Global synthesis of effects of plant species diversity on trophic groups and interactions

Numerous studies have demonstrated that plant species diversity enhances
ecosystem functioning in terrestrial ecosystems, including diversity
effects on insects (herbivores, predators and parasitoids) and plants.
However, the effects of increased plant diversity across trophic levels in
different ecosystems and biomes have not yet been explored on a global
scale. Through a global meta-analysis of 2,914 observations from 351
studies, we found that increased plant species richness reduced herbivore
abundance and damage but increased predator and parasitoid abundance,
predation, parasitism and overall plant performance. Moreover, increased
predator/parasitoid performance was correlated with reduced herbivore
abundance and enhanced plant performance. We conclude that increasing
plant species diversity promotes beneficial trophic interactions between
insects and plants, ultimately contributing to increased ecosystem
services.