Estimation of Carbon loss by fire in a burned black spruce forest in interior Alaska using radiocarbon
Abstract
Wildfire is one of major disturbances in northern forest ecosystems. Wildfire disturbances release large amount of carbon dioxide during burning process, and also change the site from sink to source for carbon. Effects of this fire are great concerns for regional environment, especially for carbon sink / source balance. Carbon loss from forest floor/top soil by wildfire was estimated at a burned black spruce forest site in Interior Alaska, using radiocarbon (14C). By comparing organic C storage and Δ14C profile at burned forest with those of a mature forest, we estimated C loss from forest floor/top soil. Soil profiles were surveyed at the mature black spruce forest in University of Alaska Fairbanks, and the burned black spruce forest in Poker Flat Research Range, which burned in 2004 summer. The Δ14C profiles at the mature forest show clear bomb 14C peak after 1960's, and plant litter and soil organic C at top of the 15cm was fixed over the past 50 years. The burned black spruce forest site were similar Δ14C profiles to the mature forest, but top of 10cm was lost. Organic carbon storage in each forest was estimated by bulk density and C contents. Decline of carbon storage after wildfire was estimated, assuming that C storage in the mature forest were same regime of C storage as burned stands before wildfire. Compare with mature forest, 4.4 kg C m-2 was lost. Wildfire disturbance in 2004 caused much C loss from forest floor, corresponding to 53% of accumulated C over the past 50 years.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2012
- Bibcode:
- 2012AGUFM.B21D0404K
- Keywords:
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- 0428 BIOGEOSCIENCES / Carbon cycling;
- 0475 BIOGEOSCIENCES / Permafrost;
- cryosphere;
- and high-latitude processes;
- 0486 BIOGEOSCIENCES / Soils/pedology;
- 1630 GLOBAL CHANGE / Impacts of global change