Publication
Title
Priming of soil organic matter decomposition scales linearly with microbial biomass response to litter input in steppe vegetation
Author
Abstract
Fresh plant litter inputs accelerate soil organic matter (SOM) decomposition through a ubiquitous mechanism called priming. Insufficient priming has been suggested as a stabilization mechanism of SOM at depth, as well as the long-term persistence of some highly degradable organic compounds in soils. Priming therefore plays a crucial, albeit unquantified and commonly neglected, role in the global carbon cycle. Because priming intensity is likely to be altered by global change-induced changes in net primary productivity, it casts substantial uncertainty to future projections of the climate-carbon cycle feedback. Using results from a large field litter manipulation experiment in Mongolian steppe, we here show that priming intensifies with increasing litter inputs, but at a decreasing efficiency: the stimulation per unit litter added declines with increasing litter inputs. This non-linear behavior originates from two antagonistic responses to fresh litter inputs: a stimulation of microbial activity versus a shift in microbial community composition (more fungi) associated to substrate shift from SOM to litter. Despite all complexity, however, the priming effect on SOM decomposition scaled linearly with the response of microbial biomass across the entire range of plant litter addition (60480 g C m−2), suggesting that priming could be modeled effectively as a function of the response of microbial biomass to litter inputs. Incorporating the priming mechanism in Earth System models will improve their estimates of the SOM-climate feedback and appears to be best addressed by explicitly representing microbial biomass in the models.
Language
English
Source (journal)
Oikos: a journal of ecology. - København
Publication
København : 2015
ISSN
0030-1299
Volume/pages
124:5(2015), p. 649-657
ISI
000356010300013
Full text (Publisher's DOI)
Full text (open access)
Full text (publisher's version - intranet only)
UAntwerpen
Faculty/Department
Research group
[E?say:metaLocaldata.cgzprojectinf]
The terrestrial Carbon cycle under Climate Variability and Extremes - a Pan-European synthesis. (CARBO-Extreme)
Publication type
Subject
Affiliation
Publications with a UAntwerp address
External links
Web of Science
Record
Identification
Creation 17.04.2015
Last edited 27.07.2017
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