Submitted Abstracts - FRSES 2017

Oral presentations     Poster presentations

Oral Presentations:

Abstracts listed alphabetically by author
Numbers refer to presentation session and order as shown in schedule

Oral Presentation Abstracts

(Number and letter refers to presentation session and order in schedule above)



Cheryl Abbate (3A)  
IN DEFENSE OF CATS: WHY "CUDDLY KILLERS" AREN'T REALLY DEVESTATING ECOSYSTEMS AND WHO IS
University of Colorado-Boulder, Graduate

In the recent publication of Cat Wars: The Devastating Consequences of a Cuddly Killer, Peter Marra and Chris Santella advise that we use "any means necessary" to remove the free-range cat population from the landscape. This sentiment is echoed, perhaps less frankly, by a number of wildlife enthusiasts who are quick to blame free-roaming cats for ecological harm, such as species extinction, and insist that cat guardians keep their "invasive" feline companions indoors for their entire lives. In this paper, I challenge the empirical claim that house cats devastate ecosystems by providing evidence that they are ineffective hunters and, moreover, when house cats venture outside, most are more concerned with territory protection rather than hunting. Moreover, I reveal the flaws of the research methods used by those scholars who charge cats with ecological devastation, illustrating that these scholars lack a sufficient understanding of cat nature and behavior, which leads them to faulty and downright dangerous conclusions. Cats, as I will show, are deeply misunderstood and unfairly demonized by many wildlife enthusiasts. Consequently, the blame for ecological destruction is wrongly and unfairly placed on cats, when in reality, we ought to be focusing on the devastating impacts of human activity if we want to succeed at alleviating ecological harms.



Eva Bacmeister (7A)  
A STUDY OF CLIMATE VARIABILITY: USING SWIMMING PERFORMANCE AS AN INDICATOR OF THERMAL TOLERANCE
Colorado State University, Undergraduate
With Alisha Shah (CSU)

Climate variability has been implicated in shaping organismal physiology and patterns of distribution. Specifically, organisms that evolve in variable climates, for example at temperate latitudes, are hypothesized to evolve a broad thermal tolerance allowing them to occupy a wider range distribution. On the other hand, organisms that evolve in stable climates, such as the tropics, should evolve a narrow thermal tolerance and limited range distributions. Aquatic insects are an excellent model system for testing the this hypothesis because their body temperatures closely match that of their environment and they occur relatively abundantly in mountain streams across elevations and various latitudes. I measured swimming performance, a thermal tolerance trait, across a range of temperatures using aquatic insects (mayflies and stoneflies) from temperate (Rockies) and tropical (Andes) mountain streams. I found that across elevations, insects from temperate mountain streams performed best over a wider range of temperatures as compared to those from tropical mountain streams. Research conducted by my collaborators also indicates that insects from temperate streams have broader thermal tolerances than their tropical counterparts. Collectively, these results suggest that due to their narrow thermal tolerances, tropical aquatic insects may be more vulnerable to the effects of climate change.



Theresa Barosh (11A)  
WHAT HAPPENS WHEN YOU TRIM A CLONAL WEED AND FEED IT TO INSECTS?
Colorado State University, Graduate
With Weiand Alexa (CSU/Western State University), Paul Ode (CSU)

Establishment of plant and insect species in novel habitats provides an opportunity to explore the significance of community composition and species abundance on colonization and persistence. As a widespread weed, Russian knapweed (Acroptilon repens) occurs throughout much of Colorado, in both wildlife reserves and agricultural lands. The gall midge (Jaapiella ivannikovi) was recently approved as a biological control agent for Russian knapweed. The gall midge induces gall formation in the apical meristems, altering plant growth to provide bloated tissue in which insect larvae develop and feed. Ramet removal, specifically through grazing by ungulates, also has implications in weed management as many land managers use grazers for knapweed control. In the summer of 2016, plant traits and insect establishment were examined in cages with and without ramet removal by simulated grazing. We asked: 1) How does Russian knapweed ramet density impact insect establishment? 2) How does insect herbivory and ramet removal impact Russian knapweed vegetative traits? Insects appear to establish better in plots with ramet removal, and the combination of treatments has a larger impact on plant traits than either treatment alone. Outcomes are highly dependent on the traits of Russian knapweed under consideration. Research outcomes inform theory related to invasion ecology, insect intraspecific interactions, and weed management.




Whitney Beck (1A)  
INFLUENCE OF EXPERIMENTAL, ENVIRONMENTAL, AND GEOGRAPHIC FACTORS ON NUTRIENT DIFFUSING SUBSTRATE EXPERIMENTS IN FRESHWATER STREAMS
Colorado State University, Graduate
With Amanda T. Rugenski (Cornell University), N. LeRoy Poff (CSU)

Stream algal growth is often limited by the availability of nitrogen, phosphorus, or both nutrients. For over thirty years, investigators have completed nutrient diffusing substrata (NDS) experiments to quantify algal nutrient limitation. Previous meta-analyses of NDS have shown that algae are commonly co-limited by nitrogen and phosphorus, and that in-stream nutrients are weakly predictive of limitation. However, no meta-analysis has comprehensively addressed the experimental, environmental, and geographic covariates affecting NDS experiments. We surveyed the literature and extracted data for algal biomass effect sizes and 30 potential covariates (n = 649 experiments). We built meta-regression models to identify significant covariates and gain insight about algal ecology. We found that experimental methods significantly changed the degree of nutrient limitation in phosphorus treatments. Furthermore, environmental variables such as in-stream nutrients, season, light, temperature, stream discharge, and stream velocity significantly affected nutrient limitation. Land use and ecoregion were also important predictors of nutrient limitation, whereby land uses with greater nutrient loadings and ecoregions with higher population development had smaller effect sizes. From these conclusions, we provide recommendations for future experiments and advocate greater reporting of experimental covariates and algal stressors such as herbivory and streamflow disturbance.  




Amanda Carlson (10A)  
COMPOUNDED DISTURBANCE EFFECTS ON VEGETATION RECOVERY FOLLOWING SPRUCE BEETLE OUTBREAK AND HIGH-SEVERITY WILDFIRE
Colorado State University, Graduate
With Jason Sibold (CSU), Tim Assal (USGS),  Jose Negron (USFS)

Spruce beetles are causing extensive mortality in Rocky Mountain subalpine forests, raising concerns that recently killed stands may pose a risk of severe wildfire. Many recent studies have attempted to determine the influence of spruce beetle disturbance on wildfire, and found that there is no significant correlation between the density of killed trees and overstory mortality from fire. However, few studies have examined the effects of interacting disturbance on patterns of fire regeneration. We used the 2013 West Fork Complex fire in southwestern Colorado as a case study to assess the influence of bark beetle severity on vegetation recovery two years after the fire, using Landsat imagery to quantify post-fire greenness using the Normalized Difference Vegetation Index (NDVI). We quantified pre-fire beetle severity using change in the Normalized Difference Moisture Index (dNDMI) from multi-date pre-fire Landsat images. Using spatial error sequential autoregression models, we determined that pre-fire beetle severity estimated by dNDMI was negatively correlated with NDVI values when accounting for the influences of topography, fire weather, and pre-disturbance NDVI. The difference in NDVI as a response to pre-fire dNDMI may indicate increased fire severity at the soil surface as a result of surface fine fuel accumulation 1-5 years after spruce beetle outbreak.




Erick Carlson (1B)  
UPTAKE AND TRANSFORMATION OF NITRATE IN AGRICULTURAL TAILWATER WETLANDS, WELD COUNTY, COLORADO
Colorado State University, Graduate
With David Cooper (CSU), Reagan Waskom (CWI)

Across the world, elevated concentrations of N and other agricultural nutrients degrade freshwater ecosystems through eutrophication and direct toxicity to plants and animals and pose a threat to human health in many developing and developed nations. Runoff in agriculturally dominated watersheds often contains high levels of nitrogen (N) primarily as ammonia (NH4+) and nitrate (NO3-) from fertilizer application. In Weld County, Colorado 80 % of irrigation wells and 45 % of domestic wells exceed the U.S. EPA drinking water standard of 10 mg/L for nitrate. Constructed treatment wetlands and riparian buffers have been used to mitigate these problems in many watersheds. I investigated a third potential solution for nitrogen sequestration and transformation. Agricultural tailwater wetlands occur at the edge of agricultural fields, and are formed and supported by surface and groundwater runoff from local and regional irrigated agriculture. I investigated N sequestration in aboveground plant biomass and transformation by microbial denitrification in wetlands adjacent to agricultural fields and effects of spatial patterns in soil properties, groundwater dynamics and plant communities. Preliminary results indicate that plant uptake and harvest could remove significantly more N from the groundwater system than denitrification alone. These results will inform large scale modeling of groundwater contamination as well as field level management of wetlands for excess nutrient management. 


Charles (Jeff) Carroll (10B)   USING COMMON GARDENS TO ISOLATE THE EFFECTS OF A WARMER FUTURE ON THE DRIVERS OF SEEDLING GROWTH Colorado State University, Graduate With Alan Knapp(CSU), Patrick Martin (CSU)
Climate change threatens to drive shifts in ecosystem composition via increased temperatures, yet isolating that effect in real-world conditions are challenging. We established three common gardens on a 1,200m elevation gradient along the Front Range attempting to untangle the effects of climate under realistic conditions. To predict the effects of temperature on growth, it is vital to first understand the sensitivities of the underlying mechanisms that govern growth. Therefore, we investigated the sensitivities of seedlings of four dominant tree species in Colorado to instantaneous photosynthesis, spring phenology, and leaf anatomy in 2016. Lodgepole pine (Pinus contorta var latifolia) and ponderosa pine (Pinus ponderosa) exhibited a lack of temperature sensitivity photosynthetically, both within and amongst sites. We observed minimal shifts in leaf area, but did detect non-linear temperature sensitivities phenologically resulting in an increased growing season with a marginal increase (3oC) in growing season temperature. In contrast, aspen (Populus tremuloides) displayed pronounced sensitivities photosynthetically and anatomically peaking at the middle site, yet exhibited a reduced phenological effect. These strategies suggest that the timing and severity of warming temperatures could alter the forest composition of Colorado potentially favoring montane conifer species due on an increased growing season without substantial photosynthetic decline or reduced leaf areas.




GraceAnne Casto (9A)  
BURROWING HERBIVORE, PRECIPITATION, AND PLANT COMMUNITY EFFECTS ON INVASIVE GRASS GERMINATION
University of Colorado-Boulder, Undergraduate

Species invasions have become a problem of global concern because of their negative impacts on native ecosystems. In the Carrizo Plain of California, two invasive grasses, Hordeum murinum and Bromus madritnesis ssp. rubens, have become the focus of management because they threaten native grassland species. Previous studies have illustrated how resource availability and burrowing herbivore activity affect the growth of these grasses, but more information on their germination is needed in order to obtain a full picture of their population dynamics. Greenhouse experiments and field manipulations have been conducted to evaluate how germination of these grasses depends on burrowing herbivores, precipitation, and plant communities. The results from this study will contribute to a larger project developing population models for the invasive grasses in order to understand what limits population growth and to aid management decisions.




Francis Chaves (9B)  
CONSTRAINTS ON A TALLGRASS PRAIRIE PLANT COMMUNITY RESPONSE TO THE LOSS OF THE DOMINANT SPECIES ANDROPOGON GERARDII
Colorado State University, Graduate
With Melinda Smith (CSU)

The loss of dominant plant species from grassland ecosystems causes dramatic declines in ecosystem function. However, it is also expected to create the opportunity for other species to become abundant and compensate in function due to competitive release, resulting in ecosystem recovery. Conversely, as in tallgrass prairie ecosystem, compensation does not always occur. Low resource availability, lack of functionally equivalent plant species and absence of functional traits that promote compensation in the community, are proposed as constraints on ecosystem recovery. Using removal field experiments combined with greenhouse experiments, I propose to address the following questions in a tallgrass prairie plant community after the loss of the dominant species Andropogon gerardii: 1) is the recovery of aboveground production after the loss of the dominant species limited by water and nitrogen availability? 2) Is aboveground biomass compensation determined by the presence and abundance of potentially functionally redundant species Shorgastrum nutans and Panicum virgatum? 3) Which traits in the functionally redundant species promote/delay aboveground biomass compensation? Preliminary results show that increasing resource availability increases aboveground biomass production, but not enough to fully compensate. Presence and abundance of functionally equivalent species may have a determinant role in community recovery.




Amy Clark (11C)  
PLANT DEFENSE HORMONES IN THE FUNGAL ATTACK ON CANADA THISTLE
Colorado State University, Graduate
With Courtney Jahn (CSU), Andrew Norton (CSU)

Cirsium arvense, Canada thistle, is one of the most detrimental weed for U.S. agricultural production and rangeland health. Biological agents show potential as a control, particularly Puccinia punctiformis (CT-rust) as it solely attacks Canada thistle. However, CT-rust rarely reaches epidemic proportions in natural populations. Insect herbivory could augment rust infection by altering plant defense hormones. Jasmonic acid (JA) increases following herbivory and acts in opposition to salicylic acid (SA) which defends against pathogens. When JA was applied to young thistle plants following inoculation the rate of symptomatic infection increased, suggesting that CT-rust could be more effective when used in conjunction with other insect biological control agents. 




Lisa Clark (3B)  
RESTORATION ON SOUTHWEST U.S. RIVERS: THE ROLE OF THE HUMAN ELEMENT
University of Denver, Graduate
With Eduardo Gonzalez (University of Denver), Rebecca Lave (Indiana University), Nathan Sayre (University of California-Berkeley), Anna Sher (University of Denver)

Riparian areas are especially vulnerable to degradation, and thus are a focus of intensive restoration efforts. However, project success is highly variable and not explained well by environmental factors alone. We propose that the human component may explain the rest. Our NSF-sponsored research asks the following questions: (1) How has restoration changed the plant community structure? (2) How does a manager's background explain attitudes toward nature and science? (3) Are there environmental factors that explain managers' attitudes? (4) Do managers' attitudes correlate with restoration outcomes? We have vegetation data from 416 sites and survey data from over 36 corresponding managers with which to address these. Previous research to address question 1 has found that Tamarix cover is reduced and native plant cover is starting to increase over time in Tamarix removal sites. Preliminary analysis has also shown that the backgrounds and attitudes of managers are variable, especially in information sources and project goals. Of particular interest is testing the assumption that managers who use scientifically-sound resources and practices and collaborate more frequently will have better project outcomes (as defined both by managers and scientists) because they draw on more than just personal experience. Through this project, we will be able to give insight into how best to improve future human intervention on ecosystems, particularly invasive species control.




