A influência dos microhabitats na estruturação das comunidades de invertebrados em cavernas na região cárstica de Bodoquena, Brasil

Abstract

The present study aimed to understand the influence of physical, trophic, and microclimatic variables of cave floors on the richness and composition of invertebrate fauna in caves of the Atlantic Forest in the state of Mato Grosso do Sul. We sampled 16 limestone caves in the Serra da Bodoquena National Park. Sampling units comprised quadrats (1m2) and sectors (3x10m), referred to as microscale and mesoscale, respectively. We assessed how the richness and composition of invertebrate fauna are influenced by variations in temperature, humidity, and distance from the nearest entrance, physical components (rock particle size), and organic resources. We recorded 445 morphotypes of invertebrates, with 280 sampled at the mesoscale and 173 at the microscale, covering 27 orders and at least 121 families. At both scales evaluated, the diversity of organic resources and the distance from the nearest entrance showed a significant relationship with richness, being positive for organic resource diversity and negative for distance from the nearest entrance. Greater diversity of resources resulted in higher richness, where different species can exploit different resources. The distance from the entrance led to a decrease in richness, as the greater the distance from the entrance, the lower the diversity of trophic resources, sustaining a smaller number of species. Variations in temperature influenced fauna composition at the mesoscale, while shelter availability influenced composition at the microscale. Finally, we observed a high taxonomic distinction between the sampled caves, resulting from the importance of para-epigean species found. The pronounced environmental heterogeneity present in the sampled caves was the most influential factor in fauna composition, both at the meso and microscales.