Front Range Student Ecology Symposium

Oral presentations     Poster presentations

Amburgey, Staci (6D)

Predicting the Effects of Climate Change on Pseudacris maculata
Staci Amburgey (CSU, Graduate), Chris Funk (CSU), Melanie Murphy (UW), Erin Muths (USGS), Larissa Bailey (CSU)

Predicting the effects of rapid climate change on biodiversity is an issue at the front of the scientific community's mind. The future of amphibian species, many of which are already in decline, is of particular concern. With climate change predicted to shift seasonal precipitation and weather patterns, interactions between amphibians and their habitats will be altered. However, the repercussions of such changes have yet to be clearly identified and understood. I am investigating the current effect of hydroperiod, predators, and other habitat characteristics on Pseudacris maculata (Boreal chorus frog) presence and absence in order to better understand the current dynamics leading to persistence of this species and how this may be changed by shifting seasonal conditions.

Asao, Shinichi (12A)

Respiration Converges Among Tree Species in a Tropical Forest
Shinichi Asao (CSU, Graduate), Jim Raich, Ricardo Bedoya-Arrieta, Ann Russell, Bill Parton, Mike Ryan

Plants in tropical forests account for 1/3 of all autotrophic respiration of the Earths land surface. The respiration fuels one of the largest and the most diverse living biomass of any ecosystem, but the diversity presents a challenge in describing and predicting the respiratory dynamics at the forest scale. Is it reasonable to ignore the differences among species, or better to represent them as continuum of traits, or to treat species separately?  To examine this question, we determined if tree species differ in: 1) the traits that control respiration, 2) respiration rates of tissue types and how they scale, and 3) annual respiratory flux. We used experimental stands in Costa Rica, with four native tree species in a complete randomized block design, where a single tree species dominated each stand. We categorized each stand into canopy positions and each position further into tissue types, and then measured their respiratory traits and respiration rates. We then identified an appropriate scaling method and estimated the annual respiratory flux. Respiratory traits and foliage respiration rate varied among species, but the traits and canopy position explained the variation in the rate. Branch and bole respiration rates did not vary. The annual respiratory flux of the stands differed slightly. Our results suggest that respiratory traits and canopy position can represent the differences in respiration among plant species in tropical forests.

Assal, Timothy (10C)

Investigation of Disturbance Legacies Despite Vanished Evidence
Timothy Assal (CSU, Graduate), Jason Sibold (CSU)

Temperate forest ecosystems are subject to various disturbances which contribute to ecological legacies that can have profound effects on the structure of the ecosystem for many years after the event. Impacts of disturbance can vary widely in extent, duration and severity over space and time. Given that global climate change is expected to increase rates of forest disturbance, an understanding of these events are critical in the interpretation of contemporary forest patterns and those of the near future (~ 50 years). We seek to understand the impact of the 1970s mountain pine beetle outbreak on the landscape of Glacier National Park and investigate any connection between this event and subsequent decades of extensive wildfire. The lack of spatially explicit data on the mountain pine beetle disturbance represents a major data gap and inhibits our ability to test for correlations between outbreak severity and fire severity. To overcome this challenge, we have initiated a study that utilizes historical, temporal data from the remote sensing archive to model the gray attack phase of the outbreak as a proxy for severity. Preliminary results indicate that this method is successful in capturing the spatial heterogeneity of the outbreak and can reduce levels of uncertainty associated with this historic disturbance. I will present preliminary results, and discuss challenges and plans for future research.

Atkinson, Sheryl (3D)

Cheatgrass and Its Relatives - a Database With Information About Brome Grasses
Sheryl Atkinson (CSU, Graduate), Sheryl Atkinson (CSU)

I am in the process of developing a database of information about Bromus species that will help researchers explore patterns of invasiveness and invasion in this genus, develop a better understanding of factors that cause some species to become invasive, and suggest areas for future research. Some grasses in the genus Bromus are an important cause of damage to natural environments. Annual bromes such as cheatgrass (Bromus tectorum) and red brome (Bromus rubens or Bromus madritensis ssp. rubens) have invaded and seriously degraded natural habitats in the western United States. Many other annual bromes have become widely naturalized outside of their native ranges. Perennial bromes are less likely to become invasive, although species cultivated for forage and revegetation, such as smooth brome (Bromus inermis), have damaged natural communities. The database is being developed in conjunction with a Bromus REENet working group that is currently conducting research on invasive Bromus species in the western United States. It contains information about taxonomy, global distribution, plant traits, ecological interactions, human uses, environmental impacts, management and research for approximately 150 species of Bromus. It is designed to provide researchers, land managers, and others with a central location for information about Bromus species, to provide easy access to additional sources of information, and to support research on invasiveness and invasion.

Blakeslee, Sarah (7A)

Investigating Whitebark Pine (Pinus albicaulis) Functional Roles in Tree Island Recruitment Within the Alpine Treeline Ecotone
Sarah Blakeslee (CU Denver, Graduate), Diana Tomback (CU Denver), Jill Pyatt (CU Denver), Elizabeth Pansing (CU Denver)

At treeline on the Eastern Front of the Rocky Mountains, whitebark pine (Pinus albicaulis) appears to facilitate tree island development. Whitebark pine is declining due to the invasive pathogen (Cronartium ribicola) causing blister rust. We are studying how whitebark pine facilitates tree island formation and how blister rust mortality may affect these processes. We are testing three hypotheses: 1) in exposed sites whitebark pine is hardier than other treeline conifers, 2) whitebark pine provides a more favorable microsite for tree island recruitment, and 3) whitebark blister rust mortality in established tree islands leads to vigor loss in leeward conifers. The first hypothesis is addressed here, using survival, condition, radial growth rates, and shoot lengths as measures of vigor. Study areas are Divide Mountain, Glacier NP/Blackfeet Reservation and Custer National Forest, MT. Branch shoots and other variables were measured for krummholz whitebark pine and associated species Engelmann spruce and subalpine fir during two field seasons. ANOVA and post hoc tests showed that krummholz whitebark pine has significantly longer shoots in most comparisons with other conifers. Tree shoots from lower elevations were compared to krummholz shoots and found to be significantly longer, likely reflecting better growing conditions. Data generally indicated that whitebark pine exhibited greater vigor, which may explain its frequency and abundance as a tree island initiator.

Bryan, Rebecca (5A)

Burrowing Owl Responses to Black-Tailed Prairie Dog Alarm Calls
Rebecca Bryan (CU Denver, Graduate), Mike Wunder (CU Denver)

Western burrowing owls (Athene cunicularia) are closely associated with black-tailed prairie dogs (Cynomys ludovicianus) in Colorado and neighboring states on the Great Plains. Owls have high nesting success on prairie dog colonies: they have pre-made nest-sites and good foraging habitat, and prairie dogs may act as an alternate prey source for predators. Desmond et al. (2000) and Beradelli et al. (2010) suggested that burrowing owls nesting on prairie dog colonies may eavesdrop on the prairie dogs as well: owls could attend and respond to the alarm calls that the prairie dogs emit, enhancing the birds survival on colonies and offering a further explanation of increased nesting success. In this study we looked at whether burrowing owls nesting on prairie dog colonies responded to playbacks of prairie dog alarm calls. We performed playback experiments with three different treatments: a prairie dog alarm call, a biological control (cattle mooing), and a non-biological control (an airplane engine). Owls reacted more quickly to the prairie dog alarm than to the biological control. They increased their vigilance significantly in response to playbacks of the alarm, but did not show a strong reaction to either the biological or the non-biological control. Our results show that owls nesting on prairie dog colonies appear to eavesdrop and increase their vigilance in response to prairie dog alarm calls.

Buhnerkempe, Michael (7B)

A Deadly Game of Hide of Seek: How Asymmetries in Dispersal Alter Coevolutionary Trajectories for Host Resistance and Parasite Virulence in a Metapopulation
Michael Buhnerkempe (CSU, Graduate), Colleen Webb (CSU)

Conventional wisdom on the coevolution of host resistance and parasite virulence predicts that hosts should generally develop better defense and parasites should become more benign. However, examples of highly virulent pathogens in almost wholly susceptible host populations abound in nature. In these systems, eco-epidemiological feedbacks (e.g., spatial structuring of host and parasite populations) may alter coevolutionary trajectories. Here, we hypothesized that asymmetries in host and pathogen dispersal (e.g., low host and high pathogen dispersal) provide a brake on coevolutionary pressures enabling highly virulent pathogens to persist in susceptible host populations. To test this hypothesis, we developed a novel theoretical framework of coevolution in metapopulations. This method combined a state-structured model with transient sensitivity analysis to calculate selection gradients for both host resistance and parasite virulence across a range of host and pathogen dispersal strategies. We found that resistance thresholds in the host prevent the evolution of highly resistant forms. These thresholds were modified by the dispersal strategies of the host and vector. In all cases, virulence was positively selected for. These methods highlight the importance of ecological dynamics in understanding host and pathogen coevolution and also provide one of the first models of quantitative trait coevolution in a metapopulation.

Craven, Katelin (9D)

Foraging Patters By Bats in Forested, Edge, and Masticated Ponderosa Pine Forest in Boulder County, Colorado
Katelin Craven (UNC, Graduate), Rick A. Adams (UNC)

We investigated bat foraging patterns and insect activity within ponderosa pine woodlands of three stand types: forested, edge, and masticated. To record sonar calls, we arrayed three Pettersson D240x detectors with digital recorders, moving them among five pseudoreplication transects and collected insects in forested and masticated stands using black-light traps. Calls were analyzed to species using Sonobat 3.0 and total number of calls for 2010 and 2011 were pooled. Overall bat activity was highest in masticated stands (443 total calls recorded), with 275 calls in forested stands, and 139 on the edge. Dunns test showed that activity was significantly different between use of masticated stands versus edge (P=3.99) and forested stands (P=2.31), but did not differ between use of forested stands and edge  (P=1.68). We also present data on species-specific use patterns of stand types. In both years average insect biomass was lower in masticated than in forested habitat: 2010 = 276.8 mg (SD=380.9) in forested habitat, whereas masticated = 2.47 mg (SD=6.4); 2011 = 13.9 mg (SD=5.1) in forested stands and 8.7 mg (SD=6.5) in masticated stands. We found significantly more bat activity in masticated habitat and contrastingly significantly more insect biomass found in forested habitat.

Crow, Kathryn (11C)

Culture of the Endangered Forest: How Profit, Tradition, and Globalization Cross Paths in the Amazon
Kathryn Crow (CU Denver, Undergraduate)

As Brazil rises in economic and political prowess, the fate of its natural resources plummets toward endangerment. While the recently-initiated construction of the Belo Monte hydro-electric dam in the Amazon River Basin promises new job opportunities and energy generation for Brazilian city-dwellers, it represents irreversible destruction of the biodiversity and indigenous culture housed in the rainforest. One indigenous group currently inhabiting the Amazon, the Kayapo, must struggle against such threats and weigh the value of their natural land against profits gained through its sale as their lives become increasingly entangled with outside material goods, the need for income, environmental NGOs, and industrial development. In this process, the interplay between culture, ecology, and conservation proves to be a crucial point of consideration. The Kayapo traditionally support and rely upon an ecologically-intact rainforest to fulfill their cultural and physical needs. Therefore, protection of the rainforest demands the safety of the Kayapo, their culture, and their place in the Amazon; their voices must earn a greater role in modern political and environmental discourse. Also, their agency in deciding how to participate in the global economy must be respected as the right of any modern people rather than disregarded as an unnecessary wish of "inherent" environmental stewards.

Dibner, Reilly (8A)

A Horned Lizards Blood, Spines, and Some Dirt Called Home
Reilly Dibner (UW, Graduate), Reilly Dibner (UW)

Horned lizards (Phrynosoma spp.) are highly specialized Iguanids with distinct morphology, physiology, and behavior. Different horned lizard species have little overlap in range and differ in habitat associations, but a variety of specialized traits are preserved within the genus. The suite of specialized traits that have enabled these lizards to thrive may make them more sensitive to anthropogenic disturbances. Highly specialized organisms, those that are tied to specific resources, are more likely to be impacted by the loss of a particular host plant, favored prey, or required soil type than generalists with alternative resource options would be. Rapid development of extractive industry operation in Wyoming is causing habitat change at a variety of scales that could put specialized organisms greatly at risk. I am exploring which traits are most limiting to horned lizards, how specialization varies within a species, and which traits most strongly determine lizard response to disturbance. One of the most striking specialist traits in these lizards is that they prey almost exclusively on ants. To explore how prey source reliability affects dietary specialization, I am investigating the spatial pattern of large ant mounds in horned lizard habitat.

Doll, Andrew (4A)

Estimating Arrival Times of Migrating Dunlin (Calidris alpina arcticola) Through Stable Isotope Analysis
Andrew Doll (CU Denver, Graduate), Michael Wunder (UCD), Craig Stricker (USGS), Richard Lanctot (USFWS)

For species that migrate to the high Arctic for breeding, timing is essential in order to maximize the potential for reproductive success. We used stable isotope analysis (SIA) to determine the isotopic turnover rate and subsequently estimate arrival times for dunlin (Calidris alpina arcticola) that breed in the vicinity of Barrow, Alaska. This subspecies winters and migrates along coastal areas feeding on prey isotopically enriched in 13C and then transition to an isotopically depleted diet in the terrestrial tundra environment where they breed. By analyzing the change in d13C of blood samples taken from individuals (n=33) at two points during the breeding period, we estimated the range of potential turnover rates of carbon isotopes. These field turnover rates are significantly higher than the rate determined in a previous study of captive pacifica dunlin. This difference is likely due to an increased metabolic requirement of the wild population for post-migrational tissue repair and investment in reproductive activities. Applying these rates to all dunlin samples (n=103), we find that the field rate yields a population arrival date 4 days later than the lab rate; which is closer to qualitative observations of arrival dates. The added value in this method is the improved ability to quantify the uncertainty of these estimates which is likely due to individual variation in diet.

Dunn, Samuel (1A)

Effects of Dry Down and Re-Wet Events On Potential Rates of Methanogenesis and Denitrification
Samuel Dunn (CSU, Graduate), Sam Dunn (CSU), Ellen Daugherty (CSU), Kateri Salk (St. Olaf College), Laurel Lynch (St. Olaf College), Stephanie Schmidt (Alaska Dept. of Fish and Wildlife), John Schade (St. Olaf College)

The production of the potent greenhouse gasses methane and nitrous oxide in flooded wetlands contributes significantly to climate change. However, it has been shown that the microbes responsible for the production of these gasses can survive in soils that frequently switch between aerobic and anaerobic conditions such as seasonal wetlands. Seasonal wetlands are crucial parts of the landscape because they are hotspots for both anaerobic and aerobic metabolism by soil microbes. The permanence of surface water in wetlands is a function of precipitation and snowmelt and strongly influences the structure and function of resident microbial communities. Several studies have suggested that precipitation events will become shorter and more intense as the climate warms. This change in precipitation patterns will likely affect the frequency at which wetlands dry down and re-wet and consequently how resident soil microbial communities function. What is unknown is how these communities respond to rapid changes between wet and dry conditions. We compared the potential production of nitrous oxide and methane in two wetlands, 1 seasonal and 1 permanent, by sampling at points along a transect that ran from the center of the wetland to the surrounding prairie. Our results suggest that seasonal wetlands harbor more metabolically diverse communities than permanent wetlands and that these soil microbes are capable of responding very quickly to changes in their environment.

