Ian Baker 1(D)
SEASONAL DROUGHT STRESS IN THE AMAZON: RECONCILING MODELS AND OBSERVATIONS
Colorado State University, Graduate Student
with Lara Prihodko (CSU) and Scott Denning (CSU)

Biogeophysical models have had difficulty reproducing the annual cycle of net ecosystem exchange (NEE) of carbon in the Amazon, generally simulating uptake during the wet season and efflux during seasonal drought. In reality, the opposite occurs. Observational and modeling studies have identified several mechanisms that explain the observed annual cycle, including 1) ability of deep roots to access moisture at depth when near-surface soil dries during annual drought, 2) movement of water in the soil via hydraulic redistribution, allowing for more efficient uptake of water during the wet season, and moistening of near-surface soil during the annual drought, and 3) photosynthetic response to elevated light levels as cloudiness decreases during the dry season. We have incorporated these mechanisms into the third version of the Simple Biosphere Model (SiB3) both singly and collectively. We find that individually, none of these mechanisms by themselves produces a simulation of the annual cycle of NEE that matches the observed. However, when all mechanisms are incorporated into SiB3, the modeled NEE follows the general trend of the observations, showing efflux during the wet season and uptake during seasonal drought.

Amy Blair 6(C)
INTERSPECIFIC HYBRIDS BETWEEN SPOTTED AND DIFFUSE KNAPPWEED IN NORTH AMERICA AND THE IMPLICATIONS FOR MANAGEMENT
Colorado State University, Graduate Student
with Ruth Hufbauer (CSU)

Diffuse and spotted knapweed are known to hybridize in their native range. There has been confusion in the literature and field about whether or not plants with morphology matching descriptions of hybrids found in North America are indeed hybrids or simply morphological variants of diffuse knapweed. To resolve this debate, extensive field surveys in the native (Eurasian) and introduced (North America) range were conducted in 2005 and 2006. Additionally, molecular techniques were employed to determine if intermediate morphology reflects hybridization at the genetic level. Plants with hybrid morphology are present frequently in diffuse knapweed sites (38 out of 39 in western North America), but not in spotted knapweed sites. Based on molecular data, the plants with hybrid morphology are of hybrid origin. It seems unlikely, however, that hybridization took place in North America; the spotted knapweed here is likely tetraploid and the diffuse knapweed is diploid and multiple attempts to make F1 hybrids between them via hand-pollination failed. Rather, the data suggest that individuals of hybrid origin were introduced with diffuse knapweed. Biological control agents, both seedhead feeders and root miners, do not discriminate between hybrid-type and diffuse-type plants within diffuse knapweed sites. Because hybridization between spotted and diffuse knapweed occurred prior to introduction approximately 100 years ago, and because biological control agents do not avoid hybrids, managers do not need to specifically target the hybrids they encounter in the field.

Eliana Bontti 3(D)
NITROGEN PARTITIONING AMING MICROBES AND DIFFERENT PLANT FUNCTIONAL GROUPS IN THE SHORT GRASS STEPPE
Colorado State University, Graduate Student
with Indy Burke (CSU) and Katrina Gillette (CSU)

Grasslands are known to be primarily water and N limited. Thus, the study of nitrogen cycling is important for understanding grassland functioning and to predict responses under natural or anthropogenic disturbances. Key to this understanding is the dynamics of plant and microbial interactions. The objective of our work is to determine nitrogen partitioning between different plant functional groups and microbes in the shortgrass steppe. To accomplish this, we measured the following pools monthly during the growing season: 1) plant biomass and plant shoot and root N under C3, and C4 grasses, and under invasive forbs, 2) soil inorganic N, and 3) microbial biomass N and C. Preliminary results showed a peak in microbial biomass C and N in July, following a peak of rainfall above the precipitation historical average. We expect that there will be a peak in C4 grass N in July, as well as in forbs, since these plant functional groups respond to July precipitation. We do not expect a peak in C3 grass N during any part of the growing season, since this plant functional type is senescent when the peak in microbial biomass N occurs. The results of this study will allow us to assess the potential for competition between microbes and plants in the shortgrass steppe.

Sara Brown 5(C)
SPATIAL DISTRIBUTION OF LIGHTNING FIRES ON THE WILLAMETTE AND GALLATIN NATIONAL FORESTS
Colorado State University, Graduate Student

Forest fire ignitions on National forest lands have many causes, however lightning remains the most consistent ignition source. Analyzing the spatial distribution of lightning fires over long time scales provides an opportunity for fire and timber managers to gain a better understanding of how to spatially locate and manage fuel treatments on these forests. The Gallatin National Forest in Montana and the Willamette National Forest in Oregon provide case studies for evaluating the controls over lightning fires. The Gallatin represents a Pinus contorta dominated, high severity fire regime while the Willamette National Forest provides a mixed-conifer mixed severity fire regime; together, they comprise over two million acres of public lands that are vulnerable to fire, and needing scientific information to guide management decisions.
I developed a detailed spatial database of 65 years of lightning fires for both forests, using publically available data, to test the hypothesis that elevation is a major control over the probability of lightning fire. From the data, we generated an inhomogeneous Poisson cluster point process model to describe the spatial distribution of lightning caused fires as a function of elevation on the Gallatin and Willamette National Forests. Our results of this study will provide suggested ranges in elevation for managers of these two forests, as well as managers of similar lands, to use for prioritizing fuel reduction efforts as well as urban interface fire suppression efforts.

Gabriela Bucini 5(D)
WOODY-COVER MAPPING AND MODELING IN THE SAVANNA OF KRUGER NATIONAL PARK, SOUTH AFRICA
Colorado State University, Graduate Student
with Niall Hanan (CSU)

The woody cover of savannas consists of two main components: trees and
shrubs. This work explores the ecological dynamics underlying the patterns
of woody cover in the savanna of Kruger National Park, South Africa. We model a discontinuity in the ecological response of tree and shrub percentage cover with respect to pedo-climatic gradients and perturbations such as fire and herbivory. This hypothesis is tested using a map of woody cover percent produced on the basis of a set of aerial photos with 3-m resolution. An object-oriented approach to classification allowed the delineation of plant crowns and produced high-detail cover information. In our models, we include explanatory variables describing both mean-field and variability indices to account for the climate stochasticity typical of arid systems. Our aim is to identify the dominant processes and variables that control woody distribution and density. An interesting aspect of this research will be the formal comparison of the responses observed in woody cover versus woody biomass.

Jessie Dulberger 1(C)
THE EFFECT OF CHRONIC WASTING DISEASE ON THE FECUNDITY OF MULE DEER
Colorado State University, Graduate Student
with Mike Miller (Colorado DOW) and Tom Hobbs (CSU)

During the last four decades, the effects of Chronic Wasting Disease (CWD) on cervid populations have become a threat to wildlife recreation-based state economies and thus a concern to both private citizens and wildlife managers throughout the country (Miller 2002, Williams et al. 2002). Our goal is to understand how CWD affects the fecundity of mule deer, since fecundity and fawn recruitment are important factors affecting the stability of deer populations (Pojar and Bowden 2004). We will compare fecundity rates for CWD infected and non-infected female deer during weaning (August-September) and create a population dynamics model based on field observations. Radio-collared does will be observed during weaning for three consecutive summers (2006-2008) to assess fawn presence or absence. Initial results in 2006 suggested that the fecundity of CWD infected does was lower than non-infected does. In 2007, no difference was detected for infected and non-infected deer fecundity. This may have been because most of the infected does only had the disease for a year or less. In 2006, it was unknown how long the infected does had the disease but their high mortality rate suggests that many of them were in their second year of the disease. In 2008, infected does will clearly be in their second year of the disease, thus we predict that infected deer populations will have a lower fecundity rate than those not infected with the disease.

