compared percentage aboveground herbivory and foliar pathogen loads on three grass species (Festuca thurberi, Poa pratensis, and Achnatherum lettermanii) using a long-term experimental warming treatment in which plots subjected to experimental warming by infrared heaters alternated with ambient control plots. Within our warming plots there was an increase in the magnitude of herbivory for two of the three subalpine grass species observed. This increase in herbivory suggests that with global warming the damage from insects on grasses will can increase, but may be species specific.

Floodplain Price Impacts by Property Type in Boulder County, Colorado: Condominiums Versus Standalone Properties - James R. Meldrum (Environmental and Resource Economics, 2016)

Phenological change in a spring ephemeral: implications for pollination and plant fitness - Z. J. Gezon; David W. Inouye; R. E. Irwin (Global Change Biology, 2016)
Climate change has had numerous ecological effects, including species range shifts and altered phenology. Altering flowering phenology often affects plant reproduction, but the mechanisms behind these changes are not well-under- stood. To investigate why altering flowering phenology affects plant reproduction, we manipulated flowering phe- nology of the spring herb Claytonia lanceolata (Portulacaceae) using two methods: in 2011–2013 by altering snow pack (snow-removal vs. control treatments), and in 2013 by inducing flowering in a greenhouse before placing plants in experimental outdoor arrays (early, control, and late treatments). We measured flowering phenology, pollinator visi- tation, plant reproduction (fruit and seed set), and pollen limitation. Flowering occurred approx. 10 days earlier in snow-removal than control plots during all years of snow manipulation. Pollinator visitation patterns and strength of pollen limitation varied with snow treatments, and among years. Plants in the snow removal treatment were more likely to experience frost damage, and frost-damaged plants suffered low reproduction despite lack of pollen limita- tion. Plants in the snow removal treatment that escaped frost damage had higher pollinator visitation rates and repro- duction than controls. The results of the array experiment supported the results of the snow manipulations. Plants in the early and late treatments suffered very low reproduction due either to severe frost damage (early treatment) or low pollinator visitation (late treatment) relative to control plants. Thus, plants face tradeoffs with advanced flower- ing time. While early-flowering plants can reap the benefits of enhanced pollination services, they do so at the cost of increased susceptibility to frost damage that can overwhelm any benefit of flowering early. In contrast, delayed flow- ering results in dramatic reductions in plant reproduction through reduced pollination. Our results suggest that cli- mate change may constrain the success of early-flowering plants not through plant-pollinator mismatch but through the direct impacts of extreme environmental conditions.

Investigating the influences of climate on the high elevation snowpack hydrology in the upper Colorado region. - Claire-Louise Bode (2016)
A change in climate in the western United States has already affected and will continue to affect the onset of snow melt in many parts of the country. The effect of climate change on snow water equivalent, snowmelt runoff and total streamflow with respect to their elevation distribution is examined across the Colorado Headwaters Basin. This is a high altitude location within the Upper Colorado Basin region. The total streamflow of this region has a significant contribution from the spring season snow melt. An increase in air temperature in the Colorado Headwaters Basin over a few years will change the onset of the spring snowmelt for that season. These changes will affect many aspects of water management and utilization that the region is extremely dependent on. Snow water equivalent (SWE), mean/minimum air temperature and USGS stream gage data were collected and analyzed using Pearson correlation to assess whether warmer air temperatures corresponded to reduced snow water equivalent and streamflow discharge for each month at each station and gage in the basin at the 5% level of statistical significance. A linear regression test followed to test for trends across a 30-year time period from 1986 to 2015, followed by a series of Runs tests for stationarity which are commonly employed statistical methods in the analysis of climate and water resource time series data. As a result we see reductions in SWE and changes in snowmelt dominated streamflow timing from higher elevations. The timing, volume, and extent of mountain snowpack, and the associated snowmelt runoff, are intrinsically linked to seasonal climate variability and change. Recent observations have documented the changes in the early onset of snowmelt in the region and further indicate that the high altitude snowpacks may now be susceptible to the warming climate.