Eads, David (7D)

Flea Ecology in Prairie Dog Colonies: Age of Colony, Type of Colony, and Soil Type
David Eads (CSU, Graduate), David A. Eads (CSU), Dean E. Biggins (USGS), Michael F. Antolin (CSU), and Kenneth L. Gage (CDC)

The endangered black-footed ferret and its main prey, prairie dogs, are highly susceptible to plague, a primarily flea-borne disease caused by the bacterium Yersinia pestis. To date, insecticides are the only stand-along tools that are feasible and effective to protect ferrets and prairie dogs from plague. With knowledge of the expected abundance of fleas in different areas, biologists could strategize their efforts to control fleas, targeting insecticides in areas with many fleas, as to limit flea populations at their sources, until a less invasive means of plague control is available. We are investigating the ecology of fleas in colonies of black-tailed prairie dogs. Current results indicate that flea ecology differs among old and new colonies, and natural and translocation colonies. We will discuss these results in light of relationships between ages/types of colonies and (1) depth of prairie dog burrows, (2) availability of organic matter (on which young fleas feed) in prairie dog burrows, and (3) use of insecticides. In addition, results indicate that fleas are most abundant in areas with soils of moderate texture. We will discuss this result in light of potential influences of soil texture and soil moisture on different flea life stages.

Farkas, Timothy (9B)

Community Consequences of Maladaptation in the Stick Insect Timema cristinae
Timothy Farkas (CU, Graduate), Timothy E. Farkas, Aaron A. Comeault, Tommi Mononen, Caroline Glidden, Ilkka Hanski, Patrik Nosil

Maladaptation is a potential consequence of gene flow in landscapes harboring locally adapted populations, but the ecological effects of maladaptation in nature have not been investigated. We demonstrate that maladaptation in Timema cristinae, a dominant, terrestrial, herbivorous insect, has far-reaching ecological consequences. Timema cristinae has two morphologically divergent ecotypes adapted to be camouflaged on two chaparral host plants in southern California, and gene flow between divergent populations of T. cristinae is known to cause variation in levels of maladaptation throughout the landscape. Using field observations, we show that levels of maladaptation are negatively correlated with T. cristinae population density, as well as the density and richness of co-habitating arthropod species. Using a field manipulative experiment, we support hypothesized causal effects of maladaptation on these population and community properties, and further demonstrate cascading effects of maladaptation on levels of herbivory. Our findings demonstrate the far-reaching effects of maladaptation in communities, and emphasize the importance of incorporating evolutionary dynamics into investigations focused on biodiversity, pest management, conservation, and ecosystem function.

Fettig, Christa (3A)

Black Henbane (Hyoscyamus niger): A Nuisance Weed or the Next Big Invader?
Christa Fettig (CSU, Graduate), Christa Fettig (CSU), Ruth Hufbauer (CSU)

Hyoscyamus niger (black henbane) is a solanaceous forb native to Eurasia and invasive in North America. Although this state-listed noxious weed is toxic to both livestock and humans, there is surprisingly little information on the invasive populations in North America. I address three main topics in this talk. First, I examine the component community of insects feeding on black henbane to evaluate whether it could act as a reservoir to pests that feed on solanaceous crops. Second, I evaluate if introduced populations follow an annual or biennial life cycle. Third, I document the characteristics of sites invaded by henbane, the average population sizes in Colorado, Wyoming and Montana, and examine trends in population growth. The data show that henbane serves as an alternate host to seven major crop pests. A greenhouse common garden experiment indicates that the plants are strongly biennial. Surveys of population characteristics and size reveal that henbane is found exclusively in highly disturbed sites, and that most populations are relatively small (<60 individuals). There is not a pattern of consistent population growth, rather over the course of two growing seasons, sites I tracked increased in size by up to 40 fold or decreased in size by up to 100 fold. Results suggest that black henbane is a justifiable concern to ranchers and farmers, however, I would argue that it may not pose long term threats to healthy rangeland and native flora.

Field, John (4B)

Biochar Amendments For Agricultural Soils:  Response Mechanisms in Winter Wheat
John Field (CSU, Graduate), Francesca Cotrufo (CSU)

Multiple studies have demonstrated the addition of biochar to certain agricultural soils can boost crop yields, though the underlying mechanisms remain poorly understood- debate continues as to whether improvements can be fully explained through modification of soil properties such as pH and water holding capacity, or whether there is a more direct stimulation of plant or microbial communities by the added char. A greenhouse experiment investigating the effect of biochar on soil pH and the production of winter wheat (Triticum aestivum Hatcher) was established in the spring of 2011. Three agricultural soils of similar texture and chemical properties but different pH (from 5 to 8) were amended with three biochars produced from different feedstocks (pine, corn stover, and wheat straw) and a pH-equivalent liming treatment. Grain and biomass yields were evaluated, and elemental and isotope analysis performed on plant tissues to monitor for changes in nitrogen nutrition and water use efficiency. Experimental results are incorporated into a mechanistic plant growth model with the goals of predicting yield response through changes in basic soil properties independent of crop species, and extrapolating response predictions regionally.

Fricks, Barbara (1B)

Effects of UVB On Surface Chemistry of Switchgrass
Barbara Fricks (CSU, Graduate), Matthew Wallenstein (CSU), Fancisco Calderon (USDA), Roger Tree (USDA), Wei Gao (CSU/USDA)

Biofuels are actively being pursued to help solve the energy crisis, but problems in processing 2nd and 3rd generation feedstocks remain. The solutions to these challenges could be informed by mechanistic studies of litter decomposition in natural environments. Recent studies suggest that in semi-arid and arid ecosystems, exposure to UV-B radiation can alter the chemical structure of lignin in leaf litter, which may increase the bioavailability of cellulose. We exposed cut switchgrass, a potential feedstock for biofuel production to three levels of UV for three months in a controlled greenhouse: no UV, ambient UV, and elevated UV. All samples received exposure to ambient PAR. UV exposures simulated outdoor intensities found at Short Grass Steppe in Colorado. We used ambient levels to better understand the effects of leaving switchgrass in the field versus harvest and removal. Elevated levels were no greater than the highest day of UV during the summer. We used FT-IR to detect changes in surface chemistry on exposed biomass. If lignin photo-degradation occurred we expected to see changes in key functional groups. Preliminary analysis of our FT-IR spectra indicates there were no significant differences among the three treatments. Future studies are needed to measure degradability to assess if truly UV had no effect on biomass.

Garza, Sarah (2B)

Ecological Characteristics of Artesian Wells in the Great Sand Dunes Ecosystem, Colorado: Impacts of Disturbance On Small Mammals and Plants
Sarah Garza (CSU, Graduate), Sarah Garza (CSU, USGS)

The Great Sand Dunes National Monument was first established in 1932 to protect the unique ecosystem at the eastern slopes of the Sangre de Cristo Mountains in south-central Colorado. In 2000, the National Monument was expanded into a National Park and Preserve to promote protection of the geological and hydrological resources of the area including the ground water system on which the sand dunes depend. Along with some 40,000 acres of wilderness formerly managed by the U.S. Forest Service, the National Park Service inherited a number of artesian wells that had been  installed by private landowners as long as 90 years ago. These wells possess containment structures that over the years have leaked and altered the vegetation communities and associated wildlife in an otherwise arid landscape. Under Park management guidelines, some wells were capped and the remainders are planned for closure. Prior to closing these wells, there is a unique opportunity to understand changes in biodiversity. After cattle grazing ended in 2005, these wells were exclusively utilized by large herds of ungulates such as bison and elk. To study the changes in ecological characteristics in this unique arid environment, I compared small mammal and plant biodiversity within areas surrounding open and recently closed wells, and control sites containing no wells. Results from my study will provide the National Park Service and resource managers some of the first information about the ecological influences of artesian wells on biodiversity and will aid in future management of the Great Sand Dunes National Park and Preserve.

Gomola, Courtney (3C)

Investigating Heterosis and Intraspecific Variation in the Invasive Aegilops trincialis (Barbed Goatgrass)
Courtney Gomola (CSU, Undergraduate)

Aegilops triuncialis has successfully invaded native California grasslands and rangeland pastures despite the genetic bottleneck associated with most invasions. Dense patches expand rapidly across the landscape, reducing native grassland diversity and palatable rangeland forage species for stock animals. A tenacious invader, A. triuncialis has also been able to proliferate in the nutrient-poor serpentine grasslands, home to highly adapted and endemic flora. The conundrum of these invasions is coupled with the evidently depauperate gene pool of A. triuncialis, with current invading populations stemming from only three genotypes that can be associated with three introduction events. Due to the ability to establish in a variety of landscapes with limited genetic variability, understanding the mechanism of invasion of A. triuncialis is critical to restoring current and potential impacted areas. An allopolyploid hybrid of A. caudata and A. umbellulata, A. triuncialis offers a prime study system to investigate the theory that successful invasion of an exotic species is stimulated by the heterosis created from certain hybridization events. Through molecular and ecological techniques our study will investigate if the genotypes present today represent a heterotic subset of those introduced, and possible variation among genotypes due to their distinct genetic origins.

Graeve, Phillip (12B)

Seedling Establishment Is Impacted By Drought-Induced Structural Changes in Pinyon-Juniper Communities of the Uncompahgre Plateau
Phillip Graeve (CSU, Graduate), Monique Rocca (CSU)

Severe drought in the last decade led to widespread and well-documented mortality of pinyon and juniper in southwestern Colorado. The consequences of this mortality for pinyon and juniper establishment and possible changes in community composition are difficult to predict due to uncertainties about the role sudden changes in overstory cover and substrate microhabitats play in pinyon and juniper establishment. To examine whether pinyon seedlings establish preferentially under specific microhabitat and overstory dynamics, and the impact of overstory mortality on establishment, microhabitat and overstory dynamics of pinyon and juniper seedling establishment were sampled on the east aspect of the Uncompahgre Plateau. A significant relationship was found between pinyon seedlings and Bare Ground, indicating preferential avoidance of this substrate, while Shrub Litter, Tree Litter and Logs exhibited preferential pinyon establishment in these microhabitats. Pinyon seedlings avoided areas of open overstory, and preferred areas of juniper overstory, though pinyon overstory was, surprisingly, insignificant. Juniper seedlings preferred nearly all substrates except pinyon litter and bare ground, and avoided pinyon and juniper overstory. These findings suggest that loss of forest structure due to overstory mortality may trigger a positive feedback loop precluding pinyon establishment and supporting juniper establishment by altering seedling substrate establishment conditions.

Grenis, Kylee (9A)

Ecological Impact of Habitat Loss and Light Pollution on Moth Communities
Kylee Grenis (DU, Graduate), Kylee Greins, Shannon Murphy

As humans convert land from natural habitats into developed areas, they leave behind smaller, remnant patches of the native ecosystem. Previous studies have shown that patch size have large effects on diurnal invertebrate communities, but relatively little is known about the response of nocturnal invertebrates, like moths, to this pressure. In addition to patch size, moths must also deal with light pollution from surrounding suburban development. In a preliminary study, I sampled 17 sites varying in size, vegetation, and light levels throughout the Front Range by collecting moths from 20:00 until 02:00. These early data show that moth abundance is unaffected by patch size and light levels.

Hardy, Amanda (8B)

Ungulate Responses to Multi-Use Pathway Construction and Use in a National Park Transportation Corridor
Amanda Hardy (CSU, Graduate), Kevin Crooks (CSU)

We conducted a Before-After-Control-Impact assessment of elk (Cervus elaphus) and pronghorn antelope (Antilocapra americana) responses to multi-use pathway construction and use along an existing road in Grand Teton National Park, USA. We repeatedly measured activities of these ungulates and humans in a 6.9 km control region (without pathway) and a 12.5 km treatment region (with pathway) between June-October before (2007) and during pathway construction (2008), and for two years after the pathway opened to public travel (2009, 2010). After pathway installation, the number of elk viewed in the treatment was stable while decreasing in the control between 2008-2009 and 2008-2010. Elk were farther from the road in the control in 2008, 2009 and 2010 compared to 2007 while elk in the treatment were only farther from the road in the treatment in 2009 compared to 2007. The probability of elk behaviorally responding in the treatment was lower compared to the control in 2008 and 2009 compared to 2007. Pronghorn shifted, on average, 164 meters farther from the road in the treatment in 2010 compared to 2007 while moving closer to the road in the control. Despite direct habitat loss, widening the human footprint, and displacement of pronghorn away from the road and pathway, pathway construction and use did not appear to reduce park visitors opportunities to see elk and pronghorn in the travel corridor.

Harrington, Alan (5B)

Foraging Frequency Among Three Colorado Habitat Types of Juvenile Mountain Plovers (Charadruis montanus)
Alan Harrington (CSU, Undergraduate)

Researchers and policymakers have recognized the importance of examining the issues surrounding population declines of the Mountain Plover. Understanding habitat relationships will help with the conservation of this species. During the summer of 2011 I examined the foraging frequency of juvenile Mountain Plovers among three habitat strata (prairie dog colonies, rangeland, and agricultural fields). Observations took place on private lands around Karval, Colorado; where a large breeding population of Mountain Plover exists. Due to an ongoing chick mortality study in place by the Colorado Parks and Wildlife, I was able to collect data from chicks equipped with radio transmitters throughout the brood rearing season. My objective was to assess the habitat-specific and age-specific foraging rates of chicks. I found foraging rates did differ among habitat types, but not by age of chicks. Grassland habitat had the highest foraging rate and the agriculture habitat had the lowest foraging rate. I will discuss my results without regards to prey availability and predation pressures.

Hoover, David (9C)

Plant Responses to Extreme Heat and Drought in the Tallgrass Prairie Ecosystem
David Hoover (CSU, Graduate), David L. Hoover (CSU), Alan K. Knapp (CSU), Melinda D. Smith (Yale)

Climate extremes, such as heat waves and drought, are expected to increase in their frequency and intensity over the next century. We examined the responses of the tallgrass prairie ecosystem to a simulated heat wave under dry and wet soil moisture regimes. Precipitation treatments were established with rainout shelters from March through September 2011, with the wet treatment receiving ambient rainfall and supplemental irrigation during the summer, while the dry treatment received 33% of ambient rainfall, resulting in a 50% reduction in soil moisture. In addition, a two-week heat wave was imposed in July at four treatment levels (+0, +4, +7 and +11 degrees C above ambient). We examined the effects of the simulated climate extremes on the physiology of the co-dominant C4 grasses (Andropogon gerardii and Sorghastrum nutans) as well as the impacts on aboveground net primary productivity (ANPP). The co-dominant C4 grasses showed similar physiological responses: 1. mid-day leaf water potential was significantly affected by both heat and drought, while 2. net photosynthesis was significantly affected by drought but not by heat. The drought impacted ANPP, with significant reductions in biomass for total (-60%), S. nutans (-54%) and the dominant forb Solidago canadensis (-75%). ANPP for A. gerardii was not affected by drought. While the effects of heat on ANPP were not statistically detected, a strong trend for an interaction between heat and precipitation was evident.