Sarah Evans 3(C)
EFFECT OF ALTERED PRECIPITATION REGIMES ON CARBON-NITROGEN LINKAGES IN THE SHORT GRASS STEPPE
Colorado State University, Graduate Student

Water and nitrogen (N) are the two most limiting resources to the shortgrass steppe ecosystem. As N deposition increases and precipitation regimes are altered through climate change, ecosystem elements are differentially affected, creating new feedbacks and irreversible community shifts. Specifically, changes in water and nitrogen availability may cause linked carbon (C) and N processes to become asynchronous, changing retention and loss patterns that control ecosystem function. My objectives for this study are to evaluate N-retention and C-N linkages (1) in prolonged drought, irrigation, and fertilized treatments and (2) in recovery from drought. I plan to carry out this study on plots that have undergone precipitation and nitrogen manipulations since 2000 on the Shortgrass Steppe Long Term Ecological Research site in northeastern Colorado. In the first year, I will examine changes in N-retention during irrigation, fertilization, and rain-out treatments by measuring inorganic N pools and fluxes (using ion exchange resin techniques). In the second year, I will remove the rainout shelters on the drought plots, allowing them to receive ambient precipitation. Finally, in order to extend my study in time and space, I will model the system in DAYCENT, compare the outputs to field data, and examine how the response of C and N to altered precipitation patterns differs among ecosystems. This project has broad implications for predicting the terrestrial response of the shortgrass steppe and other semi-arid ecosystems to climate change, for defining the dynamics of controls of N-retention in an ecosystem, and for elucidating C-N linkages.

Margaret Gaddis 6(D)
ENVIRONEMTNAL IMPACT OF RESTORATION OF RIPARIAN ECOSYSTEMS: FITTING RUSSIAN OLIVE INTO THE PICTURE
University of Denver, Graduate Student
with Anna Sher (University of Denver and Denver Botanic Gardens)

In many western riparian ecosystems, native vegetative cover is declining and invasive species like Russian olive (Elaeagnus angustifolia) are becoming the dominant cover. Russian olive is an exotic, invasive woody species introduced to the western United States in the early 1900’s. Originally planted as a windbreak and for bank stabilization, it is now naturalized in river corridors of the West. Invasive species cause ecosystem alterations that can lead to site degradation and high maintenance costs. I have explored the relationship between site attributes and plant cover to understand how Russian olive plays a role in riparian ecosystem alterations. I used site attributes such as presence of flooding, distance to permanent water, elevation, precipitation and soil texture and nutrients in regression tree modeling to explore variation in native and exotic plant cover. As a follow-up to this project, I collected additional soil samples at one site in Wheatridge, CO to further investigate inorganic nitrogen and soil moisture under Russian olive.

Miriam Galeas 4(D)
THE ROLE OF DORMANT SEASON RESOURCE INPUTS ON ECOSYSTEM SENSITIVITY AND RESILIENCE
Colorado State University, Graduate Student
with Alan Knapp (CSU)

Most ecosystems have a dormant season characterized by inactivity of the majority of above-ground biota. This dormant season can be critically important as a period when resources (water, nutrients, etc.) can accumulate below-ground prior to the next growing season. The interaction between this dormant season period of “resource recharge” and growing season patterns of resource inputs and variability may be key to understanding strategies of resource use by ecosystems. By selecting sites that have historically differed in dormant and growing season attributes, a gradient in these characteristics can be established upon which the role of dormant season resource recharge versus growing season inputs can be assessed and experimentally manipulated. This study will utilize a fully factorial experimental design to investigate several questions related to ecosystem response, sensitivity, and resilience to global climate change

Toby Gass 5(B)
TWO APPROACHES FOR UNDERSTANDIGN CONTROLS ON WATER USE AND GROSS PRIMARY PRODUCTION IN FOREST STANDS
Colorado State University, Graduate Student
with Nate McDowell (Los Alamos National Laboratory) and Mike Ryan (USDA and FS Rocky Mountain Research Station)

Carbon isotope ratios (d13C) of plant tissues are a commonly used proxy for water use and stomatal activity of plants. When plants constrain water loss by reducing stomatal conductance, the photosynthate used to grow tissues has a higher percentage of the 13C isotope and hence more positive d13C. We measured stemwood cellulose d13C in Eucalyptus saligna grown in experimental plots in Hawaii. Replicated plot treatments include age, two levels of tree density, and three fertilization regimes. Water use and stomatal activity had been previously determined in the same plots. Here we compare the published data on water use and stomatal activity with our measurements of stemwood d13C. We also compare measured stand-level gross primary production to estimates derived from d13C, leaf area index, and average stomatal conductance. The availability of instrumental and isotopic data from the same plots provides a unique opportunity to improve our understanding of the mechanisms by which climate, stand factors, and plant physiology regulate water use, stomatal conductance and photosynthesis.

Dylan George 1(B)
PERSISTENT METAPOPULATION DYNAMICS OF PRAIRIE DOGS AND PLAGUE: IMPLICATIONS FOR PRAIRIE DOG AND PLAGUE MAINTENANCE
Colorado State University, Graduate Student
with Colleen Webb (CSU), Michael Antolin (CSU) and Lisa Savage (CSU)

Recently introduced plague, caused by the bacterium Yersinia pestis, in western North America has dramatically impacted prairie dogs by depopulating infected towns, diminishing the geographical distribution and numbers, and altering population structure from a predominantly large, contiguous population to small, isolated patches. Since its introduction plague has been the most significant factor controlling prairie dog population biology in western North America. The impacts of plague on prairie dogs raise concerns regarding the long-term viability of prairie dogs. Additionally, if plague kills all prairie dogs in a town how is it maintained in the system? Thus, we developed a stochastic patch occupancy model to address whether a metapopulation dynamic involving prairie dogs and plague could persist. Within this context we developed and compared three hypotheses regarding the overall risk of plague epizootics on prairie dog towns including (1) population size, (2) population size mediated by ENSO events, or (3) connectivity to recently plagued towns explain local extinctions. To estimate model parameters we used empirical data from 1981-2000 on the Pawnee National Grassland in Colorado, selected the most appropriate model using AIC, and validated our model, in part, with data from 2001-2006. The resultant model demonstrates metapopulation structure allows the persistence of prairie dogs, and, indirectly, provides evidence indicating spatial structure allows the maintenance of plague in this system. We found population size of a particular patch best explains prairie dog town epizootics which imply prairie dogs, more than likely, do not disperse plague. Lastly, our model provides evidence consistent with the idea that plague can persist within an epizootic cycle, prairie dogs and their fleas, and does not necessarily require interaction with an enzootic species.

Zachary German 4(C)
SPECIES AND COMMUNITY RESPONSES TO CLIMATE CHANGE, NITROGEN DEPOSITION AND HERBIVORY IN SUBALPINE MEADOW COMMUNITIES
Colorado State University, Graduate Student
with Alan Knapp (CSU)

Global temperatures are expected to increase by several degrees Celsius over the next century and the impact of this increase is expected to be especially significant in high altitude ecosystems. Climate change is further expected to alter patterns of precipitation and nutrient availability and human activities are increasing the amount of nitrogen that enters the terrestrial environment. In alpine ecosystems, a large proportion of this nitrogen collects in the winter snowpack and it is released in a large pulse at snowmelt. The timing of nitrogen release is affected by snowfield depth and spring temperatures and it is expected to accelerate under climate change scenarios.
I investigate the effects of nitrogen input timing on subalpine plant communities near Crested Butte, CO to determine which phenological cohorts of species are capable of responding to altered nitrogen input timing. I also investigate the combined effects of elevated nitrogen and warming, and elevated nitrogen and grazing. In these subalpine meadows, preliminary results suggest that primary production and reproduction may be generally unaffected by increased nitrogen inputs. One possible exception are early-season species such as Delphinium nelsonii that initiate growth shortly after snowmelt. Generally, drought stress increases with time from snowmelt and may explain why later-developing species do not appear to capitalize on increased nitrogen availability.

Kirstin Holfelder 6(A)
FROM SLUDGE TO OPEN SPACE: EFFECTS AND MANAGEMENT OF SEWAGE SLUDGE DISPOSAL
Colorado State University, Graduate Student
with Indy Burke (CSU)

The disposal of sewage sludge is a global problem. As populations grow, the disposal problem grows. In the 1980’s, the US disposed of 70 million dry tons of sewage sludge yearly at a cost of $844 million. Since then, population has grown 13.2%; Colorado has experienced an increase of 30.6%. The City of Aurora is currently feeling the intense pressures of such rapid development. From 1969 to 1986, the city of Aurora had a land disposal policy for municipal sewage. Around 233,000 dry tons of biosolids were incorporated into 2 square miles of land. The current managers want to put a trail along the riparian strip through the site. Unfortunately, the majority of the land is currently covered by Russian thistle (Salsola iberica), kochia (Kochia scoparia), cheat grass (Bromus tectorum), and other exotic grasses and forbs.
My objectives are to understand why weedy plants and non-natives characterize the disposal site and to develop effective strategies for managing these weedy plants and non-natives. I have three hypotheses: 1) weeds persist because high nitrogen allows them to outcompete native plants, 2) weeds persist because high soil moisture allows them to outcompete natives and 3) heavy metals in the soil are being transferred to the vegetation through plant uptake, resulting in forage unsafe for consumption by grazers.
I will measure plant available N, soil moisture and heavy metals in the soil at three undisturbed reference sites, three sludge amended sites and three intermediate sites (between amendments and the undisturbed riparian corridor) to see if patterns are consistent with the above hypotheses. Based on the results, I will evaluate the causal mechanisms in the hypotheses, while evaluating appropriate management strategies.