An Organizational Assessment for the Boys & Girls Clubs of South Park using Community Capital Frameworks - April-Dawn Knudsen (NDSU Repository (North Dakota State University), 2016)
The Boys & Girls Clubs of South Park (BGCSP) is a youth service 501(c)3 serving Park County, Colorado. With over 60% of Park County?s workforce commuting to another county for employment the need for affordable out-of-school youth care is apparent, but the need for BGCSP goes further. These rural communities need local opportunities for children. This isolated population is a food desert, medical desert, and had limited industry. The schools lack resources and the population is projected to see unprecedented growth over the next eight years. The need for BGCSP is apparent, but what is their impact? The following chapters are an assessment of BGCSP using mixed methods research. Through the use of interviews, ripple effects mapping, various data, finances, club documents and public documents, these chapters were formed. The use of qualitative and quantitative data created a balanced, in-depth picture of this organization?s assets, accomplishments and areas of opportunity.

Natal philopatry varies with larval condition in salamanders - Michael P. Moore; H. H. Whiteman (Behavioral Ecology and Sociobiology, 2016)
An important, long-lasting role of the natal environment on reproductive site selection is suggested, and the conditions experienced in early development can strongly affect reproductive behaviors across the life cycle, as well as differences in philopatry based on natal pond.

Writing an Effective Response to a Manuscript Review - B. W. Taylor (Freshwater Science, 2016)
An author’s response to referees’ comments is a key component of the peer review process that affects whether a manuscript is accepted or rejected, the speed at which a manuscript moves through the review process, the workload of editors and referees, and the quality and clarity of published science. However, guidance on how to write a response to manuscript reviews is lacking from the instructions for authors of most journals and from science writing manuals. I offer some recommendations for authors, referees, and journals that can be implemented easily to improve the response to reviews and, thereby, enhance the publishing and reviewing process for authors, referees, and editors.

Drought, pollen and nectar availability, and pollination success - Nickolas M. Waser; Mary V. Price (Ecology, 2016)
AbstractPollination success of animal‐pollinated flowers depends on rate of pollinator visits and on pollen deposition per visit, both of which should vary with the pollen and nectar “neighborhoods” of a plant, i.e., with pollen and nectar availability in nearby plants. One determinant of these neighborhoods is per‐flower production of pollen and nectar, which is likely to respond to environmental influences. In this study, we explored environmental effects on pollen and nectar production and on pollination success in order to follow up a surprising result from a previous study: flowers of Ipomopsis aggregata received less pollen in years of high visitation by their hummingbird pollinators. A new analysis of the earlier data indicated that high bird visitation corresponded to drought years. We hypothesized that drought might contribute to the enigmatic prior result if it decreases both nectar and pollen production: in dry years, low nectar availability could cause hummingbirds to visit flowers at a higher rate, and low pollen availability could cause them to deposit less pollen per visit. A greenhouse experiment demonstrated that drought does reduce both pollen and nectar production by I. aggregata flowers. This result was corroborated across 6 yr of variable precipitation and soil moisture in four unmanipulated field populations. In addition, experimental removal of pollen from flowers reduced the pollen received by nearby flowers. We conclude that there is much to learn about how abiotic and biotic environmental drivers jointly affect pollen and nectar production and availability, and how this contributes to pollen and nectar neighborhoods and thus influences pollination success.

