| Summary: | EPA Identifier: U914999 Title: Succession and Carbon Dynamics of Boreal Permafrost Peatlands During Rapid Climate Warming Fellow (Principal Investigator): Philip Camill Institution: Duke University EPA Grant Representative: Virginia Broadway Project Period: January 1, 1996 - January 1, 1999 Project Amount: $0 RFA: STAR Graduate Fellowships Research Category: Fellowship - Ecology and Ecosystems Description Objective: The objective of this research project is to determine how succession and peat accumulation respond to changes at the local scale resulting from permafrost thaw as opposed to regional-scale changes in climate, in boreal permafrost peatlands in Manitoba, Canada. Most ecosystems will probably exhibit complex dynamics during a rapid climatic warming because: (1) local factors mediate the effects of regional climate change on vegetation migration; and (2) changes in biodiversity impact ecosystem function. Approach: I measured rates of two key successional processes, permafrost formation and thaw, as well as peat accumulation across a 4°C mean annual temperature gradient in northern Manitoba, Canada. For successional dynamics, local factors were more important controls of ecosystem dynamics than regional climate. Permafrost thawing was more rapid in warmer regions than in colder regions. However, shading by trees and the insulation properties of hummock-forming Sphagnum were sufficient to stop thawing. For permafrost formation, the local presence of tree cover was significantly more important than differences in regional climate. Peat accumulation decreased following permafrost thaw, largely because the loss of a single tree species, Picea mariana . These results suggest that local factors and species changes may control ecosystem dynamics more than the direct impact of regional climate warming over the course of the next century. Supplemental Keywords: FELLOWSHIP; CLIMATE WARMING; PERMAFROST PEATLANDS; ECOSYSTEM; PEAT ACCUMULATION; SUCCESSION; SUCCESSIONAL DYNAMICS; PERMAFROST FORMATION; THAW; MANITOBA; CANADA; ECOSYSTEM DYNAMICS.
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