Mary Jamieson 6(B)
EFFECTS OF SOIL NITROGEN ENRICHMENT ON THE GROWTH AND DEFENSIVE CHEMISTRY OF AN INVASIVE PLANT, LINARIA DALMATICA (SCROPHULARIACEAE)
University of Colorado – Boulder, Graduate Student

Research indicates that non-native plant species are most likely to invade environments where resource availability exceeds resource demand by resident species (e.g. soil nitrogen is not limiting). Thus, factors that contribute to soil nitrogen enrichment may facilitate the invasion of introduced plants. Further, increased nitrogen availability may influence plant invasion success by altering patterns of resource allocation to growth and defense. Greenhouse and garden experiments were conducted to examine the effects of soil nitrogen enrichment on the growth and defensive chemistry of an invasive plant, Linaria dalamatica. In both experiments, plants were grown at one of four levels of nitrogen availability. Nitrogen was added as ammonium nitrate at levels that simulated observed rates of nitrogen deposition. In both experiments, soil nitrogen enrichment resulted in a significant increase in plant growth. In the greenhouse experiment, but not garden experiment, nitrogen enrichment significantly decreased iridoid glycosides, the primary group of defense compounds in L. dalmatica. Such changes in defensive chemistry may have important implications for the biological control of L. dalmatica. Future research will address the effects of soil nitrogen enrichment on plant-herbivore and predator-prey interactions using Calophasia lunula (Noctuidae) as a focal species. This caterpillar has been introduced as a biological control agent of L. dalmatica and is known to sequester iridoid glycosides.

Craig Judd 3(A)
A COUPLED MOLECULAR AND FIELD-BASED APPROACH TO STUDY MICROBIAL CONTROLS ON METHANE FLUX IN UPLAND SOILS
Colorado State University, Graduate Student
with Joe von Fischer (CSU) and Noah Fierer (CU Boulder)

Predicting the responses of ecosystems to global change depends, in part, on understanding how soil microbial communities respond to external controls. To address this question, we are studying a relatively simple biogeochemical process: methane consumption in upland soils. In this process, methane molecules diffuse from the atmosphere into the soil, where they are consumed by methanotrophic bacteria. Because of the simplicity of this process, we have been able to develop a reaction-diffusion model that allows us to directly quantify methanotroph activity in situ from chamber-based measures of flux and diffusivity. Moreover, because the bacteria that oxidize methane come from a phylogenetically cohesive group, we can use molecular tools to determine its composition.
Our application of these approaches on the Shortgrass Steppe Long-Term Ecological Research (SGS LTER) site in northeastern Colorado has revealed strong temporal and spatial patterns in methane uptake rates that are driven by both methanotroph activity and soil diffusivity. Spatial patterns in methanotroph activity follow differences in soil texture, with sandier soils expressing a greater methanotroph activity than clay soils. Although methanotroph abundances did not vary across soil types, the phylogenetic structure of the methanotroph communities differed significantly between clay and sand soil types. Together, these observations suggest that the species composition of methanotroph communities reflects changes in the physical environment. We anticipate that the specific phylogenetic and physiological characteristics of methane oxidizer communities will modulate the responses of upland methane fluxes to climate change.

Kendra Morliengo-Bredlau 5(A)
THE EFFECTS OF COMPOUNDED DISTURBANCES ON NITROGEN CYCLING IN A SUB-ALPINE FOREST
University of Colorado - Boulder, Graduate Student

A majority of disturbance ecology research focuses on the effect of individual and discrete events on landscapes. However, it has been suggested that when these events occur in rapid succession, the ecosystem response is less predicable and may facilitate alternative successional trajectories through synergistic interactions between the disturbances. The goal of this research is to examine whether alterations to nitrogen cycling after disturbance may explain differences in successional trajectories observed between individual and compounded disturbances in the Routt National Forest. The forest was subject to a massive windthrow in 1997, partially logged from 1998-2001 and was also affected by the 2002 Hinman fire. In 2006, 3 plots were established in each of the disturbance combinations as well as in undisturbed forest stands for control. In 2007, empirical soil data was collected and showed significant differences in soil organic matter content and soil N and C concentrations across sites. The differences in the residual resource quality, defined by the soil C:N ratio, and quantity have strong influences on mineralization and nitrification rates. Future research will focus on determining whether quality or quantity of residual resources is most beneficial for the reestablishment of lost N stocks and which mechanisms of N cycling are conserved through disturbance combinations. This research will be useful for land managers charged with implementing appropriate remedial responses after disturbance events in an effort to promote a rapid return to the pre-disturbance state.

Matshwene Moshia 2(B)
MINERALIZATION OF NITROGEN FROM ANIMAL MANURE ACROSS SITE-SPECIFIC MANAGEMENT ZONES
Colorado State University, Graduate Student
with Rajiv Khosla (CSU), Dwayne Westfall (CSU), Jessica Davis (CSU) and Robin Reich (CSU)

Accurate quantification of Nitrogen (N) mineralization in manure from different productivity level management zones (MZs) could result in efficient and safe utilization of manure as N fertilizer. Soil characteristics and crop responses change between different MZs and the loss of N and other nutrients into the environment can occur when the supply of soil nutrients by animal manure and other sources exceeds the demand by crops. The objective of this study was to compare nitrogen mineralization rates of dairy cattle manure within and across three productivity level MZs. To accomplish this, a 120 day laboratory incubation study was conducted at the Natural Resources Ecology Laboratory (NREL) at Colorado State University using a completely randomized design set as a 2 factor factorial with 4 treatments and 3 productivity level MZs. Treatments for the study included the field equivalent of, 22 Mg ha-1, 44 Mg ha-1, 67 Mg ha-1 and 134 Mg ha-1 of applied animal manure. Soils used in the study were collected from the top 15 cm of high, medium and low productivity MZs from Fort Collins, Colorado, on a continuous corn (Zea mays L.) field. The soil was classified as fine-loamy, mixed, mesic, Aridic Haplustalfs. Results show that manure mineralization was significantly different (p=0.05) across all treatments within each of the productivity level MZs. However, manure mineralization was not significantly different (p=0.05) among all MZs on all treatments. Higher inorganic N values were observed from low productivity MZs in the 67 Mg ha-1 and 134 Mg ha-1 treatments as compared to 22 Mg ha-1 and 44 Mg ha-1 treatments. The high productivity MZs resulted in higher mineralized N values in the 22 Mg ha-1 and 44 Mg ha-1 which were not significantly different (p=0.05) from low and medium productivity MZs on the same treatment. Lower manure application rates responded positively on high MZs, while higher manure application rates responded positively on low MZs. The information obtained in this study will give support to precision manure management across productivity level MZs for crop production and environmental protection.

Florencia Pezzutti 2(C)
APUPATO: EVIDENCE OF AGRICULTURAL INTENSIFICATION AND LANDSCAPE ENGINEERING
Colorado State University, Graduate Student

The former island of Apupato, located in the lake Pátzcuaro basin in Michoacán, Mexico, represents to its population multiple meanings within different time periods. In the pre-Hispanic era, it represented a landscape where Tarascan land, property, and wealth was held; during the post-contact period, it represented an object of land dispute between the native Purépechas and the Catholic Church. Today, as an archaeological landscape, it represents an example of intensive agriculture, and its correlation to the foundation and rise of states and empires. This former island’s terraced landscape could signify one of the few well-preserved examples of the transition and formation of the Mesoamerican state. It is also a great example of the relationship between humans and their environments and how humans transform and build their landscapes to fulfill their needs. The relevance of what Apupato can provide towards the theoretical knowledge of state and empire foundation, in regards to the intensification of agriculture in this region, is highly significant, since only a small amount of work has ever been done or devoted to it in this region. This research in progress will present the gap of information regarding the rise of states and the foundation of empire as well as the intensification of agriculture, represented by Apupato’s agricultural features (preserved agricultural terraces). It will also support Fisher et al.’s (2003) argument that presents agricultural terraces as a crucial component of Tarascan state formation and for coping with Classic period land degradation in the Pátzcuaro lake basin.