The Effects of Ants on Ecosystem Dynamics: Investigating the Ecological Influence of Ant Nests in the Rocky Mountains - W. Arnold (2016)
Formica obscuripes, or the Western Thatching Ant, is a native North American ant species commonly found throughout the central and western US. Like many ant species, F. obscuripes acts as an ecosystem engineer, as colonies can significantly alter the nutrient content, moisture content, temperature, and pH of the soil when constructing and maintaining their nests. And while the immediate effects of F. obscuripes on the local environment are well known, it is not quite well understood how these shifts in the physical and chemical properties of the substrate affect larger ecosystem processes. As many plant and fungal species are sensitive to factors such as soil moisture and nutrient availability, we hypothesized these biotic communities would alter in composition, abundance, and diversity as ants altered the immediate environment. We explored the effect of ant nests on soil properties, plant community composition, and belowground fungal communities. As part of that, we sampled and assessed plant community composition, pathogen loads, and fungal colonization of abundant plant species in a sagebrush meadow in Colorado’s Almont Triangle. While we found that soil below ant nests was indeed drier and warmer than the surrounding soil, we did not find a significant difference in arbuscular mycorrhizae (AMF) or dark septate endophyte (DSE) colonization for our focal species, Chrysothamnus viscidiflorus. However, we did find that the presence of ant nests was related to an increase in the abundance of oomycete root pathogens for C. viscidiflorus. Furthermore, we found that plant diversity on and around ant nests increased as nests aged and became inactive, while the presence of woody species, especially, Symphoricarpos rotundifolius, increased with nest proximity and activity. Moreover, we found that not only was the presence of S. rotundifolius correlated with ant nest activity, its roots also saw elevated levels of AMF colonization. And though its abundance was unaffected by nest presence, A. tridentata saw increased rates of colonization by DSE when occurring on ant nests. Thus, while ants may create warmer, drier, and more nutrient dense environments, fungal and plant responses will differ between species, as mutualisms and unique mechanisms lead species and partners to experience differential success.

Persistence of high elevation fens in the Southern Rocky Mountains, on Grand Mesa, Colorado, U.S.A. - George Austin; David J. Cooper (Wetlands Ecology and Management, 2016)

Competitive context drives pollinator behavior: linking foraging plasticity, natural pollen deposition, and plant reproduction. - H. M. Briggs (2016)
Understanding the functional impacts of pollinator species losses on plant populations is critical given ongoing pollinator declines. Simulation models of pollination networks suggest that plant communities will be resilient to losing many or even most of the pollinator species in an ecosystem. These predictions, however, have not been tested empirically and implicitly assume that pollination efficiency is unaffected by interactions with interspecific competitors. By contrast, ecological theory and data from a wide range of ecosystems show that interspecific competition can drive variation in ecological specialization over short timescales via behavioral or morphological plasticity, though the potential ecosystem functional implications of such changes in specialization remain unexplored. We conducted manipulative field experiments in which we temporarily removed single pollinator species from study plots, to test the hypothesis that interactions between pollinator species can shape individual species’ functional roles via changes in foraging specialization. We show that loss of a single pollinator species reduces floral fidelity (short-term specialization) in the remaining pollinators, with significant ecosystem functional implications in terms of reduced plant reproductive output, even when potentially effective pollinators remained in the system. Our results suggest that ongoing pollinator declines may have more serious negative implications for plant communities than is currently assumed. More broadly, we show that the individual functional contributions of species can be dynamic and shaped by the community of interspecific competitors, thereby documenting a new mechanism for how 8 biodiversity can drive ecosystem services and functions, with potential relevance to a wide range of taxa and systems. 9

Productivity of Montane Meadows in a Warming World: Evidence from an Elevation Gradient and a Warming Experiment - A. N. Henderson (2016)
Climate change is expected to disproportionately impact high elevation ecosystems by disrupting current temperature and precipitation regimes. The future carbon balance of these systems is uncertain, given the interplay between longer growing season length and the potential for increased drought. Currently, the most robust inferences about ecosystem responses to changing climate come from the integration of experimental and observational methods. In this thesis, I utilize evidence from a warming experiment and an elevational gradient to gain insights into how aspects of ecosystem productivity and community functional composition change in response to the abiotic environment. First, I show that ecosystem productivity was similar in the heated and ambient treatment groups of the warming experiment. Net ecosystem productivity (NEP) was similar between treatments with only slightly increased NEP in the early season in the heated treatment. Important leaf functional traits (leaf mass per area, LMA; leaf dry matter content, LDMC) shifted with heating in directions associated with higher productivity, both at the community level and within species. While these results are counterintuitive, potential insight was provided by a soil cooling effect found in the heated plots in the early season. Second, I investigate ecosystem productivity across spatial and temporal gradients using phenology cameras. I show strong relationships between greenness indices generated from camera images and on-the-ground measurements of gross primary productivity (GPP). I also used changes in greenness indices early season to infer green-up rates, and found a strong pattern of increasing green-up rate with increasing elevation. Together, these studies highlight the importance of comparing experimental and gradient methods to assess how different spatial and temporal scales influence our conclusions about the effect of climate change on ecosystems. 6

