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.
Bibliographical noteFunding Information:
We thank M. van Kleunen, E. Siemann, X. Chen and Z.-W. Ren for useful suggestions on early versions of this paper, J. Weiner for providing the inspiration for this study, and all of the people whose data and work have been included in this meta-analysis. This study was financially supported by the Agriculture Research System of Shanghai, China (grant no. 201908), the National Natural Science Foundation of China (31401751 and 11971117), the Shanghai Academy of Agricultural Sciences Program for Excellent Research Team (2018[B-01]) and the European Union’s Horizon 2020 research and innovation programme (grant no. 727284).
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