Standardized Principal Components Analysis (PCA) of community-weighted means of trait values (CWM) and functional trait diversity based on Raòs quadratic entropy (FD_Q) of experimental grassland communities.

<p>PCA of community-weighted means of trait values (CWM) first vs. second axes (a), second vs. third axes (b), PCA of functional trait diversity (FD_Q) first vs. second axes (c), second vs. third axes (d), and PCA of CWM and FD_Q in combination first vs. second axes (e), second vs. third axes (f). Community-weighted means of trait values (CWM) and functional trait diversity (FD_Q) were calculated for each community based on species biomass proportions in the mixture and functional traits measured in species monocultures in the Jena Experiment and derived from the literature. Symbols show the position of each community sown with different numbers of species. Black arrows show CWM, red arrows show FD_Q for each trait.</p

Standardized Principal Components Analysis (PCA; first vs. second axes) of 60 grassland species characterized by 18 functional traits.

<p>Plant traits were measured in species monocultures in the Jena Experiment and derived from the literature. Symbols show species assignment to plant functional groups. For list of variables and abbreviations see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0036760#pone-0036760-t002" target="_blank">Table 2</a>.</p

Aboveground community biomass, net biodiversity effect, complementarity effect, and selection effect as a function of species richness.

<p>Biomass data were recorded at estimated peak biomass in late May 2006 in the Jena Experiment. Lines show means across all mixtures per species-richness level.</p

Summary of best statistical models based on different groups of predictor variables (community-weighted means of trait values (CWM) and functional trait diversity (FD_Q)) for community biomass, net biodiversity effects, complementarity effects and selection effects.

<p>Analyses are based on 66 experimental mixtures of varying species richness (2, 4, 8, 16 and 60 species). For estimated coefficients see (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0036760#pone.0036760.s001" target="_blank">Table S1</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0036760#pone.0036760.s002" target="_blank">S2</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0036760#pone.0036760.s003" target="_blank">S3</a>), abbreviations of variable names are explained in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0036760#pone-0036760-t002" target="_blank">Table 2</a>.</p

Appendix D. Correlation matrixes of predictors.

Correlation matrixes of predictors

Appendix E. A table presenting the different groups of soil biota sampled in year 2008.

A table presenting the different groups of soil biota sampled in year 2008

Appendix C. Maximum clade-credibility phylogeny of the 60 species in the Jena Experiment.

Maximum clade-credibility phylogeny of the 60 species in the Jena Experiment

Appendix H. Model fit estimates for the minimal adequate models.

Model fit estimates for the minimal adequate models

Appendix A. A table with the means and standard deviations of the 12 functional traits derived from the 60 species present in the Jena Experiment.

A table with the means and standard deviations of the 12 functional traits derived from the 60 species present in the Jena Experiment

Appendix F. A schematic of the maximal model used in structural equation modeling.

A schematic of the maximal model used in structural equation modeling