Beta diversity of plant–herbivore interactions is unaffected by urbanization levels in Brazilian Cerrado

Abstract

Plant–herbivore interactions are pivotal in shaping terrestrial ecosystems, influencing plant populations and insect diversity; however, little is known about how anthropogenic impacts affect the beta diversity of these interactions. In our study, we investigated plant–herbivore networks across an urbanization gradient in Brazilian Cerrado. We tested two hypotheses: (1) urbanization decreases interaction dissimilarity, and (2) herbivorous insects show greater dissimilarity than plants. To test these hypotheses, we conducted data collection across 16 sites, representing different urbanization levels—urban, rural, and wild. We sampled plant–herbivore interactions for 310 insect herbivore species and 97 host plant species. Our analysis revealed that beta diversity of interactions was consistently high across all environments studied. However, we did not find any significant differences in total interaction dissimilarity among the different levels of urbanization. We found that the primary driver of dissimilarity was species composition turnover, with herbivorous insects contributing more to dissimilarity. Our findings challenge the conventional wisdom that urbanization significantly alters plant–herbivore interactions. Instead, we observed consistent interaction dissimilarity, highlighting the resilience of ecological networks in the face of anthropogenic impacts. Our results underscore the complexity of these interactions and emphasize that plant–herbivore interactions can exhibit a high degree of dissimilarity even in urban environments.