Affiliation: | INRA, UR874 Grassland Ecosystem Research, 234, Av. du Brézet, F-63100 Clermont-Ferrand, France;;INRA, CNRS, Universitéde Lyon 1, Microbial Ecology, UMR 5557, 43 Bd du 11 novembre 1918, 69622 Villeurbanne, France;;and Max Planck Institute for Biogeochemistry, Postbox 100164, D-07701 Jena, Germany |