Lauren Connell (9C)  
INFLUENCE OF BLACK-TAILED PRAIRIE DOG HERBIVORY ON RANGELAND FORAGE QUALITY AND QUANTITY
University of Wyoming, Graduate
With Lauren Porensky (USDA-ARS), Derek Scasta (UW)

Black-tailed prairie dogs (Cynomys ludovicianus) have high dietary overlap with livestock, which can cause forage-centric conflicts between agriculture and conservation. To assess the effects of prairie dog herbivory on forage in northeast Wyoming, we collected samples on and off prairie dog colonies during June, July, and August 2016 for forage quality, and August 2016 for biomass. We collected both composite samples of all herbaceous species and samples of western wheatgrass (Pascopyrum smithii, PASM). For crude protein (CP), total digestible nutrients (TDN), in vitro true digestibility, and calcium, prairie dog colonies had significantly higher values than control sites (5-68% greater, all p-values < 0.05, except PASM-TDN: p = 0.15). The effects of prairie dogs on forage quality did not vary seasonally for PASM samples (all treatment*time p-values ≥ 0.1), but for composite samples, the effects of prairie dogs on CP and calcium shifted as the growing season progressed (treatment*time p < 0.01 and p = 0.02, respectively). There was no statistically significant difference in biomass between prairie dog towns (30.75 ± 12.37 g/m2) and control sites (72.57 ± 19.24 g/m2; p = 0.21) due to variability among sites. Our results demonstrate enhanced forage quality on prairie dog colonies is due to both compositional and phenological shifts associated with prairie dog herbivory, and that enhanced forage quality may help offset reduced forage quantity.




Michael Curran (2A)  
INSECT COMMUNITY RESPONSE TO VEGETATION TREATMENTS ON RECLAIMED WELLPADS IN A SEMI-ARID NATURAL GAS FIELD
University of Wyoming, Graduate
With Douglas Smith (UW), Pete Guernsey (Independent), Peter Stahl (UW, Wyoming Reclamation and Restoration Center)

A significant portion of rangelands throughout Wyoming have been disturbed by natural gas development. Land reclamation and ecosystem restoration associated with these disturbances are critical for wildlife and overall biodiversity. Insects and arthropods not only play significant roles in providing biodiversity, but also provide many ecosystem services to the landscape. Unfortunately, insects have often been overlooked in restoration ecology studies, especially in non-crop systems. This talk will present results from a 3 year study on insect response to reclaimed well pads in the Pinedale Anticline natural gas field in Pinedale, WY. Well pads in the reclamation process with differing vegetation were selected in this study and comparisons were made between well pad vegetation types as well as to adjacent 'reference' sites. In addition to finding significant differences in insect richness and abundance between well pad types and between well pads and adjacent 'reference' sites, a cluster analysis was conducted to determine if families of insects were impacted by types of vegetation present in the sampling areas. The focus of this talk will not only be on results of the study, but on the critical role insects play in providing ecosystem services to rangeland systems. 




Kristen Davenport (8A)  
NON-RANDOM CWD PRION SHEDDING IN THE SALIVA OF WHITE-TAILED DEER
Colorado State University, Graduate
With Brittany Mosher (FCWB, CSU), Brian Brost (FCWB, CSU)

Chronic wasting disease (CWD) is an emerging infectious disease of cervids. CWD spreads rapidly through populations and is common along the Front Range. Infected animals shed prions (the infectious agent of CWD) in saliva, urine and feces. Prion detection in saliva is variable, which we assume is related to prion shedding. The link between detection and shedding and the factors that influence shedding are important for cervid population management. Those factors are indecipherable without an approach that accounts for false positive and false positive detection errors. We developed a multi-scale occupancy model that accounts for both false positive and negative detections to assess which variables affect shedding. We inoculated 45 deer with CWD(+) tissue, then collected saliva samples for 9-24 months. We analyzed 198 saliva samples using real-time, quaking-induced conversion. Our model provides unbiased estimates of shedding probability by accounting for false positive detections that are problematic in this assay. We identified several variables that affect shedding and detection, including deer genotype and assay type. Importantly, our model makes it possible to draw conclusions about prion shedding from longitudinal data analyzed with an imperfect detection method. This approach will clarify the pattern, magnitude and frequency of prion shedding, which likely drives the ongoing CWD epidemic, and is relevant to other disease systems as well.




Kristin Davis (9D)  
HOW WEATHER, VEGETATION AND TOPOGRAPHY INFLUENCE GRASSLAND BIRD ABUNDANCE ON COLORADO’S SHORTGRASS STEPPE
Colorado State University, Graduate
With Cameron Aldridge (CSU/USGS), David Augustine (USDA), Susan Skagen (USGS)

Grassland birds are of major conservation concern in North America and have declined more precipitously than any other guild of birds since the 1970s. While numerous studies have examined vegetation or weather effects independently on grassland bird abundance, few have jointly examined these impacts. We developed generalized linear models from point count data (2013-2015) to evaluate the influence of habitat heterogeneity and a weather proxy (soil moisture) on the abundance of two breeding grassland bird species'  -  lark bunting and McCown's longspur  -  on the Central Plains Experimental Range (CPER) in northeastern Colorado's shortgrass steppe. Vegetation structural composition had the strongest influence on both species' abundances. Lark bunting abundance was most positively influenced by percent shortgrass and forb cover (β = 0.181 and β = 0.151, respectively; p <0.0001), while McCown's longspur appeared to favor intermediate amounts of shortgrass cover (β of quadratic = -2.0808, p < 0.001). Abundance was less strongly influenced by topography for both species, and by soil moisture for lark buntings. In future analyses, we will include an additional year of point count data (2016) and weather (precipitation and temperature) and grazing covariates to determine how grazing management, in conjunction with vegetation, topography and weather, affects grassland bird abundance on the CPER.  




Graham Dawson (5A)  
DEMOGRAPHICS OF PRAIRIE RATTLESNAKES IN WELD COUNTY, CO
University of Northern Colorado, Graduate
With Stephen Mackessy (UNCO)

Long-term mark-recapture studies are essential for understanding the ecology of long lived species such as snakes. Despite the necessity of these studies, there are relatively few that have been conducted on snakes. Prairie Rattlesnakes (Crotalus viridis viridis), an iconic species of the eastern plains, are long-lived and important components of the Colorado shortgrass-steppe ecosystem. For 14 years, two hibernacula in Weld County, Colorado have been part of a mark-recapture study. This study aimed to analyze the demographic characteristics of this population. Capture rate, growth rates, size distribution, venom yield, population size and den site fidelity were analyzed. 1895 unique individuals have been captured, 1003 of these individuals have been captured more than once. Of the 1895 unique individuals, 788 were female and 980 were male. Individual snout-vent lengths ranged from 155 to 1160 mm. In general, males are larger than females and produce more venom. Neonates experience rapid initial growth, which then slows as they age. This population exhibits high levels of den site fidelity, with snakes returning to the site of their original capture over 99% of the time. Demographic studies such as this can be invaluable for future animal conservation of snake species. All evidence suggests that this population is currently stable, but changes in land use and/or climate could adversely affect density and abundance, both locally and throughout their range.




David Enden (6A)  
THE IMPORTANCE OF SPECIES-SPECIFIC COGNITIVE ECOLOGY DURING A TWO-CHOICE DISCRIMINATION TASK  WITH CAPTIVE WILDLIFE
Colorado State University, Graduate

The importance of species specific cognitive ecology during a two choice discrimination task with captive wildlife|Using an animal's evolutionary history and physical adaptations to function within their ecological niche can help improve captive welfare.  Cognitive ecology investigates the animal mind with consideration of that species unique ecological niche. A two-task object discrimination task was conducted on 14 animals across 10 taxa at an AZA accredited zoo in Colorado. Of these animals, both otters were the only ones to achieve the discrimination criterion of 80% correctness for two consecutive trials. Percent correctness and learning curves were statistically analyzed to reveal that the Sun Bear and Camel had a higher learning curve despite not achieving the discrimination criterion.  An extensive review of over 300 sources demonstrated that otters are avid tool users that manipulate objects with their hands to acquire food while expressing predator avoidance behaviors.  It was concluded that otters have cognition skills and behaviors, related to their ecological niche, that are advantageous in an object-based discrimination task, whereas the other animal participants lacked these attributes. Additional research was applied and it was discovered that stereotypic (stress related) behaviors in captive giraffe species directly correlates with ecosystem type through GIS mapping. These preliminary findings demonstrate implications to enhance current animal welfare practices through an approach based on cognition and evolutionary ecology, rather than behavior alone.




Nora Flynn (3C)  
INVESTIGATING DEFICIT IRRIGATION AS A CLIMATE-SMART MANAGEMENT OPPORTUNITY
Colorado State University, Graduate
With Steven Fonte (CSU), Louise Comas (USDA-ARS), Catherine Stewart (USDA-ARS)

The pressure of rising global food demand in combination with increasingly limited water and land resources requires the application farm management practices that support the whole agricultural ecosystem and strengthen farm resilience in a changing global climate. Long term agricultural sustainability and productivity in semi-arid climates depends on an enhanced understanding of how irrigation management interacts with key soil processes. This study examines the ecological effects of deficit irrigation (DI) as a strategy to reduce water usage while minimally impacting crop yield. Little is known about how water-limited irrigation practices might affect critical belowground ecosystem services. Deeper root growth and reduced surface moisture under DI may lead to increased carbon storage potential and lower greenhouse gas emissions from the soil, thus contributing to climate change mitigation. Greenhouse gas emissions and multiple soil physical, biological and chemical properties were evaluated across a range of irrigation treatments on a corn farm in Greeley, Colorado in this study. These preliminary results suggest that DI holds potential to serve as a climate-smart alternative to traditional irrigation management strategies, particularly when DI is used in combination with an approach that promotes the belowground mechanisms that support plant growth.




Maybellene Gamboa (4A)  
SONG SPARROWS OF ICE AND FIRE: ADAPTIVE DIVERGENCE ALONG A CLIMATE GRADIENT
Colorado State University, Graduate
With T. Scott Sillett (Smithsonian Institution), W. Chris Funk (CSU), Scott A. Morrison (The Nature Conservancy), Cameron K. Ghalambor (CSU)

Locally-adapted phenotypes may arise as a product of divergent selection across an environmental gradient, but this may be mediated by the effects of gene flow. Islands are ideal for studying the interaction of genetic isolation and the environment on phenotypic variation as water is often a barrier to dispersal. Yet, the enhanced dispersal ability of birds compared to many other organisms may increase gene flow across islands thereby potentially constraining the effects of selection. Here, we assess the degree to which song sparrows (Melospiza melodia graminea) are adapted to climate given varying degrees of isolation. Previous work suggests selection acts on the thermoregulatory ability of birds inhabiting different climates. To investigate this, we measured thermoregulatory traits in birds along a temperature gradient on the California Channel Islands. We coupled this with landscape genomic analyses of 2,767 SNPs to infer population structure and identify candidate loci under selection. Song sparrows varied predictably in bill size with larger bills on hotter islands thereby facilitating increased heat dissipation. Contrary to our prediction that birds on hotter islands would have reduced basal metabolic rate (BMR), flow-through respirometry reveal no difference suggesting selection may not act BMR. Finally, we found distinct genetic clustering by island despite some gene flow which suggests that both population history and selection may yield locally-adapted phenotypes.




Magda Garbowski (2B)  
RESTORING SEMI-ARID LANDS WITH SUPERABSORBENT POLYMERS UNDER REDUCED PRECIPITATION AND THREAT OF BROMUS TECTORUM INVASION
Colorado State University, Graduate
With Cynthia Brown (CSU), Danielle Johnston (CPW), Meagan Schipanski (CSU), Stuart Hardegree (USDA-ARS)

Restoration of semi-arid lands in the western U.S. is hindered by invasion of exotic species such as cheatgrass (Bromus tectorum) and unpredictable precipitation. With their ability to absorb moisture when soils are wet and slowly release it, superabsorbent polymers (SAP) may aid in the establishment of native species. In 2014, we implemented a study to investigate effects of, precipitation, B. tectorum, and SAP on soil volumetric water content (VWC) and invasive and native species establishment. Three treatments were fully crossed at two sites in Colorado: B. tectorum seed addition, drought (66% reduction of ambient rainfall), and SAP incorporation. Effects of SAPs, B. tectorum, and drought on VWC and plant responses one year post-treatment were site dependent. At the Eastern Slope site, SAP improved seeded species establishment under ambient precipitation conditions even though VWC was lower. At the Western Slope site, native seedling densities were lower with B. tectorum treatments. Interestingly, at this site, B. tectorum under ambient precipitation had a stronger negative impact on soil moisture at 30 cm depth than drought treatments. Drought decreased soil moisture later in the growing season at both sites while B. tectorum decreased soil moisture early in the season at the Western Slope site. Our results suggest that incorporating SAP into the soil may improve plant establishment, but effectiveness likely depends on antecedent soil moisture and site specific effects.


