Above- and belowground insect herbivory modifies the response of a grassland plant community to nitrogen eutrophication

摘要: Understanding the role that species interactions play in determining rate and direction of ecosystem change due to nitrogen (N) eutrophication is important for predicting consequences global change. Insects might a major this context. They consume substantial amounts plant biomass can alter competitive among plants, indirectly shaping community composition. Nitrogen affects communities globally, but there limited experimental evidence how insect herbivory modifies response raised N levels. Even less known about roles above- belowground communities, interaction between two modify community's eutrophication. We conducted three-year field experiment where grassland were subjected with without addition, full-factorial design. found modified responses addition. Aboveground decreased aboveground by 21%, only at elevated N. When combined, had stronger negative effect on ambient (11% decrease) than (4% decrease). In shifted functional composition community, magnitude shifts depended level. The treatments synergistically conferred advantage forbs, which benefited when both types present Evenness groups increased was present, addition attenuated increase. Our results demonstrate deeper understanding plant-herbivore above below ground shape crucial making reliable predictions ecological change. This article protected copyright. All rights reserved.