Data for: Plant diversity effects on herbivory are related to soil biodiversity and plant chemistry

Insect herbivory is a key process in ecosystem functioning. While theory
predicts that plant diversity modulates herbivory, the mechanistic links
remain unclear. We postulated that the plant metabolome mechanistically
links plant diversity and herbivory. In late summer and in spring, we
assessed individual plant aboveground herbivory rates and metabolomes of
seven plant species in experimental plant communities varying in plant
species diversity and resource acquisition strategies. In the same
communities, we also measured plant individual biomass as well as soil
microbial and nematode community composition. Herbivory rates decreased
with increasing plant species richness. Path modelling revealed that plant
species richness and community resource acquisition strategy correlated
with soil community composition. In particular, changes in nematode
community composition were related to plant metabolome composition and
thereby herbivory rates. These results suggest that soil community
composition plays an important role in reducing herbivory rates with
increasing plant diversity by changing plant metabolomes.