Ben Golas (8B)  
EVOLUTION OF RESISTANCE TO PLAGUE (YERSINIA PESTIS) IN WILD HOST POPULATIONS
Colorado State University, Graduate
With Brandon Goodell, Michael Antolin (CSU), Colleen Webb (CSU)

Theoretical models have shown that for populations in decline, evolutionary rescue via natural selection can lead to renewed population growth, but if population size decreases to a small enough level, the population is at risk of extinction due to demographic stochasticity. After more than seventy generations of exposure, prairie dogs have not developed significant resistance to Yersinia pestis infections, suggesting that when prairie dog populations are infected, they succumb to stochastic effects before evolutionary rescue can occur. We use an ecologically-validated model of this scenario to explore the potential for adaptive resistance to prevent extinction following Y. pestis exposure. We find that when maladapted populations, such as prairie dogs, are exposed to a highly pathogenic and environmentally persistent pathogen, such as Y. pestis, there is no opportunity for heightened resistance to evolve, and extinction occurs as a result of mortality from infection and demographic stochasticity. In contrast, species starting with higher resistance factors are capable of evolving further increased resistance, and extinction is rare. We extend the model to evaluate the potential effects of vaccination strategies on the ability to evolve increased resistance. These findings can be used to influence management decisions regarding susceptible populations. 




Joanna Harter (10C)  
GLACIALLY-FORMED WETLANDS, CAPRICIOUS CLIMATE, AND TOMORROW'S BIRD DIVERSITY
University of Wyoming, Graduate
With Melanie Murphy (UW)

Freshwater wetlands support high biodiversity, but this biodiversity is vulnerable to hydrologic change.  Precipitation-dependent wetlands are highly responsive to climate variation, especially those that are shallow and isolated, drying and refilling in response to precipitation and temperature.  The persistence of wetlands over time, termed "wetland ephemerality," is an important factor in maintaining productive and diverse wetland habitat for waterfowl and other birds.  Effective strategies to conserve wetland biodiversity depend on a strong understanding of the factors that generate and maintain biodiversity in wetland habitats. To understand how wetland ephemerality influences bird diversity at local and regional scales, we modeled species richness of breeding birds as a function of wetland ephemerality and a suite of additional landscape variables across the Plains and Prairie Potholes Region, USA.  We estimated wetland ephemerality from probabilistic classifications of surface water in 16 time-steps of Landsat images that represent the range of climate variation from 1984 to 2013.  Understanding how patterns of bird species richness are affected by historic, climate-induced variation in wetland ephemerality can provide a foundation for predicting how richness patterns may change under different climate scenarios.  From preliminary analyses in one study area, we found that wetland ephemerality was an important variable in predicting species richness, in addition to the  proportion of grassland and wetland on the landscape.  




Tanner Harvey (7B)  
PREY SPECIFICITY OF BOIGA IRREGULARIS VENOM
University of Northern Colorado, Graduate
With Stephen Mackessy (UNCO)

The Brown Tree Snake (Boiga irregularis) is currently a problematic invasive species in Guam. A potent neurotoxin, called Irditoxin, present in its venom is highly toxic to lizards and birds but not mammals.  Irditoxin is composed of two subunits linked by a single disulfide bond, and prey specificity of irditoxin may result from the heterodimeric nature of the protein. The goal of my research is to determine if the irditoxin monomers show reduced prey-selective toxicity, which would be reflected by a lower toxicity in a reptile model and higher toxicity in a mammalian model.  Irditoxin is isolated from Guam localized Brown Tree Snake venom.  Post-reduction, the individual monomers were separated using reverse phase chromatography. Toxicity testing will be performed independently for each of the two subunits (irditoxin subunits A and B), and LD50 values will be determined for a reptilian model using Hemidactylus geckos and for a mammalian model using NSA mice.  This toxicity data will be compared to the established LD50 values for heterodimeric irditoxin in both models.  The broader implications of this research are to evaluate and understand the differential effects observed between the subunits and intact toxin toward reptiles and birds, as compared to mammals.  This information is important for our understanding of how an invasive species is able to prey so well on the susceptible avian species of Guam.




Ava Hoffman (4B)  
PHENOTYPIC DIVERSITY WITHIN DOMINANT BLUE GRAMA GRASS ACROSS A PRECIPITATION GRADIENT
Colorado State University, Graduate
With Julie A. Bushey (CSU), Troy W. Ocheltree (CSU), Melinda D. Smith (CSU)

Droughts are expected to intensify in coming years with changing climate. It is imperative that ecologically and economically important native rangeland grasses, such as blue grama (Bouteloua gracilis) of the shortgrass steppe, be investigated for their phenotypic diversity across populations. We selected ten populations where blue grama was a dominant species across a precipitation and elevation gradient in Boulder County, Colorado, plus five sites along a larger north-south gradient. From each population, clones were transplanted to controlled greenhouse conditions. When water limitation was removed, we observed extensive plasticity compared to field phenotype in all populations. However we observed that southern populations exhibited higher growth rates compared to northern and Boulder populations. We also considered differences in drought response strategy (hydroscape), where we found populations to differ in terms of anisohydric (passive) versus isohydric (active) water budgeting strategies. Finally, we observed differences in fitness (flower mass and length) across populations and clones, suggesting potential tradeoff between clonal and sexual reproduction is specific to population or individual clones and not necessarily responsive to water availability. Elucidation of phenotypic diversity along with research highlighting genetic diversity across different populations of blue grama may inform management and restoration practices in the shortgrass steppe ecoregion.




Courtland Kelly (3D)  
GRAZING COVER CROPS TO MAKE ECOLOGICAL FARMING ECONOMICAL
Colorado State University, Graduate
With Meagan Schipanski (CSU), Steven Fonte (CSU)

Dryland agricultural areas are characterized by limited water and organic matter, and are especially prone to the devastation of poor soil management (ie. Dust Bowl).  In the dryland wheat systems of the High Plains (eastern CO, western KS and NE), there is growing interest and adoption of cover crops, which are plants grown exclusively for their ecological benefits to soil health, etc. and not harvested for profit. However, there are potential costs to growing cover crops, including use of valuable soil water, seed and labor cost. Grazing animals on cover crops is one potential avenue to recoup costs associated with cover crop implementation.  In this on-farm field study, we seek to determine the difference in soil health between grazing and not grazing cover crops, also using unplanted, fallow (bare) plots for comparison. If the soil health benefits remain under grazing, this avenue could make cover crops more accessible and attractive to farmers in the High Plains, increase adoption and help improve soil health in the long term.




Dan Kotter (1C)  
WILLOW RESTORATION IN YELLOWSTONE’S NORTHERN RANGE: WHY WOLVES NEED HELP FROM BEAVERS
Colorado State University, Graduate
With David Cooper (CSU), Tom Hobbs (CSU)

In the 20th century in Yellowstone National Park, the extirpation of wolves removed top-down control on an ecosystem allowing elk populations to increase rapidly. Heavy browsing on woody vegetation degraded riparian structure and removed vital dam building material for beaver. As a consequence, streams with intermittent beaver occupancy for thousands of years were abandoned and began incising, lowering riparian water tables and converting floodplains into a Willow-Elk-Grassland state. Following wolf re-introduction in 1995, an experimental study was initiated in 2001 to determine the effects of ungulate browsing and water availability on willow growth. This study extends research after 15 years illustrating the strong association between beaver dam disturbance, increased water availability, and willow growth rates. As exceptional ambient willow sites with high groundwater availability begin to exceed a 2m height threshold, suitable biomass for beaver activities could be restored. During the summers 2015 and 2016, despite nearly a century long hiatus in dam building activities, beaver built a reasonably extensive network of dams, lodges, and food caches on five small streams. We began monitoring these sites in Fall 2015 and 2016 in procession with our current long term monitoring to understand post-occupancy mechanisms of hydrogeomorphic change and direct beaver herbivory on restoration resiliency across a gradient of ecosystem states.  




Benjamin Lagasse (5B)  
NONBREEDING SITE FIDELITY AND SUBSPECIFIC MIGRATORY CONNECTIVITY OF DUNLIN ON THE EAST ASIAN-AUSTRALASIAN FLYWAY REVEALED BY BAND RESIGHTINGS
University of Colorado-Denver, Graduate
With Richard Lanctot (USFWS), Chung-Yu Chiang (Taiwan Wader Study Group), Yoshimitsu Shigeta (Yamashina Institute for Ornithology), Michael Wunder (CU-Denver)

Individual site fidelity to breeding, wintering and migratory staging sites occurs in many arctic-breeding shorebirds. While breeding site fidelity has been shown to aid an individual's annual productivity, winter and migratory site fidelity may be important to maximize over-winter survival. Here we use incidental resightings of Dunlin banded at several breeding sites throughout the Beringian arctic and observed wintering and migrating along the East Asian-Australasian flyway (EAAF) to document 1) the extent of nonbreeding site fidelity within individuals, and 2) the level of migratory connectivity occurring within three subspecies of Dunlin on the EAAF. We analyzed 664 resights, 394 which were identifiable to 134 distinct individuals. Of the 134 individuals, 34 showed interannual site fidelity during the nonbreeding period for up to 7 distinct nonbreeding seasons (August  -  May). These data confirm this species has an affinity for returning to specific sites on the EAAF. Identifying nonbreeding site fidelity as a behavior that potentially increases annual survival is particularly relevant as intertidal habitats along the EAAF are being destroyed at an alarming rate. Preserving a network of important wintering and migratory staging sites throughout the flyway is critical for supporting healthy populations of this migratory shorebird.   




Bryn Marah (10D)  
UNDERSTANDING AND PREDICTING CONSEQUENCES OF FIRES ACROSS COLORADO AND WYOMING AND TWO NATIONAL FORESTS
University of Wyoming, Graduate
With John Scasta (UW)

Wildland fire is a dynamic system that sparks considerable global interest. Regionally, Colorado and Wyoming are western states in the southern Rocky Mountains of the US that experience both prescribed and wild fires annually. Fire is an ecological and social feature of both states that varies across dominant vegetation types, environmental drivers, and social perspectives. Evidence suggests that future fire regimes may include more frequent and intense fires. Moreover, federal agencies are increasingly aware of the need to strategically allow fire to function while continuing to protect life and property. The Grand Mesa, Uncompahgre and Gunnison National Forest in Colorado and Medicine Bow-Routt National Forest in Colorado and Wyoming experienced several fires in the year of 2016 including the Kelso Fire (Colorado), Beaver Creek Fire (Colorado and Wyoming), and Broadway Fire (Wyoming). We plan to explore three different aspects surrounding these incidents: 1) vegetative responses to wildland fire, 2) invasive species response to wildland fire, and 3) Burned Area Reflectance Classification (BARC) map accuracies in beetle kill dominated areas. This study is underway in collaboration with the United States Forest Service, University of Wyoming, and Southern Rockies Fire Science Network. The immediate, post-fire results and implications of the project will be shared during the discussion.




David Markman (8C)  
THE SEARCH FOR AN ENVIRONMENTAL PLAGUE RESERVOIR: YERSINIA PESTIS SURVIVES AND REPLICATES IN PHAGOCYTIC AMOEBA FOR UP TO 48 HOURS POST-INFECTION
Colorado State University, Graduate
With Michael Antolin (CSU), Richard Bowen (CSU), William Wheat (CSU), Mary Jackson (CSU)

Plague ecology is importantly characterized by sporadic epizootics, followed by periods of cryptic dormancy in unknown reservoirs. Building evidence suggests environmentally ubiquitous amoeba act as "feral macrophages" and permissive hosts to a wealth of competent intracellular pathogens. We performed environmental genetic surveys and laboratory infection experiments to assess the reservoir potential of various amoeba species for enzootic Yersinia pestis. This study is the first to definitively demonstrate that Y. pestis is an amoeba-resistant microorganism. We observed that Y. pestis survives intracellularly within D. discoideum amoebae for at least 48h post-infection and that Y. pestis is transiently amoeba-resistant in four other cyst-forming amoeba species under study conditions. This study demonstrates significant replication of Y. pestis within amoeba structures that appear functionally synonymous with those found in infected macrophages. Our results also indicate that Y. pestis requires the pgm locus, which contains an assemblage of virulence genes, for maintaining intra-amoeba survival. The increasing body of evidence confirming amoeba associations with other cryptically persistent pathogens stresses the importance of recognizing pathogen-harboring amoebae as potential threats to global conservation, health, agriculture, and biodefense. 




Jami Mercer (7C)  
TEMPORAL TRENDS AND POTENTIAL EFFECTS OF MERCURY EXPOSURE IN FLORIDA PANTHERS (PUMA CONCOLOR CORYI)
Florida Gulf Coast University, Undergraduate
With Darren Rumbold (FGCU)

The Florida Panther (Puma concolor coryi) is an endangered sub-species of puma whose remaining population is estimated to be less than 200 individuals in South Florida. Plagued by physiological and anthropogenic mortality, the population is regularly exposed to environmental toxicants that might result in additional mortalities. Mercury toxicosis in mammals can occur at varying degrees of chronic and acute exposure. Effects can range from general weakness, sensory impairments and ataxia, to a decline in reproductive success, tremors and death. Following the death of a Florida Panther with very high levels of mercury in its liver, Florida Fish and Wildlife Conservation Commission began monitoring bioaccumulated mercury in the species throughout its range. Almost 2 million acres of Everglades contained excessive levels of mercury, and presently remains a contamination hotspot. Due to spatial and temporal changes in prey availability (e.g., deer versus raccoon), hydrology, and methylmercury entering the food web, panthers encounter variable amounts of mercury within their range. Results from this study suggest the Florida Panther remains exposed to mercury levels that exceed critical tissue benchmarks, therefore reducing contamination in prey might be essential for population restoration.




