Prioridades de conservação para cavernas ao sul de Minas Gerais

Abstract

Around the world, few caves in non-carbonate areas have studies regarding the evaluation and conservation of invertebrate fauna. In Brazil, this situation is maintained, with inventories of invertebrates focused on large limestone rock formations. For the southern region of Minas Gerais state, besides the insufficient information concerning the cave fauna, the area has several recurring impacts, mainly fragmentation of surrounding forests and inadequate tourism in the caves. Therefore, this study aimed to evaluate the invertebrate fauna in 51 caves from southern of Minas Gerais, as well as highlight the main impacts over the cave community. The faunal evaluation was conducted by determining the biological relevance of each cave. The relevance was obtained from the total richness of invertebrate species, relative richness and richness of troglomorphic species. The impacts were categorized in relation to the presence of human alterations inside the caves and surrounding area (250 meters). Moreover, the cave size, number and size of entrances were evaluated according to the influence on fauna. For the granitic and quartzitic caves the influence of the lithology over the invertebrate composition was verified. A total of 1,114 species was recorded, distributed in at least 190 families. The average richness obtained was 38.6 (SD ±21. 67) species, the average diversity was 2. 41 (SD ±0. 74) and the average equitability was 0.67 (SD ±0.17). Eleven troglomorphic species were observed in nine caves. The total richness was significantly related to the cave size in siliciclastic and granitic rocks. The number of entrances was related to the total richness only for quartzitic caves. Finally, the lithology was influent regarding the composition of cave community. For the region, the caves Casa de Pedra and Serra Grande were selected as the greatest priorities for conservation. Furthermore, the granitic caves from municipality of Munhoz and quartzitic caves from Ibitipoca hills need more attention in function of the high biological relevance and the degree of impacts over the fauna.