Ernst-Detlef Schulze Max Planck Institute for BiogeochemistryJena, Germanydschulze@bgc-jena.mpg.de Erwin BeckUniversity of BayreuthDepartment of Plant PhysiologyBayreuth, Germanyerwin.beck@uni-bayreuth.de Nina BuchmannETH ZurichInstitute of Agricultural ScienceZurich, Switzerlandnina.buchmann@usys.ethz.ch Stephan ClemensUniversity of BayreuthDepartment of Plant PhysiologyBayreuth, Germanystephan.clemens@uni-bayreuth.de Klaus Müller-HohensteinUniversity of BayreuthDepartment of BiogeographyBayreuth, Germanykumueho@t-online.de Michael Scherer-LorenzenUniversity of FreiburgInstitute of Biology IIFreiburg, Germanymichael.scherer@biologie.uni-freiburg.de