Hopping, Kelly (11B)

When a Cold Place Heats Up: Changing Climate, Ecology, and Livelihoods in Tibet
Kelly Hopping (CSU, Graduate), Kelly Hopping (CSU), Ciren Yangzom (Tibet University), Julia Klein (CSU)

The Tibetan Plateau is experiencing a multitude of changes, ranging from shifts in climate and vegetation to altered land tenure and livelihood opportunities. The interaction of these changes jeopardizes the ability of semi-nomadic pastoralists to continue their traditional way of life in Tibet's alpine ecosystems. We predicted that local ecological knowledge and strong social networks through which knowledge is shared should be crucial starting points for successful adaptation under climate change. In January, 2012, we interviewed 48 people from a village in central Tibet about their local ecology and climate. Many reported environmental changes consistent with findings from Western science and nearly all reiterated the importance of the weather for vegetation and livestock health, but fewer people made connections between the longer term climatic and ecological trends that they observed. Preliminary results from these interviews, climate data, land cover change analyses, and our climate change and grazing experiment indicate that warming temperatures may be particularly detrimental to the ecosystems on which Tibetan pastoralists depend. Furthermore, current land management practices and reduced knowledge transmission to younger generations are likely to further constrain Tibetan nomads' ability to sustain their traditional livelihoods into the future.

Ims, Jessica (5C)

The Effects of Nesting Stage and Temperature on the Time of First Activity in Orange-Crowned Warblers
Jessica Ims (CSU, Undergraduate), Helen Sofaer (CSU). and Cameron Ghalambor (CSU)

Avian parental behavior is known to be influenced by ecological conditions such as ambient temperature. However, while traits such as incubation on- and off-bout lengths and nestling feeding rates are well studied, the time birds first leave the nest after incubating or brooding overnight has received little attention. Here, we investigated the effects of temperature and nest stage on the time of first activity in Orange-crowned Warblers (Oreothlypis celata), controlling for sunrise time. Sunrise time affected the time of first activity, but the temperature at sunrise did not. In addition, we found that females with nestlings left the nest earlier than those incubating eggs, relative to sunrise time. These data show that the females do not get off the nest as soon as it is light enough to see, particularly while incubating eggs. This result indicates that factors beyond light levels can influence the timing of first activity, and that these factors merit further study.

Kaczynski, Kristen (6C)

Interactions of Ungulate Browsing, Native Birds and Fungi in the Decline of Riparian Willows
Kristen Kaczynski (CSU, Graduate), David Cooper (CSU), William Jacobi (CSU)

Willows are critical components of Rocky Mountain riparian ecosystems, particularly within Rocky Mountain National Park where they form the dominant riparian shrub community. However, willow decline over the past 16 years has led to a dramatic change in riparian ecosystems in the Park resulting in a conversion from a tall to a short willow community leading to cascading effects throughout the ecosystem. Research on willow decline has focused primarily on the effects of ungulate browsing and altered hydrologic regimes controlled by beaver populations. However, we have determined that sapsuckers [woodpeckers] and a fungal infection by Cytospora chrysosperma are interacting in a novel way with these known factors. Cytospora is a native pathogen, requiring physical damage to the stem before infection can occur, and has been identified as a contributing factor in the widespread aspen decline. This research examines the relative roles of these interacting stressors, as no single stressor has caused the willow community decline, however, their synergistic effects have resulted in riparian community collapse. We present a new hypothesis which incorporates sapsuckers and fungal infection as contributors to the willow decline.

Kieffer Stube, Cassandra (3B)

Suppression of Cheatgrass (Bromus tectorum) Through a High Seeding Rate of Native Ruderal Species
Cassandra Kieffer Stube (CSU, Graduate), Mark Paschke (CSU)

Cheatgrass (Bromus tectorum) is one of the most widespread invasive weeds in the United States, particularly in post-disturbance settings where it often dominates the landscape and prevents the establishment of native species. Native ruderal plant species share many traits with cheatgrass such as high seed production, rapid growth and high resource use and should thus offer a reasonable source of competition. However, native ruderal species are rarely included in revegetation seed mixes and typical seeding rates are low relative to cheatgrass seed production. The objective of this study is to determine if a high seeding rate of native ruderal species could be used to suppress the establishment and persistence of cheatgrass in a disturbed site. We predicted that ruderal species would suppress cheatgrass establishment and that natives would be superior in cheatgrass competition to the sterile wheat QuickGuard. We tested these predictions in a field study where we planted test plots with cheatgrass, QuickGuard and a native ruderal mix. High rates of native ruderals were broadcast onto plots and tilled into the top 10cm to mimic a native ruderal seed bank. QuickGuard and/or cheatgrass were then broadcast into the plots. Results based on the first growing season indicate suppression of cheatgrass by native ruderals. If this trend continues, it would suggest that a high seeding rate of native ruderals could be a viable approach for reducing cheatgrass dominance.

Leach, Clinton (7C)

Environmental Pathogen Reservoirs and Habitat Heterogeneity in a Metapopulation
Clinton Leach (CSU, Graduate), Colleen Webb (CSU), Paul Cross (USGS)

Disease and habitat fragmentation represent two significant threats to the persistence of wildlife populations across a landscape. How these two factors interact is poorly understood. Management and conservation approaches considering either disease or habitat structure in isolation are inadequate to capture the dynamics of the host population. Many wildlife diseases, like Chronic Wasting Disease (CWD), are able to persist for long periods of time in the environment. In a fragmented habitat, one can imagine that high-quality habitat patches might more quickly become contaminated with the pathogen. The spread of infection from these areas could transform high-quality patches from sources to sinks as a result of disease-induced mortality. In this situation, low quality patches might serve as refuges that are critical to the persistence of the host population. To investigate this situation, I have developed and explored a stochastic patch occupancy model, the insights from which will help inform management and conservation decisions, potentially highlighting the importance of low-quality habitat for the persistence of wildlife populations and the importance of high-quality habitat for the persistence of wildlife disease.

Lewis, David (8C)

Managing Urban Black Bear Population in Stochastic Environments
David Lewis (CSU, Graduate), Stewart Breck (NWRC), Kenneth Wilson (CSU), and Colleen Webb (CSU)

Black bears (Ursus americanus) population vital rates are influenced by variation in annual natural food production, availability of human food resources, human-bear conflict management, and hunter harvest. Human-bear conflict rates increase in urban areas adjacent to bear habitat when natural food production fails. Managers need to know how natural food production, available human food sources, removal of conflict bears, human-bear conflict rates, and hunter harvest relate in order to manage for reduced human-bear conflicts and a viable bear population. We used stochastic population projections to model urban bear populations, evaluating the potential cost-benefit of urban areas. We used data generated from our 6 year study in Colorado along with published studies, to develop vital rate distributions for five management scenarios in which natural and human food availability and management intensities varied. We combined perturbations and vital rate elasticity values to evaluate cost-benefit differences between scenarios. Results suggest that anthropogenic food available in urban areas benefit the population through increased cub production, but these benefits can be offset by decreased adult survival from conflict removals, resulting in overall population reductions. Management of urban bear populations requires balance between conflict management and a viable bear population; our results guide managers toward this balance.

Miller, Adam (4C)

Distribution Modeling and Restoration Ecology: Bridging the Gap to Better Understand Vertebrate Assemblages in Restoration Corridors of the Australian Wet Tropics
Adam Miller (CSU, Undergraduate), Rohan Wilson, Steve Williams

Forest clearing during European settlement in the Australian Wet Tropics has left vertebrate populations fragmented with limited levels of connectivity and mobility. Recently, wildlife corridors have been advocated for to increase connectivity across the landscape to maintain viable populations and therefore make species more resilient to climate change and other stochastic events. This study looks to investigate the usefulness of species distribution models in restoration ecology to make inferences about vertebrate usage of corridors. Model predictions were combined with data from a meta-analysis to infer of the predicted present species how many species may or may not be using corridors. Results showed birds and mammals were mostly using corridors while reptiles and amphibians were not. All habitat linkages with the lowest species use were nested around the evolutionarily rich Herberton Range. Additionally, our study identified target species for each fauna group that remained fragmented across the landscape. Finally, this investigation tested maximum entropy models against real survey data to infer its usefulness in restoration ecology. Our study concluded that Maxent was a useful tool in conservation but was more accurate in predicting species absences than presences. Therefore this study identified a fairly novel methodology using Maxent as a starting point to make better inferences about corridor usage.

Nagle, Lauren (5D)

Incubation in the Orange-Crowned Warbler: A Latitudinal Comparison of the Effects of Ambient Temperature
Lauren Nagle (CSU, Undergraduate), Helen Sofaer (CSU). and Cameron Ghalambor (CSU)

Phenotypic variation within and between populations can be explained by genetic and environmental differences, but partitioning these sources of variation in natural populations is notoriously difficult. However, comparing the reaction norms between populations is a useful first step towards understanding phenotypic variation. Here, we compared the incubation behavior of two orange-crowned warbler (Oreothlypis celata) populations to see if ambient temperature could explain behavioral differences between birds breeding in Alaska and California. We videotaped nests and found that birds in Alaska spent more time on the nest than birds in California. Yet, while some of the variation within the Alaskan population was explained by variation in temperature, temperature did not explain the difference between populations. Our data also indicate that the slope of the reaction norms differed between populations, with Alaskan birds responding more strongly to changes in temperature. Although the genetic basis of variation in incubation behavior is not understood, our results support the hypothesis that at least some of the variation is explained by fixed differences between populations.

Northrup, Joseph (4E)

Mule Deer Behavioral Response to Natural Gas Development in the Piceance Basin, Colorado
Joseph Northrup (CSU, Graduate), Chuck Anderson (Colorado Division of Parks and Wildlife), George Wittemyer (CSU)

Anthropogenic development related to the extraction of energy resources has increased rapidly in North America over the last decade, with numerous documented impacts to wildlife. Understanding the behavioral response of wildlife to habitat alterations from energy development is a critical issue as wildlife displaced from preferred habitat may experience decreased survival or reproduction. However, such an understanding is complicated by the dynamic nature of developments and individual differences among deer (e.g. age, reproductive status, and condition). We examined the behavioral response of mule deer to ongoing natural gas development on their winter range in the Piceance basin of Northwestern Colorado. Using global positioning system radio telemetry data from collars deployed on 53 female mule deer we fit habitat selection models in a Bayesian hierarchical framework to obtain coefficient estimates for individual and population-level responses to habitat and development. We compared the predictive ability of habitat selection models for deer in developed and undeveloped areas to examine the potential for development-induced alteration of behavioral patterns. Our results indicate varying behavioral modifications of deer in response to developments of differing type (i.e. well pads during different phases of development, and roads). These findings can be used to guide management and mitigation plans during the coming decades as natural gas development continues on public lands in Colorado.

Oles, Kristin (2C)

Does Competition From Native Seedlings Affect the Development of a Nonnative Species Verbascum thapsus (Common Mullein)?
Kristin Oles (CSU, Undergraduate)

Common mullein (Verbascum thapsus) is an nonnative species that can rapidly colonize bare ground after disturbances in rangeland systems, often displacing native species in the process. In this greenhouse experiment, native species seedlings were paired with common mullein seedlings in a 49 mL conetainers to determine which native species, if any, were good competitors with common mullein. Good competitors could potentially be used in restoration treatments to competitively exclude or reduce common mullein establishment. Fourteen species were chosen for the experiment: twelve native forbs, one native grass, and one sterile hybrid grass commonly used in restoration for erosion control (Regreen, Triticum aestivum x Secale cereale). Competition was indicated by reduced common mullein biomass when paired with native species relative to its biomass when planted alone. Desert princesplume (Stanleya pinnata) and Regreen were the most successful competitors with common mullein. Winterfat (Ceratoides lanata) was the least successful competitor. Seeding desert princesplume and Regreen after disturbances is recommended based on these data because their competitive ability can potentially inhibit common mullein establishment growth and allow for better establishment of native species after a disturbance.

Perez-Umphrey, Anna (6E)

Evidence That Rearing Environment Affects Time Budgets in Guppies
Anna Perez-Umphrey (CSU, Undergraduate), Emily Broder (CSU), Lisa Angeloni (CSU)

The subject of plasticity and adaptation is of importance to todays flora and fauna in the light of altering environments. A better understanding of how organisms respond to new and changing environments will help answer important questions in management and conservation work. The Trinidadian guppy, Poecilia reticulata, was used to study this question of behavioral plasticity, because past research suggests that the traits of this small freshwater fish vary genetically and plastically in response to the presence or absence of predators as well as to the quantity of available food. We reared fish from the Guanapo River, Trinidad and Tobago, to the second generation in the laboratory and split them into four treatments where we varied food levels and the presence of chemical predation cues and thus perceived predation threat. In an experiment where males had access to females, other males, and food, we recorded individual time budget data noting swimming, foraging, freezing, and courting behavior. Time spent foraging and courting did not differ among treatments. However, fish reared with exposure to predator chemical cues and on a high food diet spent less time swimming and more time engaged in interference courtship (courting a female that was already being courted by another male) than all other treatments, showing some evidence for behavioral plasticity.

Renwick, Katherine (2A)

Recruitment Patterns in Mixed Aspen-Lodgepole Stands: Will the Mountain Pine Beetle Outbreak Benefit Aspen?
Katherine Renwick (CSU, Graduate), Katherine Renwick (CSU), Monique Rocca (CSU)

A recent outbreak of the mountain pine beetle (Dendroctonus ponderosae) has caused widespread mortality of lodgepole pine (Pinus contorta) throughout western North America. In forests where lodgepole pine forms the majority of canopy trees, high rates of mortality have created gaps that may allow seedlings and saplings present in the understory to experience a period of growth release. Because aspen (Populus tremuloides) regenerates readily via root suckering and can achieve higher growth rates than competing conifer species, we hypothesized that the mountain pine beetle outbreak would result in increased aspen recruitment. Sampling conducted in Rocky Mountain National Park, however, indicates that high browse rates may limit aspen recruitment within the Park. Other confer species will likely replace lodgepole pines killed in the outbreak where elk populations remain high.

Salo, Jessica (10B)

Estimating Potential Riparian Ecosystems: A Comparison of GIS-Based Methods
Jessica Salo (CSU, Graduate), David Theobald (CSU)

Riparian ecosystems are among the most biologically diverse, productive, and most threatened ecosystems in many regions. Yet, a reasonable map of riparian areas is lacking, making it difficult for land managers and scientist to understand the extent riparian ecosystems. Riparian ecosystems are composed of narrow bands of vegetation surrounding streams and are often not captured well by terrestrial ecosystem mapping efforts because they are difficult to distinguish from upland habitats at medium resolution (30-100 m). Our research goal was to identify a method to estimate potential riparian areas that is robust to hydrologic data scale, synthetic streamlines, and to changes in resolution of topographic data. We reviewed the literature and found 17 different methods that use landscape data to estimate riparian location. We replicated these methods and tested them within the Big Thompson watershed. We calculated each method using 10 m and 30 m DEMs, synthetic stream lines (catchment area  0.5 square km), and two NHD datasets (1:24,000 and 1:100,000). We compared these methods to our estimation of truth: riparian areas digitized from recent (2005), high resolution (1 m) imagery, to identify the best method to predict potential riparian ecosystems in semi-arid mountain regions. We found that many of the existing estimates of riparian areas perform poorly, and those that include estimates of both longitudinal and latitudinal stream processes perform the best.

