Graduate students in my lab are currently working on two projects:
The first project investigates how streams are linked to their catchments, and focuses on how permafrost influences groundwater inputs of nutrients and organic matter to streams. The boreal forest in interior Alaska is underlain with discontinuous permafrost, which has a major affect on watershed hydrology. Where permafrost is present, groundwater flowpaths through catchments are largely restricted to soils, whereas in the absence of permafrost water can infiltrate into deeper bedrock regions of watersheds. In addition to affecting hydrology, permafrost stores a lot of soil organic matter that will potentially be released to streams and the atmosphere with climatic warming and permafrost thaw. This research is particularly exciting to me in the context of how groundwater inputs of nutrients and organic matter may shift with changing climate and resulting alterations in the extent of permafrost. An interesting sidelight of this research is the role of forest fires and their influences on permafrost. Fire alters the albedo of soil and, as a consequence, can lead to thawing of permafrost. Fire frequency has been increasing in interior Alaska, which has important implications for permafrost and watershed hydrology. This work is funded through the Bonanza Creek Long Term Ecological Program (http://www.lter.uaf.edu/) and is being conducted in the Caribou-Poker Creeks Research Watersheds (CPCRW; located near Fairbanks). CPCRW covers an area of ~100 km2, and has a number of sub-catchments and streams that we have been studying. Of these sub-catchments, we conducted a controlled burn of one watershed in July of 1999, and another sub-catchment was burned extensively in summer 2004 by a wild fire.
For the second project, we have been studying the impacts of thermokarsts on Arctic and boreal forest ecosystems. A thermokarst is a feature of landscapes with permafrost. As permafrost thaws, the underlying soil can collapse generating mass wasting of the ground surface. Depending on where these features form, thermokarsts can result in rather dramatic scares on the landscape, mobilize a lot of sediment, and rapidly release a large amount of old soil organic matter (organic matter that was previously stored in permafrost). We are interested in the age and nature/quality of carbon released from soil following thermokarst formation, trace gas emissions, and role thermokarsts play on watershed nutrient cycling. Our work on thermokarsts is being conducted near the Toolik Lake field station in northern Alaska (http://www.uaf.edu/toolik/) and in the Noatak National Preserve (http://www.nps.gov/noat/) in north-western Alaska. More information on the broader project goals and personnel can be found at http://thermokarst.psu.edu/.
If you are interested in learning more about these research projects and graduate school at the University of Alaska Fairbanks, please send me an email introducing yourself and your potential research interests.
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