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Drivers of postfire soil organic carbon accumulation in the boreal forest.
- Source :
-
Global Change Biology . Oct2018, Vol. 24 Issue 10, p4797-4815. 20p. 1 Color Photograph, 3 Diagrams, 3 Charts, 1 Graph, 1 Map. - Publication Year :
- 2018
-
Abstract
- Abstract: The accumulation of soil carbon (C) is regulated by a complex interplay between abiotic and biotic factors. Our study aimed to identify the main drivers of soil C accumulation in the boreal forest of eastern North America. Ecosystem C pools were measured in 72 sites of fire origin that burned 2–314 years ago over a vast region with a range of ∆ mean annual temperature of 3°C and one of ∆ 500 mm total precipitation. We used a set of multivariate a priori causal hypotheses to test the influence of time since fire (TSF), climate, soil physico‐chemistry and bryophyte dominance on forest soil organic C accumulation. Integrating the direct and indirect effects among abiotic and biotic variables explained as much as 50% of the full model variability. The main direct drivers of soil C stocks were: TSF >bryophyte dominance of the FH layer and metal oxide content >pH of the mineral soil. Only climate parameters related to water availability contributed significantly to explaining soil C stock variation. Importantly, climate was found to affect FH layer and mineral soil C stocks indirectly through its effects on bryophyte dominance and organo‐metal complexation, respectively. Soil texture had no influence on soil C stocks. Soil C stocks increased both in the FH layer and mineral soil with TSF and this effect was linked to a decrease in pH with TSF in mineral soil. TSF thus appears to be an important factor of soil development and of C sequestration in mineral soil through its influence on soil chemistry. Overall, this work highlights that integrating the complex interplay between the main drivers of soil C stocks into mechanistic models of C dynamics could improve our ability to assess C stocks and better anticipate the response of the boreal forest to global change. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 13541013
- Volume :
- 24
- Issue :
- 10
- Database :
- Academic Search Index
- Journal :
- Global Change Biology
- Publication Type :
- Academic Journal
- Accession number :
- 132003416
- Full Text :
- https://doi.org/10.1111/gcb.14365