Canopy height, rather than neighbourhood effects, shapes leaf herbivory in a tropical rainforest

Abstract

Factors shaping the interspecific variations in herbivory have puzzled ecologists for decades and several hypotheses have been proposed. In a tropical rain forest in Yunnan Province, China, we collected 6,732 leaves from 129 species with canopy heights ranging from 1.6 m to 65.0 m above the ground. We tested the role of plant apparency, leaf traits and the diversity, composition and structural heterogeneity of neighbors in shaping the interspecific variations in herbivory. Results show that leaf herbivory decreased with canopy height and specific leaf area and increased with leaf size. However, neighboring species’ diversity, composition, and structural heterogeneity showed no association with herbivory. Therefore, neither the plant apparency hypothesis nor the associational resistance hypothesis was supported in this hyper-diverse tropical rainforest. Our results highlight the importance of vertical structures and organic sizes in shaping herbivory patterns in natural communities.