Variações na diversidade de invertebrados na Lapa Nova, vazante-MG: implicações para o plano de manejo da cavidade

Abstract

Lapa Nova is a dolomitic cave that is located in Vazante, Minas Gerais. The cave is quite large, with 4.5 kilometers, occupying a prominent position, 35th place, among the largest Brazilian caves. Lapa Nova is a tourist-religious use cave, through which thousands of tourists visit during the Festa em Louvor a Nossa Senhora da Lapa (Feast in Honor of Our Lady of Lapa). The associated invertebrate fauna of this cave was shown quite rich, being represented by 218 species. Richness and diversity decreased considerably from the rainy season to the dry. The complexity was higher in the dry period, varying from 14.3 to 16.9, reaching values never before registered in Brazilian caves. Variations in the community in function of the tourist-religious use were also sampled. Populations that live in areas of more intense visitation suffer changes in their distribution after the Feast. These move from the visited area to outlying places that serve as refuge for the invertebrates. From these results, a management plan appropriate for the use of the cave was proposed that basically consists of the delimitation of a tourist hiking trail, isolating high population density areas. Special attention was given to the places of occurrence of troglobite species and brown spiders (Loxosceles variegata), species of medical importance. A differentiated methodology was also proposed for the sampling of a large guano deposit. Physiochemical parameters of the guano (pH, humidity, organic matter, nitrogen and phosphorus) were correlated with biotic variables. The humidity was the parameter that most influenced the distribution patterns and number of individuals of the most abundant species. Finally, the representation of a trophic web of the most abundant species in the guano was elaborated, based on literature data, correlation among species, micro-habitat preference and population´s abundance proportions.