Schliep, Erin (4D)

Evaluating Wetland Health: A Multivariate Multi-Level Latent Variable Model
Erin Schliep (CSU, Graduate), Jennifer Hoeting (CSU), Joanna Lemly (Colorado Natural Heritage Program), Laurie Gilligan (Colorado Natural Heritage Program)

We examine the problem of spatially correlated, multivariate ordinal data in the assessment of health of an ecological system. A common approach is to use an index to combine various biological or physiochemical metrics that are typically ordinal-scaled variables. For example, stream health is often measured by the Index of Biotic Integrity (IBI), which is the weighted-sum of a collection of metrics at a site. Indices such as these are criticized because the weights assigned to each metric are determined arbitrarily. In this work, we overcome this shortcoming. We propose a latent model for multivariate ordinal data and consider several extensions. We demonstrate our methods using a US Environmental Protection Agency supported study of wetland health in Colorado. Our aim is to predict the spatial distribution of wetland type and ecological condition. In achieving this goal, we estimate the unobserved, or latent, health of each wetland location as predicted by a suite of potential threats and stressors.

Schook, Derek (6A)

Climatic and Hydrologic Processes Leading to Recent Wetland Losses in Yellowstone National Park, USA
Derek Schook (CSU, Graduate), Derek Schook (CSU), David J. Cooper (CSU)

Wetlands provide vital habitat and act as landscape indicators by integrating catchment-scale hydrologic processes. Wetland drying during the past few decades in Yellowstone National Park has caused concern among land managers and the public at large. My research was initiated to develop an understanding of the processes controlling wetland water levels and contributing to wetland decline in the Northern Range. In 2009 I established 24 study wetlands and instrumented each with an average of five groundwater monitoring well-and-piezometer nests. To quantify historic wetland area I mapped hydric soils, analyzed aerial photographs, and identified geomorphic indicators of higher water. Climate data indicated that warming and drying occurred during the 20th century, but that this pattern was within the natural range of variation for the study region during the past 800 years. Hydrologic regimes were classified and seven wetland classes were characterized. Aerial photographs and hydric soil delineation both confirmed formerly greater wetland abundance. Wetland plant species inhabited areas of distinct water table depth and variation, and can be used to infer subsurface hydrologic regime in the absence of extensive monitoring well networks. Continued monitoring of these wetlands and their watersheds is critical to expanding our understanding of the processes supporting Northern Range wetlands and allowing us to better manage these valuable habitats.

Scott, David (2D)

Determining Disturbance History and Trends in the San Juan Mountains, CO
David Scott (CSU, Graduate)

Disturbance events trigger rapid and long-lasting ecological changes and interactions among disturbances, climate, and topography may influence susceptibility and post-disturbance trajectory. The disturbance history of subalpine forests in the San Juan Mountains is poorly understood compared with areas of Central and Northern Colorado, yet the ranges extreme topography, bi-modal precipitation regime and numerous disturbance agents present opportunities to gain a better understanding of the drivers and interactions that influence disturbance regimes. The current spruce beetle (Dendroctonus rufipennis) outbreak in the San Juans presents specific research opportunities to investigate the influence that climate, topography, and disturbance history have regarding the onset, spread and severity of insect epidemics. During 2011, five subalpine valleys in the eastern San Juans were sampled using dendrochronological methods to determine outbreak and stand-initiation history. Preliminary results and field observations suggest a complex history of past disturbance including avalanche activity, blowdown, fire and past insect outbreaks. Aerial survey data show that the outbreak is continuing to grow in size. Multi-centenary survivors of the current outbreak show unprecedented increases in radial growth post-outbreak suggesting that perhaps the ongoing outbreak is exceptionally severe compared with other outbreaks over the last 200 years. Research will continue in 2012.

Shaw, Elizabeth (1D)

Following Carbon Through the Soil Food Web: Do Long-Term Burning Practices Affect Carbon Trophic Dynamics in Grasslands?
Elizabeth Shaw (CSU, Graduate), Karolien Denef (NREL), Francesca Cotrufo (CSU), and Diana Wall (CSU)

Soil carbon (C) dynamics are a central component of global C cycling. Human activities, such as land management practices, impact decomposition processes, soil communities, and soil C storage. For example, annual burn of grasslands promotes higher decomposition rates (compared to unburned) and impacts soil C mineralization. In addition, annual burning alters populations of bacteria, bacterivore nematodes, and other invertebrates and thus, may affect soil food webs C cycling. Our greenhouse study, through a novel 13C tracer approach, examines how tallgrass prairies annual burn affects root litter decomposition, soil food web structure, and C dynamics.        Andropogon gerardii was grown from rhizomes in a continuous labeling chamber of 13C-CO₂ atmosphere as part of an NSF-DEB project (F. Cotrufo, PI). Later, in a randomized, replicated greenhouse study, the 13C-labeled dead roots were buried in soil collected from 2 differently managed systems: a) annually burned or b) unburned areas at the Konza Long Term Ecological Research site. At 8 destructive harvests, biota (i.e., microbes and their nematode consumers: fungivores, bacterivores, omnivores, predators) are extracted and analyzed for biomass, microbial community composition, faunal trophic position, and C isotope signature of the different communities to trace root C through soil trophic levels. The first 4 harvests preliminary results show differences in nematode populations and C pathways in burned and unburned soil.

Soong, Jennifer (1C)

Biological Mechanisms Controlling Atmospheric Loss vs. Belowground Storage of Decomposing Litter: A Stable Isotope Approach
Jennifer L. Soong (CSU, Graduate), Uffe N. Nielsen, Karolien Denef, William Parton, Diana H. Wall, M. Francesca Cotrufo

Quantitative information on the fate of plant derived carbon (C) during decomposition is critical to our understanding of the global C cycle. The biological processes involved in litter respiration, leaching, and fragmentation, determine the amount of C lost from the system as mineralized C vs. that stored in the soil during decomposition. Stable isotopes can be used as a powerful tool to trace the fate of plant derived C as litter decomposes and cycles within and out of terrestrial ecosystems, and to understand the biotic controls on these processes. In September, 2010, we began a three year decomposition experiment in the Konza LTER tallgrass prairie using 13C enriched Andropogon gerardii leaf litter. Using 13C data, we can trace the fate of this mass loss into CO₂, soil organic matter (SOM) fractions, dissolved organic matter, microbial biomass, and phospholipid fatty acid microbial biomarkers (PLFAs) and soil fauna. Stable isotope probing is applied to identify the microbial community groups most active on C transfers. By modeling CO₂ fluxes based on continuous climate data we can also estimate quantitative C losses from microbial respiration of litter. A soil fauna exclusion treatment also allows us to tease out the role of soil fauna in litter decomposition processes. We present the first year results from this experiment, and shed light on the biological mechanisms responsible for C storage and loss in this system. We will also discuss whether or not the results of this study indicate that the role of soil biota must be integrated into ecosystem models of C cycling.

Sowa, Wanda (5E)

Nest-Site Selection of Cliff Swallows (Petrochelidon pyrrhonata) in a Metropolitan Area
Wanda Sowa (Metropolitan State College of Denver, Undergraduate), Keely Nolan (MSCD), Christy Carello (MSCD), Nels Grevstad (MSCD)

Cliff Swallows (Petrochelidon pyrrhonata) benefit humans by consuming large quantities of insect pests. They have adapted to artificial environments and frequently nest under bridges that span rivers and creeks in the Denver metropolitan area. Our objective in doing this study was to find which aspects of a bridge and its surrounding habitat are significant to nesting Cliff Swallows. We counted intact swallow nests and nest remnants on the undersides of 80 bridges. These counts were done along two rivers and their tributaries in both urban and suburban settings. We evaluated bridge construction material and the adjacent vegetation buffer between the water and recreation path. We found significantly more nests on bridges in urban areas and on concrete bridges. We also found that the number of nests on the underside of a bridge was positively correlated with the size of the buffer and was also related to the type of vegetation of the buffer. In order to provide adequate habitat for nesting Cliff Swallows and allow them to expand their realized niche, we recommend that city planners consider concrete bridge construction and provide a large vegetation buffer adjacent to the bridge with heterogynous vegetation structure.

Sueltenfuss, Jeremy (6B)

Wetlands of Irrigated Agriculture
Jeremy Sueltenfuss (CSU, Graduate)

Due to the arid climates of the western United States, irrigation has long been a necessity for successful agricultural operations. In northern Colorado, irrigation canals have been in place for over 100 years to deliver a limited supply of water to crops and pasture. Because large amounts of water seep from these earthen canals during transport, agricultural water inefficiencies are the center of debate between economists, managers, regulators, irrigators and environmentalists who argue that leakage results in wasted water which could be put to better use. Though research has shown the importance of canal seepage to raising local water tables, nothing has been done on the role of canal seepage in creating and maintaining wetland habitat. To understand the hydrology of agricultural wetlands, I installed 72 groundwater monitoring wells and six pressure transducers in 21 wetlands north of Fort Collins, CO. Water chemistry and stable oxygen isotope data were also collected to identify the water source of specific wetlands. Groundwater wells, water chemistry and stable oxygen isotope data all show canals as a major water source for these wetlands. Because irrigation canals are integral to the maintenance of existing wetlands, future water transfers and agricultural water conservation measures should thus be carefully thought out to mitigate the drying of wetland habitat.

Swanson, Jennifer (8D)

Factors Influencing Survival and Mark Retention in Post-Metamorphic Boreal Chorus Frogs
Jennifer Swanson (CSU, Undergraduate), Larissa Bailey (CSU), Chris Funk (CSU), Erin Muths (USGS)

The ability to track individual animals is crucial in many field studies and often requires applying marks to captured individuals. Toe clipping has historically been a standard marking method for wild amphibian populations, but more recent marking methods include visual implant elastomer. Unfortunately, few studies have investigated the influence and effectiveness of marking methods for recently metamorphed individuals and as a result little is known about this life history phase for most amphibians. The focus of this study was to explore survival rates, mark migration, and both short- and long-term mark retention in post metamorphic Boreal Chorus Frogs (Psuedacris maculata) in a controlled laboratory setting. Three treatments were randomly assigned among 147 individuals: frogs were either injected with visual implant elastomer, toe clipped, or left unmarked as control individuals. Growth and mortality were recorded monthly for one year and resulting data was analyzed using known-fate models in program MARK. Model selection results suggested that survival probabilities of frogs varied with time and showed some variation among marking treatments. Frogs with multiple toes clipped on the same foot had lower survival probabilities than individuals in the other treatments. Frogs treated with visual implant elastomer had a mark migration rate of 4% and mark loss rate of 6% while no mark migration or loss was observed in toe clipped individuals.

Tredennick, Andrew (10A)

Patterns and Sustainability of Rural Fuelwood Demand in Sub-Saharan Africa
Andrew Tredennick (CSU, Graduate), Niall Hanan (South Dakota State University), Gabriela Bucini (University of Vermont), William Parton (CSU)

Humans have gathered firewood in African savannas for over 50,000 years. Today some 75% of African families depend on wood for cooking and heating. Despite this crucial role, no current and comprehensive assessment of the status of wood harvesting for energy in Sub-Saharan Africa (SSA) exists. We will present new high-resolution estimates of fuelwood demand for SSA as well as preliminary estimates of fuelwood supply (i.e., annual growth of woody biomass) based on remotely sensed data. We used FAO data of annual wood demand in conjunction with a spatial database of human population density to derive a fuelwood demand map. To estimate annual wood growth we first used remotely sensed estimates of woody cover in Africa to derive both actual and potential woody biomass for SSA. We then used a modified logistic growth model to estimate annual wood growth at 1km resolution. Using these two maps (demand and supply) we created a fuelwood spatial balance sheet. Our results suggest that, as a whole, African ecosystems produce sufficient wood to meet the current demand. However, the spatial distribution of fuelwood demand and supply is highly variable, with demand in population hotspots far outweighing local supply and thus requiring horizontal flows (i.e. marketing) of wood towards the cities and a number of high-population rural areas. Since demand for wood energy is projected to increase, we will discuss the sustainability of fuelwood harvest and the ecological implications.

Urza, Alexandra (12C)

Niche Differentiation During Canopy Recruitment Promotes Coexistence Between Shade Intolerant Conifer Species
Alexandra Urza (CSU, Graduate), Jason Sibold (CSU), Monique Rocca (CSU)

Western larch (Larix occidentalis) and lodgepole pine (Pinus contorta var. latifolia) are shade intolerant species that cohabit the subalpine zone of Glacier National Park, where recent fires have produced a large area of regenerating forest. Provided that seedlings can establish after fire, growth rates during canopy recruitment will impact seedling survival, determining the composition of the future forest. We used annual growth measurements to develop hierarchical models of seedling growth based on site, weather, and seedling age. Our results show that differential responses to environmental variability may have historically promoted coexistence between these two species, but projected climate changes that simultaneously increase disturbance frequency and favor lodgepole pine following fire may lead to a regional decline of larch.

Beebe, Chelsea (2)

An Ecological Study of Perognathus fasciatus: Estimating Species Abundance, Density, Home Range Size, and Seasonal Survival
Chelsea Beebe (CU Denver, Graduate), Michael Wunder (CU Denver)

The Olive-backed Pocket Mouse (Perognathus fasciatus) is a poorly studied member of the Heteromyidae family that has historically lived on the short/mixed grass prairies of the Colorado Front Range. Recorded captures have occurred at numerous sites along the Front Range including Larimer, Jefferson, Fremont, and Custer counties. Rapid human population growth on the eastern slope, especially in and around the city and county of Denver, has greatly reduced the habitat of P. fasciatus. A small population was found at the Plains Conservation Center (PCC), near Strasburg Colorado in August of 2010. Through a mark recapture study conducted at the PCC, I will estimate species abundance, density, and seasonal survival. Additionally, this project will gather basic information about P. fasciatus home range size through radio telemetry. These data will be useful for finding and describing additional populations of this species in the Front Range area of eastern Colorado. Study results will contribute to a more thorough understanding of the ecological role that this species plays in the prairie ecosystem, and provide insights that can be used to guide management practices designed to promote species survival and prosperity.

Bella Romero Elementary School, Greeley, CO (3)

Guppy Reactions to Predators
Katie Guilbert (4th grade teacher), Dale Broder (CSU), Lisa Angeloni (CSU)

Many small animals have to worry about getting eaten by larger animals called predators. Guppies are a small fish native to Trinidad and Tobago, but today you can also buy them at the pet store. We made a hypothesis that native guppies would react to a predator but that store bought guppies would not because they have never seen a predator before. We fed native and store bought guppies for five minutes and observed them eating. Then, we revealed the picture of the predator (a pike cichlid) and observed the guppies eating for five more minutes. We actually found that the store bought guppies responded more than the native guppies by eating less after seeing the predator. Store bought guppies have been away from Trinidad and predators for many generations, but they still remember what they look like. So it must be very important for guppies to recognize predators. We had fun doing scientific research and learned a lot about how native and store bought guppies react to predators.