Lewis Messner (2C)  
VASCULAR BIOMASS PRODUCTION ON A RECLAIMED FEN
Colorado State University, Graduate
With David Cooper (CSU)

Peatlands comprise the majority of wetland habitat impacted by oil sands mining in northern Alberta, Canada.  The government of Alberta has mandated that wetlands disturbed by mining be reclaimed to preexisting conditions. This requires innovative methods for forming a vegetation cover in an experimental fen capable of recreating a peat accumulating ecosystem. My research focuses on quantifying the influence of vegetation planting treatments and salinity on vascular biomass production and competition interactions on a 2.9 ha reclaimed fen. This site was planted using five treatments and subdivided into four cover treatments. Juncus balticus and Carex aquatilis seedlings were planted and their above and below-ground biomass was quantified across all treatments. In 2015, total above and below-ground biomass production was not influenced by planting treatment or cover type. Carex aquatilis produced the most average above and below-ground biomass (C. aquatilis 328.40 ± 25.5, 521.00 ± 47.49 g m-2) across the fen, but matches Juncus balticus above-ground production (C. aquatilis: 564.43 ± 86.07 g m-2; J. balticus: 501.96 ± 74.82 g m-2) in plots where seedlings were planted. Below-ground production was similar between the two species in seedling and moss + seedling plots. Results from this research provide insights into future plant community development in post-mined reclaimed peatlands and the biomass produced on an annual time step that can support peat accumulation processes.




Clifton (Clif) McKee (8D)  
HOST PHYLOGENETIC DISTANCE AND ECTOPARASITE OVERLAP PREDICT BARTONELLA SHARING BETWEEN EUROPEAN BATS
Colorado State University, Graduate
With Aleksandra Krawczyk (RIVM), Michael Kosoy (CDC), Colleen Webb (CSU), Hein Sprong (RIVM)

Much research has focused on assessing the diversity of zoonotic infections in wildlife and the risks they pose to humans and domestic animals. However, there remain large gaps in our understanding of the structure and maintenance of bacterial species assemblages in their hosts, especially for vector-borne bacteria. Nested levels of dependence among bacteria, arthropod vectors, and vertebrate hosts may have measurable effects on the evolution and structure of bacterial species assemblages. We hypothesize that these dependent relationships between mammal hosts, ectoparasites, and bacteria can be resolved into communities linked by bacterial transmission. Furthermore, we expect that phylogenetic distance, ectoparasite sharing, and geographic range overlap among mammalian hosts are ecological predictors of bacterial species assemblages. Using 452 Bartonella sequences from bats and ectoparasites in nine European countries and a combination of network analysis, Bayesian phylogenetics, and linear modeling, we detected eight communities of bat, ectoparasite, and Bartonella species that mostly separate by bat families or subfamilies. Bat cross-species transmission of bartonellae was negatively correlated with bat phylogenetic distance and sharing of Bartonella species was strongly predicted by both phylogenetic distance and ectoparasite sharing among bat species. Finally, we found significant evidence of evolutionary codivergence among bat and Bartonella species. 




John (Grey) Monroe (4C)  
THE EVOLUTION OF A CRITICAL PLANT LIFE HISTORY TRAIT IS PREDICTED BY REMOTELY SENSED DROUGHT FREQUENCIES
Colorado State University, Graduate

A central goal of evolutionary biology is to identify the environmental factors that drive the evolution of ecologically important traits. Because plants display extraordinary diversity in life history strategies - from tiny Arabidopsis thaliana, which germinate as a seed and can complete reproduction in a matter of weeks, to bristlecone pines that live for thousands of years  -  identifying the factors that drive the evolutionary transition between these strategies is critical for understanding plant evolution. Here we investigated the evolution of two alternative life history strategies, comparing annual vs. perennial species belonging to a genus of flowering plants native to South Africa, Heliophila.  Because annual plants can escape droughts by completing their life cycle before the onset of drought, we predicted that annual species would come from environments where the historic frequency of drought would be greater.  We calculated the historic frequency of drought across the native range of Heliophila during different seasons using the remotely sensed Vegetative Health Index. We then used Heliophila herbaria records to determine the historic frequency of drought for different species. We found that even when controlling for phylogeny, annual species do come from environments where the historic frequency of drought is significantly greater. These results provide novel insight into plant evolution, suggesting that historic drought frequency is an important driver of life history strategies.  




Michelle Moyer (6B)  
EFFECT OF SALINITY ON POECILIA PICTA MATE CHOICE
Colorado State University, Undergraduate
With Cameron Ghalambor (CSU), Craig Marshall (CSU)

Range limitations can affect where species persist within an environment and can be affected by a variety of factors, including mate choice. Mate choice studies are vital to determine the mechanisms and patterns of population evolution and dispersal. If populations become isolated, genetic divergence can eventually lead to speciation. Poecilia picta, or the swamp guppy, is found on the island of Trinidad in both brackish and freshwater environments. Assuming each population is locally adapted to their respective salinities, reinforcement could lead to reproductive isolation if hybrids between the two populations have decreased fitness in either salinity. In this current study, we sought out to determine if brackish and freshwater male P. picta are visually different, and if females from each population displayed a preference for males from the same salinity of origin. Morphological and color data was collected on each male, while females were exposed to males from each population and their preference assessed by which male they spent the most time with. Though brackish males were found to have more intense caudal coloration, females from either population displayed no significant preference for a specific male population. These findings could be due to the allopatric nature of the study species and suggests that the selection pressures against hybridization may not have formed in these populations.




Ryan Parker (5C)  
PREDATOR-PREY INTERACTIONS BETWEEN MOUNTAIN PLOVER, BURROWING OWL, AND SWIFT FOX ON PRAIRIE DOG COLONIES ON THUNDER BASIN AND PAWNEE NATIONAL GRASSLANDS
University of Colorado-Denver, Graduate
With Tyler Michels (CU Denver), Allison Pierce (CU-Denver), Courtney Duchardt (UW), Angela Dwyer (Bird Conservancy of the Rockies) Michael Wunder (CU Denver)

Mountain Plover (Charadrius montanus), Burrowing Owl (Athene cunicularia), and Swift Fox (Vulpes velox) are species of conservation concern that rely on short-grass prairie disturbances for breeding habitat and prey requirements. Literature provides support for their individual dependence on this ecosystem; however, interactions between the species remains unclear. We examine a case where predator-prey dynamics offer an insight into multi-species interactions on a grazed landscape. Survey data was collected by the Forest Service over a 7-year span (2010-2016) on Thunder Basin National Grassland (TBNG) in Wyoming and a 27-year span (1990-2016) on Pawnee National Grassland (PNG) in Colorado. After overlaying the data from each, a pattern emerges between plovers, owls, and foxes at the population level. Plovers and foxes remain common and owls sparse on TBNG, whereas plovers and foxes are sparse and owls common on PNG. We hypothesize that there is a correlation at the population level for the three species in this potential predator-prey relationship. For example, a positive correlation may occur when plover numbers increase because fox numbers will also increase. This sets the stage for a proposed multi-species occupancy model combining detection/non-detection data from plovers, owls, and foxes, using a subset of black-tailed prairie dog (Cynomys ludovicianus) colonies on TBNG and PNG as our sample frame. Continued research aims to offer multi-species management recommendations important for land-management agencies, and provide opportunities for further research on prairie ecosystems at the species-interaction level.  




Stephanie Pitt (6C)  
TESTING THE FUNCTION OF SONG REPERTOIRE SIZE IN ROCK WRENS, SALPINCTES OBSOLETUS
University of Northern Colorado, Graduate

Complex communication systems like human languages are thought to have arisen after selection for signal variability, which is an important precursor for functional flexibility. Birdsong is a well-studied highly variable communication system, and song repertoire size as a measure of complexity is often studied in regards to the selective pressures driving its evolution. Often it is evaluated in terms of female choice, but male-male competition may also select for large song repertoires. By using field observations of color banded birds and field playback experiments in the Rock Wren, Salpinctes obsoletus, my research examines whether large song repertoires confer benefits to males in mate acquisition and/or territory defense. During my first field season in 2016, I successfully completed playback experiments to 12 pairs of Rock Wrens and verified the feasibility of all of my field methods, including using motion-activated cameras to learn more about the little known nesting ecology of this species. I gathered breeding success data for eight of those pairs, which are currently being analyzed for significance, along with playback response data. Results will help me assess the role of inter and intraspecific sexual selection on song repertoire size in this species, and could inform how complex communication systems evolve in general.




Abbie Reade (6D)  
INTER-INDIVIDUAL VARIATION IN NUTRITIONAL REQUIREMENT INFLUENCES FOOD SHARING AND SOCIALITY IN THE HONEYBEE (APIS MELLIFERA)
Colorado State University, Graduate
With Dhruba Naug (CSU)

Obtaining adequate nutrition is a fundamental contributor to fitness in all animals. In a social group, individuals differing in their own nutritional needs may contribute unequally to the nutritional resources acquired by the group, thereby setting up a potential conflict between individual and group level fitness. Using the honeybee colony as a model, we investigated this question by measuring the energetic requirement of different individuals and the amount of food they share with the colony. Our results elucidate the role of nutritional constraints in group living and how these may have contributed to the evolution of eusocial behavior.




Andrew Reed (7D)  
COMPARATIVE GASTROINTESTINAL MICROBIOMES OF SCIURUS ABERTI AND S. NIGER
University of Colorado, Colorado Springs, Graduate
With Jeremy Bono, Meghan Lybecker, Helen Pigage, Jon Pigage

We compared the gastrointestinal microbiomes of Abert's squirrels (Sciurus aberti) and Eastern fox squirrels (S. niger) to evaluate interspecific and intraspecific microbial community composition.  We hypothesized that the dietary and gastrointestinal morphological differences between the two species of tree squirrels would result in uniquely different communities and abundance of gut bacteria.  Abert's squirrels exhibit a specialized diet consisting predominately of ponderosa pine (Pinus ponderosa) structures.  Fox squirrels exhibit a generalist diet.  Abert's squirrels have a gastrointestinal tract that is longer and composed of more surface area than fox squirrels.  Four females of each species were collected (n=8) from a mixed conifer forest at the United States Air Force Academy, Colorado Springs.  We collected tissue samples from the stomach, small intestine, cecum, and large intestine, in addition to a fecal sample.  Bacterial DNA was isolated and the V4 region of the 16s rRNA was used for sequence alignment.  Operational taxonomic units (OTUs) were assigned using the workflow provided by QIIME.  Results show a divergence in the bacterial species present along the gastrointestinal tract, with differences becoming more pronounced towards the cecum, large intestine, and fecal samples. 




Ian Sexton (2D)  
PILE BURN SCAR RESTORATION IN ROCKY MOUNTAIN NATIONAL PARK
Colorado State University, Graduate
With Cynthia Brown (CSU), Lindsay Ringer (NPS)

Invasive species threaten the natural resources national parks strive to preserve. Disturbance caused by common management practices on public lands can promote invasion of non-native plants. Foresters reduce hazardous fuels and manage forest structure by piling the woody material and burning it during the winter. This practice can destroy native plants and seeds and cause other changes under burn piles that favor invasive, non-native plants. Restoration has been suggested as a means to mitigate these impacts. The effect of restoring burn pile scars was studied at Lily Lake near Estes Park, CO. While preliminary results showed that restoration increased the cover of native graminoids (grasses and grass-like plants) (p = 0.003) and native shrubs (p = 0.002), we were unable to detect a significant effect of restoration on non-native graminoids (p = 0.91) or non-native forbs (p = 0.152). Non-native graminoid cover was very low for all plots and likely indicates low invasion pressure. Non-native forb cover tended to be lower near the edge of scars, but high variation in control plots and the small number of samples make it difficult to detect this effect statistically. Restoration is likely still an important part of integrated pest management in pile burn scars. Coupling the benefits of increased native plant cover through restoration with other treatments such as herbicide application, will enable managers to achieve greater success than reliance on a single means of control.




Cara Smith (4D)  
EXPRESSION OF DIVERGENT VENOM PHENOTYPES: USING VENOM PROFILES TO EVALUATE POTENTIAL RATTLESNAKE  HYBRIDS IN WESTERN COLORADO
University of Northern Colorado, Graduate
With Stephen Mackessy (UNCO), Joshua Parker (Fresno City College)

In western Colorado, populations of Crotalus oreganus concolor (Midget Faded Rattlesnake) contact the known distribution of Crotalus viridis viridis (Prairie Rattlesnake). Though not yet documented, interbreeding between these species may lead to novel venom phenotypes.  Crotalus v. viridis venom is known as a type I venom because it induces hemorrhage and myonecrosis, partially due to the abundance of snake venom metalloproteases (SVMPs). In contrast, venom from C. o. concolor, a type II venom, has low SVMP activity but exhibits potent toxicity due to concolor toxin, a neurotoxin based on a phospholipase A₂ scaffold. This study aims to distinguish hybrids of C. v. viridis and C. o. concolor using a venom profiling approach, where potential hybrid venoms are tested for characteristics that are distinct for each parent species. The snake venoms that displayed moderate to high metalloprotease activity in conjunction with concolor toxin provided the most striking evidence of hybridization in these zones, as several of these venoms contain both type I (degradative) and type II (neurotoxic) characteristics.  In addition, the majority of snakes that displayed a hybridized venom profile had mitochondrial sequences corresponding to a C. o. concolor matrilineage, indicating the possibility of unidirectional hybridization between a female C. o. concolor and a male C. v. viridis with potential backcrossing of subsequent generations. Venom compositional and genetic analyses of rattlesnakes found in this area of range overlap can provide initial clues about rattlesnake hybridization in western Colorado and contribute to the understanding of venom gene inheritance and expression.




Jared Stewart (11B)  
ACCLIMATION OF PHOTOSYNTHESIS AND MINOR VEINS IN ARABIDOPSIS THALIANA
University of Colorado - Boulder, Graduate
With William W. Adams III (CU), Barbara Demmig-Adams (CU)

Advances in understanding the link between sugar production and distribution in plants may contribute to meeting the increasing demand for plant-based food and materials.  The numbers, sizes, and ultrastructure of phloem cells in foliar minor veins, responsible for the loading and subsequent export of sugars out of the leaves to the rest of the plant, have recently been identified by our group as strong predictors of leaf photosynthetic capacity.  To follow up on these findings, we investigated ecotypic variation in phenotypic plasticity of photosynthesis and foliar minor veins in the model organism Arabidopsis thaliana by growing plants under contrasting light intensities and temperatures.  In this presentation, light acclimation and temperature acclimation will first be compared and contrasted in the widely studied Col-0 ecotype, and subsequently compared in locally adapted ecotypes originating from sites near the northern and southern extremes of its native European range.  The differences among ecotypes in acclimatory responses of photosynthesis, leaf thickness, and phloem features are consistent with temperature patterns of the location from which the ecotypes originated, whereas ecotypic responses of transpiration, vein density, and xylem features reflect native precipitation patterns.  Collectively, our findings further support the hypothesized structure-function relationship between the vascular system and photosynthesis.




