Drivers of species diversity and distribution of ants in the southwest brazilian amazon

Abstract

Identifying areas with high species richness and understanding the factors that determine this distribution provide both theoretical and practical advancements. Factors such as temperature, precipitation, and forest cover, which vary geographically, shape species diversity and reflect differences among ecological communities. These characteristics exemplify local ecological constraints, influencing metacommunity dynamics. The state of Acre, in the southwestern Brazilian Amazon, exemplifies significant climatic and environmental variation with diverse forest cover. Despite conservation efforts, 13% of the area has lost its original cover due to socioeconomic changes. Organisms such as ants, with high diversity and rapid response to environmental changes, are important ecological models due to their biomass, role in nutrient redistribution, and participation in several other ecosystem functions. Although the ant fauna of the Neotropical region has evolved in forest areas, some species tolerate greater environmental variations, being classified as generalists or specialists in open habitats. Thus, this thesis presents two original chapters organized as manuscripts to be submitted to scientific journals. Here, we investigated the diversity and distribution of ants in the southwestern Brazilian Amazon. We found that ant species richness is associated with increased forest cover, especially for forest specialists. This highlights the importance of forest cover conservation for maintaining ant biodiversity. Geographic distance was the primary factor in ant species composition, surpassing the influence of forest cover and precipitation, indicating that dispersal limitation is an important mechanism in community structuring. Metacommunity patterns showed that local communities were well-defined and structured by environmental gradients. Habitat use guilds exhibited distinct responses to ecological mechanisms. The results of this thesis are useful for guiding new conservation efforts and understanding the mechanisms that structure ant communities. By using habitat use specificity or affinity, we obtained a detailed view of species-specific responses to environmental changes. The conservation of forest cover is necessary to maintain the biodiversity of ant species and the fundamental ecological processes they perform, especially in deforested and fragmented areas such as the Amazon.