UAA awarded $622,000 for International Polar Year project

By: Jessica Hamlin Sep 5, 2006

Research will determine how increase in shrubs affects Alaska’s arctic regions

ANCHORAGE – Dr. Jeff Welker of the University of Alaska Anchorage’s (UAA) Environment and Natural Resources Institute (ENRI), recently received a $622,000 grant from the Office of Polar Programs at the National Science Foundation (NSF) for his research project associated with the International Polar Year (IPY) investigations. The proposed project will quantify how increases in shrubs have altered the abiotic environment, causing a fundamental change in the functional attributes of these systems in arctic Alaska.

The grant will join other IPY projects researching the “State of the Arctic”, and target specific research themes of Tundra Experiments, Cold Land Processes and Climate Changes in Alaska. Welker’s co-principal investigators on this project are Professor Bjartmar Sveinbjornsson and Dr. Paddy Sullivan.

The IPY, held every 50 years, is a program with international participation designed to better understand the significance of the earth’s remote Polar Regions, and how the climates operate and interact with polar environments and societies. The three fastest warming regions in the last two decades are Alaska, Siberia and parts of the Antarctic Peninsula, raising concern for the future of polar ecosystems and Arctic society.

The arctic terrestrial landscape is undergoing structural changes that appear to be the result of climate warming and altered precipitation regimes, including shrub expansion in parts of arctic Alaska. These vegetation changes may have local to global consequences, including shifts in the albedo-climate feedback, altered animal abundances, and changes in carbon and nitrogen cycling, according to Welker.

The project will utilize in part Welker’s long-term snow manipulation experiment in northern Alaska where he and colleagues have been studying how increases in snow depth and warmer summer temperature affect: a) vegetation composition, b) shoot and root growth, c) plant mineral nutrition, d) year-long nitrogen cycling and e) carbon exchange processes since 1994.

“Our research is essential,” said Welker. “Understanding the mechanisms and the consequences of shrub encroachment are very important to determine the controls on structural and functional changes in the arctic.”

The goals of this IPY project are to: a) quantify how shrub increases affect the year-long temperature and water regimes of arctic tundra, quantify how shrub increases change the energy balance of the system and how these changes in vegetation community attributes may feedback to climate; b) delineate the processes controlling shrub increases, especially soil and plant N mineral nutrition and the physical protection of shrub meristems and branches by deeper snow; and c) quantify how shrub density increases have affected the patterns and magnitudes of carbon cycling (C gain, C loss and C allocation), water relations and growth above and below ground.

This IPY project complements Welker’s high arctic (Northwestern Greenland) studies of tundra responses to coupled changes in climate. In 2004, ENRI was awarded $820,000 to articulate the complexity of arctic system responses to changes in conditions and the controls on carbon and water dynamics. Welker and colleagues from the University of Washington and the University of California are providing details as to how multiple levels of warming are changing the biology, chemistry and physical processes in some of the most extreme terrestrial ecosystems in the arctic. This project has involved three UAA undergraduates, two UAA Biology Master of Science students and one postdoctoral scientist from UAA. Findings from this project will be highlighted at the American Association for the Advancement of Science (AAAS) Arctic Section meeting in Fairbanks this October.

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Jessica D. Hamlin ● Office of University Advancement ● (907) 786-1288