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Extramural Research

Grantee Research Project Results

Grantee Research Project Results

Edge Effects on Carbon and Nitrogen Cycling in Fragmented Oldgrowth Forests of the Pacific Northwest

EPA Grant Number: U915219
Title: Edge Effects on Carbon and Nitrogen Cycling in Fragmented Oldgrowth Forests of the Pacific Northwest
Investigators: Hayes, Thomas D.
Institution: University of California - Berkeley
EPA Project Officer: Smith, Bernice
Project Period: August 1, 1997 through August 1, 2000
Project Amount: $102,000
RFA: STAR Graduate Fellowships (1997)
Research Category: Academic Fellowships , Ecological Indicators/Assessment/Restoration , Fellowship - Ecology and Ecosystems



The objective of this research project is to address the indirect impact of clearcut edges on biogeochemical processes affecting nitrogen (N) retention within adjacent fragmented oldgrowth Douglas-fir forests in the Pacific Northwest. This research project examines the relationship between the magnitude of the edge effect on biogeochemical processes and the distance the effect penetrates into the forest, in order to more accurately predict the influence of land use on regional biogeochemical processes.


Prior research has documented edge effects on microclimate and vegetation at the field site in Wind River Experimental Forest in southern Washington. Initial field and laboratory assays of N mineralization, litter decomposition, and related soil processes reveal increases in C loss and N availability in near-edge (0-30 m from edge) forest soils, and higher rates of litterfall and C storage within far-edge (30-120 m) forest, relative to interior forest (more than 120 m). Also, south-facing forest edges have greater magnitude of effect and depth of influence for all assayed processes, relative to north-facing edges. Initial results were used to design a three3-year experiment, which concurrently measures edge effects on microclimate, litterfall, decomposition, and N mineralization.

Supplemental Keywords:

fellowship, edge effects, biogeochemistry, fragmented forests, nitrogen and carbon cycling, microclimate, decomposition, litter fall, forest structure.

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The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.

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