Other Environmental Sciences Commons^™

High Winds And Melting Sea Ice Trigger Landward Movement In A Polar Bear Population Of Concern, Annie Kellner, Todd C. Atwood, David C. Douglas, Stewart W. Breck, Colorado State University - Fort Collins

USDA Wildlife Services: Staff Publications

Some animal species are responding to climate change by altering the timing of events like mating and migration. Such behavioral plasticity can be adaptive, but it is not always. Polar bears (Ursus maritimus) from the southern Beaufort Sea subpopulation have mostly remained on ice year-round, but as the climate warms and summer sea ice declines, a growing proportion of the subpopulation is summering ashore. The triggers of this novel behavior are not well understood. Our study uses a parametric time-to-event model to test whether biological and/or time-varying environmental variables thought to influence polar bear movement and habitat selection …

Plague Risk In The Western United States Over Seven Decades Of Environmental Change, Colin J. Carlson, Sarah N. Bevins, Boris V. Schmid

USDA Wildlife Services: Staff Publications

After several pandemics over the last two millennia, the wildlife reservoirs of plague (Yersinia pestis) now persist around the world, including in the western United States. Routine surveillance in this region has generated comprehensive records of human cases and animal seroprevalence, creating a unique opportunity to test how plague reservoirs are responding to environmental change. Here, we test whether animal and human data suggest that plague reservoirs and spillover risk have shifted since 1950. To do so, we develop a new method for detecting the impact of climate change on infectious disease distributions, capable of disentangling long-term trends (signal) and …

Satellite-Detected Ammonia Changes In The United States: Natural Or Anthropogenic Impacts, Yaqian He, Rongting Xu, Stephen A. Prior, Di Yang, Anni Yang, Jian Chen

USDA Wildlife Services: Staff Publications

Ammonia (NH3) is the most abundant alkaline component and can react with atmospheric acidic species to form aerosols that can lead to numerous environmental and health issues. Increasing atmospheric NH3 over agricultural regions in the US has been documented. However, spatiotemporal changes of NH3 concentrations over the entire US are still not thoroughly understood, and the factors that drive these changes remain unknown. Herein, we applied the Atmospheric Infrared Sounder (AIRS) monthly NH3 dataset to explore spatiotemporal changes in atmospheric NH3 and the empirical relationships with synthetic N fertilizer application, livestock manure production, and climate factors across the entire US …

Predicting Range Shifts For The Virginia Opossum In Maine, Sara Griffin

Honors College

Species distribution and movement are increasingly influenced by climate change and human expansion. The Virginia opossum (Didelphis virginiana) has been observed expanding their range northward due to the warming temperatures and urbanization. The Virginia opossums’ northern range is thought to be restricted by two abiotic winter factors, snow cover and low temperatures, which prevents foraging and ultimately leads to starvation. For this study, I predicted the movement of the Virginia opossum northward into central Maine and beyond based on current climate change trends. Microclimate temperatures were recorded using data-loggers and climate variable datasets were used to determine if …

The Ecological Resilience Of A Tropical Montane Pine Forest To Droughts, Fire, And Hurricane Disturbance, Daniel Erland Brugger Swann

Electronic Theses and Dissertations

Owing to the geographic isolation and unique climatic conditions which occur in tropical montane forests (TMFs), these systems are highly sensitive to changes in both climate and disturbance. Therefore, as ongoing climate change alters disturbance regimes – potentially facilitating multiple disturbance interactions much greater than that of isolated disturbances – TMFs may be shifted to alternate stable states. However, study of TMF resilience is essentially unknown given the lack of long-term studies in these systems. We address the resiliency of the tropical montane pine forests of the Cordillera Central, Dominican Republic using long-term climate records, remeasured vegetation data, and reconstructed …

Local Adaptation Constrains Drought Tolerance In A Tropical Foundation Tree, Kasey E. Barton, Casey Jones, Kyle F. Edwards, Aaron B. Shiels, Tiffany Knight

USDA Wildlife Services: Staff Publications

1. Plant species with broad climatic ranges might be more vulnerable to climate change than previously appreciated due to intraspecific variation in climatic stress tolerance. In tropical forests, drought is increasingly frequent and severe, causing widespread declines and altering community dynamics. Yet, little is known about whether foundation tropical trees vary in drought tolerance throughout their distributions, and how intraspecific variation in drought tolerance might contribute to their vulnerability to climate changE.
2. We tested for local adaptation in seedling emergence and establishment with a full-factorial reciprocal transplant experiment including 27 populations and 109,350 seeds along a 3,500 mm precipitation gradient for …

