Food resources and vegetation structure mediate climatic effects on species richness of birds

摘要: Aim Climate is widely recognized as a major predictor of species richness patterns along large-scale environmental gradients. Nevertheless, the mechanisms by which climate influences are still matter debate. We disentangle whether birds directly via physiological limitations or indirectly vegetation structure availability food resources. Location Mount Kilimanjaro, Tanzania. Methods We recorded bird an elevational gradient from 870 to 4550 m a.s.l. quantified local climatic conditions, and resources, applied path analysis their direct indirect effects on all birds, frugivores insectivores. Results Overall, we 2945 individuals 114 species. Species was closely correlated with temperature, invertebrate biomass both (via resources) were important for diversity whole, trophically heterogeneous community. The insectivorous linked biomass, while strongly associated fruit abundance. Climatic factors influenced avian feeding guilds exclusively resources. Main conclusions We reveal importance trophic interactions generating Our results challenge general assumption that temperature water influence mostly directly, underscore resources principal mediators macroecological scales.