Spatiotemporal analysis of black spruce forest soils and implications for the fate of C

Journal of Geophysical Research
By: , and 

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Abstract

Post-fire storage of carbon (C) in organic-soil horizons was measured in one Canadian and three Alaskan chronosequences in black spruce forests, together spanning stand ages of nearly 200 yrs. We used a simple mass balance model to derive estimates of inputs, losses, and accumulation rates of C on timescales of years to centuries. The model performed well for the surface and total organic soil layers and presented questions for resolving the dynamics of deeper organic soils. C accumulation in all study areas is on the order of 20–40 gC/m2/yr for stand ages up to ∼200 yrs. Much larger fluxes, both positive and negative, are detected using incremental changes in soil C stocks and by other studies using eddy covariance methods for CO2. This difference suggests that over the course of stand replacement, about 80% of all net primary production (NPP) is returned to the atmosphere within a fire cycle, while about 20% of NPP enters the organic soil layers and becomes available for stabilization or loss via decomposition, leaching, or combustion. Shifts toward more frequent and more severe burning and degradation of deep organic horizons would likely result in an acceleration of the carbon cycle, with greater CO2 emissions from these systems overall.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Spatiotemporal analysis of black spruce forest soils and implications for the fate of C
Series title Journal of Geophysical Research
DOI 10.1029/2011JG001826
Volume 117
Issue 1
Year Published 2012
Language English
Publisher American Geophysical Union
Publisher location Richmond, VA
Contributing office(s) Volcano Science Center
Description 9 p.