Storage and stability of organic carbon in soils as related to depth, occlusion within aggregates, and attachment to minerals

Abstract

The LF at three sites were rather depleted in C-14, indicating the presence of fossil material such as coal and lignite, probably inherited from the parent material. At the other sites, modern Delta C-14 signatures and positive correlations between specific mineralization rates and fLF-OC indicate the fLF is a potentially available energy and nutrient source for subsurface microorganisms throughout the profile. Declining specific mineralization rates with soil depth confirm greater stability of OC in subsoils across sites. The overall importance of OC stabilization by binding to minerals was demonstrated by declining specific mineralization rates with increasing contributions of HF-OC to bulk soil OC, and the low Delta C-14 values of HF-OC. The stability of HF-OC was greater in subsoils than in topsoils; nevertheless, a portion of HF-OC was active throughout the profile. While quantitatively less important than OC in the HF, consistent older ages of oLF-OC than fLF-OC suggest that occlusion of LF-OC in aggregates also contributes to OC stability in subsoils. Overall, our results indicate that association of OC in soils, irrespective of vegetation, soil type, and land use.

Published in

Biogeosciences
2013, volume: 10, number: 3, pages: 1675-1691
Publisher: COPERNICUS GESELLSCHAFT MBH

SLU Authors

• Persson, Tryggve

  • Department of Ecology, Swedish University of Agricultural Sciences
    

Global goals (SDG)

SDG15 Life on land

UKÄ Subject classification

Ecology
Other Earth and Related Environmental Sciences
Soil Science

Publication identifier

• DOI: https://doi.org/10.5194/bg-10-1675-2013

Permanent link to this page (URI)

https://res.slu.se/id/publ/52379