Assembleias de morcegos influenciam comunidades de invertebrados subterrâneos e atuam sobre a dinâmica de cavernas ferríferas no Brasil?

Abstract

Chiroptera are among the most diverse and geographically dispersed mammals, they exploit different resources and occupy the most varied habitats, participate in numerous ecological processes in tropical ecosystems and have adaptations associated with the types of shelters they use, such as caves. These habitats are essential to bats because they have a direct impact on their survival rates, ecology and evolution, while chiropterans are crucial because they contribute to the input of nutrients into these environments. In the Tropical region, there are caves with unique physical and biological characteristics - hot and bat caves, some of which have been recognized for the Carajás region. This region has the largest number of known iron caves in Brazil and is considered an important economic center for the extraction of mineral goods, as it is home to the country's largest mining project. In view of this, the study aimed to characterize the chiropterofauna associated with 20 caves in the Floresta Nacional de Carajás and the Parque Nacional dos Campos Ferruginosos, learn about the structure of their communities, recognize the invertebrate fauna associated with bat guano, carry out biological and microclimate monitoring, identify possible bat/hot caves and the conditions for their establishment, and propose actions for the conservation of speleological heritage. To this end, faunal inventories were carried out from August 2021 to March 2023 (with the collection of Chiroptera and invertebrates) and biological and microclimate monitoring of the cavities. Based on the data obtained, descriptive assessments of the chiropteran communities and the invertebrates associated with their guano were carried out, as well as diversity (alpha and beta) and correlation (CCA) analyses. As a result, 16 bat species were recorded, with the Phyllostomidae family being the most representative in terms of species. The cavities studied showed variation in the composition of their communities, which can be explained, for the most part, by species exchange - either due to environmental changes or species-specific demands. More diverse, numerous and permanent colonies of bats were essential for the entry of varied nutrients that served a wider range of invertebrates. Therefore, the presence of bats in the caves was an important determining factor (but not a limiting one) for the variation in invertebrate diversity. Finally, the identification of permanent bat colonies, the invertebrate fauna associated with the different types of guano and the microclimatic and geomorphological conditions of the cavities were fundamental for the delimitation of bat and hot cave. Therefore, knowing how chiropteran communities are structured and how they relate to biotic factors (interactions with invertebrates) and abiotic factors (species-specific temperature and relative humidity requirements) is essential for detecting their functional relationships and social organizations, as well as for identifying how bats respond to environmental changes and how this impacts other organisms associated with them. From this, more effective conservation actions can be structured and proposed, serving to support the management, maintenance and protection of the national speleological heritage.