BIODIVERSITY AND LITTER DECOMPOSITION IN TERRESTRIAL ECOSYSTEMS

• Published in: Annual review of ecology, evolution, and systematics evolution, and systematics, 2005-12, Vol.36 (1), p.191-218
• Main Authors: Hattenschwiler, S, Tiunov, A.V, Scheu, S
• Format: Article
• Language: English
• Subjects: Agricultural soils; biodegradation; Biodiversity; Biodiversity loss; Biogeochemical cycles; Decomposition; Ecological function; Ecological succession; Effects; Environmental conditions; Flowers & plants; Forest soils; Fungi; Keystone species; literature reviews; Litter; microbial ecology; Microorganisms; mineralization; Monoclonal antibodies; nitrogen; Nutrient dynamics; Nutrient loss; Plant litter; Soil biochemistry; soil biology; Soil ecology; Soil fauna; soil food webs; Soil fungi; Soil microorganisms; Species diversity; Terrestrial ecosystems; Trophic levels
• ISSN: 1543-592X; 1545-2069
• DOI: 10.1146/annurev.ecolsys.36.112904.151932

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.