Carolina Quintero 4(B)
EFFECTS OF PREVIOUS HERBIVORY ON SUBSEQUENT HERBIVORE PERFORMANCE
University of Colorado – Boulder, Graduate Student
with Deane Bowers (CU Boulder)

Plant secondary compounds play an important role in herbivore performance as well as mediating inter- and intra-specific competition among herbivores. Induced defenses after damage can change plant quality and palatability, indirectly affecting subsequent herbivores. Because induced defenses can be species-specific, the identity and history of herbivores inflicting damage on the same host may be essential for understanding plant and herbivore population dynamics. A greenhouse experiment used Plantago lanceolata (Plantaginaceae) to assess the effect of previous herbivory on performance of a specialist sequestering caterpillar, Junonia coenia (Nymphalidae). We used three diet-treatments: undamaged plants, plants damaged by specialist caterpillars (J. coenia), or plants damaged by generalist caterpillars (Spilosoma virginica, Arctiidae). Twenty plants/treatment were harvested to measure levels of plant toxins, while another 20 plants/treatment were used to rear J. coenia larvae from 3rd to 5th instar. Plants from the three diet-treatments did not differ in secondary compounds. However, caterpillars reared on undamaged plants gained more biomass than caterpillars reared on previously damaged plants; those reared on plants damaged by generalists compared to specialists did not differ. In contrast, caterpillars reared on undamaged plants sequestered significantly less toxins than those reared on damaged plants. Moreover, caterpillars’ toxin levels were higher if feeding on plants previously damaged by specialist rather than generalist caterpillars. These results suggest a possible trade-off between growth rate and defense in this sequestering caterpillar.

Joana Roque de Pinho 2(D)
WHICH GOD ARE WE TALKING ABOUT? CHRISTIANITY AND ATTITUDES TOWARDS WILDLIFE IN SOUTHEASTERN MAASAILAND, KENYA
Colorado State University, Graduate Student

As part of an ethnographic study on human-wildlife interactions in the Amboseli Ecosystem, southeastern Kenya, I investigated cultural and socio-economic predictors of Maasai attitudes towards wildlife. Comparing three study areas with contrasting land tenure and land use systems and examining the influence of nine variables on attitudes, a multinomial regression analysis showed that religion, gender and land tenure are predictors, with Christian men living on communal land being the most likely to hold positive attitudes towards wildlife. Christianity thus unexpectedly emerged as the strongest predictor of positive attitudes. This result seems to contradict the notion that it is mostly indigenous/traditional religions and life ways that predispose to display benign attitudes towards the natural environment (“God’s creation”) and presents interesting avenues for inquiry into the role that major religions can play in environmental conservation and management.

Thomas Wilding 1(A)
PREDICTING EFFECTS OF FLOW CHANGE FROM ECOLOGICAL THEORY
Colorado State University, Graduate Student

The science of environmental flows aims to predict the ecological effects of flow alteration to guide the sustainable management of streams and rivers. How ecological processes and patterns vary along gradients of streamflow is well documented, but few studies have quantified the ecological responses of flow change per se. Thus, despite ample commentary about the potential effects of flow alteration, predictive models lack quantitative accuracy.
New research will seek answers to these problems. Ecological theory can direct us to where effects are most likely to be measurable. For example, large changes to the major environmental drivers of river ecosystems (disturbance, temperature, river morphology) are expected to produce pronounced effects. Taking this further, a heuristic model (e.g. Bayes Nets) will be constructed to predict the combinations of ecosystem-type and type of flow-change that are most likely to produce measurable effects. Flow interacts with other major drivers of stream ecosystems, so it cannot be examined in isolation. By predicting which functional traits (populations or life stages) are most susceptible to proposed changes in flow (directly or indirectly), we can better target monitoring efforts. Potential applications for predicting ecosystem response will also be explored.

Connie Uliasz 2(A)
CLIMATE SCIENCE, THE IPCC AND ADVOCACY
Colorado State University, Graduate Student

As a card-carrying ethicist funded by the National Science Foundation, I have found myself in the position of trying to help climate scientist’s work out some of the moral issues relating to advocacy. People I have worked with range from lead authors in the IPCC to graduate students just starting on their master's degrees. All of them are interested in what moral responsibilities scientists have regarding whether they should be advocating for better climate policies or just sticking to "facts only" science. While some scientists see themselves as planet-doctors ethically working to improve the health of the planet, others feel that taking a stand on planetary health would be unprofessional. This presentation is a brief look at my experiences as we have sought possible solutions to this difficult issue.

Amariah Anderson (3)
ASPECTS OF SWIFT FOX (VULPUS VELOX): BEHAVIORAL ECOLOGY IN RELATION TO A BUBONIC PLAGUE EVENT IN NORTHEASTERN COLORADO
Colorado State University, Graduate Student
with Mike Antolin (CSU) and Kevin Crooks (CSU)

An analysis of the relationships between swift fox (Vulpes velox) home range and prairie dog colonies (Cynomys ludovicianus) on the Central Plains Experimental Range (CPER) in northeastern Colorado is presented. Data from the years 2003 – 2007 is used in conjunction with home range kernel density estimates illustrating swift fox home range distribution and overlap onto prairie dog colonies. The intent of the study is to determine swift fox dependence on prairie dogs for their burrows and food resources. The bubonic plague (Yersinia pestis) epizootic that occurred in 2005 dramatically altered the distribution of prairie dog colonies on the CPER. This event offers a unique opportunity to compare swift fox distribution from the pre- and post- plague time periods. Future work will entail scat analysis to determine the presence of prairie dogs found in swift fox diet, ectoparasite collection and analyses using PCR to determine if fox fleas contain plague positive antibodies.

Tracy Baldyga (5)
WATERBUCK (KOBUS ELLIPSIPRYMNUS DEFASSA) AS AN ECOSYSTEM CHANGE INDICATOR IN LAKE NAKURU NATIONAL PARK, KENYA
University of Wyoming, Graduate Student
with Scott Miller (UW), Jeffrey Beck (UW) and Geoffrey Bundotich (Kenya Wildlife Service)

Lake Nakuru National Park was created in 1968. In 1987, as local human population pressures increased, an electric fence was erected around the park. Lake Nakuru Basin has undergone extensive and rapid land cover and land use change, including significant upland forest losses resulting in changes to the timing and amount of flow reaching the Park from the River Njoro. While many studies analyze land use changes and their environmental impacts at site specific scales, this research looks toward broad-scale landscape changes and their potential impact with regard to forage availability for waterbuck (Kobus ellipsiprymnus defassa) within the enclosed park. Once the most abundant ungulate within the park, it’s numbers are decreasing possibly as a result of upstream land cover changes. Consequently, this species may serve as an indicator of threats to ecological services within the Park. In addition, intraspecific competition with Buffalo is also explored as a factor.

Aaron Berdanier (11)
ALPINE AND SUBALPHINE PRIMARY PRODUCTION DETERMINED BY PATTERNS OF SEASONAL PRECIPITATION
Colorado State University, Graduate Student
with Julia Klein (CSU)

Precipitation in alpine and subalpine ecosystems is variable from year to year and exerts a strong influence on ecosystem properties. Annual precipitation is dominated by winter snowfall, making the growing season short and soil moisture levels dependent on spring snowmelt. Primary production in these ecosystems is predicted to be highly vulnerable to variations in precipitation, especially changes in seasonality. To begin exploring this issue, we collected samples of aboveground biomass from alpine and subalpine sites throughout Colorado in 2007. Across all sites, aboveground biomass decreased significantly with increasing winter precipitation. This response is hypothesized to be due to differences in species composition and growing season length. Aboveground biomass responded in a quadratic form to the ratio of winter to summer precipitation. This is hypothesized to be due to the interactive effects of growing season length and soil moisture on production. These preliminary results have implications for the response of alpine and subalpine carbon cycling to climate variability and change

Jim Bromberg (20)
THE DISTRIBUTION OF CHEATGRASS IN ROCKY MOUNATIN NATIONAL PARK OVER TIME USING PREDICTIVE COMPUTER MODELLING
Colorado State University, Graduate Student

Maxent is a predictive model that has been used to predict the distributions of species based on environmental parameters. However, the model has not been used to look at a species over time to examine changes in its range at different time periods. The Maxent model was applied to data collected on cheatgrass in Rocky Mountain National Park between the mid 1990s to the present to examine changes in predicted distributions over time. While major changes in the distribution and range of cheatgrass were not observed over different time periods, the model made stronger predictions on the potential distribution of cheatgrass based on the larger dataset obtained in 2007. The model also determines which environmental predictors have the greatest influence on the distribution of cheatgrass. By overlaying the 2007 observed data with the 1996 and 1999 model predictions, we can test the validity of the model. An examination of the 1996 modeled distribution does show that we can predict many of the new cheatgrass locations observed in 2007. Since all of the recorded cheatgrass locations are in the general vicinity of the east entrance of Rocky Mountain National Park, further ground truthing will be conducted to validate the model predictions for other areas of the park.