Thomas Timberlake (3E)  
IMPROVING THE SCIENCE-MANAGEMENT INTERFACE: KEY COMPONENTS OF CLIMATE CHANGE VULNERABILITY ASSESSMENTS
Colorado State University, Graduate
With Courtney Schultz CSU)

The uncertainty and complexity inherent in projecting future climate change and associated ecological responses has necessitated increased coordination between ecologists, climate scientists, and land managers. In the U.S. Forest Service, researchers and managers have begun to convene science-management partnerships in order to join managerial expertise and high-quality science to inform on-the-ground climate change adaptation activities. These partnerships are developing vulnerability assessments to analyze and summarize scientific information on the expected impacts of and resources' vulnerabilities to climate change. Despite the existence of a wide range of vulnerability assessments across different settings, there remains a need to improve the ability of scientific research to inform management actions that seek to create systems resilient to climate change. We are in the process of conducting a systematic analysis of the first generation of Forest Service vulnerability assessments. To inform the analysis, we conducted interviews with nine scientists with expertise conducting vulnerability assessments. This presentation will report on findings from these interviews pertaining to key components of vulnerability assessments. This research seeks to benefit both land managers and scientists by improving the delivery of scientific information that is salient at a local scale, actionable, and robust.




Christa Torrens (1D)  
TEMPORAL SIGNATURES OF HYPORHEIC EXCHANGE AND STREAM METABOLISM IN GLACIAL MELTWATER STREAMS, ANTARCTICA
Colorado State University, Graduate
With Michael Gooseff (CU Boulder/ INSTAAR)

Streams in the McMurdo Dry Valleys, Antarctica flow 4-12 weeks per year and are fed only by glacial melt. Algal mats provide most of the primary production; there are no vascular plants. Extensive hyporheic zones host heterotrophic respiration. During the austral summer, there is continuous daylight and potentially continuous photosynthesis.   To determine temporal patterns of hyporheic exchange and stream metabolism in this system, we measured specific electrical conductance [EC], instream dissolved oxygen [DO] and discharge on a long (Von Guerard) and a short stream (Green).  EC is a proxy for hyporheic exchange; glacial meltwater is dilute, and rapid weathering in the hyporheic zone increases EC. DO is a proxy for instream metabolic processes. We expected DO to follow diel irradiation patterns, decreasing at "night" when the solar aspect is relatively low. We also expected DO and EC to be negatively correlated, as hyporheic exchange adds both dissolved solutes and less-oxygenated water to the stream. However, we found that DO remained high regardless of solar aspect or EC fluxes, indicating consistently high primary productivity and relatively low levels of respiration.  Green Creek had consistently higher DO than Von Guerard Stream. This may be due to greater algal mat coverage in Green Creek, increasing Green's total productivity; or greater hyporheic exchange in the longer Von Guerard Stream, increasing the impact of hyporheic respiration.




Scott Yanco (5D)  
SCALE-DEPENDENT HABITAT SELECTION BY A SENSITIVE FOREST RAPTOR FOLLOWING WILDFIRE
University of Colorado-Denver, Undergraduate
With Brian Linkhart (Colorado College)

Many western ecosystems undergo regular disturbance in the form of wildfire. However, the adaptive responses of the faunal inhabitants of these ecosystems to disturbances such as fire is poorly understood. As landscape-scale processes such as management practices and global warming increase the frequency, severity, and extent of fires, it is critical to understand faunal responses. We sought to determine how the 2002 Hayman Fire affected habitat selection by one such faunal inhabitant of fire-prone ecosystems: the Flammulated Owl (Psiloscops flammeolus). We examined the species' habitat selection at multiple spatial scales. Males (n=5) established breeding home-ranges in areas containing significantly more low-severity burn, and less high-severity burn, than was present across the entire burn scar. Home-ranges of males had a mean size of 13.1 ± 3.2 ha, which was similar to that reported by Linkhart et al. (1998) in a nearby, unburned forest. Burn severity did not appear to be an important factor for selection of any of the micro-sites associated with foraging or day-roosting behaviors. Our results indicated that habitat selection patterns were altered by the fire only at the scale of the home-range, while at the micro-site scale, habitat selection mimicked patterns observed in unburned forests. These data suggested a certain level of inflexibility in habitat selection such that following fire owls settle only where post-burn landscapes resemble unburned forest.


 

 


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Poster Presentations:

Abstracts listed alphabetically by author
Numbers refer to poster order as shown in schedule

Poster Presentation Abstracts
(Number refers to poster order in schedule above)




Bethany Avera
IMPLICATION OF SALVAGE LOGGING ON SOIL ORGANIC MATTER PHYSIO-CHEMICAL PROTECTION IN BARK BEETLE INFESTED LODGEPOLE PINE FORESTS
Colorado State University, Graduate
with Rhoades, Charles (3USDA Forest Service, Rocky Mountain Research Station, Fort Collins, CO), Cotrufo, M. Francesca (Soil and Crop Sciences, Colorado State)

Mountain pine beetle (Dendroctonus ponderosae Hopkins; MPB) outbreaks have affected over 7 million hectares of lodgepole pine (Pinus contorta) dominant forests in western North America with high overstory mortality. The outbreak occurred from the early-2000's to a peak in 2006-2009 and in response to the mortality salvage logging increased. Consequences of salvage logging and logging residue (i.e., biomass) management practices on soil organic matter (SOM) protection and soil carbon (C) and nitrogen (N) stocks, as well as short- and long-term productivity are not known. At 12 sites in Northern Colorado we compared untreated bark beetle-infested forest and similar, adjacent salvage logged stands that received either woody residue retention or removal. Using a physical fractionation approach - density and size - we quantified the size of the light (<1.85 g cm-3), particulate (> 53 μm), and mineral-associated (< 53 μm) soil organic matter (OM) fractions and the total soil C and N in each management treatment. Six years after harvesting there are significant differences in tree species composition and seedling growth between management treatments. We anticipated the distribution of C and N amongst the SOM fractions would differ with quality and quantity of residue inputs, helping to elucidate the linkages between woody biomass retention or woody biomass removal on ecosystem productivity and SOM stocks in MPB-killed forests.

Melissa Booher
THE ROLE OF CAREX SCOPULORUM IN RESTORING CARBON SEQUESTRATION DYNAMICS IN THE DEGRADED TUOLUMNE MEADOWS, YOSEMITE NATIONAL PARK
Colorado State University, Graduate with Lydia Baldwin (Colorado State University), David J. Cooper (Colorado State University), Evan Wolf (University of California, Davis)

Wetlands provide outsized ecological benefits compared to their abundance on the landscape by creating biodiversity hotspots of habitat for threatened and endemic species, storing and filtering water, and sequestering carbon. In Yosemite National Park, only 3% of the land area is covered by wetlands and many are severely degraded. Significant losses of plant cover have been attributed to late 19th century sheep grazing. These legacy effects continue to have a major impact on wetland functions of production and sequestration. Recent studies in the degraded Tuolumne Meadows wetland demonstrated that restoring plant cover has potential to increase biomass production and reverse soil carbon loss. To further evaluate these effects, we are testing if planting Carex scopulorum can restore the carbon storage function of this meadow. Not only is this species native and highly productive, it is also predicted to re-establish wetland function by building organic soils, reducing erosion, and providing habitat for the Yosemite Toad, a threatened species indigenous to the Sierra Nevada. Our research will examine the effects of restoration by measuring C. scopulorum seedling survival, tiller spread and growth, above and below-ground biomass production rates, and net carbon fixation by photosynthesis. Understanding how C. scopulorum contributes to the recovery of this meadow will help land managers effectively restore similarly degraded areas throughout the Park and greater Sierra Nevada.


Dale Broder
TO HIDE OR NOT TO HIDE: DOMESTIC AND WILD GUPPY MICROHABITAT PREFERENCES
Bella Romero Academy, High School with 2021 Science Club (Bella Romero Academy), Katie Guilbert (Bella Romero Academy), E. Dale Broder (University of Denver)

All animals need to find food, reproduce, and avoid predation. They may have preferences for specific habitats that allow them to do this. Based on the environments in which animals evolve and their individual experiences, they may have preferences for where they live. Guppies are small, colorful, freshwater fish that live in streams in Trinidad and Tobago. These streams differ in predator communities, amount of shade and plant cover, and many other characteristics. Guppies have also been domesticated in an unnatural environment, and these guppies have not experienced predators in their lifetime. Do native and domestic guppies have different preferences for microhabitats, specifically plants/open water and light/shade? We expected wild guppies to prefer plant cover and shade because these environments protect them from predators. We expected domestic guppies to prefer the opposite (open water and light) because they have been domesticated in well-lit, open tanks away from a natural environment. By measuring the proportion of time individual guppies spent on different sides of an experimental tank, we measured preferences for open water versus plants and light versus shade. We did not detect a strong preference for plants or open water for wild or domestic guppies. Wild and domestic guppies had different preferences for light versus shady environments. Future work should measure microhabitat preferences in the presence of a predator.


Julie Bushey
IS IT PLASTIC OR JUST FANTASTIC? UNDERSTANDING THE LINK BETWEEN LOCAL ADAPTATION AND DROUGHT RESPONSE IN BOUTELOUA GRACILIS
Colorado State University, Graduate
with Troy W. Ocheltree (CSU), Melinda D. Smith (CSU)

Droughts are expected to intensify in coming years with changing climate. It is imperative that ecologically and economically important native rangeland grasses, such as blue grama (Bouteloua gracilis) of the shortgrass steppe, be investigated for their phenotypic diversity across populations. We selected ten populations where blue grama was a dominant species across a precipitation and elevation gradient in Boulder County, Colorado, plus five sites along a larger north-south gradient. From each population, clones were transplanted to controlled greenhouse conditions. When water limitation was removed, we observed extensive plasticity compared to field phenotype in all populations. However we observed that southern populations exhibited higher growth rates compared to northern and Boulder populations. We also considered differences in drought response strategy (hydroscape), where we found populations to differ in terms of anisohydric (passive) versus isohydric (active) water budgeting strategies. Finally, we observed differences in fitness (flower mass and length) across populations and clones, suggesting potential tradeoff between clonal and sexual reproduction is specific to population or individual clones and not necessarily responsive to water availability. Elucidation of phenotypic diversity along with research highlighting genetic diversity across different populations of blue grama may inform management and restoration practices in the shortgrass steppe ecoregion.


Caleb Cofsky
ABRUPT TREELINE MICROCLIMATE: FROM TURBULENT STRUCTURES TO SEEDLING RECRUITMENT
Colorado College, Undergraduate
with Lani Chang (Colorado College Student) Misha Kummel (Palmer HIgh School Student)

Treelines are climatically constrained ecosystem boundaries and therefore should move in response to climate-change. However, abrupt treelines are not sensitive to a warming climate, likely a result of microclimatic feedbacks. The airflow regime at our field site on Pike's Peak is characterized by a nighttime downward airflow, and a daytime cross-slope airflow (parallel or skewed to the treeline). At night, the abrupt treeline dams the cold downward airflow, creating a cold pocket right above treeline. During the day, the effects of the treeline depend on the wind direction. In parallel flow, there is no detectable stationary turbulent structure. The air slows down close to the trees and creates a warm pocket of air directly above treeline. In askew flow, there are complex stationary turbulent structures that create a sheltered zone. At night, ground temperatures in the tundra above treeline are cold. Moving downslope toward treeline, ground temperatures decrease dramatically as a result of the damming of cold air. Within the treeline, temperatures are surprisingly warm. During the day, this temperature regime is reversed, with the coldest temperatures in the treeline and the warmest temperatures upslope of treeline, but the tundra is still cold. A chi-square analysis shows that seedlings preferentially recruit into the areas where it is warmest during the day. Surprisingly the dead seedlings are mostly found within the lower edge of the warmest zone.


Erin Cubley
RIPARIAN COMPOSITION AND GUILD STRUCTURE IN SOUTHWEST COLORADO
Colorado State University, Graduate

Riparian areas throughout the western U.S. are threatened by a variety of factors including dams, diversions, groundwater pumping, and climate change that alter streamflow and ultimately, riparian vegetation and the provisioning of ecosystem functions and services. Studies to assess the ecological water needs of riparian vegetation are often time consuming and costly, and the use of flow response guilds has emerged to predict vegetation response to changes in the flow regime. Vegetation data was collected from five sites along the Dolores and San Miguel River in Southwestern Colorado. Our objectives were to assess differences in overall composition and environmental variables among sites, , and test whether species divided into distinct guilds based on traits related to water availability. We found that riparian vegetation composition differed across all five sites, driven mainly by differences in average annual precipitation, level of flow regulation, mean June discharge, June depth to groundwater, percent cover of wood, gravel, sand/soil, litter, and vegetation structure. Woody and herbaceous species separated into 10 distinct guilds based on trait data. Future analyses will determine the relative abundance of these guilds at each site and model how changes in flow will affect guild structure and riparian vegetation composition.


Carolyn Cummins
BIG BILLS, BABY TRILLS: INVESTIGATING THE EFFECT OF BILL SIZE ON FREQUENCY BANDWIDTH IN AN INSULAR SPECIES
Colorado State University, Undergraduate
with Maybellene Gamboa, Cameron Ghalambor

Environmental heterogeneity may cause divergent selection across populations leading to adaptive phenotypic variation. However, evolution by natural selection may be constrained by sexual selection if the phenotype of interest is involved in both mate acquisition and adaptation to the environment. Previous work suggests that divergent selection acts on bill size in Channel Islands song sparrows with relation to climate; birds in hotter regions have larger bills presumably for heat dissipation. However, the role of sexual selection on bill size in this system remains unexplored despite the tight link between bill size and vocal performance, or mate acquisition. Here, I assess the potential role of sexual selection by comparing bill size and trill frequency bandwidth (vocal performance) across nine male song sparrows on Santa Cruz and Santa Rosa Islands. As predicted, I found that birds on Santa Cruz Island (hotter island) trended toward larger bills and smaller frequency bandwidths than birds on Santa Rosa Island (cooler island). Although these differences were not significant, this suggests that sexual selection on trill rate may partially explain or reinforce bill divergence across island populations. Future work will increase sampling and assess repertoire size, another metric of assessing performance in passerines.


