title: Biotic and abiotic properties mediating plant diversity effects on soil microbial communities in an experimental grassland.
abstract: Plant diversity drives changes in the soil microbial community which may result in alterations in ecosystem functions. However, the governing factors between the composition of soil microbial communities and plant diversity are not well understood. We investigated the impact of plant diversity (plant species richness and functional group richness) and plant functional group identity on soil microbial biomass and soil microbial community structure in experimental grassland ecosystems. Total microbial biomass and community structure were determined by phospholipid fatty acid (PLFA) analysis. The diversity gradient covered 1, 2, 4, 8, 16 and 60 plant species and 1, 2, 3 and 4 plant functional groups (grasses, legumes, small herbs and tall herbs). In May 2007, soil samples were taken from experimental plots and from nearby fields and meadows. Beside soil texture, plant species richness was the main driver of soil microbial biomass. Structural equation modeling revealed that the positive plant diversity effect was mainly mediated by higher leaf area index resulting in higher soil moisture in the top soil layer. The fungal-to-bacterial biomass ratio was positively affected by plant functional group richness and negatively by the presence of legumes. Bacteria were more closely related to abiotic differences caused by plant diversity, while fungi were more affected by plant-derived organic matter inputs. We found diverse plant communities promoted faster transition of soil microbial communities typical for arable land towards grassland communities. Although some mechanisms underlying the plant diversity effect on soil microorganisms could be identified, future studies have to determine plant traits shaping soil microbial community structure. We suspect differences in root traits among different plant communities, such as root turnover rates and chemical composition of root exudates, to structure soil microbial communities.
authors.affiliation: Max Planck Institute for Biogeochemistry, Jena, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Lange
authors.affiliation: Max Planck Institute for Biogeochemistry, Jena, Germany.
authors.forename: Maike
authors.initials: M
authors.lastname: Habekost
authors.affiliation: Institute of Ecology, Friedrich- Schiller-University Jena, Jena, Germany.
authors.forename: Nico
authors.initials: N
authors.lastname: Eisenhauer
authors.affiliation: UFZ, Helmholtz Centre for Environmental Research, Department of Community Ecology, Halle, Germany.
authors.forename: Christiane
authors.initials: C
authors.lastname: Roscher
authors.affiliation: Department of Plant Nutrition, Faculty of Agriculture and Horticulture, Humboldt-Universität zu Berlin, Berlin, Germany.
authors.forename: Holger
authors.initials: H
authors.lastname: Bessler
authors.affiliation: Department of Plant Nutrition, Faculty of Agriculture and Horticulture, Humboldt-Universität zu Berlin, Berlin, Germany.
authors.forename: Christof
authors.initials: C
authors.lastname: Engels
authors.affiliation: Geoecology/Geography, Eberhard Karls University of Tübingen, Tübingen, Germany.
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Oelmann
authors.affiliation: J.F. Blumenbach Institute of Zoology and Anthropology, Georg August University Göttingen, Göttingen, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Scheu
authors.affiliation: Soil Science Group, Geographic Institute, University of Berne, Bern, Switzerland.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Wilcke
authors.affiliation: Max Planck Institute for Biogeochemistry, Jena, Germany.
authors.forename: Ernst-Detlef
authors.initials: ED
authors.lastname: Schulze
authors.affiliation: Max Planck Institute for Biogeochemistry, Jena, Germany.
authors.forename: Gerd
authors.initials: G
authors.lastname: Gleixner
mesh_terms: D001419:Bacteria / Q000254:growth & development / Q000378:metabolism; D044822:Biodiversity; D018533:Biomass; D002849:Chromatography, Gas; D005227:Fatty Acids / Q000378:metabolism; D005658:Fungi / Q000254:growth & development / Q000378:metabolism; D008401:Gas Chromatography-Mass Spectrometry; D065948:Grassland; D008962:Models, Theoretical; D010743:Phospholipids / Q000378:metabolism; D018517:Plant Roots / Q000378:metabolism; D010944:Plants / Q000145:classification / Q000378:metabolism*; D012987:Soil / Q000737:chemistry; D012988:Soil Microbiology; D014867:Water / Q000378:metabolism
chemical_list: D005227:Fatty Acids; D010743:Phospholipids; D012987:Soil; D014867:Water