As respostas das comunidades de formigas à cobertura florestal da paisagem

Abstract

Habitat loss is one of the primary causes of global biodiversity decline, affecting landscape connectivity and composition, especially in tropical environments. This results in changes in forest cover and other land uses, increasing environmental heterogeneity. Habitat fragmentation leads to the formation of multiple smaller and isolated fragments, affecting species within that landscape. Such changes also influence habitat quality, species interactions, and ecosystem functioning. To better understand the consequences of these environmental changes, we must focus on appropriate study objects and data collection. Data sampling in scientific studies should minimize costs and collection time without compromising scientific rigor. Ants can be considered good bioindicators because, besides having relatively simple sampling, they play crucial roles in tropical ecosystems and are sensitive to habitat disturbances. In addition to participating in processes such as seed dispersal, pollination, and ecosystem engineering, they are important indicators of environmental changes. In this study, I aimed to i) assess the difference in the effectiveness of traps used for ant capture installed in the presence and absence of baited traps for beetles. Testing the prediction that the presence of beetle traps will not affect the richness and species composition of ants captured in baitlesspitfalls. After statistical analyses, no significant difference was found in ant species richness between areas with and without baited beetle traps, both for arboreal and ground-dwelling ants. There was also no variation in species composition between areas with and without baits. Therefore, beetle traps do not influence the composition or richness of ant species. Thus, conducting both collection methodologies, for both beetles and ants, simultaneously can reduce field time and expedite the collection of both groups. Additionally, ii) investigating how forest cover loss in the landscape affects ant communities. To do this, I tested the following predictions: 1) Forest fragments inserted into landscapes with higher percentages of forest cover, associated with ant habitat affinity (specialized in open areas, forested areas, or generalists), will have higher species richness of ants; 2) Forest fragments inserted into landscapes with higher forest cover will have more dissimilar species compositions than landscapes with lower forest cover; 3) There is a threshold of forest cover loss in the landscape that generates a sharp decline in ant species richness in forest fragments. There was a significant negative relationship between landscape forest cover and the richness of ants specialized in open and forest habitats, while ants with generalist habits were not affected by changes in forest cover. There were no clear differences in species composition among forest fragments, regardless of landscape forest cover. Additionally, we identified an inflection point around 30.02% ± 2.677% forest cover, indicating a change in the trend of the relationship between species richness and forest cover. Therefore, ants respond negatively to forest cover loss, being influenced by the interaction between habitat affinity and the percentage of forest cover in the landscape.