Distribuição espaço-temporal de insetos herbívoros em ilhas de florestas naturais altimontanas sob distúrbios antrópicos

Abstract

Understanding the spatiotemporal patterns and the mechanisms that structure herbivorous insects’ metacommunities associated with natural forest islands of the Espinhaço Range was the main objective of this thesis. In the first chapter, we showed that both spatial and temporal factors have mixed contributions to herbivorous insects’ diversity and distribution, where the great change in their composition was especially shaped by seasonal variations in climatic characteristics. In the second chapter, we highlighted the complexity of the outcomes of disturbance by fire and large grazers in the study system, emphasizing fire as a major threat but also surprisingly indicating that cattle grazing can mitigate the negative effects of fire on the fire-sensitive forest islands. In the third and final chapter, we evaluated the influence of these both disturbances, along with local properties of the forest islands, on the spatiotemporal distribution of herbivorous insects over years. We evidenced fire as the only variable influencing the stability of herbivorous insects and the canopy cover variation as the only one explaining species gains and losses. Comprehending the dynamics underlying the stability of insect metacommunities provides a robust way to predict how the organization of biodiversity and ecosystem functionality will change in response to further environmental and climatic changes, that are more pronounced in high-elevation areas.