Bergstrom, Robert (4)

The Role of Wetlands in Elemental Cycling in Forested Subalpine Ecosystems
Robert Bergstrom (CSU, Graduate)

Although wetlands constitute a very small relative percentage of Earths surface, they play a significant role in many critical ecosystem services. For example, wetlands are key areas for C sequestration and nutrient cycling. The biogeochemical regime that exists in wetlands differs from their upland counterparts, leading to the idea that C and nutrients such as N and P exist in markedly different concentrations in wetlands and uplands. These substances are effectively stored in wetland sinks. The goal of our study is to evaluate the role of subalpine wetlands and uplands in C and nutrient cycling at the Fraser Experimental Forest (FEF), CO. We propose to examine the flow of elements such as C, N, and P across catenary sequences in multiple watersheds. This project has begun with an intensive study of wetland soils in FEF, which will be tied to chemical data gathered in order to establish the pedological controls of elemental cycling in FEF. In developing a soil mass balance model, we expect to find that the upland soils are negatively strained and that the wetlands soils are positively strained due to elemental gains.

Betzen, Jake (5)

Determing the Effeciency of Microbial Biomass Measurement For a Tallgrass Prairie Soil, Using Fumigation-Centrifugation and Phospholipid Fatty Acid Assays
Jake Betzen (CSU, Undergraduate), Jenny Soong, Karolien Denef, Francesca Cotrufo

This work stems from a Research Experience for Undergraduate, in the context of the Bluestem Project (NSF DEB #0918482, PI:Francesca Cotrufo). The Bluestem Project aims at the fate of C and N from decomposing litter into the atmosphere and soil organic matter pools, by the use of stable isotopes. Microbes are one of the key drivers of decomposition in soil, and understanding and quantifying them is crucial to understanding the ecological processes underlying decomposition. Therefore accurate measurements of C and N in the soil microbial biomass are required. This research concerns determining the efficiency of microbial biomass measurements (i.e., k-factor), for the tall grass soil at the Konza Long-Term Biological Station, which is used for the Bluestem Project. The k-factor of a soil is the ratio of microbial biomass that is extracted and quantified after fumigation, over the total actual microbial biomass in the soil. A k-factor of 0.5 for carbon is usually used, but it was calculated for a range of silt loam and silty clay loam soils, that were involved in agricultural production, so it is important to know the specific k-factor for tallgrass prairie soils, which could be very different. A very novel side of this project, is that in addition to determining the k-factor for our soil using the fumigation-centrifugation method, we are also quantifying the extraction efficiency of the PLFA (phospholipid fatty acid, which are components of the microbial cell membrane) extraction method and the ratio between PLFA-C and microbial biomass-C, on the same soil. This will enable us to accurately quantify microbial biomass C from PLFA concentrations, which are already analyzed in our study for determining microbial community composition. Preliminary results from this work will be presented.

Borkenhagen, Andrea (6)

Developing Methods For Establishing Vegetation on Constructed Fens in Alberta's Oil Sands Region
Andrea Borkenhagen (CSU, Graduate), David Cooper (CSU)

The first self-sustaining reclamation fen of its kind is being constructed in an abandoned oil sands extraction area in Fort McMurray, Alberta, Canada. Our research focuses on determining the most effective methods for establishing moss and vascular species to vegetate the constructed fen and initiate the peat forming process. In 2011, we planted six moss and 11 native vascular fen species in a random split-box design. We are testing two moss planting methods, plugs and 1:10 ratio transfer, and vascular species seeds and seedlings. To impede desiccation and increase survival rates for mosses, we are experimenting with three protective cover treatments: a suspended 50% shade barrier to mimic a natural herbaceous layer, an appressed fabric cover to retain moisture and prevent invasive species, a shrub cover to provide shade and structure for moss growth, and a no-cover control. Additionally, rock phosphate fertilizer was applied to test whether it would encourage establishment and root-growth. First year survival data indicates that the fabric cover and optimal water levels (0-10cm below the peat surface) facilitated rapid establishment of certain moss species (Tomenthypnum nitens and Sphagnum warnstorfii). These data will be used to select the appropriate species and planting methods in the constructed fen. The overall goal is to create a functioning fen comparable to natural fens in the region and develop a globally applicable strategy for similar restoration projects.

Bryant, Heather (7)

Does Weather Influence Patterns of Hantavirus Infection in Natural Host Populations? Implications For Human Health
Heather Bryant (Fort Lewis College, Undergraduate), Erin Lehmer (FLC)

Infectious diseases often follow seasonal trends of human infection and Sin Nombre virus (SNV), a North American hantavirus, is no exception. Previous research has shown that human infection with SNV increases following periods of increased precipitation. However, whether SNV prevalence follows these seasonal trends in the natural host, the deer mouse (Peromyscus maniculatus), remains unclear. Therefore, our objective was to determine the extent to which SNV prevalence in deer mice is influenced by weather. In this process, we conducted a capture-mark-recapture study in which we live-trapped deer mice monthly (April to September 2011) in Hesperus, CO. After capture, we collected blood samples and demographic data from deer mice. We will use capture data and weather data collected from on-site weather stations to determine how temperature and precipitation influence SNV prevalence. Because body mass is correlated to immunocompetence, we will also determine the extent to which SNV infection status, body mass and weather variables are correlated. We predict that SNV prevalence will rise following periods of reduced temperatures and precipitation and will decline following warmer, drier months. Our research will provide much needed information regarding the mechanisms in which SNV is regulated in natural host populations, which will improve our ability to predict when humans are at greatest risk of infection.

Buma, Brian (8)

Urban Ecology, Vegetation Phenology, and Landscape Design: Towards Building More Ecologically Sensitive Cities.
Brian Buma (CU, Graduate), Travis Flohr (CU), Carol Wessman (CU), Brian Muller (CU), Mahda Bagher (CU) Mehdi Heris (CU), Daryoosh Ardalan (CU)

Building ecologically sensitive and responsible cities is one of the primary goals of urban ecology. A first step in designing such urban spaces is discovering relationships between urban green spaces, ecosystem services, socioeconomic variables, urban design and landscape planning, and natural areas. For example, green spaces within a city may partially ameliorate urban heat island effects, but at the cost of increased water usage. Such green spaces (e.g. parks, golf courses) may also be related to socioeconomic variables such as income and land values. As an exploratory step towards responsible designing cities going forward, this study looks at the Denver metropolitan area and its phenology, using seasonal patterns in vegetation growth and die-off as a proxy for vegetation density and type. Relationships of vegetation phenology (seasonality and productivity) with socio-economic variables such as income, variables associated with density of population and housing, and surface variables such as impermeable surface are significant. Moreover, proportions of built elements appear to be important, which suggests that urban design related to features such as impervious cover and configuration of building footprints may affect ecosystem services. Trends in phenologic change also correlate with increasing suburban development, indicating that current designs are not in sync with local vegetation patterns. However, the results also give clues as to designs which may present a lighter environmental footprint.

Burnett, Jonathan (9)

Forest Vegetation Cover of Fraser Experimental Forest Using Landsat Imagery
Jonathan Burnett (CSU, Undergraduate), Paul Evangelista (NREL), Rob Hubbard (USFS), Charles Rhoades (USFS)

The purpose of this project is to determine if land cover classifications based on LANDSAT imagery can accurately describe forest species composition at Fraser Experimental Forest. To test this, classifications will be conducted using a CART model, an unsupervised classification method and an unsupervised classification method. The CART model will utilize NDVI, elevation, aspect, climate, LANDSAT band and species composition to model the forest vegetative land cover. Supervised and unsupervised classifications will use field data to assign classification categories in terms of species composition. Each classification method will be validated and error checked using set-aside field data. The most accurate layer is intended to serve as a data layer for other ecological modeling projects. The results of this project will also be used to determine the feasibility of combining LANDSAT data with field data to model forest structure and to detect changes to forest vegetation as a result of disturbances from MPB or wind throw.

Burris, Lucy (10)

Modeling North American Playa Wetland Sedimentation Risk From Climate Change and Land Use, 1940-2100
Lucy Burris (CSU, Graduate),  Susan Skagen (USGS)

The ca 80,000 shallow playa wetlands on the semi-arid western Great Plains of North America are susceptible to sediment infilling from upland erosion, placing ecosystem services and habitats of wetland-dependent biota at risk. Climate predictions indicate reduced precipitation for this area which potentially may alter upland erosion rates, surface runoff, and sedimentation of playas. To evaluate this potential, we forecasted erosion rates, sediment depths, and resultant playa depths and examined the relative roles of surrounding land use context and projected changes in precipitation in the sedimentation process. We estimated upland erosion with the Revised Universal Soil Loss Equation (RUSLE) using historic values and downscaled precipitation predictions from three general circulation models and three emissions scenarios. RUSLE data requirements include only upland slope, annual precipitation, landuse, and soil properties  all values easily accessible across our large study area. We calibrated erosion results using field sediment measurements. Our estimates indicate that sediment accumulation rates will continue near historic levels through 2070 and are sufficient to cause most playas (if not already filled) to fill with sediment within the next 100 years in the absence of mitigation. Surrounding landuse, whether grassland or cropland, is more influential on sediment accumulation than climate-driven precipitation change.

Campbell, Eleanor (11)

Modeling Deep Soil Carbon
Eleanor Campbell (CSU, Graduate), Bill Parton (CSU), Keith Paustian (CSU)

The complexity and extended time periods associated with changes in soils make ecosystem modeling an important tool for understanding how different types of land management impact characteristics such as total soil carbon. Carbon cycling activity, particularly in the short-term, tends to be concentrated in surface soil layers. Therefore most models that simulate plant/soil interactions focus on the top 20  30cm of soil. These are important depths for capturing soil carbon changes, particularly as they relate to relatively short-term effects of land management decisions. However there is increasing interest in using deep soil layers to sequester atmospheric carbon as a climate change mitigation strategy, by developing, for example, plants that divert a larger portion of biomass to deeper root growth. While intriguing, these types of scenarios are not easily incorporated into existing models, where the simulated dynamics of surface soil carbon may not accurately reflect the dynamics of the diffusion of organic material, decomposition of fresh inputs of carbon, and the resulting carbon mass and residence time in deeper soil layers. We are developing and testing models to simulate changes in deep soil carbon, based on a series of hypothesis for the movement and decomposition characteristics of carbon in soils from 0 – 100cm.

Carter, Lane (12)

Spatial Gradients and Their Effect On the Ecological Modeling of Exotic Plant Invasion
Lane Carter (CSU, Undergraduate), Paul Evangelista (NREL), Tom Stohlgren (CSU), Kristin Saltonstall, Nicholas Young, Lane Carter

The aim of our study is to identify how environmental conditions that foster exotic plant invasions vary across geographic and spatial gradients in the United States. Our research focuses on Phragmites australis, an invasive plant originating from Europe. Occurrence points representing the presence of Phragmites were acquired from the National Institute of Invasive Species Science (NIISS) database and multiple field data collected by the co-authors. Spatial modeling was conducted using  the Maximum Entropy (Maxent) modeling package, fit with 19 bioclimatic variables from the WorldClim database.Spatial scales that were compared include three separate Landscape Conservation Cooperatives (LCCs) across the nation where Phragmites is known to be present, the southeastern United Sates, and the conterminous United States. To reduce covariates, consistent Phragmites occurrence data was utilized in all models with uniform model settings and methodologies allowing direct comparison between results and outputs. Statistical evaluations suggest that all of models had performed well. The environmental predictor variables and their predictive contribution varied significantly across our study areas suggesting that geographic and spatial extents affect predictive model results and our ability to forecast invasions.

Casar, Brad (13)

Climate Change and Grazing Impacts on Soil Carbon and Nitrogen Pools in the Tibetan Alpine Plateau
Brad Casar (CSU, Undergraduate), Kelly Hopping (CSU), Jorin Botte (CSU), Julia Klein (CSU), Francesca Cotrufo (CSU)

The ecosystem in the alpine grasslands of Tibet is expected to undergo dramatic changes in precipitation events and warming. These changes are expected to alter soil carbon and nitrogen pools and affecting the fauna and flora in the grasslands, which maintain soil composition, and provide the forage diet for grazing herds and nomadic peoples in the region. This study is investigating the independent and combined effects of climate change and grazing on soil carbon pools in the Tibetan alpine grasslands. By manipulating two expected climate changes; warming and snow additions, we are investigating shifts in future carbon and nitrogen pools in soil fractions. The experiment also includes yak and pika grazing treatments, and their effect on fauna composition and soil additions. After three years of manipulation, soil carbon and nitrogen levels were measured within three soil organic matter fractions (e.g., light fraction, free OM, and mineral-associated OM). According to the preliminary results, none of the treatments produced significant changes in carbon or nitrogen for any of the investigated OM fractions. Highly variable climatic conditions among the three years of the experiment may have mediated any treatment effects on the soil and carbon pools. In order to evaluate the impact of climate change and grazing on soil carbon and nitrogen stocks a longer experiment duration may be required.

Courtney, Cory (14)

Food Preferences in the Denver Urban Fox Squirrel (Sciurus niger)
Cory Courtney (Metropolitan State College of Denver, Undergraduate), Clare Ennis (MSCD)

Choosing the correct food type can increase a mammals fitness, especially going into the winter months. Preferences of three different nutritional foods were compared between two urban park populations of fox squirrels (Sciurus niger) in Denver City Park and Denver Cheesman Park under controlled conditions in October. Male and female squirrels of varying maturation showed preference of selection and consumption for high fat content, nutrient rich walnuts over high carbohydrate strawberries and nutritionally poor corn. There were no significant differences in food type preference or total food consumption between City Park and Cheesman Park. Additionally, there was no significant difference in total walnut food selection/consumption observed between males and females of the urban park populations. Urban fox squirrels of both urban park populations demonstrated the following three food-related behaviors: stay and eat; select and run; select and bury. Urban fox squirrel preference for walnuts in October may relate to its storability and its relatively high energy content and high efficiency of metabolism.

Craig, Apryle (15)

The Effects of Rocky Mountain Elk (Cervus elaphus) Browse On Biological Diversity in Montane Riparian Willow Communities of Rocky Mountain National Park
Apryle Craig (CSU, Graduate), Barry Noon (CSU)

Research conducted in Rocky Mountain National Park (RMNP) indicates that the elk population is denser, less migratory, and more concentrated than it would be under natural conditions. This unnatural condition has led to changes in plant communities in the core elk winter range and the potential for significant declines in biodiversity within montane riparian willow communities.      To protect vegetation from elk herbivory and promote habitat recovery, RMNP's Elk and Vegetation Management Plan calls for fencing up to 260 acres of riparian willow communities on the parks east side. Park staff monitor the willow plant communities inside and outside of the exclosures for changes in vegetation. However, no studies in RMNP have directly addressed the impacts of elk browse on biodiversity. Our research will measure terrestrial invertebrate and small mammal diversity inside and outside fenced exclosures of different ages and in different areas of the park. We seek to determine the effects of elk herbivory on invertebrate and small mammal species composition and abundances, assess the effects of the exclosure installation date on the temporal dynamics of biodiversity response, and identify invertebrate and small mammal species that may be indicators of willow plant community response to declines in levels of herbivory.

