Students

Julia Angstmann

http://www.uwyo.edu/plantecofizz/jangstmann.html

My research project focuses on water transport in trees and is located in the boreal forest of northern Manitoba. Development of a wildfire chronosequence in the northern Canadian boreal forest provides an opportunity to study the effects of fire and stand age on water cycles and their implications on global change scenarios. I am specifically interested in quantifying the interactions between spatial and temporal patterns of transpiration, determining the mechanisms driving this variability, and utilizing this information to accurately scale from individual-level measurements to holistic canopy resolutions.

Morgan Churchill

My research interests are focused on the evolution and paleoecology of marine mammals. In particular, I am interested in factors relating to the initial adaptative radiation of mammals into aquatic habitats, as well as patterns of faunal succession resulting in our modern marine mammal communities. My current research emphasis focuses on the investigation of the evolution and ecology of fossil pinnipeds (seals and walruses) in the North Pacific, using stable isotopes and morphometric techniques.

Jamie Crait

Introduced lake trout have contributed to a severe decline in the native cutthroat trout population of Yellowstone Lake. I found that river otters depend heavily on cutthroat trout as prey, especially during summer when the fish make spawning migrations from the lake into tributary streams. In addition, as part of their social behavior, otters deposit excreta at scent-marking sites along these spawning streams and fertilize riparian plants with aquatically-derived nutrients such as nitrogen (N). Continued declines in cutthroat trout may reduce the abundance and distribution of otters and sever this nutrient link between water and land. Currently I am using DNA from otter hair and scat to monitor changes in Yellowstone Lake’s otter population since the decline in cutthroat trout. I am also measuring N in tree-rings collected from otter scent-marking sites to investigate whether N contributions from otters have changed with historical changes in the cutthroat trout population.

Emiliano Donadio

http://uwstudentfpweb.uwyo.edu/e/emiliano

My research interests include predator-prey and competitive interactions and their role in structuring biological diversity, the impact of invasive prey species on predator communities, and natural history and conservation of terrestrial vertebrates. My dissertation research aims to elucidate if spatially heterogeneous puma predation on South American camelids, guanacos and vicuñas, triggers a behaviorally-mediated trophic cascade, which results in a mosaic of safe and risky habitats partially responsible for structuring biodiversity in the high-altitude plateaus of the Andes, northwestern Argentina.

Eriek Hansen

For my research I will be looking at landscape influences on fish in the Laramie River. I am continuing an on going project mapping habitat patches and how they change in response to disturbance events (i.e., spring floods). I will also be looking at how different types of land use influence fish communities using stable isotopes.

Erin Hotchkiss

http://uwstudentweb.uwyo.edu/e/ehotchki

I am interested in the roles of organisms (ranging from microbes to humans) in biogeochemical cycles. I am currently studying the links between carbon and oxygen cycling in stream ecosystems, focusing on primary production, community respiration, and organic carbon availability. Other research projects include: modeling the productivity of streams and rivers, impacts of invasive snails on stream carbon cycling and native invertebrate diversity, controls on nitrate uptake in streams, seasonal changes in organic carbon concentration and quality in alpine lakes, and the role of denitrification in the nitrogen budget of a tropical Andean stream.

Ben Koch

http://uwstudentfpweb.uwyo.edu/B/BKOCH

My research interests are defined by the processes that link population biology to freshwater ecosystem function. I am interested in the roles that aquatic animal populations play in mediating ecosystem processes such as nutrient cycling and how these roles vary in different landscape contexts. In addition, I am investigating how biotic interactions regulate the patterns of energy flow within stream ecosystems. My dissertation research aims to quantify the consequences of trout predation on the population energetics of invertebrate prey species through both consumptive and non-consumptive mechanisms.

Lisa Kunza

http://uwstudentweb.uwyo.edu/l/lisa

My research interests include human impacts on aquatic systems, stream biogeochemistry, ecosystem processes and function, and restoration ecology. My dissertation work is focused on measuring controls on nitrogen fixation rates in streams and putting these rates in context with nutrient cycling. I have found that N-fixation can contribute greatly to the N budget of some streams. I am currently investigating short-term and long-term nutrient effects on N-fixation.

