Higher temperature sensitivity for stable than for labile soil organic carbon - Evidence from incubations of long-term bare fallow soils

Lefevre, Romain; Barre, Pierre; Moyano, F.E.; Christensen, B.T.; Bardoux, Gérard; Eglin, T.; Girardin, Cyril; Houot, Sabine; Kätterer, Thomas; van Oort, F.; Chenu, Claire

doi:10.1111/gcb.12402

Research article2014Peer reviewed

Higher temperature sensitivity for stable than for labile soil organic carbon - Evidence from incubations of long-term bare fallow soils

Lefevre, Romain; Barre, Pierre; Moyano, F.E.; Christensen, B.T.; Bardoux, Gérard; Eglin, T.; Girardin, Cyril; Houot, Sabine; Kätterer, Thomas; van Oort, F.; Chenu, Claire

Abstract

The impact of climate change on the stability of soil organic carbon (SOC) remains a major source of uncertainty in predicting future changes in atmospheric CO2 levels. One unsettled issue is whether the mineralization response to temperature depends on SOC mineralization rate. Long-term (>25years) bare fallow experiments (LTBF) in which the soil is kept free of any vegetation and organic inputs, and their associated archives of soil samples represent a unique research platform to examine this issue as with increasing duration of fallow, the lability of remaining total SOC decreases. We retrieved soils from LTBF experiments situated at Askov (Denmark), Grignon (France), Ultuna (Sweden), and Versailles (France) and sampled at the start of the experiments and after 25, 50, 52, and 79years of bare fallow, respectively. Soils were incubated at 4, 12, 20, and 35 degrees C and the evolved CO2 monitored. The apparent activation energy (E-a) of SOC was then calculated for similar loss of CO2 at the different temperatures. The E-a was always higher for samples taken at the end of the bare-fallow period, implying a higher temperature sensitivity of stable C than of labile C. Our results provide strong evidence for a general relationship between temperature sensitivity and SOC stability upon which significant improvements in predictive models could be based.

Keywords

activation energy; long-term bare fallow experiments; soil carbon dynamic; stable soil carbon; temperature sensitivity

Published in

Global Change Biology
2014, volume: 20, number: 2, pages: 633-640
Publisher: WILEY-BLACKWELL

SLU Authors

Kätterer, Thomas
- Department of Ecology, Swedish University of Agricultural Sciences

Global goals (SDG)

SDG13 Climate action
SDG15 Life on land

UKÄ Subject classification

Soil Science

Publication identifier

DOI: https://doi.org/10.1111/gcb.12402

Permanent link to this page (URI)

https://res.slu.se/id/publ/51835