Editor's note: Through its George Melendez Wright Climate Change Interns and Fellows program, the National Park Service enables university students to visit national parks to investigate issues related to climate change. Here are two of the studies being investigated by students. Thanks to the Park Service's Climate Change Response Program for making the profiles available.

Understanding Diatom Communities in Lassen

Kerry Howard, a PhD student in the department of Geological Sciences at the University of Nevada, Reno, is investigating the effects of environmental change on diatom community composition in the small subalpine lakes of Lassen Volcanic National Park. (Diatoms are an important type of plankton that help form the foundation of the marine food chain.)

Changes in diatom community composition may be attributed to increasing temperatures (climate change), modifications in landscape, increases in atmospheric nutrient deposition, or a complex interaction of these forcing factors, particularly where multiple forcing factors affect the region.

Kerry Howard is studying the impacts of climate change on alpine lakes at Lassen Volcanic National Park. NPS photo.

Ms. Howard is examining modern diatom community composition in park lakes and the associated physical and chemical parameters in these lakes. She has also extracted sediment cores from several lakes to study algae community composition changes and environmental changes through time. Since both regional and local environmental changes impact lake ecosystems on differing scales, her work will help park resource managers approach resource management decisions from multiple perspectives.

Data from her study are being merged with lake monitoring data from the park so managers can also gain a more detailed picture of the status of park lakes. Ms. Howard's research is directed toward improved knowledge of diatom community response to environmental change and the varying nature of water resources in small subalpine watersheds. She is also a middle school science/math teacher.

Wildfire Patterns and Forest Transitions in the Rockies

For national parks and wilderness areas in the northern Rocky Mountains, the combination of warmer climate and altered fire regimes (fire frequency, size, and severity patterns) will likely cause rapid, widespread, and lasting changes in vegetation and wildlife habitat. Fire frequency and annual area burned have steadily increased in recent decades, but very little is known about how spatial patterns of fires may be changing. Are fires becoming less “patchy” with more uniform burn severity patterns? What climatic, topographic, or biological factors are related to spatial patterns of burn severity?

Brian Harvey is studying the changing fire regimes in the Rocky Mountain parks. NPS photo.

Where are spatial patterns of burn severity changing fastest? How do these changes in fire regime and post-disturbance climate potentially interact to affect tree regeneration in common northern Rockies forest types?

These are some of the questions that Climate Change Fellow Brian Harvey seeks to answer through his doctoral research. Mr. Harvey is a third-year PhD student at the University of Wisconsin and is combining extensive field data with satellite remote sensing to test for changes in burn severity patterns and postfire forest reestablishment in Yellowstone, Grand Teton, and Glacier national parks and surrounding wilderness areas. His research will generate new understanding that is directly relevant for managing fire-prone forested landscapes in national parks in the face of climate change.