Mark Lesser

http://uwstudentfpweb.uwyo.edu/m/mlesser

I am interested in studying conifer migration patterns at multiple temporal and spatial scales. Using ponderosa pine as a model species I am looking at genetic population structure, using microsatellites, in combination with dendrochronological analysis of disjunct ponderosa stands to assess dispersal, colonization and recruitment dynamics. I am also using pack-rat middens to assess longer term (i.e. thousands of years) migration patterns of ponderosa pine. A further interest is how these processes relate to environmental factors.

David McKenzie

My main focus is forest ecology with an emphasis on vegetation succession following disturbance. I am especially interested in fire and its impact on species composition, distribution, and abundance. Fire tolerance and fire adapted reproductive strategies are also of interest. In addition, I am interested in oak savanna restoration and deciduous forest succession following long-term removal of fire.

Arthur Middleton

I am a first-year doctoral student studying predator-prey interactions and their dynamic influence in populations and communities. In particular, I am interested in behavioral responses of prey to the risk of predation, and problems of scaling related theory among divergent predator-prey systems. I am currently developing research linking prey condition with interaction strength in a temperate large mammal system. As a student in the Wyoming Cooperative Fish and Wildlife Research Unit, I work on elk population dynamics and elk-wolf interactions in Wyoming's Absaroka Range . I am strongly interested in the management and conservation implications of my work, and of ecological research more broadly

Kusum Naithani

I'm working on sagebrush steppe ecosystems in Wyoming and Colorado. Prescribed burning of sagebrush ecosystems is very common range management tool which creates a nice opportunity to study the succession of sagebrush and how it is effecting climate. The primary objective of my study is to quantify the effect of environmental drivers such as light, temperature, soil moisture and vapor pressure deficit on carbon and water fluxes during succession of sagebrush ecosystem.

Christopher North

Our work in the Bering Sea examines the effects of global warming, particularly decreases in the extent and duration of sea ice cover, on the bottom-dwelling (benthic) community. Reorganization of the benthic community due to climate change could have major impacts on species of conservation interest, such as the spectacled eider, gray whales, and walruses. Important snow crab and ground fish fisheries, among the most productive in the world, will also be impacted. Our group is building a food web-based ecosystem model to help managers plan for the changing future. I’m looking at the effect of climate change on the prey base, including abundant clams, which are the main food for many benthic predators (eiders, walruses, crabs, etc.). I’m also investigating the diet of sea stars and snails which are largely understudied but potentially important predators of the shared prey base.

Jonathan N. Pauli

http://students.uwyo.edu/jpauli

Areas in which I currently have interest include predator-prey relationships, effects of large scale disturbances on vertebrate community assemblages, factors influencing competitive success in closely related species, the role of parasites and pathogens in population ecology and conservation biology. For my doctoral research, I am examining the effects of forest fragmentation on two distinct subspecies of American marten (Martes americana) in the temperate rainforests of southeast Alaska.

Amber J. Ulseth

I’m interested in research on ecosystem processes and function and how organisms (including people) can alter and change these processes. I’ve had the opportunity to conduct research in a variety of aquatic systems from the Arctic to the Tropics. Previous projects include using natural abundances of stable isotopes to trace anthropogenic N and C into urban stream food webs as well as studying N dynamics in tropical streams in relation to a migratory fish. My dissertation research will involve looking at nutrient dynamics on the Colorado River in the Grand Canyon.

Mark Williams

Management and restoration of public forested lands is often based upon deviation from the historical forest condition prior to European influence. Most studies used to model the historical forest condition have focused at fine spatial scales and in only a few isolated areas. My research will focus on quantifying historical forest structure at coarse spatial scales in the Rocky Mountains of Colorado and across the west. It is important to understand the spatial variability of forest structure because forest structure affects wildlife habitat, watershed values, and timber resources.

Jim Zier

I’m striving to understand present, past, and future biogeographic patterns across western landscapes, primarily in the context of climate shifts and human land uses. Current dissertation research focuses on the ecology of kettle ponds in the Bighorn Mountains, Wyoming. Research questions include: How have pond organisms responded to past climatic shifts? How are pond organisms responding to current drought conditions? Can we predict future changes in pond habitats under varying climate change scenarios?