Resources, recruitment limitation and invader species identity determine pattern of spontaneous invasion in experimental grasslands

Summary 1 A number of experimental studies have supported the hypothesis that diversity increases invasion resistance, but several mechanisms were proposed to explain this relationship. We studied spontaneous invasion in experimental grasslands varying in species richness (1–16 (60)) and plant functional group richness and identity (1–4; grasses, legumes, tall herbs small herbs) during the first 3 years after establishment on large-area plots of 20 × 20 m size. 2 Invader species number, biomass and density decreased with increasing community species richness. The identity of successful invaders changed through time as the relative importance of external invaders (= species not belonging to …