Katherine (Katie) Dirsmith
TRANSMISSION OF A LOW PATHOGENICITY AVIAN INFLUENZA VIRUS FROM MALLARDS (ANAS PLATYRHYNCHOS) TO HOUSE SPARROWS (PASSER DOMESTICUS)
Colorado State University, Graduate
with Jeremy Ellis (USDA National Wildlife Research Center), Kevin Bentler (USDA National Wildlife Research Center), Susan Shriner (USDA National Wildlife Research Center)

Influenza A viruses (IAVs) cause economic losses in the poultry industry. IAV bridge hosts, which can transport IAV from a reservoir population to a target population, may transmit viruses by contaminating poultry feed, water, or environment. House sparrows (Passer domesticus) have been identified as potential IAV bridge hosts and often reside in proximity to poultry operations. In this study, we are investigating the susceptibility of house sparrows to a low pathogenicity avian influenza virus (LPAIV) and the probability that house sparrows may become infected with LPAIV by exposure to a water source shared with infected mallards. In an initial experimental infection study, sparrows were inoculated orally with H4N6 LPAIV. Preliminary results indicate that approximately 75% of the sparrows shed virus and 88% of the sparrows developed IAV specific antibodies, which were detected as early as seven days post inoculation. For the transmission phase of our study, three mallards (Anas platyrhynchos) were placed in one of four pens with a shared water source and were inoculated with H4N6 LPAIV. Sparrows were housed in adjacent pens. As early as ten days post exposure, 52% of sparrows produced detectable antibodies. Shedding results are pending for all replicates of the transmission phase. This study exhibits successful transmission of LPAIV from mallards to sparrows by use of a shared water source and emphasizes the importance of investigating species-specific transmission dynamics.


Richard Evans
DOES THE EURYHALINE FISH SPECIES, POECILIA PICTA HAVE A SALINITY PREFERENCE FOR FRESH OR BRACKISH WATER?
Colorado State University, Undergraduate
with Porsche M. Robison (CSU), Craig A. Marshall (CSU), Cameron Ghalambor (CSU)

A fundamental question in biology is to investigate why species are found in some environments and not others given that a species is physiologically capable of tolerating environments beyond their realized niche. For both land-dwelling and aquatic organisms, the distribution of a species can be limited by both biotic and abiotic factors that they experience in their environment. In fish, salinity tolerance can be a driving factor shaping range limits for a particular species. The swamp guppy, Poecilia picta, is a euryhaline species that is capable of tolerating wide ranges of salinities. On the island of Trinidad this species is found in salinities ranging from fresh (0 ppt) to brackish water (32 ppt). Previous work suggests that populations in fresh and brackish water may be locally adapted. In this study, we attempt to determine if P. picta, exhibit a salinity preference given their site of origin. We used a Y-maze experimental apparatus to determine salinity preference for both fresh and brackish water fish using site-specific water from the Caroni River where they were captured. The Y-maze gave each fish the option of swimming towards its "home" salinity or their "away" salinity. If these fish are locally adapted to their current environment, then we expect them to choose their "home" salinity. However, if fish from both populations prefer the same salinity, these results may provide insight into the ancestral history of this species. We found when given a choice, P. picta prefer their "home" salinity, suggesting they may be locally adapted.


Ashley Foster
PEOPLE, WILDLIFE AND CONSERVATION IN SAMBURU COUNTY, KENYA
Colorado State University, Undergraduate

In East African drylands, including Kenya's Samburu County, pastoral livestock herders share the landscape and its resources with wildlife, presenting challenges for both people and wildlife. The purpose of this study is to 1) identify the benefits and burdens of wildlife for local Samburu communities, 2) determine how wildlife conservation rules and policies affect communities, across seasons, and 3) explore how the local people's and wildlife practitioners' views on wildlife and wildlife conservation differ from and are similar to each other. These questions are of interest because human-wildlife conflict is a major concern of wildlife conservation worldwide. In Kenya, conservation is an important contributor to the national economy, but it also contributes to conflicts at the local community level. Wildlife conservancies, community based efforts at natural resource conservation, have become major players in Kenya's drylands and are an important mechanism of bringing conservation to local communities. In Samburu County, conservancies work to protect wildlife and provide local people with increased income and security. Interviews were conducted with 14 Samburu men and three Samburu wildlife officials to explore the complex relationships. I expect to find evidence that most burdens of wildlife are experienced by Samburu communities in the dry season, a time of resource limitation. Many Samburu pastoralists expressed that they suffered several wildlife related losses, such as loss of human and livestock lives. These losses were, for most people, uncompensated, which presented hardship and is viewed as a cost of wildlife.


Emily Grabowsky
THE EFFECT OF HABITAT ON RATTLESNAKE VENOM COMPOSITION IN TWO LIZARD SPECIALIST SPECIES, CROTALUS PRICEI PRICEI (TWIN-SPOTTED RATTLESNAKE) AND SISTRURUS CATENATUS EDWARDSII (DESERT MASSASAUGA RATTLESNAKE)
University of Northern Colorado, Graduate
with Dr. Stephen Mackessy (University of Northern Colorado)

Environmental effects on rattlesnake venom composition are largely unknown, but may significantly shape the venom proteome. Crotalus pricei pricei and Sistrurus catenatus edwardsii are both dietary specialists, feeding on lizards and occupying a narrow niche in their respective habitats. C. p. pricei are a high elevation species restricted to rocky slopes on mountain tops in Arizona and Mexico, while S. c. edwardsii, which has similar natural history characteristics (diet, adult size), is only found in lower elevation shortgrass prairies in the southwestern United States. This project aims to provide a comprehensive analysis of C. p. pricei and S. c. edwardsii venom characteristics in order to examine predator-prey dynamics of these distantly related species with similar dietary demographics. To determine if prey immobilization techniques are influenced by habitat, venom toxin identities (shared or unique), fang morphology and habitat characteristics will be compared between S. c. edwardsii and C. p. pricei. Since these species share morphological and ecological features, but inhabit very different environments, venom composition analysis and prey toxicity studies will provide important insights into whether venom efficacy toward lizard prey is an apomorphic or plesiomorphic trait. Because both species are potentially threatened by habitat loss and climate change, a deeper understanding of venom ecophysiology may contribute to formulation of more relevant conservation plans.


Gabrielle (Gabby) Gurule-Small
EFFECTS OF ANTHROPOGENIC NOISE ON MATING BEHAVIOR AND FITNESS
University of Denver, Graduate
with Robin Tinghitella (PI)

Anthropogenic noise can have dramatic effects on organisms' physiology and behavior. Animals that signal acoustically may be especially affected. I am working to determine the effects of anthropogenic noise on signaling, mate location and choice, and investment in offspring, using Teleogryllus oceanicus as a model system. Male crickets use calling songs to locate females and courtship songs to entice females into mating. Noise may hinder either step in mating, lowering reproductive success. However, plasticity may buffer these effects. If crickets shift behavior in response to rearing environment (developmental plasticity) or immediate noise encountered (contextual plasticity) this could reduce negative fitness effects. I placed juvenile female crickets in one of three acoustic environments for rearing (masking noise that overlaps in frequency with the calling song, non-masking noise that does not, or silence) to test developmental plasticity. At adulthood, females undergo phonotaxis trials, also in one of the three treatments, to test more immediate effects on the mate search. Finally, after phonotaxis, females are assigned to mating trials in one of the noise conditions, and given two weeks to lay eggs. Experiments are ongoing. Preliminary data suggest females raised in noise (masking or not) may be less efficient mate searchers, and that experiencing masking noise during phonotaxis also reduces mate location efficiency.


Trent Hawkins
EFFECTS OF ANTHROPOGENIC NOISE FROM OIL AND GAS DEVELOPMENT ON BAT ACTIVITY IN THE PICEANCE BASIN
Colorado State University, Undergraduate
with Rachel Buxton (Post-doctoral Adviser)

The Piceance Basin of Colorado is one of the most productive natural-gas reserves in North America. Development and activity, however, have steadily declined since 2010 due to reduced global oil prices. Recent ecological studies show that the noise produced by oil and gas development negatively impacts wildlife that rely on acoustic communication to carry out life processes, but little is known about how animal communities recover after noise mitigation. Bats rely on acoustics to locate prey, attract mates, and avoid predators. To assess the potential effects of oil and gas development on bat activity and recovery after noise ceases, we deployed 18 ultrasonic recorders in the Piceance Basin. We used a space-for-time substitution, where recorders were placed near dormant well pads that varied in the amount of time since drilling activity ceased, at well pads still producing noise, and at control sites far from development. We addressed three questions: 1) does oil and gas infrastructure affect the distribution of bats in the Piceance Basin 2) does bat activity increase as time since drilling ceased increases, and 3) does noise from the remaining infrastructure have an effect on bat activity? Both the lingering effects of past drilling and the current effects of remaining infrastructure could have negative repercussions for bat populations in the Piceance Basin. Understanding these effects could guide the management of bats as oil and gas infrastructure continues to grow.


Edward Hill
INVESTIGATION OF SPECIES-SPECIFIC COMPETITION THROUGH A NEIGHBORHOOD COMPETITION INDEX MODEL IN A COLORADO SPRUCE-FIR FOREST
Colorado State University, Undergraduate
with Seth Ex (CSU), Wade Tinkham (CSU)

Understanding competitive interactions among commonly co-occurring tree species can facilitate more spatially-explicit silvicultural decisions that aim to incorporate structural complexity. While many previous studies have approached spruce-fir coexistence from demographic and life history perspectives, few have explicitly addressed species-specific competitive pressures and responses. This project is a case study that uses a neighborhood competition model to evaluate crown morphological responses to competitive pressures for two species. For this study, a stem map was created in a high-elevation Colorado forest stand dominated by subalpine fir and Engelmann spruce. Neighborhoods of a 2m radius were assessed around 201 qualifying "target trees." Neighborhood analysis examined height, distance, species, and density of individuals surrounding a target tree as an index, relative to target crown length. Results show that crown lengths varied from 50-100%, but analysis revealed no meaningful relationship to the competition index. Initial assessment of results suggests the study area lacks a level of density at which the effects of neighborhood competition pressures are observable as crown morphological responses, as reflected in the index. Further study might improve understanding of: the value of the neighborhood competition model as a suitable research or management tool in Colorado; and, dynamism of species-specific competitive interactions throughout stand development.


Sara Hines
HEALTH OF WOMEN AND FAMILIES IN SAMBURU, KENYA: CHIEF CONCERNS AND TREATMENTS
Colorado State University, Undergraduate
with Stacy Lynn (Natural Resource Ecology Laboratory)

This study examined chief health concerns and approaches to curing diseases of women and their families in Samburu County, Kenya. The research objectives involved: 1) identifying Samburu women's greatest health concerns and their perceived severity, frequency and fear incitement, 2) determining how women use modern medicine and local treatments, and 3) identifying access to and gaps in available health services. Local people in Samburu County, a semi-arid rural county in central Kenya, regularly face health challenges exacerbated by food insecurity, lack of clean water, seasonal factors, and sometimes stigmatization of disease. With a local female translator, fourteen focus groups, averaging eight individuals per group, were conducted with Samburu women across six villages. After identifying their most concerning health conditions, the women evaluated each condition's frequency, severity, fear incitement, demographic impact, seasonality, cause, and treatments. Some of the most prominent concerns were HIV/AIDS, diarrhea, flu, arthritis, malaria, and pneumonia. Women of all groups used both traditional and modern medicine to treat and cure diseases, collectively naming fifty-seven medicinal plants used in traditional treatments. However, even with a wealth of traditional medicinal knowledge, 70% of focus groups reported their community as generally unhealthy. This study's identification of Samburu's most severe, frequent, and concerning diseases can help Kenyan government workers and NGOs prioritize health services to best meet the needs of the local people of Samburu.


Alison Hogeboom
EFFECTS OF DIETARY PHYTOCHEMICAL SUPPLEMENTATION ON LONGEVITY IN HONEYBEES
Colorado State University, Graduate

Bee pollinators are vital for ecosystem function and human food security. Honeybees (Apis mellifera) are the most commonly used pollinator in agricultural systems, providing services valued above $626 million annually in the United States. While demand for pollination services increases, honeybee populations continue to decline at an annual rate of nearly 30%. Honeybee population losses can be attributed to a number of anthropogenic stressors, including nutritional deficiencies. The limited diversity of nutritional resources provided by large agricultural mono-cropping systems, and intensive commercial management practices may cause significant physiological stress. Honeybee diets are comprised of carbohydrates, proteins, and phytochemicals found in plant nectar and pollen. These phytochemicals are essential macronutrients that can promote bee health, and colony productivity. Here we examine the effects of dietary phytochemical supplementation on longevity in honeybee foragers. In laboratory assays, naturally occurring floral chemicals were fed ad-libitum at 25, 250 and 2500 ppm to honeybee foragers. Our findings indicate that caffeine supplementation at 250 ppm significantly increased longevity by 10.5 days (p-value = 0.001). We tested three additional phytochemicals, but these compounds did not significantly increase longevity. Our results can be used to promote colony health and productivity through dietary supplementation. Future research will examine the role of phytochemicals on pathogen tolerance in honeybees.


