Storage and Flux of Carbon in Live Trees, Snags, and Logs in the Chugach and Tongass National Forests.

摘要

Carbon storage and flux estimates for the two national forests in Alaska are provided using inventory data from permanent plots established in 19952003 and remeasured in 20042010. Estimates of change are reported separately for growth, sapling recruitment, harvest, mortality, snag recruitment, salvage, snag falldown, and decay. Although overall aboveground carbon mass in live trees did not change in the Tongass National Forest, the Chugach National Forest showed a 4.5 percent increase. For the Tongass National Forest, results differed substantially for managed and unmanaged forest: managed lands had higher per-acre rates of sequestration through growth and recruitment, and carbon stores per acre that were higher for decomposing downed wood, and lower for live trees and snags. The species composition of carbon stores is changing on managed lands, with a carbon mass loss for yellow-cedar but increases for red alder and Sitka spruce. On unmanaged lands, the Chugach National forest had carbon mass increases in Sitka spruce and white spruce, and the Tongass National Forest had increases in western redcedar and red alder.