Herpetofauna de Inselbergues na Paraíba: Diversidade e influência de fatores bióticos e abióticos na ocorrência das espécies

Abstract

Inselbergs are granitic rocky outcrops frequently found in the northeastern region of Brazil. These relict geomorphological formations present distinct characteristics from the matrix area in which they are inserted, providing a greater possibility of niches, especially for xerophytic species. According to the hypothesis of habitat heterogeneity, the more complex and heterogeneous an environment is, the greater the diversity of species it harbors. Based on this, the objective of this work was to analyze how environmental variables in these inselbergs influence the occurrence of herpetofauna. The two inselbergs that were studied are located in a Caatinga area, in the municipality of Patos, state of Paraíba. Data collection was carried out monthly for a period of one year, recording sightings by active search of transects and occasional encounters. To identify the structure of environmental variables, 20 quadrants/parcels of 16m² were delimited. Vegetation characteristics and abiotic variables were recorded. A total of 1,874 sightings were recorded, of which 148 were amphibians (17 spp), 1689 were lizards (13 spp), and 37 were snakes (7spp). The anurans consisted of 5 families, with Leptodactylidae (n=8) and Hylidae (n=5) showing the highest richness. For lizards there were 7 families, with Gekkonidae (n=3) and Teiidae (n=3) having the highest richness and for snakes, 2 families were recorded, Dipsadidae (n=6) showed the highest richness. PCA analysis showed that variables related to vegetational structure, such as tree height and density, leaf litter height, understory density and number of fallen branches, explained the species richness the most. Sites with greater vegetational structure and humidity favor the richness of reptiles and amphibians, thus demonstrating that environmental heterogeneity plays an important role in local species diversity.