Hurricanes lead to declines in taxonomic, phylogenetic, and functional richness and shifts in moth community composition

Abstract

Disturbances play a central role in shaping biodiversity, influencing both community structure and ecosystem function. The responses of biodiversity to disturbance are inherently multidimensional, often leading to shifts in taxonomic composition, functional traits, and evolutionary dynamics within biological communities. Unraveling these dimensions offers valuable insights into ecosystem resilience and how communities adapt under changing disturbance regimes. This study examines the immediate effects of large-scale hurricane disturbance on the taxonomic, phylogenetic, and functional dimensions of moth biodiversity in a tropical forest. We conducted monthly moth surveys in two forest types within the Luquillo Mountains of Puerto Rico, 5 months before and 6 months after Hurricanes Irma and María (September 2017). We collected 6152 individuals from 244 species across 19 families, performed DNA barcoding for phylogenetic analysis, and classified them by functional traits such as body size, coloration, and proboscis presence. Our findings show that hurricane disturbance reduced species richness across all diversity dimensions, while functional diversity among dominant species increased, suggesting potential stabilization of ecosystem functions despite reduced richness. In addition, the hurricanes altered both taxonomic and phylogenetic composition, with smaller grass-feeding species increasing in abundance post-hurricane, while larger arboreal-feeding species, especially geometrid moths, declined markedly. These shifts highlight potential effects on trophic interactions, given moths' key roles as herbivores, pollinators, and prey. Although these systems have evolved under repeated hurricane disturbances, the long-term consequences of a changing climate remain uncertain, particularly as more frequent and severe hurricanes may reset successional pathways and hinder forest recovery. By integrating multiple dimensions of biodiversity, our study provides a more holistic understanding of the complex consequences of hurricanes on insect communities and can inform conservation strategies aimed at enhancing ecosystem resilience.