Abstract Insect herbivory on plant seedlings is crucial for understanding plant community dynamics, exhibiting significant variability along environmental gradients. However, empirical research has primarily focused on mean herbivory levels, overlooking the roles of herbivory variability in species coexistence. In this study, we used a standardized field protocol to collect herbivory data from 11,811 seedling leaves of 415 woody species along five elevational transects in (sub)tropical mountains. We compared the mean and variability of herbivory across seedlings of woody species within each site and examined how plant size, plant diversity and abiotic conditions influence herbivory patterns in trees and shrubs. We found that herbivory variability across species significantly declined with increasing elevation in shrubs but not in trees, while mean herbivory showed a marginally significant decline with elevation irrespective of tree or shrub growth form. Plant size significantly affected herbivory variability but not mean herbivory. Leaf area was negatively associated with variability, while seedling height had a positive effect, and these patterns differed between growth forms. Plant diversity mainly shaped how herbivory was distributed among species, rather than affecting mean herbivory. Among abiotic factors, canopy cover and soil temperature were the main drivers of herbivory variability. Synthesis . We demonstrate overall, but growth‐form‐dependent, elevational declines in both mean and variability of herbivory at community level, with plant size, plant diversity and abiotic conditions influencing herbivory variability but not the mean. This study provides new evidence that herbivory variability should be considered in predicting how plant–herbivore dynamics respond to climate and biodiversity changes, with important implications for ecosystem stability and species coexistence.
Wang et al. (Mon,) studied this question.