Indirect Effects of Cattle Trampling on the Structure of Fruit-Feeding Butterfly Assemblages Inhabiting Restinga Forests in Southern Brazil

Abstract

The impacts of anthropogenic activities are increasing at alarming rates, leading to biodiversity loss and the displacement of native habitats. One of the main contributors to human disturbances is livestock farming, which degrades native habitats through cattle grazing and trampling. To understand these impacts, we investigated the effects of cattle trampling on the structure and diversity of fruit-feeding butterflies in Restinga forests of southern Brazil. We addressed questions regarding the effects of cattle raising on butterfly diversity and composition, identified indicator species, and examined the influence of environmental variables on butterfly richness, dominance, abundance, and species composition. Our dataset comprises the long-term monitoring of fruit-feeding butterflies in Restinga forests from 2014 to 2019, across sites with low, medium, and high levels of disturbance due to cattle trampling. We found that medium and high levels of disturbance increased butterfly richness and abundance, whereas low-level disturbance was associated with lower abundance. Additionally, the species composition of butterflies in medium to highly disturbed sites differed from that in preserved Restinga forests, indicating that any perturbation can markedly alter alpha and beta diversity parameters. These changes simplify the native forest structure, open the canopy, disrupt the understory, and favor butterfly species commonly associated with disturbed forests.