BIODIVERSITY AND LITTER DECOMPOSITION
IN TERRESTRIAL ECOSYSTEMS
Citation
Stefan Scheu, BIODIVERSITY AND LITTER DECOMPOSITION
IN TERRESTRIAL ECOSYSTEMS: .
Summary
We explore empirical and theoretical evidence for the functional significance of plant-litter diversity and the extraordinary high diversity of decomposer organisms in the process of litter decomposition and the consequences for biogeochemical cycles. Potential mechanisms for the frequently observed litter-diversity effects on mass loss and nitrogen dynamics include fungi-driven nutrient transfer among litter species, inhibition or stimulation of microorganisms by specific litter compounds, and positive feedback of soil fauna due to greater habitat and food diversity. Theory predicts positive effects of microbial diversity that result from functional niche complementarity, but the few existing experiments provide conflicting results. [...]
Summary
We explore empirical and theoretical evidence for the functional
significance of plant-litter diversity and the extraordinary high
diversity of decomposer organisms in the process of litter decomposition
and the consequences for biogeochemical cycles. Potential mechanisms for
the frequently observed litter-diversity effects on mass loss and
nitrogen dynamics include fungi-driven nutrient transfer among litter
species, inhibition or stimulation of microorganisms by specific litter
compounds, and positive feedback of soil fauna due to greater habitat
and food diversity. Theory predicts positive effects of microbial
diversity that result from functional niche complementarity, but the few
existing experiments provide conflicting results. Microbial succession
with shifting enzymatic capabilities enhances decomposition, whereas
antagonistic interactions among fungi that compete for similar resources
slow litter decay. Soil-fauna diversity manipulations indicate that the
number of trophic levels, species identity, and the presence of keystone
species have a strong impact on decomposition, whereas the importance of
diversity within functional groups is not clear at present. In
conclusion, litter species and decomposer diversity can significantly
influence carbon and nutrient turnover rates; however, no general or
predictable pattern has emerged. Proposed mechanisms for diversity
effects need confirmation and a link to functional traits for a
comprehensive understanding of how biodiversity interacts with
decomposition processes and the consequences of ongoing biodiversity
loss for ecosystem functioning. Published in Annual Review of Ecology
Evolutionary Systems, volume 36, on pages 191 - 218, in 2005.
