Graduate student assistantships at University of Alaska-Fairbanks Graduate student assistantships are available in the laboratory of Dr. Jay Jones (http://users.iab.uaf.edu/~jay_jones/) at the University of Alaska, Fairbanks. Please contact Dr. Jones (jay.jo...@alaska.edu) regarding interest in the following projects. The application deadline for the graduate program in the Department of Biology & Wildlife (http://www.bw.uaf.edu/graduates/index.php) is Jan 15.
1. Scale, Consumers and Lotic Ecosystem Rates (SCALER) A Ph.D. assistantship is available to support research related to the multi-site, collaborative SCALER project. This project focuses on issues of scaling in stream ecology and is part of a larger collaborative effort to be conducted at sites across North America. Students working at the University of Alaska Fairbanks will focus their field work in the boreal forest at the Caribou-Poker Creeks Research Watersheds (CPCRW; located near Fairbanks), but will be involved in cross-site synthesis. SCALER will address the following overarching question: How can small-scale ecological experiments be applied to understand the behavior of entire ecological systems? The broader SCALER project includes sites in the tropical forest, temperate deciduous forest, prairie, and tundra biomes. Streams in each of these five regions will be examined at scales of centimeters to 1000s of meters in streams of varying size. Rates of stream metabolism (photosynthesis and respiration) and nutrient uptake will be measured, as well as the way these ecosystem processes respond to animal exclusions (used to mimic loss of animal diversity in streams) in small headwater to mid-order stream reaches. Reach scale studies will be linked to the scale of watersheds and regions by modeling, and verified by broader, but less intensive sampling. 2. Climate-mediated coupling of hydrology and biogeochemistry in arctic hillslopes We are seeking an M.S. student to develop a thesis related to biogeochemistry of arctic hillslopes. The student will join a team that is investigating coupled hydrology and biogeochemistry of arctic hillslopes, in effort to understand how climate-induced changes in water and nutrient cycles on land are propagated to stream networks. Observed increases in fluxes of water, nitrogen, and phosphorus from river networks to the Arctic Ocean may be caused by release of nutrients from thawing permafrost, changing precipitation patterns, increased rates of biogeochemical reactions, or expanded storage capacity in thawed soils. However, the flowpaths connecting terrestrial ecosystems to stream networks remain poorly understood. We will focus on transport and reaction of water and solutes within water tracks, which are linear regions of surface and subsurface flow that connect hillslopes to streams and account for up to 35% of watershed area in arctic tundra. The research team includes watershed ecologists (Tamara Harms, Jay Jones) at the University of Alaska-Fairbanks, and hydrologists (Sarah Godsey, Mike Gooseff) at Idaho State University and Pennsylvania State University. Field work for the project will be based at the Toolik Field Station, and will begin 5/12. 3. Watershed, Permafrost and Climate Change Controls on Stream Ecosystems The third 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 soil organic matter that will potentially be released to streams and the atmosphere with climatic warming and permafrost thaw. In particular, groundwater inputs of nutrients and organic matter may shift with changing climate and 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).
