Interactions among predators and the cascading effects of vertebrate insectivores on arthropod communities and plants

摘要: Theory on trophic interactions predicts that predators increase plant biomass by feeding herbivores, an indirect interaction called a cascade. also predators, or intraguild predation, will weaken cascades. Although past syntheses have confirmed cascading effects of terrestrial arthropod we lack comprehensive analysis for vertebrate insectivores—which virtue their body size and habits are often top in these systems—and how predation mediates cascade strength. We report here meta-analysis 113 experiments documenting the insectivorous birds, bats, lizards predaceous arthropods, herbivorous plants. insectivores fed as strongly reducing arthropods (38%), they nevertheless suppressed herbivores (39%), indirectly reduced damage (40%), increased (14%). Furthermore, predatory were positively correlated. Effects strongest plants communities with abundant strong but weak depauperate predation. The naturally occurring ratio relative to varied tremendously among studied communities, skew site primary productivity trees shrubs. has been shown herbivore suppression, find this paradigm does not extend communities. Instead, preda-tion is associated strengthened cascades, function dominant plant-arthropod