thumbnail

Litter quality versus soil microbial community controls over decomposition: a quantitative analysis

Oecologia

By:
, , , , , , and
DOI: 10.1007/s00442-013-2758-9

Links

Abstract

The possible effects of soil microbial community structure on organic matter decomposition rates have been widely acknowledged, but are poorly understood. Understanding these relationships is complicated by the fact that microbial community structure and function are likely to both affect and be affected by organic matter quality and chemistry, thus it is difficult to draw mechanistic conclusions from field studies. We conducted a reciprocal soil inoculum × litter transplant laboratory incubation experiment using samples collected from a set of sites that have similar climate and plant species composition but vary significantly in bacterial community structure and litter quality. The results showed that litter quality explained the majority of variation in decomposition rates under controlled laboratory conditions: over the course of the 162-day incubation, litter quality explained nearly two-thirds (64 %) of variation in decomposition rates, and a smaller proportion (25 %) was explained by variation in the inoculum type. In addition, the relative importance of inoculum type on soil respiration increased over the course of the experiment, and was significantly higher in microcosms with lower litter quality relative to those with higher quality litter. We also used molecular phylogenetics to examine the relationships between bacterial community composition and soil respiration in samples through time. Pyrosequencing revealed that bacterial community composition explained 32 % of the variation in respiration rates. However, equal portions (i.e., 16 %) of the variation in bacterial community composition were explained by inoculum type and litter quality, reflecting the importance of both the meta-community and the environment in bacterial assembly. Taken together, these results indicate that the effects of changing microbial community composition on decomposition are likely to be smaller than the potential effects of climate change and/or litter quality changes in response to increasing atmospheric CO2 concentrations or atmospheric nutrient deposition.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Litter quality versus soil microbial community controls over decomposition: a quantitative analysis
Series title:
Oecologia
DOI:
10.1007/s00442-013-2758-9
Volume
174
Issue:
1
Year Published:
2014
Language:
English
Publisher:
Springer
Contributing office(s):
Southwest Biological Science Center
Description:
12 p.
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Oecologia
First page:
283
Last page:
294
Number of Pages:
12