Casey Brown (26)
COLORADO FRONT RANGE GK-12 FELLOWSHIP: RESEARCH SCIENCE IN THE CLASSROOM
Colorado State University, Graduate Student
with Kim Melville-Smith (CSU and NSF)

Colorado Front Range GK-12 Fellowship is a National Science Foundation grant that fosters the collaboration between graduate fellows, K-12 teachers, and university faculty. Together these groups provide students with authentic science experiences bringing research into the classroom. Teachers and fellows use inquiry based methods, which are tied to state standards, to guide students through real world scientific questions. Student are actively engaged in the scientific process during in-class lessons and projects, data collection in the school yard, and field trips to local ecological research sites. Projects are on going throughout the year culminating in the spring with student led science fairs, independent research projects, and poster/paper presentations. The GK-12 project also gives fellows a unique opportunity to gain communication skills while explaining science to all age groups. This month a group of fellows, teachers, and faculty will participate in the NSF GK-12 Annual Meeting in Washington DC. This meeting will provide both networking opportunities and a chance to share ideas with peers from around the country. This poster will be submitted for presentation at the annual meeting.

Amanda Broz (19)
REDUCED EXPRESSION OF DEFENSE-RELATED TRANSCRIPTS OF AN INVASIVE WEED IN ITS INTRODUCED RANGE
Colorado State University, Graduate Student
with Amanda Broz (Center for Rhizosphere Biology and CSU), Daniel Manter (USDA-ARS), Gillianne Bowman (Université de Fribourg/Pérolles), Heniz Müller-Schärer (Université de Fribourg/Pérolles), Jorge Vivanco (Center for Rhizosphere Biology and CSU )

Ecological and physiological studies have thus far provided an incomplete picture of why some plants become invasive; therefore we used genomic resources to complement and advance this field. The evolution of increased competitive ability (EICA) hypothesis predicts that in the introduced range invaders rapidly evolve to put fewer resources into defense and more resources into growth and/or fecundity compared to plants in the native range, a phenomenon which can potentially be studied at the level of gene expression. Using sequence information from the invasive plant spotted knapweed, Centaurea maculosa, we characterized and compared expression of candidate genes that may be involved in constitutive defense or rapid evolution between native (Eurasian) and invasive (North American) populations of greenhouse grown C. maculosa plants. We found evidence that invasive populations had reduced expression of defense and secondary metabolism-related transcripts in comparison to their native tetraploid counterparts, as might be expected based on EICA. Measurements of several vegetative and reproductive traits were similar for all plant populations, contrary to the expectations of EICA; however, invasive populations had significantly greater survival rates following flowering and a simulation of seed production suggests that invasive tetraploids have the greatest reproductive capacity of the three geo-cytotypes. Ploidy also had a significant effect on gene expression. Our results suggest that characterizing gene expression in an invasive species using populations from both its native and introduced range can provide insight into the biology of plant invasion that may not be revealed by traditional measurements of plant performance.

Lucy Burris (8)
WESTERN HARVESTER ANTS: LITTLE HELPER ON A BIG LANDSCAPE
Colorado State University, Graduate Student
with Larry Todd (CSU)

Western harvester ants (Pogonomyrmex occidentalis) are significant bioturbators on western North American short grass prairies creating distinctive and sometimes massive gravel covered mounds. Although their seed collection behaviors have been extensively studied, their gravel collection patterns are not well understood. Gravel collection among these ants is eclectic including gravel-like objects like minerals, fossils, and culturally produced items. Presence of these materials on an ant mound can potentially help investigators find their source even in when it may be hidden in vegetation or below ground. The current research addressed two key questions: 1) is surface gravel collection predictable and of a useful scale and 2) can investigation of ant colonies provide a reliable indication of the presence of small items on a landscape. Study of 37 ant colonies in northwestern Nebraska in response to deposition of over 300,000 glass beads showed that 98 percent of collected material came from within 20 m of the colonies. Collected materials were found significantly more often on seeded colonies (and not found on unseeded colonies) than could be explained by chance alone. Interspatial colony distance averaged 31 m indicating that colony foraging areas have peripheral overlap. In combination, these results indicate that harvester ants can completely and reliably canvas a landscape for small objects and the presence or absence of these objects on mounds is a reliable indication of the presence or absence of these same items within a reasonable human survey distance.

Kerry Byrne (18)
THE EFFECT OF EXOTIC PLANT SPECIES ON PRODUCTION IN PONDEROSA PINE WOODLANDS IN THE FRONT RANGE OF COLORADO
Colorado State University, Graduate Student
with Bill Lauenroth (CSU)

Ponderosa pine forests and woodlands of the southwest U.S. have been substantially altered over the past 150 years by livestock grazing, fire suppression, logging, and exotic species introductions. These human activities have caused large changes in both the understory and overstory. Understory changes are especially visible in the Front Range of Colorado, where a variety of exotic grasses and forbs have invaded, including smooth brome (Bromus inermis), cheatgrass (Bromus tectorum), and dalmation toadflax (Linaria dalmatica). We conducted research during the summer of 2007 to answer the following question: has the invasion by exotic plant species changed aboveground net primary production in ponderosa pine woodlands of the Colorado Front Range. We sampled production by species so that we could evaluate the relationship between native-exotic species richness and production-diversity relationships. We sampled aboveground biomass in 150 0.25 m2 circular plots across a gradient from low to high presence of exotic plant species. We collected data from south facing slopes at five sites along the Front Range, from Poudre Canyon in the north to Golden Gate Canyon in the south. The sampling sites ranged in elevation from between 1,840 to 2,440 meters. We found that each site had 31.4 +/- 6.2 native species, and 5.8 +/-3.1 exotic species. Each 0.25 m2 plots had 6.6 +/- 3.3 native plant species, and 1.2 +/- 1.2 exotic species, with maximum values of 17 and 5, respectively. Grasses accounted for 58% of average aboveground production, forbs accounted for 25%, and dwarf shrubs and succulents accounted for the remaining 17%. There was a positive relationship between production and species diversity.

Natasha Davis (22)
REVEGETATION OF FLUVIAL MINE TAILING DEPOSITS: THE USE OF FIVE RIPARIAN SHRUB SPECIES
Colorado State University, Graduate Student
with Paul Meiman (CSU), Joe Brummer (CSU) and Jim Ippolito (USDA-ARS)

Fluvial mine tailing deposits cause extensive damage to riparian ecosystems throughout the West. Willows are often used for revegetation of these deposits but some species accumulate toxic concentrations of metals in leaves and stems. A two month greenhouse experiment was conducted to determine the value of thinleaf alder Alnus incana (L.) Moench spp. tinuifolia (Nutt.)Breitung, water birch (Betula occidentalis Hook.), red osier dogwood (Cornus sericea L. spp. sericea), and shrubby cinquefoil Dasiphora fruticosa (L.) Rybd. compared to Geyer willow (Salix geyeriana Andersson) for revegetation of fluvial tailing deposits along the Upper Arkansas River. Bare root seedlings were grown in tailings collected from three acidic and metal contaminated deposits along the Arkansas River south of Leadville, Colorado which were amended with lime and composted biosolids. All shrubs survived the experiment and increased in total biomass by 5 to 8 times compared to initial weights. Cadmium (Cd), Pb and Zn were more concentrated belowground by all species. Cadmium concentrations in aboveground tissues of birch, cinquefoil, and especially willow were at levels potentially harmful to livestock and wildlife, whereas alder and dogwood had 0.15 and 0.04 mg/kg Cd, respectively. No shrub species evaluated in this experiment exhibited superior growth when compared to Geyer willow, but the ability of alder and dogwood to nearly exclude Cd aboveground would make them suitable for in situ field restoration of fluvial mine tailing deposits.

