title: How do earthworms, soil texture and plant composition affect infiltration along an experimental plant diversity gradient in grassland?
abstract: BACKGROUND
  Infiltration is a key process in determining the water balance, but so far effects of earthworms, soil texture, plant species diversity and their interaction on infiltration capacity have not been studied.
  
  
  RESULTS
  We measured infiltration capacity in subplots with ambient and reduced earthworm density nested in plots of different plant species (1, 4, and 16 species) and plant functional group richness and composition (1 to 4 groups; legumes, grasses, small herbs, tall herbs). In summer, earthworm presence significantly increased infiltration, whereas in fall effects of grasses and legumes on infiltration were due to plant-mediated changes in earthworm biomass. Effects of grasses and legumes on infiltration even reversed effects of texture. We propose two pathways: (i) direct, probably by modifying the pore spectrum and (ii) indirect, by enhancing or suppressing earthworm biomass, which in turn influenced infiltration capacity due to change in burrowing activity of earthworms.
  
  
  CONCLUSIONS
  Overall, the results suggest that spatial and temporal variations in soil hydraulic properties can be explained by biotic processes, especially the presence of certain plant functional groups affecting earthworm biomass, while soil texture had no significant effect. Therefore biotic parameters should be taken into account in hydrological applications.
authors.affiliation: Institute of Geosciences, Friedrich-Schiller-University Jena, Jena, Germany; Max Planck Institute for Biogeochemistry, Jena, Germany.
authors.forename: Christine
authors.initials: C
authors.lastname: Fischer
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: J. F. Blumenbach Institute of Zoology and Anthropology, Georg August University of Göttingen, Göttingen, Germany.
authors.forename: Britta
authors.initials: B
authors.lastname: Jensen
authors.affiliation: Institute of Ecology, Friedrich Schiller University Jena, Jena, Germany.
authors.forename: Nico
authors.initials: N
authors.lastname: Eisenhauer
authors.affiliation: Department of Geography, Friedrich Schiller University Jena, Jena, Germany.
authors.forename: Jussi
authors.initials: J
authors.lastname: Baade
authors.affiliation: Institute of Geosciences, Friedrich-Schiller-University Jena, Jena, Germany; UFZ, Helmholtz Centre of Environmental Research, Department of Computational Hydrosystems, Leipzig, Germany.
authors.forename: Sabine
authors.initials: S
authors.lastname: Attinger
authors.affiliation: J. F. Blumenbach Institute of Zoology and Anthropology, Georg August University of Göttingen, Göttingen, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Scheu
authors.affiliation: Technical University Munich, Terrestrial Ecology Research Group, Department of Ecology and Ecosystem Management, Center for Food and Life Sciences Weihenstephan, Freising, Germany.
authors.forename: Wolfgang W
authors.initials: WW
authors.lastname: Weisser
authors.affiliation: Institute of Stochastics, Friedrich Schiller University Jena, Jena, Germany.
authors.forename: Jens
authors.initials: J
authors.lastname: Schumacher
authors.affiliation: Institute of Geosciences, Friedrich-Schiller-University Jena, Jena, Germany; Max Planck Institute for Biogeochemistry, Jena, Germany.
authors.forename: Anke
authors.initials: A
authors.lastname: Hildebrandt
mesh_terms: D000818:Animals; D044822:Biodiversity; D018533:Biomass; D065948:Grassland; D062070:Hydrology; D009835:Oligochaeta / Q000502:physiology*; D006109:Poaceae / Q000502:physiology; D012987:Soil / Q000737:chemistry*
chemical_list: D012987:Soil