Derr, Morgan (16)

Mountain Pine Beetle: Knowing the Facts
Morgan Derr (CSU, Undergraduate)

The United States is unique in that it conserves vast expanses of land for its citizens to use and enjoy. With this comes public responsibility in caring and managing our natural resources. As a student of forestry, I have come to understand that practical and efficient forest management requires collaboration between those who use the resource and those who manage it. Fundamental to this collaboration is comprehensive information made available to the public to educate people about the causes, the preventions and the cures of issues impacting todays forests. As the Rocky Mountain region faces one of its most drastic ecological challenges yet, the mountain pine beetle infestation, education of the public becomes essential in developing partnerships and solutions. Therefore, as a component of my senior honors thesis, I have developed a bilingual brochure that provides up-to-date, yet easily understood information for those who use and enjoy the forests affected by the mountain pine beetle. The brochure is an attempt to bring forest managers and the public together toward protecting a vital resource.

Ex, Seth (17)

Production Efficiency and Growth Dominance: Two Measures of Relative Productivity in Forest Stands
Seth Ex (CSU, Graduate), Frederick W. Smith (CSU)

Productivity differences between trees in stands can influence resource management and reflect ecological processes. Foresters commonly compare productivity using stemwood growth per unit leaf area as a metric of production efficiency. Growth dominance analysis is an alternative method that compares proportion of stand biomass held by a tree to proportion of stand biomass production. Stem biomass or volume are often substituted for whole tree biomass. Both techniques attempt to indirectly measure resource use efficiency. Production efficiency analysis explicitly assumes leaf area estimates light capture, while dominance analysis implicitly assumes tree biomass is proportional to resource acquisition. This implies both methodologies should chart similar trends in a given stand. We tested this proposition using data from over 1,400 ponderosa pine trees from 21 stands in the Black Hills. Production efficiency analysis showed large trees were ~20% more efficient than small trees. Surprisingly, growth dominance analysis using stem volume suggested small trees were more efficient. We maintain change in the relationship between leaf area and stem volume over a range of tree sizes was responsible for this apparent disparity. Both leaf area and stem volume increased as trees grew. However, leaf area increase slowed relative to stem volume increase over time. Results from both techniques were comparable when growth dominance analysis was repeated using leaf area instead of stem volume.

Fernholz, Lisa (18)

Microbial Community Affects Methane Uptake Across the North American Great Plains
Lisa Fernholz (CSU, Undergraduate), Jackie Sitko, Rachael Jorgensen, Evan Rosenlieb, Shreya Pokharel, Joe von Fischer (CSU)

How is an ecosystem affected by its microbial community composition? Our approach to this question begins with measurement of methane uptake by methanotrophs in soil across the Great Plains grasslands. To add depth we are also measuring the physiological attributes of the methanotrophs, their community composition and the properties of their location. We have 22 sites from seven grassland locations that span the physical and climate diversity of the Great Plains. In the first year of study we have measured and built a data base for methane uptake rates, Michaelis-Menton enzyme kinetics, soil moisture, temperature, pH, soil diffusivity, soil textures, and ammonium and nitrate concentration data. The preliminary results demonstrate that in sites located further upland the conditions were much drier, the pH was higher and methane uptake rates by methanotrophs were slower than in most lowland sites. Our results also indicated that soil diffusivity was related to soil moisture and texture. In our experiments testing Michaelis-Menton enzyme kinetics we found that maximum saturation and Km were achieved at greatly different rates from site to site. In conclusion, the sites we have chosen are a strong representation of varying environmental properties and methane uptake rates. We hope that in the next few years of this project new insights in the understanding of ecosystem function can be discovered.

Frank, John (19)

Errors in Measured Sensible Heat Flux Due to Vertical Velocity Measurements in Non-Orthogonal Sonic Anemometers
John Frank (UW, Graduate), Bill Massman (USFS), Brent Ewers (UW)

Sonic thermometry and anemometry are fundamental to all eddy-covariance studies of surface energy balance and ecosystem carbon and water relations. Recent studies have suggested that sonic anemometers with non-orthogonal transducers can underestimate vertical wind velocity (w) and sensible heat flux (H) when compared to tradition orthogonal designs. In this study errors in measurements of u, v (horizontal wind velocity components), w and H were tested in a non-orthogonal sonic anemometer (CSAT3, Campbell Scientific, Inc.) and compared to an orthogonal sonic anemometer (SATI/3Vx, Applied Technologies, Inc.) at the GLEES AmeriFlux site (southeastern Wyoming, USA). Four CSAT3s and one SATI/3Vx were mounted symmetrically on top of the AmeriFlux scaffold and in close enough proximity to allow covariance measurements between neighboring sonic anemometers. The CSAT3 sonics were paired and tested by alternatively rotating each one 90o around its u-axis, essentially forcing the sonic v-axis to measure the true w-axis, and vice versa. Analysis was performed only on data corresponding to substantial gusts of wind located within the 15o cone defined around the u-axis. Treatment effects due to rotation were considered evidence of bias errors in either the sonic v and/or w measurements. Results show that in the non-orthogonal sonic anemometers w and H increased by 6.5% and 9.6% when they were rotated 90o horizontally while only minor changes were found in the u and v measurements. Simultaneously, w and H from the orthogonal sonic anemometer was about 10% greater. Although this evidence is only suggestive that the discrepancy between sonic anemometer designs can be traced to erroneous w measurements, its implications could be far reaching for ecosystem flux research considering the prevalence of the non-orthogonal design.

Fulbright, Scott (20)

Characterization of the Bacterial Metagenome in an Industrial Algae Bioenergy Production System
Scott Fulbright (CSU, Graduate), Shi Huang (QIBEBT), Xiaowei Zeng (QIBEBT), Greg Wardle (Solix), Peter Lammers (NMSU), Stephen Chisholm (CSU)

Cultivation of microalgae for fuel generally requires growth of an intended species. The presence of undesired competitors, pathogens and grazers in cultivation systems will create competition for nutrients in the growth medium and potentially decrease microalgal triglyceride production. Pathogenic bacteria may also directly impact the metabolism or survival of individual microalgal cells. Conversely, symbiotic bacteria that enhance microalgal growth may also be present in the system. These considerations underscore the need to understand bacterial community dynamics in microalgal production systems in order to assess microbiome effects on microalgal productivity and pathogen risks. Here we focus on the bacterial component of microalgal production systems and describe a pipeline for metagenomic characterization of bacterial diversity in industrial cultures of an oleaginous alga, Nannochloropsis salina. Environmental DNA was isolated from 12 marine algal cultures grown at Solix Biofuels, a region of the 16S rRNA gene was amplified by PCR, and 16S amplicons were sequenced using a 454 automated pyrosequencer. The majority of sequences belonged to thirteen phyla. At the genus level, sequences from all samples represented 169 different genera. Of all sequences, 79.92% corresponded to 169 genera and 70 other taxa. We apply a principal component analysis across the initial sample set to draw correlations between sample variables and changes in microbiome populations.

Gasch, Caley (21)

Spatial Patterns of Vegetation and Soil Properties in Sagebrush Steppe Change in Response to Drastic Disturbance and Reclamation
Caley Gasch (UW, Graduate), Peter Stahl (UW), Snehalata Huzurbazar (UW)

Reclamation efforts across Wyoming have been successful in reestablishing herbaceous biomass, but restoration of the sagebrush component has proven difficult. The sagebrush steppe community possesses patchiness and heterogeneity. These shrub-associated spatial patterns are apparent belowground in abiotic and biotic soil properties and influence distribution of water and nutrient cycling. We hypothesize that drastic disturbance alters the spatial structure of aboveground and belowground communities. Specifically, we predict that disturbed and reclaimed areas experience homogenization in above- and belowground properties. We established plots on a recently reclaimed pipeline and an adjacent undisturbed reference area in south central Wyoming. Vegetation and soils were sampled on a small spatial scale (0-10 m) and soils were analyzed for physical, chemical, and biological properties. Preliminary results indicated that the reclaimed area had more vegetative biomass, and more homogeneous and continuous vegetative cover. Conversely, undisturbed plots displayed a more patchy distribution of a more diverse plant community. Reclaimed plots demonstrated less variability in spatial patterns of soil characteristics, and these belowground patterns appeared to be associated with the vegetation. These findings emphasize the potential importance of reestablishing the sagebrush component on disturbed lands for successfully restoring ecosystem structure and function.

Gates, Brian (22)

The Effect of the Environmentors Program On Increasing Students Interest in Pursuing Environmental-Related College Majors and Careers
Brian Gates (CSU, Graduate), Brett Bruyere (CSU), Kirsten Broadfoot

EnvironMentors is a national mentoring program that prepares high school students from under-represented backgrounds for college majors in environmental and related science disciplines. Students conduct environmentally-related research projects over the course of the academic year at their local EnvironMentors chapter and then compete in chapter science fairs for trip to the National Fair in Washington, DC. To examine whether EnvironMentors was preparing high school students for majors in environmental and related science disciplines, focus groups were conducted with National Fair participants in both 2010 and 2011 to capture their reflections on program process. In both years, students reported that the mentoring relationship experience, positive/rewarding program experiences, and project experiences and skill development contributed greatly to their success in EnvironMentors. These student growth factors led some students to change their college/career plans to a science-related track as a result of EnvironMentors while others clarified their current college/career plans. Conversely, several students reported no change in their career plans, regardless of the influence of EnvironMentors. Given the varied results of the EnvironMentors programs impact on influencing students attitudes toward pursuing environmental- and science-related college majors and careers, further emphasis is needed on presenting these disciplines to the students as desirable options.

Hammond, Boyd (23)

Do Guppies Establish a Dominance Hierarchy in Foraging?
Boyd Hammond (CSU, Undergraduate), Sarah Westrick, Boyd Hammond, Dale Broder, Lisa Angeloni

The position of an individual within a dominance hierarchy in a social group can influence its fitness by determining its access to resources. Wild-caught Trinidadian guppies have been shown to form linear hierarchies based on sex, size, and aggressiveness. Guppies also display aggression while foraging and may monopolize foraging patches. However, we have never observed the formation of dominance hierarchies or foraging patch monopoly in our thirty-minute foraging trials with second-generation lab-reared fish. We, therefore, designed a longer-term foraging trial to determine whether social interactions, including patch monopoly and aggression, might change over time if groups of lab-reared guppies are allowed to interact over a longer time period. After rearing males to the second generation in recirculation systems, we placed three fish in a 2.5- gallon tank and let them interact with each other over the course of four days. The guppies were fed a food patch each morning and afternoon, and individual bites and aggressive acts were recorded. No patch monopoly was observed, and rates of aggression and foraging did not change over time. We found no evidence of dominance hierarchies based on patch monopoly, aggression, or foraging rates. Because our findings differ from the findings of other studies conducted on wild-caught fish, these results have implications for behavioral studies on lab-reared guppies, particularly those involving aggression.

Harrington, Rachel (24)

Diversity and Turnover of Benthic Macroinvertebrate Taxa and Functional Traits Along an Elevational Gradient in Colorados Front Range
Rachel Harrington (CSU, Graduate), Brian Gill (CSU), Alisha Shah (CSU), Carolina Gutierrez (CSU), Boris Kondratieff (CSU), and LeRoy Poff (CSU)

In the face of rapid environmental change, ecologists are increasingly challenged to understand how spatial patterns of biodiversity and functional composition of communities are shaped by local environmental conditions. Changes in biological organization along steep elevational gradients in mountain ranges can offer insight into how temperature and hydrologic regime naturally regulate species distribution. Thus, these relationships can provide a basis for predicting the vulnerability of individual species and broader community composition to rapid change in precipitation and temperature. We sampled macroinvertebrates in 1st and 2nd order streams at 200 meter elevation bands from 1600-3600m in 3 drainages along Colorados Front Range. Environmental variables (substrate, slope, riparian shading, temperature, flow, etc.) were collected at each site and related to turnover of taxa richness and functional traits of benthic macroinvertebrate communities. We determined inter-site distances within elevation bands and compared differences among replicate sites to taxonomic and trait turnover across elevations to examine species and community vulnerability to climate change. These results will eventually be compared to similar data across elevation gradients in tropical montane streams in Ecuador.

Hassler, Andrea (25)

An Analysis of Burn Severity, Vegetation Regrowth and Restoration in the Hayman Burn Area
Andrea Hassler (CU Colorado Springs, Graduate), Matt Sidor, Bret Bellezio

This work presents a study which used Landsat TM and ETM+ satellite imagery to analyze burn severity and vegetation regrowth in the Hayman burn area. Band 7 was used to identify patterns by image differencing multiple dates. An assesment of BAER rehabilitation, current restoration and potentials for effective restoration is discussed. Further research will include vegetation indices, regression analysis, and ground truthing. Initial results have shown a correlation of burn severity with vegetation regrowth and the potential for identifying areas of soil rehabilitation. This research hopes to contribute to the greater wealth of knowledge in the field of watershed scale restoration ecology as well as methodology for planning, monitoring and evaluating restoration efforts.

Horton, Andrew (26)

Investigating the Fate of Nitrogen From Leaf Litter Into Soil, Soil Organisms and Plants at a Tall Grass Prairie, By the Use of 15N Enrichment
Andrew Horton (CSU, Graduate), Jennifer Soong (CSU), and Francesca Cotrufo (CSU)

Decomposition is an essential step in the recycling of nutrients. The decomposition of dead organic matter is the largest source of nitrogen (N) for plants, and N is the most limiting nutrient for primary productivity in the Northern Hemisphere. The general fate of N during decomposition is well understood in a broad sense, due to extensive studies of litter mass loss and total N concentration in litter. However, the relative contribution of litter N to a) mineral N available for plants and b) immobilized N in microbial biomass and further stabilized in soil organic matter pools remains unknown. This understanding is important in the context of reactive N dynamics and global change. We present here results from a study conducted in the context of a larger NSF-DEB funded experiment, which is currently ongoing at the Konza LTER site, located in the flint hills region of Kansas. Isotopically labeled (e.g., 13C and 15N enriched) big bluestem (Andropogon gerardii) litter, the dominant native species at the site, was incubate in October of 2010 inside raised collars. A fauna suppression treatment (naphthalene) was applied to half of the collars. Litter and soils were collected in May and October of 2011. Soils were separated by depths (0-2, 2-5, 5-10, and 10-20 cm) and density (e.g., LF, free-OM, mineral associated-OM), and analyzed for N and 15N. We will present results of N fluxes within and between the litter and soil, and the effect of faunal suppression on these fluxes.