Phalen Kohlruss
BIRDS OF A FEATHER: THE EFFECTS OF CLIMATE VARIATION ON FEATHER MORPHOLOGY
Colorado State University, Undergraduate
with Maybellene P. Gamboa (CSU), Cameron K. Ghalambor (CSU)

Strong divergent selection and limited gene flow across varying environments may lead to unique population phenotypes. Archipelagos are unique evolutionary models to understand the role of divergent selection on phenotypic differences given the relative isolation of island populations. On the California Channel Islands, song sparrows (Melospiza melodia graminea) are found along a strong climate gradient and exhibit low dispersal across islands. Geographic isolation and divergent selection due to climate are linked to variation in bill size, a tool used to radiate heat. However, the bill represents only a small proportion of the body that can lose heat, and studies suggest plumage may buffer birds from experiencing climate variation. Here, we present preliminary results examining the relationship between climate and feather structure. Specifically, we looked at breast contour feathers from birds on islands representing different climates and compared characteristics of the plumulaceous section of feathers, the portion of the feather most closely associated with insulation ability. Contrary to our predictions, we did not find a significant difference in the proportion of the feather that was plumulaceous, but we did find evidence for greater barb density in the plumulaceous section in birds from colder islands. Higher barb density closer to the body provides better insulation, and this suggests selection due to climate differences may facilitate these population differences.


Holliday (Holly) Lafferty
MACROINVERTEBRATES IN SMALL MOUNTAIN STREAMS: WHO SURVIVES AND WHO THRIVES
Colorado State University, Graduate

Small streams often go overlooked in stream ecology but can play an important role in contributing to the biodiversity of macroinvertebrates. Headwater streams fall along a gradient of stream discharge, ranging from streams with widths of several meters to small streams with widths well under a meter. Streams found at the small extreme of this gradient contribute to the heterogeneity of the habitat available to macroinvertebrates by offering areas without fish and with low velocities, and they potentially provide valuable habitat to macroinvertebrates that are poor competitors in larger streams. However, these streams are also more prone to drying in late summer and fall, especially in areas dependent on stochastic rainfall rather than snowmelt. This study examines how macroinvertebrate communities differ in taxon richness and functional trait diversity along a stream-discharge and elevation gradient in the Poudre Canyon. With climate change predictions forecasting less snowfall and earlier snowmelt in many mountainous areas, it is more important than ever to understand the communities of these small streams because many more streams may soon decrease in size.


Whitley Lehto
PREDATOR-INDUCED PARENTAL EFFECTS ON FEMALE OFFSPRING MATE CHOICE
University of Denver, Graduate
with Robin M. Tinghitella (University of Denver)

Interactions between parents and offspring during development and beyond are affected by parents' experience with ecology. Through parental effects (non-genomic contributions to offspring phenotypes) information in the parents' environment may be indirectly passed to offspring. Parents exposed to predators during offspring development produce offspring with altered survival characteristics. However, the impact of predator-induced parental effects on offspring reproductive characteristics is largely unknown. We tested whether predator-induced parental effects impact female offspring mate choice using the threespine stickleback (Gasterosteus aculeatus). Because both parents make distinct and important contributions to offspring development, we also examined the influence of maternal and paternal effects separately and in combination. Laboratory crosses were made to produce offspring that varied in whether one, neither, or both of their parents were exposed to a predator model. Female offspring mate choice behavior was measured in mating trials using males that varied in their nuptial coloration and courtship behavior. We found evidence for predator-induced parental effects on female offspring mating behavior. Female offspring with one parent exposed to the predator model preferred duller, less active males, relaxing or reversing typical preferences for showy males, whereas when both parents were predator-exposed, female offspring exhibited typical preferences for showy males. This study is the first to demonstrate that predator-induced parental effects extend late in life to influence mating behavior, which may depend differently on the ecology each parent experiences.


Victoria Faith Leirheimer
QUANTITY AND QUALITY OF AVAILABLE MATES ALTERS MATE CHOICE BEHAVIOR BUT NOT FEMALE INVESTMENT IN THE PACIFIC FIELD CRICKET, TELEOGRYLLUS OCEANICUS
University of Denver, Graduate
with Robin Tinghitella (University of Denver)

An individual’s experience with conspecific signaling during development can lead to shifts in their mating signals and behavior later in life. It is unclear whether experience with sexual signals also alters receivers' fitness via changes in offspring investment. Male field crickets attract mates using a long distance calling song. To determine how developmental experience with calling song quality and quantity alters mate choice and fitness, we raised juvenile female Teleogryllus oceanicus in five acoustic environments. These environments mimicked two mate quantities (high/low) crossed with two mate qualities (high/low), and a silent control. At adulthood, we measured females' mating responses in phonotaxis trials. Following phonotaxis, females were offered opportunities to mate and lay eggs. We measured egg number and proportion hatching as components of fitness/reproductive investment. Verifying previous work, female crickets raised in silence approached a broadcast calling song nearly 45% faster than their counterparts reared hearing the high quantity/high quality combination. Females also adjusted other parts of phonotaxis behavior in response to quantity, but not quality of song. We found no evidence that females changed mating rates or investment in offspring. Our results show that female mating behavior is responsive to a lack of mating opportunities, but less so to variation in mate quality. Reproductive investment may be also less plastic than mating behavior.


Eva Horna Lowell
THE EFFECT OF CONSPECIFIC DENSITY ON HONEYBEE RECRUITMENT
University of Denver, Undergraduate
with Shannon Murphy, Julie Morris

An individual’s experience with conspecific signaling during development can lead to shifts in their mating signals and behavior later in life. It is unclear whether experience with sexual signals also alters receivers' fitness via changes in offspring investment. Male field crickets attract mates using a long distance calling song. To determine how developmental experience with calling song quality and quantity alters mate choice and fitness, we raised juvenile female Teleogryllus oceanicus in five acoustic environments. These environments mimicked two mate quantities (high/low) crossed with two mate qualities (high/low), and a silent control. At adulthood, we measured females' mating responses in phonotaxis trials. Following phonotaxis, females were offered opportunities to mate and lay eggs. We measured egg number and proportion hatching as components of fitness/reproductive investment. Verifying previous work, female crickets raised in silence approached a broadcast calling song nearly 45% faster than their counterparts reared hearing the high quantity/high quality combination. Females also adjusted other parts of phonotaxis behavior in response to quantity, but not quality of song. We found no evidence that females changed mating rates or investment in offspring. Our results show that female mating behavior is responsive to a lack of mating opportunities, but less so to variation in mate quality. Reproductive investment may be also less plastic than mating behavior.


Craig Marshall
THE EFFECTS OF SHORT- VERSUS LONG-TERM SALINITY ACCLIMATION ON RESTING METABOLIC RATE IN TRINIDADIAN SWAMP GUPPIES
Colorado State University, Graduate
with Cameron K. Ghalambor (CSU)

Salinity tolerance is a defining factor in shaping geographic range limits of many species. Nonetheless, the influence of salinity tolerance on patterns of dispersal and local adaptation are relatively understudied for most species. In aquatic environments, euryhaline species are capable of acclimating to a wide range of salinities; however, most species typically exhibit a preference for a particular salinity. For example, previous work in euryhaline teleosts indicates that crossing along a salinity gradient typically results in increased oxygen uptake, incurring an energetic cost for the organism. In Trinidad, swamp guppies, Poecilia picta, are typically found in adjacent fresh and saltwater habitats, but the degree to which these populations are locally adapted to different salinities is unknown. We investigated their physiological response (metabolism) to changes in salinity on different temporal scales as a means to determine whether the physiological response to variations in salinity is locally adaptive. To do so, we split wild-caught individuals from each population and laboratory acclimated them to fresh (0ppt) and saltwater (30ppt) over a 5-month period. By gradually acclimating wild P. picta to alternate salinities, we simulated slow movement along the salinity gradient. We then tested the effect of a rapid acclimation on a different subset of individuals through a fast-changing salinity titration to simulate conditions these fish might encounter during dispersal or flooding events. If the populations are locally adapted, we predict that elevations in metabolic rate will be higher when fish are exposed to their "away" salinity conditions in both treatments.


Alexander (Alex) Mauro
THE IMPACT OF COMPETITION AND SALINITY ON THE RANGE LIMITS OF TWO SYMPATRIC EURYHALINE FISH
Colorado State University, Graduate
with Julian Torres-Dowdall (University of Konstanz), Cameron K. Ghalambor (CSU)

A question in evolutionary biology is: why does natural selection not favor the evolution of greater environmental tolerance and the expansion of ranges. We begin to answer that question in the case of two sympatric euryhaline fish: Poecilia reticulata and Poecilia picta. Both P.reticulata and P.picta can persist in brackish and freshwater, yet P.reticulata behaviorally avoids brackish water and P.picta only occurs in freshwater near the salinity transition zone where the two species' ranges briefly overlap. Both species grow quicker in freshwater when food is scarce, suggesting that both prefer freshwater. To start to understand why P.picta does not further expand its range into freshwater zones and why P. reticulata does not expand its range into brackish water, we measured the effect of salinity and competition on the growth rate of the two species in their home and away environments and in the lab and in nature. Our results suggest that P. picta's range is limited by competition with P. reticulata whereas P. reticulata's range is limited by salinity. We further found that P. reticulata's competitive dominance is context dependent and only occurs in freshwater. Our results warrant future research on this apparent tradeoff between competition and physiological tolerance. Further, our results highlight why a broad, integrative approach incorporating both abiotic and biotic factors is needed to explain range limitations.


Paul McPhail
ECTOPARASITE POPULATIONS WITHIN NESTS OF CLIFF SWALLOWS (PETROCHELIDON PYRRHONOTA)
University of Northern Colorado, Undergraduate
with Lauryn Benedict, Nora Covy

Parasites act as ecosystem engineers by affecting predator prey dynamics, altering energy budgets and nutrient cycling, and influencing biodiversity. My research aims to compare abiotic and biotic factors that may influence these vital members of the community. To do this, I analyzed the arthropod populations that were present within Cliff Swallow nests, with a focus on parasitic swallow bugs (Oeciacus vicarius). Seventy-four nests were collected from colonies that differed in factors including size, substrate of the colony, and last date of nest use. Arthropod specimens were extracted, counted, and measured. Correlations between parasite population variables and the nest colony variables were detected using statistical analyses. We found that the population of O. vicarius is positively correlated with the size of the host colony, being in an urban colony, and having other arthropods present. There is no significant difference between O. vicarius populations in the spring and winter. The length and width of the swallow bugs are currently being measured, and these will enable an estimation of biomass, which will be compared with the nest colony variables in a future analysis. This study is the first to look at Cliff Swallow nests in Larimer county, and adds to what little is known about their parasites.


Scott Morton
VARIATION IN BEHAVIOR AND PHYSIOLOGY OF AQUATIC MACROINVERTEBRATES IN RESPONSE TO PREDATION AND TEMPERATURE: IMPLICATIONS FOR TROPHIC CASCADES
Colorado State University, Graduate

Trophic cascades - the indirect effects of carnivores on plants mediated by herbivores, are a central idea of ecology. In streams, algae are consumed by macroinvertebrate grazers, some of which are vulnerable to predation. Stonefly predators have been documented to influence the distribution and abundance of benthic invertebrates and indirectly affect algal production by modifying grazer behavior. Density mediated interactions (DMI) occur when community composition is influenced by changes in herbivore population density due to consumption by predators. When behavioral changes, such as anti-predatory behavior lead to fluctuations in prey density, behavioral or trait-mediated interaction (TMI) become important. It is the combination of both TMI and DMI that are involved in mediating macroinvertebrate communities in streams. Temperature directly affects macroinvertebrate metabolism, altering their physiology. Temperature thus creates a context-dependent gradient upon which species interactions occur. Using artificial stream mesocosms the effect of a macroinvertebrate community on algal composition was examined across a thermal gradient. Variation in algal consumption increased with temperature. As the earth's surface continues to warm the trophic dynamics of ectotherms will change. In this study we show the mechanisms controlling trophic cascades can be altered under a simulated climate and increases in variation yield difficulties for future predictions.


Patricia Nease
NATURAL PERIPHYTON UPTAKE OF SELENIUM IN GUNNISON RIVER WHOLE WATERS
Colorado State University, Undergraduate
with Travis Schmidt (USGS), William Clements (CSU)

Selenium is both an essential element and a toxicant. In aquatic food chains selenium is accumulated from the water column into particulates or algae, and continues to bioaccumulate up the food chain. Between the aqueous phase and algae/particulates selenium concentrations can increase by a factor of 1000x; however, concentrations rarely increase in other linkages by more than a factor of 3. Thus, selenium bioavailability in ecosystems depends on enrichment to algae/particulates. The Gunnison River is a turbid environment with a watershed larger than 20,000km2. To quantify the rate at which selenium is accumulated into Gunnison River food webs, natural periphyton mats were exposed to four Gunnison River whole waters differing in selenium concentration. The site with background concentrations of selenium was used as a natural control. The concentrations of dissolved selenium and algal/particulate selenium were measured over a 48-hour time interval in each treatment. Algae in all three treatments reached a plateau at a similar selenium concentration within 48 hours, despite a gradient of aqueous concentrations between 1.45 and 2.85 µg/L. Thus, enrichment factors ranged from 0.81 to 1.84. This suggests that selenium within the Gunnison River is extremely bioavailable to the base of the food web, and is taken up rapidly. Suspended sediment in the treatment waters was related to dissolved and algal selenium concentrations, however the mechanisms of these relationships are unknown.


