Non‐Native, Non‐Naturalised Plants Suffer Less Herbivory Than Native Plants Across European Botanical Gardens

Abstract

Aim The enemy release hypothesis states that the invasion success of non‐native species is partly due to their escape from natural enemies, e.g., herbivores. Large‐scale studies of herbivory using multiple species across multiple sites are needed to test the generality of herbivory release in non‐native plants. Location Europe. Methods We carried out leaf‐herbivory surveys from 2007 to 2021 in 15 botanical gardens ranging in latitude from 47°N (Switzerland) to 63°N (Norway) to investigate how herbivory levels differed between (i) native and non‐native species, and (ii) native and non‐naturalised or naturalised species. Results Overall, we found that herbivory levels were lower on non‐native than native species. In addition, we found that non‐naturalised plants suffered less herbivory than natives and that naturalised plants showed similar levels of herbivory to native plants. Main Conclusions We find broad support for lower herbivory of non‐native plant species compared to natives. However, the stronger reduction in herbivory for non‐naturalised plants suggests that herbivore release may be transient and less pronounced for naturalised non‐native species that have become abundant and integrated into resident communities. This has implications for the management of naturalised non‐native plants, which are performing well in their non‐native ranges despite suffering comparable herbivory levels to native species.