Testing for the genetic basis of cold tolerance in a wild mustard - W. De Vries (2016)
Overwinter survival and cold tolerance are complex quantitative traits that are important in understanding adaptation to different environments. I evaluated 422 genotypes of Boechera stricta, originating form different geographic locations and elevations, in a common garden genome wide association study (GWAS) experiment in the Rocky Mountains. I measured overwinter survival in 3895 GWAS plants that have been fully sequenced as a part of the original experiment. Using sequenced genetic information from the plants, I looked for correlations between survival and genetic variation in a quantitative trait locus previously implicated in cold tolerance adaptation in this species. I found variation in overwinter survival across broad population groups reflecting different genetic and evolutionary histories, as well as in relation to one aspect of genetic variation within the quantitative trait locus specifically. The population groups Utah and West had higher survival rates than those from Colorado in the Colorado common garden experiment. In a test for local adaptation, population group was a significant predictor of overwinter survival, while elevation, latitude and longitude were not. This indicates that the cold tolerance trait is likely not locally adapted.

The effects of Na pulses on subalpine ecosystems - R. Fitzpatrick (2016)
Sodium is an essential nutrient for all animals, and in terrestrial ecosystems it is often difficult for plant consumers to obtain the necessary amount of Na since plants generally do not prosper in high salt environments. While carnivores get adequate salt due to bioaccumulation from their prey, herbivores are limited by Na and often must seek out salt deposits or drink urine to maintain osmotic balance. In ecosystems far from the ocean this Na craving is thought to be even higher. In this study, I used three different experiments in and around the Gothic townsite in the Rocky Mountains of Colorado to examine the use of Na in subalpine ecosystems. These ecosystems have significant Na shortfall; plant and nectar consumers are drawn to resourcess that have higher salt concentrations. Large mammalian herbivores (e.g., deer) grazed selectively in plots sprayed with a 1% NaCl solution suggesting that they have adapted to detect even small amounts of salt. This grazing had cascading consequences: plots with higher Na were grazed more, had higher light availability, and therefore higher soil temperatures. I then examined whether plots with higher temps had higher colonization rates by ant nests. I found that there was an interaction between Na and N and between Na and heat in some instances with ​T. sessile preferring to colonize warm and salty areas suggesting that heat and Na in conjunction help to increase metabolic efficiency. Given these results, there is a strong indication that Na (though an often overlooked nutrient) may be an important limiting factor in subalpine ecosystems. Thus, with further study we may be able to better understand the activity of food webs whose biochemistry has previously been examined only through biochemical lense of N, C and P.

How diploidization turned a tetraploid into a pseudotriploid - T. Mandakova; A. D. Gloss; Noah K Whiteman; M. A. Lysak (American Journal of Botany, 2016)

Controls on selenium distribution and mobilization in an irrigated shallow groundwater system underlain by Mancos Shale, Uncompahgre River Basin, Colorado, USA - Taylor J. Mills; M. Alisa Mast; Judith Thomas; Gabrielle Keith (Science of The Total Environment, 2016)
Groundwater Se concentrations ranged from below detection limit (<0.5μgL(-1), and primarily are controlled by high groundwater nitrate concentrations that maintain oxidizing conditions in the aquifer despite low dissolved oxygen concentrations, which indicate nitrate is largely derived from natural sources in the Mancos Shale and alluvial material.