Abstract

Ecological gradients are expected to be associated with structural rewiring of species interaction networks. The study of network structures along geographic and ecological gradients, however, remains marginal because documenting species interactions at multiple sites is a methodological challenge. Using a standardized DNA metabarcoding method applied to feces, we examined how structural properties of plant--orthoptera networks reflecting specialization and resilience vary with elevation. We found an increase in levels of generality and nestedness with decreasing temperature, and the correlation was stronger than in null models. These relationships corresponded to greater robustness and reduced importance of keystone species in alpine habitats. In cold environments, plant--herbivore networks are wired in a way that may reinforce the resilience of the system to species extinction. Documenting ecological networks along ecological gradients allows a better understanding of the influence of climate on the structure of ecosystems.