Natural enemies do not contribute to negative-frequency dependence in native and exotic grassland plants

摘要: Abstract Species’ responses to antagonists, such as fungal pathogens and insect herbivores, are part of a species’ niche thought contribute species coexistence. In theory, coexistence is supposed be maintained by the effects equalizing mechanisms that reduce fitness differences among species, stabilizing result differences. The presence hallmarked negative frequency-dependent per capita rates increase. However, rigorous experimental testing how herbivores frequency dependence co-occurring plant in particular context biological invasions, scarce. We present an study grassland central Germany, which we established native exotic-dominated communities on 1 m²-plots, reduced above- belowground applying pesticides. manipulated frequencies six exotic focal order assemble one dominant five rare community. quantified productivity diversity for each community, recorded data increase other components two over three years. found did not differ their diversity. Reduction fungi insects increased but effect was similar both origins, suggesting enemy release transitory or existent. Negative frequency-dependence common our could linked interactions with antagonists. Although responded reduction these were only at low frequency, greater importance intraspecific competition, e.g. resources, explaining observed Offsetting antagonist groups highlight significance community level. Our demonstrates invasions differential contributions antagonistic mechanisms.