FIGURE 2.

Importance and traits of key and keystone species. (a) productivity improvement per percent cover (effect size) and explained deviance added to the reference model (overall contribution) of all species considered. Key species are shown as squares and coloured according to plant type (see legend), their subset of keystone species is shown as triangles, and ordinary species are shown as grey circles. (b and c) key species and keystone species, respectively, in a two‐dimensional representation of trait space (PCA axes with explained variance in brackets, see Methods). Isolines are Gaussian mixture density functions of the distributions of key species (black) and ordinary species (grey) respectively. Note that for one key species trait information was not available (see Table S1)