A Multi-Scale Analysis Of Jaguar (Panthera Onca) And Puma (Puma Concolor) Habitat Selection And Conservation In The Narrowest Section Of Panama., Kimberly A. Craighead

Antioch University Dissertations & Theses

Over the past two centuries, large terrestrial carnivores have suffered extreme population declines and range contractions resulting from the synergistic anthropogenic threats of land-use change and indirect effects of climate change. In Panama, rapid land use conversion coupled with climate change is predicted to negatively impact jaguar (Panthera onca) and puma (Puma concolor). This dissertation examined the environmental variables and scales influencing jaguar and puma habitat selection by season (annual, wet, and dry), using multi-scale optimized habitat suitability models and a machine-learning algorithm (Random Forests), in the narrowest section of Panama. The models derived from the data of an intensive …

Responses Of Agroecosystems To Climate Change: Specifics Of Resilience In The Mid-Latitude Region, Menas Kafatos, Seung Hee Kim, Chul-Hee Lim, Jinwon Kim, Woo-Kyun Lee

Mathematics, Physics, and Computer Science Faculty Articles and Research

This study examines the productivity and resilience of agroecosystems in the Korean Peninsula. Having learned valuable lessons from a Chapman University project funded by the United States Department of Agriculture which concentrated on the semi-arid region of southwestern United States, our joint Korea—Chapman University team has applied similar methodologies to the Korean Peninsula, which is itself an interesting study case in the mid-latitude region. In particular, the Korean Peninsula has unique agricultural environments due to differences in political and socioeconomic systems between South Korea and North Korea. Specifically, North Korea has been suffering from food shortages due to natural disasters, …

Understanding The Structure And Functioning Of Polar Pelagic Ecosystems To Predict The Impacts Of Change, E. E. Murphy, R. D. Cavanagh, K. F. Drinkwater, S. M. Grant, J. J. Heymans, E. E. Hofmann, G. L. Hunt Jr., N. M. Johnston

CCPO Publications

The determinants of the structure, functioning and resilience of pelagic ecosystems across most of the polar regions are not well known. Improved understanding is essential for assessing the value of biodiversity and predicting the effects of change (including in biodiversity) on these ecosystems and the services they maintain. Here we focus on the trophic interactions that underpin ecosystem structure, developing comparative analyses of how polar pelagic food webs vary in relation to the environment. We highlight that there is not a singular, generic Arctic or Antarctic pelagic food web, and, although there are characteristic pathways of energy flow dominated by …

Precipitation Variability And Nitrogen Deposition Alter Root Distribution In A Tallgrass Prairie, Emmalyn P. Terracciano, Michael Schuster, Jeffrey Dukes

The Summer Undergraduate Research Fellowship (SURF) Symposium

Climate change and increases in nitrogen deposition impact ecosystems globally. Projected atmospheric warming allows rain to fall in larger events with longer dry periods in between, increasing rainfall variability in many regions. Concurrently, the combustion of fossil fuels and the heavy use of nitrogen fertilizers continue to increase the availability of nitrogen globally. However, not much is known about how these global change factors, increased rainfall variability and nitrogen deposition, interact with each other to affect ecosystem functions, particularly belowground where root production contributes to soil carbon pools- an important component in regulating climate. In order to study these factors, …

Exposure Of U.S. National Parks To Land Use And Climate Change 1900-2100, Andrew J. Hansen, Cory Davis, Jessica Haas, David M. Theobald, John E. Gross, William B. Monahan, Tom Olliff, Steven W. Running

Ecosystem and Conservation Sciences Faculty Publications

Many protected areas may not be adequately safeguarding biodiversity from human activities on surrounding lands and global change. The magnitude of such change agents and the sensitivity of ecosystems to these agents vary among protected areas. Thus, there is a need to assess vulnerability across networks of protected areas to determine those most at risk and to lay the basis for developing effective adaptation strategies. We conducted an assessment of exposure of U.S. National Parks to climate and land use change and consequences for vegetation communities. We first defined park protected-area centered ecosystems (PACEs) based on ecological principles. We then …

Evaluating Habitat Vulnerability And Sustainability Of Urban Seagrass Resources To Sea Level Rise, Cynthia A. Meyer

USF Tampa Graduate Theses and Dissertations

The seagrass resource provides essential ecosystem functions for many marine species. This research evaluated the vulnerability and sustainability of the seagrass resource in an urbanized area to the effects of sea level rise. The assessment required analysis of information regarding the biogeography of the seagrass resource, and developing a method to model the spatial extent of the suitable habitat for seagrass, and applying the model to predict the implications of simulated sea level rise scenarios on the seagrass resource.

Examining the biogeography of the seagrass resource required the development of a seagrass monitoring and assessment field survey and a comprehensive …