Emily Freitasand Jillian Yamartino (13)
DECOMPOSITION DYNAMICS OF FOREST LITTER TRANSPLANTED TO A NATIVE SAND PRAIRIE
Colorado State University, Undergraduate Students
with Nathan Mellor (CSU), Rich Conant (CSU), Sherri J. Morris (Michigan State University) and Eldor Paul (CSU)

Afforestation is providing soil carbon sequestration of atmospheric CO2 in both the plant biomass and soil. Tree growth on prairies can also sequester C. Its other effects such as those on the soil profile, microorganisms and nutrient cycling are not well established. The Nebraska National Forest at Halsey was sampled to explore the effects on amounts and distribution of SOM and associated microorganisms under cedars and pines planted on native sandy prairie approximately 75 years ago. Cedars contained the largest amount of soil C attributed to large input of fine roots and litter. Pine stands contained the largest amount of litter C but contained the least amount of total soil C. Results of field #61540; 13C analysis indicated there was very litter decomposition of prairie C under cedars pines accelerated decomposition. Litter was exchanged between all three sites to determine differences in decomposer communities. Following ten day incubations, QPCR was performed to analyze the microbial community. Chloroform fumigations measured changes in microbial biomass. Our research suggests changes in soil C and nutrient content following land conversion from prairie to forest are dependent on the species planted. Overall, if ecosystems are to be used as sinks for atmospheric C, then we must know the relative impacts of different management strategies on soil C pools and microbial populations to prescribe the best management options.

Thomas Grant (16)
USE OF NATIVE SOIL INOCULUM IN THE RESTORATION OF LANDS INVADED BY EXOTIC WEEDS
Colorado State University, Graduate Student
with Mark Paschke (CSU)

The interaction between soil micro-organisms and plants has gained increasing attention as a potential factor in the development and transformation of plant communities. The feedback systems between plants and soil organisms can alter biogeochemical cycles, cause modifications of soil physical properties, decomposition rates, and influence the richness and diversity of plant species, micro-organisms and macro-invertebrates. A study was installed on military training lands in Washington and Wisconsin to determine if addition of a whole soil inoculum from adjacent native vegetation affects the restoration of weed infested lands with native plant seed. The Washington site is primarily dominated by the invasive Acroptilon repens (Russian knapweed), while the Wisconsin site has been invaded by Centaurea stoebe (spotted knapweed) and Euphorbia esula (leafy spurge). Small study plots (1 by 1 meter) were inoculated in 2005 and again in 2006 with either fresh soil collected from an adjacent reference area or a sterilized portion of the same soil. All plots were seeded with five native plant species in the fall of 2005. In Washington, no statistically significant differences were determined between the native and sterilized soil inoculum for species richness, Russian knapweed density, native or exotic species cover in 2007. Similarly, the Wisconsin site had no statistical differences in richness, cover, or invasive density, although a significant reduction in the number of bolting spotted knapweed plants was documented in the native soil inoculum treatment. Additional monitoring and potential re-inoculation with a liquid delivery system may be utilized to determine if soil inoculation can be used as a potential tool in the restoration of degraded lands.

Elizabeth Harp (2)
FUNCTIONAL GENETIC DIVERSITY AND PATHOGEN RESISTANCE IN BLACK-TAILED PRAIRIE DOGS (CYNOMYS LUDOVICIANUS)
Colorado State University, Graduate Student
with Mike Antolin (CSU)

Wildlife face ever-increasing threats from emerging pathogens, many of which also cause disease in humans. Host genetic diversity may play an important role in buffering populations against infectious disease. The genes encoding the major histocompatibility complex (MHC) of the vertebrate immune system are highly polymorphic and well-characterized for many species, and have thus been an attractive target to discern relationships between genetic diversity and disease. However, evolutionary dynamics of MHC remain unclear, likely because other immune system genes are also important in responses to pathogens and parasites. Recent immunogenetic discoveries make it practical to isolate immune system genes besides MHC in wildlife, and examine responses of specific immune system genes to different types of parasites. The vast majority of association studies in non-model vertebrates focus on the relationship between a single pathogen and usually one or a few MHC genes. I am going beyond the single-pathogen single-gene approach by investigating the relationship between allelic diversity in four functionally different immune system genes and the entire parasite community of black-tailed prairie dogs. Currently we have PCR-cloned the MHC class II DRB1 gene, and I am developing genetic markers for the chemokine receptor CCR5, and toll-like receptors 2 and 4 (TLR2, TLR4), all of which have been implicated in immune responses to known prairie dog parasite taxa, including Yersinia pestis, the causative agent of plague.

Mary Hunter-Laszlo (28)
HOW MANY PLANETS DO YOU NEED TO LIVE?
Werner Elementary School, Teacher

Three percent is the amount of land people and animals have to share for food and shelter, and some people use more than their fair share. Currently our planet has 6.6 billion people, which means that each person is entitled to about 4.2 acres. We have learned that Werner Elementary is responsible for adding 105 tons of Greenhouse gases to our planet each year. To educate our school community we did an energy audit to see where we could save energy. This led to calculating the ecological footprint of different parts of the school. Our project soon led to a survey of 200 people from across United States and four continents. We asked individuals to take an online Earthday Ecological Footprint Quiz and report the results to us. The quiz provided information on the number of acres they used to support their way of life, and the number of planets that would be needed if everyone lived like them. Individuals in the United States require the most planets, averaging 5.6 planets, while Germany averages about 2.8 planets. Our survey showed that activities that cause a large ecological footprint and an increased demand on the planet are: air travel, large houses, inefficient energy use, excessive driving, inefficient cars, and source of food.

Jennifer Klutsch (21)
ASSESSMENT OF WHITEBARK PINE REGENERATION IN BURNED AREAS OF THE SHOSHONE AND BRIDGER-TETON NATIONAL FORESTS AND WIND RIVER RESERVATION
Colorado State University, Graduate Student
 with Besty Goodrich (CSU) and Bill Jacobi (CSU)

Wyoming whitebark pine (Pinus albicaulis) forests in northwestern Wyoming, including the Wind River Reservation, Shoshone National Forest and Bridger-Teton National Forest, have been severely affected by bark beetle, wildfire, and white pine blister rust induced mortality. In previously burned areas, there is limited critical information on the regeneration of whitebark pine seedlings. The purpose of this study was to determine the amount of regeneration in recent and old fires as compared to non-burned areas and also to determine what site factors impact regeneration occurrence. A survey of whitebark pine regeneration within six areas that have experienced stand replacing fires 8 to 32 years previous was conducted in the Wind River Mountain Range in summer 2007. Fires were divided into polygons of similar aspects, elevations, and forest types; with each polygon comprising a minimum area of burned forest of 1.76ha (80m x 220m) and an associated minimum area of non-burned forest of 1.10ha (50m x 220m). A total of 14 polygons were samples, with 74 transects in burned areas and 28 in non-burned areas. Each transect was 2m in width and a minimum of 200m in length, and in which tree regeneration was tallied by height class. To assess the nearest whitebark pine seed source, variable radius plots were established every 80m in the non-burned perimeter of the fire. This study will benefit restoration activities in the region by providing information on the survival and health of whitebark pine regeneration in previously burned areas.

Emma Lynch (24)
RECORDING, MEASURING, AND IDENTIFYING SOUNDS IN NATIONAL PARKS
Colorado State University and NPS, Graduate Student
with Damon Joyce (CSU), Charlotte Formichella (CSU) and Ericka Pilcher (CSU)

A recent survey of the American public revealed that 95 percent of respondents thought that providing opportunities to experience natural quiet and the sounds of nature was an important reason for having national parks. In fact, 72% of those respondents felt that it was very important. The NPS Natural Sounds Program Center (NSPC) develops methods for monitoring sounds and utilizes these to quantify current conditions in park units. NSPC is concerned with ambient sound levels (which affect listening opportunities), identifying sources of sound, and quantifying their patterns of occurrence. Improved equipment makes it easier and less expensive to monitor acoustic environments: the new systems cost less, are more compact and lightweight, and use less energy. Rapid characterization of sound levels is now possible using new data processing routines; daily images of received sound levels can be computed in less than a minute, and summary statistics for a month of monitoring data can be computed in less than an hour. NSPC is currently using a team of listeners to identify sound sources in recordings. These identifications will provide opportunities to develop and test automatic software to monitor the activity of recognizable sound sources. The combination of these improvements will make acoustic monitoring increasingly accessible to all managers of parks and natural areas.