Jones, Nathan (27)

The Impact of Energy Sprawl on Biodiversity and Ecosystem Services
Nathan Jones (CSU, Graduate), Liba Pejchar (CSU)

The benefits of wind energy include reduced emissions and cleaner air. However, much like oil and gas, wind development leaves a footprint on the landscape. To understand the relative nature and magnitude of this footprint, we will quantify the impacts of wind, oil and natural gas development on biodiversity and ecosystem services using a diverse set of indicators. These include wildlife mortality, habitat loss, noise and light pollution, fragmentation, edge effect, invasive species, water resources and carbon storage. A stratified random sample of one kilometer diameter plots was selected from within Colorado and Wyoming to represent a variety of land uses, including energy development. Aerial imagery will be supplemented with empirical data and development plans to determine the impacts to each indicator for each land use. The objectives of this research will be to measure the variation in impacts to assess how differences in land characteristics and development design affect biodiversity and ecosystem services. In addition, comparisons will be based on standardized units of energy production in order to more accurately compare the two alternative energy sources. Our goal is to provide the conservation community, the energy industry and the average American with a better understanding of the impacts of energy sprawl on the landscape.

Kirk, Kathryn (28)

Investigating Plasticity of the Intromittent Organ in Guppies
Kathryn Kirk (CSU, Undergraduate), E. Dale Broder (CSU), Lisa M. Angeloni (CSU)

There has been long-standing interest in the factors that drive the evolution of reproductive organs and contribute to the diversity of genital morphology within and among sexually reproducing species. Genital evolution has been studied in Poecillid fishes, including the Trinidadian guppy, where males use a gonopodium to inseminate females. Previous studies have shown that guppies in different environments that vary in predation pressure have different gonopodium lengths, which has been attributed to selection for shorter gonopodia in environments where protruding genitalia may increase predation risk. We investigated whether the gonopodium exhibits developmental plasticity by rearing brothers in two laboratory treatments, with or without predator chemical cues. We anesthetized and photographed each male at maturity and measured standard body length and gonopodium length. We found that the absolute length of the gonopodium did not differ depending on the rearing treatment. However, because fish exposed to predator cues had shorter bodies but not shorter gonopodia at maturity, their gonopodia were larger relative to body size than their brothers reared in predator-free water. This study is the first investigation of plasticity of genitalia in a Poecillid fish, and suggests that investment in genitalia may be less plastic than investment in other body tissues resulting in environmentally altered ratios of genitalia to body size, which may have consequences for fitness.

Lewis, Jesse (29)

Estimating Mountain Lion Density With Motion-Activated Cameras Using Mark-Resight
Jesse Lewis (CSU, Graduate), Kevin Crooks (CSU), Larissa Bailey (CSU), Sue VandeWoude (CSU), Ken Logan (CSU)

Reliable population estimates of wildlife are critical for management and conservation. Large carnivores present challenges to estimating population size due to their secretive nature, inherently low population densities, and wide-ranging movements. It has been particularly difficult to obtain reliable population estimates of mountain lions, and this information would be especially useful to wildlife agencies in western states which manage hunting seasons on these populations. Our goal in this project was to estimate lion density with camera grid and mark-resight methods to inform improved designs and field operations. Using mark-resight techniques in program MARK, we evaluated density estimates for a mountain lion population on the Uncompahgre Plateau, CO that has been the subject of an intensive radio-collaring and demographic study since 2004. Over a 3.5 month period during summer and fall 2009, we obtained 80 photographs of lions (51 marked, 29 unmarked) across 40 motion-activated camera sites spaced approximately 2-km apart within two 80 km2 grids. We detected 7 out of 9 collared lions using our sampling grids. Home ranges were estimated for lions wearing GPS collars and this information was used to relate the density of mountain lions to our sampling grids. These results can inform camera grid designs scaled specifically to mountain lions to obtain better population estimates and might also be useful for designing camera and mark-resight methods for other large carnivores.

Liu, Yao (30)

Modeling Vegetation of the Past: Integrating Fossil Pollen Data With Vegetation Modeling
Yao Liu (UW, Graduate), Simon Brewer (UW and UUtah), and Stephen T. Jackson (UW)

Dynamic global vegetation models (DGVMs) can be used to predict terrestrial ecosystem changes under future climate predictions. Data from paleoecological studies allows us to test the predictive ability of a DGVM (LPJ-GUESS) under past environmental conditions that are different from the present. We simulated the vegetation over the past 15,000 years using inputs of transient past-climate simulation with the CCSM General Circulation Model (Liu, Z., et al., 2009, Transient Simulation of Last Deglaciation with a New Mechanism for Bolling-Allerod Warming. Science, 325) at representative pollen sites in eastern North America. We modeled changes in plant functional types (PFTs) at these sites, and compared the simulation result with the observed fossil pollen record. Our preliminary results show that simulated pollen sequences in eastern North America are generally consistent with the pollen record. Significant mismatches indicate i) issues in comparing simulated vegetation with pollen-inferred vegetation, ii) inaccurate parametrization of North American PFTs. Our work provides a framework for similar model-data comparison, experiments for identifying important climatic factors for terrestrial ecosystems, and hypothesis testing of past ecological events. Currently we are conducting experiments using this framework to explore hypotheses regarding driving mechanisms of the late-glacial novel vegetation communities, and the mid-Holocene hemlock decline.

Lopez Elementary School, Fort Collins, CO (31)

Guppies Foraging Without and With a Predator Smell
Britney Delehoy (Lopez Elementary teacher), Dale Broder (CSU), Lisa Angeloni (CSU)

We learned that the scientific method is one way researchers gather information about the word around them. In order to better understand this method, we investigated the guppy since their behavior is easy to observe and we can keep them in our classroom. We focused on foraging behavior and response to a predator. We used chemical cues from a pike cichlid predator combined with distress cues from a guppy and compared number of bites taken before and after this chemical cue. We compared males versus females as well as pet store guppies versus Trinidadian native guppies. We found support for our hypothesis that pet store would eat more than native, but not for our hypothesis that females eat more than males. We also found support for our hypothesis that pet store guppies would be more scared of a predator but not for our hypothesis that females would be more scared than males. During this project, we learned a lot about guppies and increased our confidence in our ability to conduct science.

McLaughlin, Sara (32)

Effects of Microclimate Conditions at Cache Sites on American Pika (Ochotona princeps) Survival
Sara McLaughlin (CSU, Undergraduate), Chris Ray (CU)

The American Pika (Ochotona princeps), is a small, hamster-like mammal that resides in rocky habitats (talus) throughout much of western North America. To cope with extreme alpine habitats, in which the species most commonly occurs, the pika has evolved efficient behavioral and physiological methods of thermoregulation. MacArthur and Wang (1973) discovered that pikas have a very high resting body temperature, 40.6C. This temperature is dangerously close to their upper lethal level of 43.0C, leaving very little cushion for temperature increases. In summer months pika rely on behavioral strategies to regulate body temperature and keep from over-heating. It has been observed that when ambient temperatures are high, they avoid prolonged surface activity and find refuge in cooler, sub-surface locations under the talus (MacArthur and Wang, 1973). Many sources in the pika literature suggest that access to cooler microclimates within the talus is critical to pika survival during the summer. This project will use data on pika survival and microclimate from the Niwot Ridge Long-term Ecological Research site in Colorado to understand how these microclimates will effect pika survival. In addition, over the course of one summer, temperatures from cache sites will be compared to temperatures recorded in other locations throughout the territories of several pikas to help explain any findings relating survival to temperature at cache sites.

McShane, Ryan (33)

Climatic and Hydro-Geomorphic Controls of Riparian Woody Plants in the Western United States
Ryan McShane (CSU, Graduate), Dan Auerbach (CSU), LeRoy Poff (CSU), Jonathan Friedman (USGS), Greg Auble (USGS)

Riparian vegetation is integral to western US landscapes, shaping riverine biodiversity and ecosystem processes. However, ongoing hydrologic alterations, land-use transformations, non-native species introductions and rapid climate change are profoundly modifying riparian communities. To better understand the relative importance of these forces, we analyzed data from a riparian vegetation survey conducted at 456 sites near streamgages with at least 20 years of record. We used conditional inference classification and regression trees to discriminate among 14 climatic and hydro-geomorphic variables as controls of 9 riparian species distribution and abundance. Our analysis was conducted both across the western US and within the Missouri and Colorado River basins to determine the importance of environmental controls at different scales. Climate controls sub-continental distribution of the dominant riparian species, but within the river basins, valley form and streamflow regime influence their abundance. We will apply this information to forecasting the distribution of tamarisk and plains cottonwood in the upper Green River basin of Wyoming, using a model that integrates spatially-explicit hydrology and geomorphology with changing climatic conditions and water-infrastructure operations. These efforts will inform managers challenged with mitigating and adapting to the effects of global change on western US rivers.

Miller, Adam (34)

Pollination By Native and Non-Native Bees in Large-Scale Forest Restoration in Hawaii
Adam Miller (CSU, Undergraduate), Liba Pejchar (CSU)

The biodiversity of the Hawaiian Islands has long been of interest to ecologists. However due to habitat loss and the introduction of non-native species, many native species are in danger of extinction. Because of important species interactions like seed dispersal and pollination, the decline or loss of some species could have cascading effects on the ecosystem. For example, there is only one native genus of bees with only 60 species in it. The genus Hylaeus has gone unnoticed by biologists for many decades and therefore the conservation status and ecological role of these species is virtually unknown. Our project will investigate how members of the Hylaeus genus interact with flowering plants in a large-scale forest restoration system. Specifically, we will compare the pollination role of native bees and non-native bees and determine how pollen load varies with habitat type and distance to mature forest. We used pan traps to collect bees at 130 stations in mature forest, planted stands and open pastureland. This will be the first investigation into whether non-native bee species in Hawaii are beneficial or detrimental to restoration efforts and the first study to document the role of Hylaeus spp. in restoration of native forest.

Nelson, Ron (35)

Restoration of a Riparian Buffer: Traditional and Non-Market Benefits and Costs
Ron Nelson (CSU, Graduate), Heather MacKay (FHB Consulting)

This paper reports on the estimation of non-market values for ecosystem services associated with stream buffer restoration on Fourmile Creek in the Nooksack watershed, Washington State. A partnership was established with the Conservation District, local landowners and Washington Department of Fish and Wildlife (WDFW). Funding was provided by grants from WA Department of Ecology, WDFW and local matching funds. The restoration project involved removal of accumulated sediments and non-native reed canary grass from the stream channel to improve drainage, and then planting of native trees and shrubs in riparian buffers between 15 and 30 feet in width. Since the project was completed in 2005, some maintenance and replanting of vegetation has occurred, but the channel remains clear of sediments and reed canary grass and the water quality meets requirements at the confluence with Tenmile Creek downstream. Since the initial investment in restoration, the project has generated tangible benefits for agricultural landowners, fish habitat and water quality. In an attempt to quantify these, a pre-analysis of the benefits and costs was undertaken using non-market valuation methods and the benefit transfer method to estimate ranges of values for the ecosystem services provided by the stream restoration. Ecosystem services included increased pollinator habitat, aesthetic value, water quality and biodiversity.

Paddock, Sherry (36)

Effect of Sin Nombre Virus on Rate of Co-Infection in Peromyscus maniculatus
Sherry Paddock (Fort Lewis College, Undergraduate), Alena Simpkiss, Nellie McClean, Erin Lehmer

Hantavirus is found throughout the world, but the Sin Nombre strain is highly prevalent in the Southwest region of the United States. Sin Nombre virus (SNV) is a rodent-borne zoonotic pathogen that causes Hantavirus Pulmonary Syndrome (HPS) in humans, a disease with exceptionally high (~40%) mortality rates. The natural reservoir for SNV is the deer mouse (Peromyscus maniculatus). Once infected with SNV, deer mice remain infected for life without exhibiting symptoms; however, it is unknown whether chronic infection with SNV impacts the ability of deer mice to respond to other immune challenges. Thus, our objectives are to determine whether deer mice infected with SNV are more likely to become infected with other pathogens, specifically Bartonella, a bacterial pathogen that is endemic in rodents. As part of this study, we are conducting a capture-mark-recapture study in which we live-trap deer mice monthly from April to November. Upon capture, we collect blood samples from individual deer mice and test these samples for both SNV and Bartonella. Using this study design, we will determine the extent to which infection with SNV is correlated to infection with Bartonella. This research will shed light on patterns of co-infection and immunocompetence of wild rodents, which ultimately will improve our ability to predict human patterns of infection with zoonotic pathogens.

Richards, Andrew (37)

Impacts of Russian Olive on Riparian Ecosystems
Andrew Richards (CSU, Undergraduate), Graham Tuttle (CSU)

Russian olive (Elaeagnus angustifolia) is an invasive tree commonly found in riparian habitats in western North America. This tree can greatly impact ecosystems, potentially creating a feedback loop that allows other exotics to invade. However, the ecological impacts of this tree have not been fully evaluated. Our study is designed to quantify the extent and duration of the impacts that Russian olive may have, and to evaluate the impact of removal efforts on plant communities. Using a paired plot design, we collected plant species percent cover and plant available nitrogen data from plots underneath Russian olive canopy (Russian olive plots) and at least three meters away from its canopy (reference plots). After two years of data, several interesting patterns emerged. Exotics had significantly higher percent cover and natives had significantly lower percent cover in Russian olive plots than reference plots. Plant available nitrogen (estimated using resin bags) was on average 56.7% higher under Russian olive than in adjacent reference plots. Russian olive will be mechanically removed from a subset of my plots and stumps will be treated with herbicide to prevent regrowth. We will continue to monitor the effects of nitrogen on Russian olive or its removal on plant community structure for the next three years.

Rodman, Kyle (38)

Bluffs Trail Reconstruction: A Study on the Social, Economic and Environmental Benefits of Recreational Trails and Restoration to the UCCS Campus
Kyle Rodman (CU Colorado Springs, Undergraduate)

The University of Colorado at Colorado Springs (UCCS) campus contains a significant portion of open space that is currently undeveloped, and much of this area has no plans for development in the future. The open space would best serve the University as a natural outdoor recreational amenity that might be enjoyed by students, faculty and staff for years to come. In addition to this, well planned recreational usage maintains many of the important utilitarian functions of the landscape such as preventing damage to water quality through erosion and sedimentation. Though not ideal for all types of maintenance, volunteer labor can be utilized effectively for many of the projects on campus open space. One such project took place on the fitness trail behind Main Hall at UCCS on October 9th and 15th. During this two day period, many goals of trail maintenance and designation were successfully implemented with the help of 18 volunteers (both students and faculty) from the school.

