A estacionalidade climática revela efeitos do isolamento espacial na estrutura funcional de comunidades de abelhas em sistemas de montanhas

Abstract

Ecological patterns of biological communities are strongly shaped by spatiotemporal environmental variation. A trait-based approach allows for understanding how these variations structure communities, particularly in sensitive groups such as bees. In tropical montane environments, characterized by pronounced climatic fluctuations, these processes remain poorly understood. In this context, the present study aimed to evaluate variation in the functional traits of bee communities inhabiting mountaintops, considering climatic seasonality and distance among mountaintops. The study was conducted in three mountainous regions in the state of Minas Gerais, Brazil, sampled during the dry and rainy seasons over a period of two years, with two areas located in close spatial proximity and one situated at a greater distance from the others. Bees were sampled using pan traps and identified to the lowest possible taxonomic level. Continuous and categorical functional traits were considered and used to calculate functional diversity indices, including functional richness, functional evenness, and functional divergence. The results indicate that the effects of spatial distance on the functional structure of bee communities – functional traits and functional diversity indices – are modulated by climatic seasons. Functional richness exhibited higher values during the dry season. In spatially proximate mountaintops, differences in the functional richness of communities emerged during the dry season, whereas during the rainy season, functional richness became similar among proximate areas. In contrast, at the mountaintop located farthest from the others, seasonality affected trait distributions, resulting in higher functional stability during the dry season, suggesting the action of more restrictive environmental filters under conditions of increased climatic stress. Overall, the results highlight the importance of considering both climatic seasonality and spatial characteristics in analyses of functional diversity in mountaintop ecosystems. This study contributes to the understanding of ecological mechanisms structuring bee communities in tropical montane environments and provides relevant insights for pollinator conservation strategies in the face of environmental and climatic change.