Plant neighbours mediate bird predation effects on arthropod abundance and herbivory

摘要: Tritrophic interactions among plants, herbivores and predators are expected to be influenced by the surrounding vegetation. Neighbouring plants can influence focal plant colonisation herbivorous insects foraging behaviour of natural enemies, such as insectivorous birds. The aim experiment was disentangle interactive effects neighbouring avian predation on arthropod abundance insect leaf damage in oak tree seedlings, using exclusion cages vegetation removal. The presence or removal herbaceous differentially mediated top-down birds distinct guilds herbivore seedlings. Avian reduced sawfly larval regardless neighbours; lepidopteran only when neighbours were removed; spider left intact. The increased prey accessibility for decreased chewer density concealed-feeder (leaf miners) with neighbour seedlings less damaged guild, suggesting intraguild competition. These results highlight strong indirect tritrophic involving a species, its associated upper trophic level predators.