PLANT DIVERSITY, SOIL MICROBIAL COMMUNITIES, AND ECOSYSTEM FUNCTION: ARE THERE ANY LINKS?

A current debate in ecology centers on the extent to which ecosystem function depends on biodiversity. Here, we provide evidence from a long-term field manipulation of plant diversity that soil microbial communities, and the key ecosystem processes that they mediate, are significantly altered by plant species richness. After seven years of plant growth, we determined the composition and function of soil microbial communities beneath experimental plant diversity treatments containing 1-16 species. Microbial community bio- mass, respiration, and fungal abundance significantly increased with greater plant diversity, as did N mineralization rates. However, changes in microbial community biomass, activity, and composition largely resulted from the higher levels of plant production associated with greater diversity, rather than from plant diversity per se. Nonetheless, greater plant pro- duction could not explain more rapid N mineralization, indicating that plant diversity affected this microbial process, which controls rates of ecosystem N cycling. Greater N availability probably contributed to the positive relationship between plant diversity and productivity in the N-limited soils of our experiment, suggesting that plant-microbe in- teractions in soil are an integral component of plant diversity's influence on ecosystem

[1]  R. Ryel,et al.  Mechanisms of positive biodiversity–production relationships: insights provided by δ13C analysis in experimental Mediterranean grassland plots , 2001 .

[2]  David Tilman,et al.  Secondary Succession and the Pattern of Plant Dominance Along Experimental Nitrogen Gradients , 1987 .

[3]  D. Tilman,et al.  PLANT PRODUCTION AND SOIL MICROORGANISMS IN LATE-SUCCESSIONAL ECOSYSTEMS: A CONTINENTAL-SCALE STUDY' , 1994 .

[4]  R. Bardgett,et al.  Linkages between plant litter diversity, soil microbial biomass and ecosystem function in temperate grasslands , 1999 .

[5]  Jeffrey L. Smith,et al.  The significance of soil microbial biomass estimations. , 1990 .

[6]  J. L. Gittleman,et al.  The Future of Biodiversity , 1995, Science.

[7]  B. Schmid,et al.  Plant diversity affects culturable soil bacteria in experimental grassland communities , 2000 .

[8]  Michel Loreau,et al.  Microbial diversity, producer–decomposer interactions and ecosystem processes: a theoretical model , 2001, Proceedings of the Royal Society of London. Series B: Biological Sciences.

[9]  D. Wardle,et al.  PLANT REMOVALS IN PERENNIAL GRASSLAND: VEGETATION DYNAMICS, DECOMPOSERS, SOIL BIODIVERSITY, AND ECOSYSTEM PROPERTIES , 1999 .

[10]  D. F. Grigal,et al.  Carbon and nitrogen cycling during old-field succession: Constraints on plant and microbial biomass , 1990 .

[11]  K. Pregitzer,et al.  Soil temperature, matric potential, and the kinetics of microbial respiration and nitrogen mineralization , 1999 .

[12]  David A. Wardle,et al.  Biodiversity and Plant Litter: Experimental Evidence Which Does Not Support the View That Enhanced Species Richness Improves Ecosystem Function , 1997 .

[13]  Michel Loreau,et al.  Partitioning selection and complementarity in biodiversity experiments , 2001, Nature.

[14]  S. Goldhor.  Ecology , 1964, The Yale Journal of Biology and Medicine.

[15]  C. David,et al.  Sensitive assay of phospholipid glycerol in environmental samples , 1983 .

[16]  J. P. Grime,et al.  Biodiversity and Ecosystem Functioning: Current Knowledge and Future Challenges , 2001, Science.

[17]  J. Suflita,et al.  Detection of the anaerobic dechlorinating microorganism Desulfomonile tiedjei in environmental matrices by its signature lipopolysacchride branched-long-chain hydroxy fatty acids , 1994 .

[18]  D. Greenland.  The Climates of the long-term ecological research sites , 1987 .

[19]  D. Tilman,et al.  Productivity and sustainability influenced by biodiversity in grassland ecosystems , 1996, Nature.

[20]  W. J. Dyer,et al.  A rapid method of total lipid extraction and purification. , 1959, Canadian journal of biochemistry and physiology.

[21]  D. Tilman.  Resource competition and community structure. , 1983, Monographs in population biology.

[22]  Pereira,et al.  Plant diversity and productivity experiments in european grasslands , 1999, Science.

[23]  D. White,et al.  Determination of the sedimentary microbial biomass by extractible lipid phosphate , 2004, Oecologia.

[24]  P. Reich,et al.  Diversity and Productivity in a Long-Term Grassland Experiment , 2001, Science.

[25]  Peter M. Vitousek,et al.  Effects of plant composition and diversity on nutrient cycling , 1998 .

[26]  P. Reich,et al.  The Influence of Functional Diversity and Composition on Ecosystem Processes , 1997 .

[27]  Michael A. Huston,et al.  Hidden treatments in ecological experiments: re-evaluating the ecosystem function of biodiversity , 1997, Oecologia.