Original Research ARTICLE
Modulation of litter decomposition by the soil microbial food web under influence of land use change
- 1Biometris, Wageningen University & Research, Netherlands
- 2Institute of Environmental Biology, Utrecht University, Netherlands
- 3Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Netherlands
- 4Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Netherlands
Soil microbial communities modulate soil organic matter (SOM) dynamics by catalyzing litter decomposition. However, our understanding of how litter-derived carbon (C) flows through the microbial portion of the soil food web is far from comprehensive. This information is necessary to facilitate reliable predictions of soil C cycling and sequestration in response to a changing environment such as land use change in the form of agricultural abandonment. To examine the flow of litter-derived C through the soil microbial food web and it’s response to land use change, we carried out an incubation experiment with soils from six fields; three recently abandoned and three long term abandoned fields. In these soils, the fate of 13C-labeled plant litter was followed by analyzing phospholipid fatty acids (PLFA) over a period of 56 days. The litter-amended soils were sampled over time to measure 13CO2 and mineral N dynamics. Microbial 13C-incorporation patterns revealed a clear succession of microbial groups during litter decomposition. Fungi were first to incorporate 13C-label, followed by G- bacteria, G+ bacteria, actinomycetes and micro-fauna. The order in which various microbial groups responded to litter decomposition was similar across all the fields examined, with no clear distinction between recent and long-term abandoned soils. Although the microbial biomass was initially higher in long-term abandoned soils, the net amount of 13C-labeled litter that was incorporated by the soil microbial community was ultimately comparable between recent and long-term abandoned fields. In relative terms, this means there was a higher efficiency of litter-derived 13C-incorporation in recent abandoned soil microbial communities compared to long-term abandoned soils, most likely due to a net shift from SOM-derived C towards root-derived C input in the soil microbial food web following land-abandonment.
Keywords: soil microbial community, decomposition, PLFA-SIP, Carbon Cycle, agricultural abandonment, soil food web
Received: 01 Sep 2018;
Accepted: 06 Nov 2018.
Edited by:Eoin L. Brodie, Lawrence Berkeley National Laboratory (LBNL), United States
Reviewed by:Egbert Schwartz, Northern Arizona University, United States
Philippe Constant, Institut National de la Recherche Scientifique (INRS), Canada
Copyright: © 2018 Heijboer, de Ruiter, Bodelier and Kowalchuk. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Dr. Amber Heijboer, Wageningen University & Research, Biometris, Wageningen, Netherlands, email@example.com