Experimental drought reduces the transfer of recently fixed plant carbon to soil microbes and alters the bacterial community composition in a mountain meadow
Article first published online: 31 OCT 2013
© 2013 The Authors. New Phytologist © 2013 New Phytologist Trust
This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Volume 201, Issue 3, pages 916–927, February 2014
How to Cite
Fuchslueger, L., Bahn, M., Fritz, K., Hasibeder, R. and Richter, A. (2014), Experimental drought reduces the transfer of recently fixed plant carbon to soil microbes and alters the bacterial community composition in a mountain meadow. New Phytologist, 201: 916–927. doi: 10.1111/nph.12569
- Issue published online: 9 JAN 2014
- Article first published online: 31 OCT 2013
- Manuscript Accepted: 24 SEP 2013
- Manuscript Received: 18 JUL 2013
- Austrian Science Fund. Grant Number: P22214-B17
- European Community's Seventh Framework Programme. Grant Numbers: FP/2007.2013, 226701
- 13C pulse-labelling;
- carbon allocation;
- microbial community composition;
- mountain grassland;
- phospholipid fatty acids
- Drought affects plants and soil microorganisms, but it is still not clear how it alters the carbon (C) transfer at the plant–microbial interface. Here, we tested direct and indirect effects of drought on soil microbes and microbial turnover of recent plant-derived C in a mountain meadow.
- Microbial community composition was assessed using phospholipid fatty acids (PLFAs); the allocation of recent plant-derived C to microbial groups was analysed by pulse-labelling of canopy sections with 13CO2 and the subsequent tracing of the label into microbial PLFAs.
- Microbial biomass was significantly higher in plots exposed to a severe experimental drought. In addition, drought induced a shift of the microbial community composition, mainly driven by an increase of Gram-positive bacteria. Drought reduced belowground C allocation, but not the transfer of recently plant-assimilated C to fungi, and in particular reduced tracer uptake by bacteria. This was accompanied by an increase of 13C in the extractable organic C pool during drought, which was even more pronounced after plots were mown.
- We conclude that drought weakened the link between plant and bacterial, but not fungal, C turnover, and facilitated the growth of potentially slow-growing, drought-adapted soil microbes, such as Gram-positive bacteria.