Marques Munis (17)
PROCESS-BASED MODELING OF ECOLOGICAL THRESHOLDS: A TOOL FOR MANAGEMENT OF BROMUS TECTORUM INVADED COMMUNITIES
Colorado State University, Graduate Student
with Cynthia Brown (CSU), Michael Coughenour (CSU) and Roy Roath (CSU)

Land managers from Colorado and Wyoming have formed a diverse group, the Southeast Wyoming Cheatgrass Partnership (SWCP) to manage one of the most prolific invaders of western rangelands, Bromus tectorum. B. tectorum increases fire frequency, decreases wildlife and livestock habitat value and limits use of prescribed fire as a management tool. The project will help develop integrated pest management practices (IPM) to restore and maintain ecosystem processes that sustain desirable ecological states in low production agro-ecosystems. A combination of process-based simulation modeling and field experiments will be used to evaluate chemical control, seeding, and grazing to offset the effects of B. tectorum invasion under different fire histories. B. tectorum invasion risk assessment maps of southern Rocky Mountain rangelands will be developed for rapid response and IPM prescription. Products of this research will be disseminated in peer reviewed publications, stakeholder meetings, and a website.

Sarah O’Neil (1)
DOES COINFECTION INFLUENCE SUSCEPTIBILITY TO PLAGUE IN BLACK-TAILED PRARIE DOGS
Colorado State University, Undergraduate Student
with Liz Harp (CSU)

Prairie dog (Cynomys spp.) populations have steadily declined throughout the last century, due in part to plague epizootics. Prairie dogs are highly susceptible to plague (85-100% mortality). Although plague is a factor to the decline of prairie dogs, little is known about the dynamics of plague in prairie dog populations, and factors contributing
to susceptibility. Recent research indicates that pathogen virulence is often higher during coinfection with other pathogens than it is during single-pathogen infections. Microparasites (bacteria and viruses) and macroparasites (e.g., protozoans) elicit quite different immune responses from their hosts, and often the immune response to one type of parasite will inhibit the host's ability to mount an immune response to other types of parasites. We live-trapped black-tailed prairie dogs (C. ludovicianus) in Northern Colorado and are in the process of testing for antibodies to Yersina pestis (causative agent of plague) and West Nile Virus, and direct evidence of infection with species of the protozoan parasites Eimeria, Cryptosporidium, and Giardia. We hypothesize that
prairie dogs showing evidence of exposure/infection with or West Nile Virus will have higher rates of infection with protozoan parasites because of an inability to effectively mount an immune response against both micro- and macroparasites at the same time.

Anthony Potthoff (25)
THE INFUSION OF IN DEPTH SCIENCE CONTENT INTO FOURTH GRADE CURRICULUM THROUGH THE GK 12 PROGRAM
University of Northern Colorado, Graduate Student
with Rebecca Ramirez (McAulliffe Elementry), Chuck Cal (McAulliffe Elementry), Theresa Rupp(McAulliffe Elementry), John Moore(CSU) and Bill Hoyt (UNC)

The GK12 Program enables graduate students to bring their knowledge and expertise to primary and secondary schools and enhance those schools’ curriculum. The fourth graders at McAuliffe Elementary, Greeley, CO have been participating in this program and have taken part in an in-depth investigation of aquatic ecosystems systems in the Greeley area. The fourth graders at McAuliffe elementary investigated if there are any changes in the water quality conditions along the life zones of the Poudre River and an adjacent pond along the Poudre River, specifically at the Poudre Learning Center in Greeley. Water quality was measured using the biodiversity of aquatic invertebrates, nutrient content (nitrogen and phosphorous levels), and pH levels. This project was incorporated into the fourth grade curriculum, specifically the Colorado Wildlife Unit.

Mathew Pyne (4)
PREDICTION OF SPECIES ABUNDANCE USING ENVIRONMENTAL GRADIENTS AND TRAITS IN A BAYESIAN BELIEF NETWORK
Colorado State University, Graduate Student

Prediction of species distribution and abundance has long been a goal of community ecology. Multiple statistical techniques (e.g. linear regression, neural networks) have been used to make these predictions from environmental variables, but often cannot incorporate multiple species responses or determine which environmental variables are important to individual species. Bayesian Belief Networks have potential for use in this field because they incorporate multiple environmental gradients and multiple species, are hierarchical in structure, and integrate previous knowledge about species-environment relationships. In this poster, I describe how to use a basic, user-friendly Bayesian Belief Network software package (Netica [TM] software, Norsys Systems Corporation, Vancouver, British Columbia) to construct empirical relationships that describe how species abundance can vary along environmental gradients. This model estimates the probability of specific species traits (e.g. feeding habits, thermal tolerance, body size) occurring given specific environmental conditions (e.g. temperature, stream flow, habitat conditions) and then estimates the probable abundance of a given species based on what traits that particular species possesses. The model will be developed using aquatic insects found in western United States stream ecosystems. The benefits and limitations of this type of software program will also be discussed.

Melissa Reyes (12)
INTERACTIVE EFFECTS OF ELEVATED CO2, WARMING AND WATER ADDITIONS ON THE TIMING AND RATE OF PLANT DEVELOPMENT IN A MIXED-GRASS PRAIRIE ECOSYTEM
Colorado State University, Graduate Student
with Joe Trlica (CSU), Allan Andales, (USDA-ARS and CSU)

Global change will undoubtedly affect the mechanisms that govern natural processes. For this particular study, the effects of CO2 enrichment, warming and water additions on primary phenological growth phases of dominant mixed-grass prairie species are investigated. Preliminary data analyses of Bouteloua gracilis, Pascopyrum smithii and Stipa comata suggests that treatment effects differ within species for plant emergence, anthesis, maturation and end of growth but trends are largely species specific. It is likely that changes in temperature and CO2 concentrations also influence soil moisture and seedling recruitment, potentially altering the structure of plant communities. Intraspecific seed production also varied according to interactive treatment effects where those plots that remained non-irrigated flowered less frequently than those that were exposed to either a deep or shallow irrigation regime. Shifts in species abundance may adversely affect organisms that depend on certain species for forage (i.e. cattle). To simulate grazing and in order to estimate net primary production, half of the total aboveground biomass was clipped at the height of the growing season.  Observational data suggests that individuals were least likely to exhibit regrowth after harvest under heated conditions.  An additional component of this research is to develop a regression model from field data collected to parameterize plant development as a function of CO2, temperature, and soil moisture.  This information will then be used to enhance the GPFARM model (J.C. Ascough II et al. 2002) which is a decision support tool developed by the USDA to assist ranchers with managing site-specific areas to optimize production and economic benefits while minimizing environmental impact.

Robin Roberts (23)
DOING HISTORIAL ARCHAELOGY ON THE PAWNEE NATIONAL GRASSLAND
Colorado State University, Graduate Student

The Pawnee National Grassland (PNG) has an interesting historical beginning. Unlike the National Forests, the land within the PNG was under private ownership at one time. Many of these original private owners were homesteaders or pioneers who headed west in response to the 1862 Homestead Act and the subsequent homesteading acts that followed. In the 1930s and the 1940s this land was purchased by the federal government as part of a New Deal initiative to preserve the grasslands. The government paid the land owners for all “improvements” they had made to the land. My current MA research at Colorado State University focuses on locating and documenting those homesteads in the West Stoneham Quadrangle on the PNG. This poster discusses preliminary results from field research completed during the summers of 2006 and 2007 as well as the analysis of historical documents located at the PNG Ranger Office in Greeley, Colorado. Historical documents played an important role in interpreting the archaeological evidence; often presenting conflicting ancillary evidence. I argue that every available resource should be closely examined when “doing” historical archaeology and placing importance to any one source can be detrimental in interpreting the final results. Finally, GIS technology was employed to map homestead site locations and a predictive model has been created to help locate previously unknown or unrecorded homestead sites. Preliminary results of this predictive model are presented which, when combined with the historical documents, indicate two different occupational episodes which are not clearly seen in either the historical documents or the archaeological record alone.