Salley, Shawn (39)

Soil Landscape Development in the Short-Grass Steppe Ecosystem
Shawn Salley (CSU, Graduate)

Today, remarkably similar soils mantle the short-grass steppe ecosystem on the northern Colorado Piedmont. Pedologic factors that make those soils so similar are both a semiarid climate and a resilient plant community. While spatial heterogeneity does indeed exist among soils in the short-grass steppe, the combined effects of vegetation and climate have created a uniquely spatial homogenous soil-landscape mosaic when compared to soil of other ecosystems. We identified dominate soil conditioning factors by combining Soil Survey Geographic data with geologic, geomorphic, and elevation data in northeastern Colorado, therefore isolating geographic areas where contributions of single state factor outrank the combined contribution of other factors. In water limited systems areas such as the short-grass steppe, three broad phases of soil development can be identified according to landscape age that we believe to be ecologically and biogeochemically significant. We described these pedologic phases in which soils are: Aggrading or Building, Intermediate or Equilibrium, and Degrading or Declining. This geographic approach to modeling pedologic and ecohydrologic dynamics identify regions where soil capacity to store water and mobile atoms like Ca, Mg, and K area at a relative maximum.

Schmidt, Bradley (40)

Evaluating the Relationship Between Physical Variables and Vegetative Composition and Biomass in the Loch Vale Watershed
Bradley Schmidt (CSU, Undergraduate), Dr. Stephanie Kampf (CSU), Kelsey Forrest (CSU), Julia Klein (CSU)

The Loch Vale watershed is located east of the continental divide in Rocky Mountain National Park, ranging from 3110 m to 4009 m in elevation. The watershed is 660 ha in size and has been studied as a long-term ecological site since 1981. Predicted changes in precipitation and temperature patterns as a result of climate change have created the need to research factors currently affecting the spatial distribution subalpine vegetation communities like those found in this watershed. We explored the role of summer soil moisture in affecting tree species composition and biomass since it is an important driver of ecological processes, and will likely vary in response to changes in climate. Other variables evaluated were elevation, aspect, and slope. We georeferenced two 200 m transects where we had previously recorded all tree locations, species, heights, and diameters at breast height within 20 m of the transect. For the next stage of the project, we will combine the tree data with the measured abiotic and physical data collected at the site, and with soil moisture data from a spatially-explicit hydrologic model of soil moisture created for the same area, with the goal of examining the connections between subalpine tree species composition and biomass as it relates to the timing and amount of soil moisture and other abiotic and topographic variables.

Scott, Heather (41)

The Effects of Bark Beetle Moratily on Ecosystem Carbon Cycling
Heather Scott (CSU, Graduate), Mike Ryan (CSU), Bill Massman (RMRS), Brianna Miles (RMRS), and John Frank (RMRS/UW)

Bark beetle epidemics have killed much western North America forests. This mass mortality has had significant impacts carbon flux of these forests. In this study, we investigate how the ecosystem is responding; both from the standpoint of individual component fluxes and as the entire ecosystem. The GLEES AmeriFlux site (southeastern Wyoming, USA) was constructed in 2005 and attacked by bark beetles in 2008. This old-growth Engelmann spruce (Picea engelmannii) and subalpine fir (Abies lasiocarpa) has experienced an excess of 80% basal area mortality due to the bark beetle outbreak. As a whole, the system has transformed from a carbon sink to a source. This transformation is almost entirely due to a loss in gross primary production; surprisingly the ecosystem respiration rates have remained constant at pre-outbreak levels. This stands in contrast to standing theories that mortality results in a sharp loss of ecosystem respiration. Obviously there is much more to disturbance carbon cycling that warrants investigation.

Shah, Alisha (42)

Oxygen-Limited Thermal Tolerance in Aquatic Insects in Temperate and Tropical Streams: Are There Differences in Vulnerability?
Alisha Shah (CSU, Graduate)

My research project uses physiology as a measure of vulnerability of freshwater organisms to rapid climate change. Using a respirometer, I will determine the range of thermal tolerance and critical levels of dissolved oxygen for entire communities of phylogenetically related aquatic insects along an elevational gradient at temperate and tropical latitudes. This provides an understanding of the role that temperature and dissolved oxygen play in determining the range-limit of freshwater organisms. As dissolved oxygen decreases with increasing temperature, I will establish which species are most vulnerable, and how this might alter community structure. I will then use an individual-based approach to explore the relationship between dispersal and physiological tolerance. Dispersal data (inferred through population genetics) will be collected from a related project. Do long-distance dispersers have a higher thermal tolerance and resistance to hypoxia than non-dispersers as theory suggests? This two-tier approach provides a mechanistic understanding of species distributionsa topic of great significance especially in the context of rapidly changing environments. Thus, charting vulnerabilities in freshwater organisms across temperate and tropical zones provides insight to which regions are most imperiled, informing conservation management of freshwater ecosystems in the wake of global climate change.

Shah, Syed (43)

Estimation of Willingness to Pay For Water Quality Improvement of River Swat
Syed Shah (CSU, Graduate)

Terrestrial fresh water resources, such as rivers and lakes, are valuable assets because they provide a number of goods and services that directly or indirectly benefit human societies. These include water supply for drinking, irrigation, industrial use and hydropower generating; goods such as fish and waterfowl; regulating services such as pollution control, water purification and flood control; habitat services for wildlife; and cultural services such as recreation (Carpenter et al. (1999), MES (2005)). Over the past 10 years, concern has been raised over the impacts of human activities on the quantity and quality of fresh water resources. In developing countries, rapid population growth and other activities associated with it, such as unsustainable agricultural practices and deforestation, are affecting the flow of services provided by fresh water resources. This raises the question of why people or government allows such activities that affect the flow of ecosystem services. The two possible reasons are: (1) People have limited knowledge about the full range of goods and services provided by ecosystem and the trade-offs between their activities and ecosystem functioning; and (2) Ecosystem managers have little economic incentive for ecosystem management because of the free/ public good nature of ecosystem services. For sustainable management of ecosystem, it is highly important to reveal the hidden trade-offs between human activities and ecosystem functioning. For this reason ecologist and social scientists recommend the valuation of goods and services provided by ecosystem. This study is designed with the same intention to estimate economic value for River Swat water quality and make ground for its sustainable management. River Swat watershed, also known as Swat Valley, is located in the north west of Khyber Pakhtunkhwa Province of Pakistan. The valley is famous for its fascinating landscape, crystal clear water, pleasant climate and fertile soil. River Swat, which drains the entire valley, plays important role in the economic life of the area. Its esthetic beauty attracts local and foreign tourist and is the main reason for growth in hoteling industry. It supply water for agriculture, fisheries, industries and municipal use; and is habitat for wildlife. Over the past two decades, due to rapid increase in population and growth in agricultural and tourism activities, the river water quality has been degraded. Continuous discharge of solid and liquid wastes from residential, commercial, industrial and agricultural areas has polluted water and is a serious threat to the heath of people and river associated biodiversity. Increase in sediment load, due large scale deforestation of the watershed and flooding in monsoon season, is another source of water pollution and a threat to biodiversity. Several studies have been done to highlight the individual impacts of urban wastes, agricultural practices, and deforestation on water quality. Unfortunately, no work has been done to quantify the welfare loss due to degradation of river water quality; and to select/ design sound policies, in-terms of associated cost and benefits, for sustainable management of River Swat. This study is designed to estimate the demand/ economic value for water quality of River Swat. For this purpose a Contingent Valuation Method (CVM) will be used. This study will help policy makers in designing sound policies for sustainable management River Swat.

Simms, Crystal (44)

Ecosystem Reconstruction at Arene Candide: The Evolution of Gathering Behavior Under Different Eco-Climatic Conditions in the Pleistocene and Holocene
Crystal Simms (CU Denver, Undergraduate), Julien Riel-Salvatore (CU Denver)

The site of Arene Candide, in the Liguria Region of Italy, has yielded a wealth of archaeological material accompanied by fine-grained paleoecological data. This study presents an ecological reconstruction based on faunal habitat research drawn from the fauna recovered at the site. By extrapolating effective temperature (ET) ranges from these data, it is also possible to infer the most likely human foraging patterns over the course of the ca. 24, 000 years during which the site was occupied. While this interval comprises episodes of severe climatic fluctuations including the Younger Dryas and the Last Glacial Maximum, this analysis suggests that the area around site experienced very little variation in temperature during that time. These data indicate a much more stable paleoenvironment here than in the rest of Upper Paleolithic Europe, suggesting that Arene Candide may have served as an ecological refugium during this period of time.

Stammer, Amanda (45)

Doing Real Science With Insects in the Classroom
Amanda Stammer (CSU, Undergraduate), Dhruba Naug (CSU), Sarah Jaumann (CSU), Jacob Scholl (CSU), Chris Mayack (CSU)

In order to expose elementary school students to the scientific method and get them excited about science, we are designing teaching modules for fifth graders. We use insects to demonstrate some fundamental ideas in animal behavior and our priority is not only to make some complex ideas comprehensible to children but also to instill in them an understanding for why experiments are important. Our first module consisted of an exercise that, using crickets and bark beetles, illustrated how mere observation of these insects in their natural habitats is not enough to conclude whether temperature plays a role in habitat selection. We used a gradient to test the temperature preference of these insects. The second module consisted of an experiment about how an animal searches for food in its complex environment. Using houseflies in a foraging arena, the students mapped the search pattern of a hungry fly and how the pattern evolves upon finding food. In both the experiments, the students learned to form hypotheses, test them by designing experiments and collect quantitative behavioral data, and analyze the data to make inferences. We are currently designing more modules and making them available on a website in order to have them accessible to elementary school teachers who can use the activities that can be done at little cost and get children excited about pursuing science.

Steen, Valerie (46)

Potential Effects of Climate Change on the Distribution of Waterbirds in the Prairie Pothole Region, U.S.A.
Valerie Steen (CSU, Graduate), Abby Powell (University of Alaska Fairbanks)

Freshwater wetlands and wetland-dependent birds are considered at particularly high risk for negative climate change effects. The Prairie Pothole Region (PPR) of the north-central U.S. and south-central Canada contains millions of small prairie wetlands that provide critical habitat to many migrating and breeding wetland-associated birds. To look at the potential effects of climate change on these birds we predicted current and future distributions of five waterbird species common in the Prairie Pothole Region (PPR) using bioclimatic species distribution models (SDMs). We created fine-scale SDMs for the U.S. PPR using breeding bird survey occurrence records for 1971-2000 and wetland and climate parameters. For each waterbird species we predicted current distribution based on climate records and projected future distributions to four future climate scenarios and averaged the four to create an ensemble projection. Averaged for all five species, range reduction for the ensemble projections was 64%. However, individual species projections varied widely with one species projected to be absent from 99% of its current range. This study emphasizes the need to plan and prepare to mitigate against species habitat loss under climate change.

Stoddard, Matthew (47)

Effects of Summer Gondola Operation on Bird Populations in a High Elevation Wetland System
Matthew Stoddard (Metropolitan State College of Dencer, Undergraduate), Christy Carello (MSCD)

Cucumber Gulch is a high elevation wetland system in Colorado that contains rare fens and numerous beaver ponds. A high level of biodiversity is associated with Cucumber Gulch, and thus the EPA has designated it an Aquatic Resource of National Importance (ARNI). Extensive development has occurred on the perimeter of this wetland system and a gondola that crosses over the wetland system and fragments the mixed conifer buffer habitat was recently completed. Avian populations have been monitored by circular point counts monthly during the summer and bi-monthly during the winter since 2003. We have found that avian abundance and species richness have consistently peaked during the months of June and July. The gondola ran daily starting July 1, 2010. Our objective was to identify the immediate affects gondola operation had on avian populations. We conducted avian point counts under the gondola and along a control transect for seven mornings prior to and seven mornings following the onset of gondola operation. Gondola operation showed a minimal impact on the avian community found along the gondola path. Using a linear mixed effects model we found that avian abundance showed a statistically significant decrease while species richness, diversity, and evenness did not change significantly.

West, Amanda (48)

Predicted Distribution of Cheatgrass in Rocky Mountain National Park
Amanda West (CSU, Graduate), Tewodros Wakie (CSU), Sunil Kumar (CSU), Jim Bromberg (NPS), and Melinda Laituri (CSU)

Cheatgrass (Bromus tectorum L.) is a self-pollinating winter annual grass that was introduced into the United States from Eurasia in the late 19th century, and has since altered the structure and function of native and agro- ecosystems throughout the western United States. In Rocky Mountain National Park (RMNP), cheatgrass has been implicated in threats to ecological preservation such as interspecific competition with native flora and increased fire intensity. Given predicted climate change scenarios, cheatgrass may be expected to habit areas where it is not currently present in RMNP, including areas of great importance to the preservation of native habitats. Using field collected cheatgrass occurrence data in RMNP, maximum entropy distribution modeling (Maxent), climate data (Climate WNA), and geographic information systems (GIS) we created maps of predicted cheatgrass distribution based on its climatic niche. The Maxent model was statistically significant, with an AUC value of 0.96. The worst-case climate change scenario modeled from the year 2011 to the year 2050 showed an increase from approximately 5% to 23% of the total area of the Park being habitable by cheatgrass. The cheatgrass distribution maps we created from the models may be useful to land managers in selecting areas where cheatgrass removal and management efforts should be focused. They will also assist managers and the general public in understanding the impacts of climate change on cheatgrass distribution in RMNP.

Wiebush, Molly (49)

The Effects of Periodicity in Precipitation on C3 and C4 Grasses in Colorado's Shortgrass Steppe
Molly Wiebush (CSU, Undergraduate), Amy Angert (CSU)

Temperature, CO2 concentrations and precipitation all affect plant distributions and community structure. The ecological consequences of changes in these variables due to climate change remain poorly understood. Some plant species might have higher survival and growth than others in the face of altered precipitation regimes. For example, C4 species should have higher fitness under variable precipitation than C3 species because their photosynthetic pathway allows them to lose less water to the surrounding environment. We tested this prediction in a comparative study of the effects of constant versus variable precipitation regime on fitness components in C3 and C4 species. In a common garden experiment, we simulated constant and variable precipitation conditions through different watering regimes and measured growth-related fitness components in four grass species from the shortgrass steppe: Bouteloua gracilis and Sporobolus cryptandrus (C4), and Pascopyrum smithii and Hesperostipa comata (C3). Our results did not support our prediction that C4 species would have higher fitness under a variable watering regime than C3 species. Instead, each species reacted differently to the watering regimes. These results suggest that, independent of the potential effects of photosynthetic pathway, species individualistic responses to altered precipitation regimes will likely alter species distributions and relative abundances within communities as precipitation patterns change.

Wuenschel, Amarina (50)

Influences of Spatial Scale and Ecological Site Location on Greater Sage-Grouse Nesting Habitat Characteristics
Amarina Wuenschel (UW, Graduate), Ann Hild (UW), and Ginger Paige (UW)

Management efforts to maintain and improve habitat for western North American wildlife species are limited by our understanding of key vegetative components, how scale alters our perception of habitat and the ability of ecological sites to meet wildlife habitat guidelines. In the past decade habitat for greater sage grouse has been greatly altered by energy development in the Green River Basin, Wyoming. Near Pinedale, Wyoming we performed intensive vegetation monitoring centered on sage-grouse nests and in random locations on two identified ecological sites to document habitat structural characteristics. Using detailed vegetative monitoring methods including basal and canopy gap, intensive shrub canopy and spatial arrangement data we are developing spatial vegetation structural metrics to examine the influence of ecological site and spatial scale on habitat characteristics. We are working on relating spatial habitat configurations to ecological site, nest versus random locations and nest success.

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