Erica Patterson
THE NATURAL VALUE RESOURCE CENTER: AN ECOSYSTEM SERVICES DATA INTEGRATION AND DISTRIBUTION FRAMEWORK FOR THE DEPARTMENT OF THE INTERIOR
Colorado State University, Graduate
with Chris Huber (USGS), James Meldrum (USGS), Rudy Schuster (USGS), Megan Eberhardt-Frank (Cherokee Nation Technology), Thomas Miller (Cherokee Nation Technology), Tim Kern (USGS), Gail Montgomery (USGS), John Long (USGS), and Brian Quay (CDC)

The Natural Value Resource Center (NVRC) demonstrates the implementation of an ecosystem services approach across the bureaus of the Department of the Interior (DOI). This is intended to improve the efficiency of natural resource management in two ways: 1) helping understand tradeoffs associated with land management decisions; and 2) foster interagency engagement, thereby facilitating transfer of expertise across bureaus. The NVRC is supported by the U.S. Geological Survey's (USGS) Sustaining Environmental Capital Initiative (SECI), which has the mission of showcasing the best-available scientific resources for understanding, valuing, and communicating ecosystem services production and tradeoffs. The SECI builds on USGS expertise in natural and social sciences, and consists of a portfolio of on-going applied research projects that demonstrate and advance best practices. The NVRC showcases the USGS SECI research portfolio, and provides resources intended to help other practitioners incorporate ecosystem services in their decision making. In particular, the NVRC search capabilities are intended to improve the efficiency of internet searches for ecosystem services websites, data repositories, and online documents by pulling results from a curated set of sources. The NVRC is a living resource intended to grow with the state of the science of ecosystem services. The poster will showcase key components of the NVRC and can help point conference attendees to this valuable resource.


David Schutt
A COMPARISON OF MERCURY CONCENTRATIONS IN GENTOO PENGUINS (PYGOSCELIS PAPUA) ACROSS A WIDE LATITUDINAL RANGE
University of Colorado-Denver, Graduate

Anthropogenic pollution has been detected in remote regions of the planet for several decades. Mercury in particular, a byproduct of fossil fuel combustion and various industrial processes, has been shown to have deleterious effects on wildlife and humans alike. As a potent neurotoxin causing a range of impairments such as reproductive insufficiencies, immune compromise and endocrine disruption, mercury bioaccumulates through the food web and can ultimately be found in human populations that consume fish. Penguins, as mesopredators localized to the Antarctic and sub-Antarctic region, serve as suitable biomonitors of mercury loads reaching this isolated system from global burdens. For my study, I am investigating mercury concentrations in Gentoo penguins along a latitudinal gradient from the Falkland Islands at approximately 51º S latitude to the farthest southern extent of the species' range on the Antarctic peninsula at approximately 66º S latitude. The aim of this study is to 1) Specify the spatial gradient of bioavailable mercury in this system and 2) To explore the mechanisms that generate disparities in mercury bioavailability between Antarctic and sub-Antarctic systems.


Eden Senay
AN ENDOPARASITIC NEMATODE HUNTS A SUITABLE HOST: EXPLORING THE DOMINANT GRASSES FROM THE SHORTGRASS AND TALLGRASS PRAIRIES
Fossil Ridge High School
with André Franco (CSU), Cecilia Tomasel (CSU), Diana Wall (CSU)

The root lesion nematode Pratylenchus penetrans is widely distributed in temperate regions, including U.S. grasslands. This study investigated whether dominant grass species from two LTER grassland sites are suitable hosts for the endoparasitic P. penetrans. During summer 2016, P. penetrans obtained from laboratory monoxenic cultures were inoculated into twelve growth pouches containing seedlings of two grass species: blue grama (Bouteloua gracilis) and big bluestem (Andropogon gerardii). Four pouches of each grass species containing approximately 25 seedlings each were inoculated with a 1-ml solution (163 nematodes mL-1). Roots were collected 15 days after inoculation and stained using the red food coloring technique. Observations of stained roots under the microscope revealed that P. penetrans successfully penetrated the roots of blue grama and big bluestem grasses. P. penetrans appeared to successfully infect and carry out their life cycle based on the consistent presence of eggs and mature nematodes in the root tissues of the two grasses. The results show that P. penetrans infects dominant grass species in the arid shortgrass and moist tallgrass prairies. Based on results of this experiment, a greenhouse study will be launched to examine nematode parasitism and grass biomass production.


Wilson Sinclair
THE BENEFIT TRANSFER TOOLKIT FOR ECOSYSTEM SERVICE VALUATION
Colorado State University, Graduate
with Chris Huber, James Meldrum

Non-market economic valuation estimates are often required when assessing the value of goods and services provided by ecosystems because of the absence of a conventional pricing mechanism found in most markets. There are several methodological approaches to estimate the values of these goods and services. Benefit transfer is a technique of meta-analysis that uses value estimates of non-market goods and services reported in previously conducted primary studies to estimate the value of that same good or service in a policy-relevant area where a primary study has not been conducted. The Benefit Transfer Toolkit is designed to facilitate the economic valuation of multiple recreation uses and other ecosystem services using secondary data. The web-based Toolkit includes spreadsheet databases of non-market valuation studies, average value tables, and meta-regression analysis models that can be used to conduct various types of benefit transfer. The Toolkit also includes an interactive user map that shows where each study was conducted. The Toolkit provides instruments and data that allow resource planners and managers to incorporate non-market values into their planning and decision-making without spending time and money necessary to obtain original data.


Hollie Skibstead
INFLUENCE OF CLIMATE VARIABILITY ON SAMBURU PASTORALISM
Colorado State University, Undergraduate
with Stacy Lynn (NREL)

This study seeks to determine how local climate variability and extreme events, including drought and floods, affect Samburu County, Kenya pastoralism. Components of dryland systems are important when considering impacts of climatic conditions and potential climate change on the livelihoods and resilience of people and animals residing within them. Dryland systems are characterized by low and variable precipitation, and high rates of evaporation. In Samburu County, pastoralism - i.e., extensive livestock herding - is a prevalent livelihood practice; the region's highly variable rainfall is insufficient for cultivation. Pastoralists rely heavily on multiple species of livestock for subsistence because of their ability to withstand climatic stresses. Pastoralists maintain the health of their livestock through herd mobility and other management practices. Fourteen semi-structured interviews concerning seasonal changes, extreme climatic event recall, land use, management methods, and conflicts were conducted with male herders. During dry months and periods of drought, pastoralists reported traveling up to 100 kilometers with cattle to find sufficient water and pasture, with small stock traveling less. Communities exposed to resource limitations during dry periods see increased frequency of conflict and competition with neighboring pastoral groups, local populations, and wildlife. These results serve as indications of implications for a climate change future in dryland systems.


Brittany (Britt) Smith
USING A TRI-TROPHIC SYSTEM TO ADDRESS PLANT CHEMISTRY IN A CHANGING CLIMATE: A RESEARCH PROPOSAL
Colorado State University, Graduate

Optimal defense theory would state that plant tissues commonly consumed will be strongly defended from herbivores, while tissues that are less likely to be consumed will have fewer defenses and higher defense-inducibility. Although, there have been many studies outlining the role of climate change with alterations in natural range distribution and phenology; there are fewer studies that address how plant chemical defenses adapt in a changing environment. Thus, I will present a research proposal using the wide spread herbaceous biennial plant Heracleum lanatum Michx. (common cow parsnip: Apiaceae) to investigate defensive chemicals from Colorado populations in the Summer of 2017. Populations of H. lanatum will range between (1500-3300m) in elevation, and sites will be colonized or uninhabited by the introduced, specialist herbivore Depressaria pastinacella Duponchel (parsnip web worm) (Lepidoptera: Oecophoridae). Known to survive at a narrower elevational range (1500-2600m), parsnip webworm hosts the polyembryonic parasitoid wasp Copidosoma sosares Walker (Hymenoptera: Encyrtidae). I plan to address the degree of potential range expansion of all three species and to determine if there are phenological mismatches in the tri-trophic model system of cow parsnip, parsnip web worm, and Copidosoma sosares by conducting reciprocal transplants. Observations and experimental outcomes will provide further understanding to how climate change potentially effects natural enemy systems.


Mayra Vidal
TOP-DOWN AND BOTTOM-UP EFFECTS ON FITNESS OF INSECT HERBIVORES: A META-ANALYSIS
University of Denver, Graduate
with Shannon M. Murphy (University of Denver)

Top-down and bottom-up forces can have significant effects on the fitness of herbivorous insects. However, we still do not know the relative strength of bottom-up and top-down forces and whether their relative magnitude might vary in effect across taxonomic groups, feeding guilds and diet breadth of herbivores. In this meta-analysis, we used 62 published studies with 114 effect sizes to test the relative impact of top-down and bottom-up forces on insect herbivores fitness and test related paradigms. We analyzed the effect of bottom-up and top-down forces in relation to: 1) herbivore diet breadth, 2) feeding guild, 3) taxonomy, 4) habitat, 5) type of bottom-up effects, 6) type of top-down effects and 7) how the fitness effects are measured on the herbivore. We found that both top-down and bottom-up forces had significant effects on herbivore fitness for all of the measures listed above, but interestingly these forces had no consistent effect on several key groups. For example, we found that generalists were not significantly affected by either top-down or bottom-up forces. Chewers and lepidopteran herbivores were not affected by bottom-up forces, but were significantly affected by top-down forces. Vertebrate predators had no effect on herbivore fitness. Development time was not affected by bottom-up or top-down forces when used as a measure of fitness. Our meta-analysis gives strong support for the tri-trophic approach when studying insect-plant interactions and we showed that the strength of selective forces exerted by plants or natural enemies can vary depending on the study system.


Sarah Waybright
VARIATION OF TAIL COLORATION IN ASCAPHUS TRUEI: DO “EYE SPOTS” INCREASE TADPOLE SURVIVAL?
Indiana University, Undergraduate
with Brett Seymoure, Chris Funk

Animals exhibit coloration for many purposes ranging from thermoregulation to camouflage to distractive markings. Many species have variation in coloration within and among populations. One hypothesis for this variation posits that differential predation pressures dependent upon predator composition and predator sensory abilities select and maintain variation in coloration. We investigate variation in tail coloration of tadpoles of the coastal tailed frog (Ascaphus truei) and Rocky Mountain tailed frog (A. montanus), which putatively have an "eye spot" on the tail of some individuals, whereas other individuals have only dark homogenous coloration. Eye spots are less vulnerable body parts are proposed to deflect predation and increase prey survival, however, empirical research is lacking. Thus, this study has four aims: 1) quantify variation in tail coloration, focusing on eye spots; 2) test for differences in tail coloration within and between different populations; 3) correlate known predator composition and abiotic factors with tail coloration; and 4) determine if Ascaphus is a feasible study system for testing the eye spot hypotheses. We developed a rubric for tail coloration and scored over 300 individuals to test for differences within and between populations in color patterns. Current analyses suggest that variation in tail coloration varies dependent upon population, predator composition, and abiotic factors. Future directions include studying predation on different phenotypes under different ecological conditions.


Sarah Whipple
POLLINATOR INVENTORIES AT BANDELIER NATIONAL MONUMENT: SUPPORTING CLIMATE SCIENCE RESEARCH IN THE U.S. NATIONAL PARK SERVICE
Indiana University, Undergraduate
with Annie Armstrong (Texas A&M Prairie View), Djulia de Azevedo (CSU), Michelle Bahnick (Western Washington University), Arlene Cortez (Texas A&M Kingsville), Lysa DuCharme (CSU), Kelsey Giles (CSU), Jasmine Hayes (Texas A&M Prairie View), Madison Holden (University of New Mexico), Parker Hopkins (University of Colorado-Boulder), Gregory Lujano (Texas A&M Kingsville), Mariana Rodriguez-Gonzalez (University of Yucatan), Lucie Royer (AgroSup Dijon), Philipp Wickey (Western State University), and Jenna Yonenaga (UC-Davis)

Under national BioBlitz initiatives of the National Park Service (NPS), research on pollinator interactions within different environments was undertaken at Bandelier National Monument in 2016 to support answering the question: How are pollinator species distributions changing inside the National Parks as a result of climate change? A BioBlitz is a 24-hour species identification event, where citizens and scientists come together to learn about the biodiversity of an area. Serving as a student team leader for the Bandelier BioBlitz, I developed the field guides for student teams to ensure accurate species identification using the citizen science application iNaturalist. On site, the team conducted three inventories focused on pollinator and plant interactions at elevations ranging from 7,000-11,000 feet. After the field-based data collection was completed, team members helped Bandelier classify the pollinators for reporting purposes. The final species counts for the team included 192 observations with 42% of these observations identified as pollinators. The findings from these data are being used as part a larger national study on pollinator responses to climate change, with analyses of the collective data still under review by NPS. Because of the success of our team's contributions, our faculty mentor has been asked to organize student teams affiliated with the CSU's Natural Resource Ecology Laboratory through 2021 to further research pollinator distributions.


Tahir Zaman
THE EFFECTS OF HUMAN-CAUSED FIRES ON UNDERSTORY VEGETATION COMPOSITION IN WESTERN HIMALAYA COMSATS
Institute of Information Technology, Graduate
with Kiramat Khan, Shaukat Zaman, Chuck Rhoades, Tim Fegel

Mountain ecosystems of northern Pakistan are threatened by climate change and land use pressure. The frequency and extent of human-caused burning has increased throughout the region in recent decades, raising concerns for understory vegetation in native pine forests and plantations. In the Kaghan Valley of Western Himalaya, more than half the native forest area has been converted to agriculture and rangeland. In this region, pastoralists under-burn Pinus roxburghii plantations to improve livestock forage. This study compares vegetation density in five adjacent tree plantations that were burned biennially or were unburned for at least a decade. Herbaceous vegetation, shrubs and tree density were sampled in 25, 100, and 900 m2 quadrats in burned and unburned conditions in the Balakot Hills, Pakistan (elevation 1020 to 2100 m). A total of 30 forbs, 4 shrub and 2 tree species occurred in the study area. Three months after burning, the density of the most abundant five forb species decreased by 71%. Four forb species declined significantly (Oreganum vulgare, Launaea nudicaulis, Gerbera sp. and Oxalis corniculata). The density of a handful of weedy species, including Taraxacum officinale, was increased by burning. Grass density decreased up to 64% after burning. Herbaceous biomass was 52% lower than in the unburned plots; conflicting with local pastoralists' perceptions that burning increases forage biomass. Burning had no effect on woody species. In general, understory burning reduces the density of forb and grass species. The implications of loss of vegetation cover combined with forage harvesting and changing climatic conditions on ecosystem productivity remain uncertain.