Carol Seemueller (9)
SOIL NITROGEN PATTERNS VARY BETWEEN MICROSITES AT THE HAZALEUS NATURAL AREA
Rocky Mountain High School, Teacher
with Tom Creegan (Rocky Mountain High School), Marion Annis (Rocky Mountain High School) and Karl Wyant (CSU)

The Fort Collins Natural Areas Program provides a unique opportunity to learn about ecology. We initiated a study during the fall of 2006 on the Hazaleus Natural Area in south Fort Collins. The area is 168 acres in size and is currently designated by the city as restorative grassland. The Hazaleus Natural Area is unique because it contains a prairie dog town, a small stream, and a wetland area. These areas provide an interesting opportunity to investigate how ecosystem parameters correspond with different prairie microsites. We chose four microsites to study: roadside, prairie dog town, riparian, and off town. We trapped arthropods via pitfall traps, measured soil nitrogen, estimated plant percent cover, and measured plant canopy height across each habitat with six reps each. Our results indicate that plant and arthropod communities along with soil nitrogen differ bewteen microsites.

E. Apple Snider (6)
INSECT DIVERSITY AND NATURAL HISTORY OF MESA VERDE NATINOAL PARK, COLORADO
Colorado State University, Graduate Student
with Kenneth Wilson (CSU), Rebecca Preleyko (CSU), Will Stacy (CSU) and Kathryn Weglarz (CSU)

Since 1996, more than 70% of Mesa Verde National Park, southwestern Colorado, has been burned by wildfire. Previous studies have documented significant differences in insect communities 1-2 years after stand-replacing wildfire. As part of a larger study designed to assess prey availability to insectivorous bats, we sampled nocturnal insect communities from May to August 2006-2007 in burned and unburned pinyon-juniper woodlands 4-5 years after a 1,053 ha wildfire. Paired burned and unburned sites were randomly selected using a GIS. We used three sampling methods—light traps, sweepnets, and beating—to decrease the bias inherent in any one method, and because these methods were the most likely to capture the insect prey of our bat focal species. Sites were sampled for two consecutive nights every two weeks to detect seasonal changes in insect species richness and abundance. We have identified over 40,000 insects belonging to 19 orders and 159 families, adding 2 orders and 47 families to the park’s previously documented insect fauna. Burned sites showed lower total numbers of insects and species richness, but higher evenness and diversity, as measured by Simpson’s Index, than unburned sites. We report on species richness and diversity, and highlight the natural history of some of the most fascinating insects we’ve encountered.

Shannon Spencer (10)
DELELOPING A LONG-TERM MONITORING NETWORK FOR SOIL CARBON STOCKS IN US AGRICULTURAL LANDS
Colorado State University, Graduate Student

Agricultural lands represent a large portion of the US land base and play a significant role in carbon exchanges between the atmosphere and the terrestrial environment. Agricultural soils can be net sinks for carbon and have the potential to mitigate green house gas emissions while improving soil quality. Yet, large uncertainties of soil carbon estimates exist; reducing uncertainties surrounding these estimates can benefit national policy for greenhouse gas mitigation on agricultural lands. A national long-term soil monitoring network is being established on agriculture lands to monitor soil carbon and provide data for independent model evaluation. These data will be used with land management data and remotely sensed data to conduct a formal uncertainty analysis of agricultural soil carbon stocks at the regional scale. The monitoring network will consist of permanent sample sites associated with the USDA-NRCS National Resource Inventory (NRI), with re-sampling every 5-10 years. Sampling will be stratified using USDA’s Major Land Resource Areas (MLRA) and is designed to minimize variance associated with soil carbon stock changes for similar land use and climate-soil combinations.

A pilot phase is currently underway to establish this soil carbon monitoring network. Site-scale sampling is utilizing a triangular design to minimize within site variance. Three subplot triangles are sampled at each site. A formal uncertainty analysis of modeled results will be conducted using initial carbon data measured at 45 sites from the central U.S., comparing CENTURY modeled data to measurements. The monitoring network will provide much-needed model evaluation dataset at a broad scale, which is anticipated to improve the quantification of carbon stock changes and their uncertainty.

Shannon Spencer (27)
BRINGING K-12 ECOLOGICAL SCIENCE OUT OF THE CLASSROOM AND INTO THE FIELD
Colorado State University, Graduate Student
with Kim Melville-Smith (CSU and NSF)

The Natural Resource Ecology Laboratory has developed partnerships with teachers and their students in Greeley and Fort Collins to assist them in exploring hands-on ecological research. This has involved a series of workshops funded by the Warner College to provide teachers with field-level research techniques and classroom interactions to assist teachers in developing their own school yard ecological research topics. Background on NREL’s outreach activities and a local case study will be presented.

Megan Steinweg (15)
DOES MICROBIAL ACCLIMATIN PLAY A PART IN SOIL CARBON DYNAMICS UNDER WARMING?
Colorado State University, Graduate Student
with Matt Wallenstein (CSU) and Rich Conant (CSU)

Global climate change will affect the turnover of soil organic matter (SOM); however, poorly-understood soil carbon dynamics contribute to the uncertainty surrounding soil organic matter decomposition rates due to climate change. The microbial community is responsible for a majority of processes in the soil that affect substrate decomposition. Temperature can affect two components of decomposition, the structure of the soil microbial community and the type of carbon and nitrogen compounds being decomposed. There has been a transient increase in respiration seen in field and laboratory experiments, with two hypotheses introduced to explain the response, depletion of labile carbon and microbial acclimation.
I am proposing to look at what mechanisms might be controlling microbial acclimation with increasing temperature while substrate availability remains constant. There are three ways in which the microorganisms could be acclimating, (1) a shift in community structure, (2) a change in growth in individual microbial population, or (3) both could be occurring. Tracking changes in soil microbial community structure will give me a better understanding of how temperature impacts the community as a whole as well as certain populations of microorganisms Understanding the mechanism behind microbial acclimation will enable us to better predict how microorganisms will change decomposition tactics with climate change.

William Vieth (14)
MORELLA FAYA AND ACTINORHIZAL BEHAVIOR
Colorado State University, Undergraduate Student
with Julie Rieder (CSU)

Our experiment was designed to investigate the ability of the actinorhizal shrub, Morella faya, to form nodules with Frankia bacteria. The association between M. faya and Frankia bacteria is seen as symbiotic, providing the plant with nitrogen, and the bacteria with a source of carbon. In turn, the ability to form nodules with Frankia is critical to the
establishment of actinorhizal shrubs in the absence of sufficient nitrogen, and thereby may influence a plant's ability to become established outside its normal range. Thus, we propose that invasive, actinorhizal shrubs should be promiscuous with Frankia bacteria, forming associations regardless of the geographic origin of those bacteria. In this experiment, we tested this idea with M. faya, a highly invasive, actinorhizal shrub,
currently invading the Hawaiian islands. We grew 70 M. faya shrubs in sterilized soil then starved them of nitrogen for two weeks prior to inoculation with soils from around the world. Nine soils were tested (Japan, Peru, Spain, Hungary, Rwanda, Alaska, Colorado Mountains, Colorado Short-grass Steppe, and Hawaii) against a water control, and asked if M. faya was capable of nodulating with Frankia bacteria regardless of
the geographic origin of soil. Plants are currently being given 16 weeks to form nodules with Frankia bacteria, while being deprived of other nitrogen sources. Expected results will show M. faya is capable of harboring Frankia bacteria from soils from around the world, and will suggest that the promiscuous nature of M. faya may in part be responsible for its invasiveness. Results will contribute to a larger experiment investigating the relationship between nodulation and invasiveness using 13 actinorhizal shrub species and 10 soil origins.

Karl Wyant (7)
EFFECTS OF FERTILIZATION ON SURFACE ACTIVE SPIDERS
Colorado State University, Graduate Student
 with Paula Cushing (Denver Museum of Nature and Science), Boris Kondratieff (CSU) and John Moore (CSU)

Arctic soils are nutrient limited because organic matter contained in permafrost is not available. Climate change models suggest that as the Arctic becomes warmer the permafrost will melt, making labile nutrients available to microbes. This may prompt higher rates of net primary productivity, changes in plant community structure, and alteration of soil food web structure and dynamics. We initiated a study to assess changes of a major soil predator group as a result of simulated climate change. 1,758 spiders were collected from pitfall traps in moist acidic and dry heath tundra from the Toolik Lake LTER, AK during the 2004 growing season. The field site is arranged into three blocks, each with factorially-arranged nitrogen-phosphorus addition and grazing treatments. Fertilization treatments show significant increase of spider populations (p=0.003). Diversity and richness measurements yielded contrasting results for the two study sites (p=0.274), and (p=0.003), respectively. We attribute these results to differences in plant cover on the fertilized plots.