Diversidade de lagartos e serpentes de um brejo de altitude no Nordeste do Brasil e influência de variáveis ambientais.

Abstract

The Brejos de Altitude, located north of the São Francisco River, are remnants of the Atlantic Forest biome that emerged in the Pleistocene, being surrounded by the Caatinga biome and acting as refuges places for a fauna of reptiles and amphibians of ombrophilous characteristics, maintaining great affinity with species that make up the fauna of neotropical forests and that possibly includes some species of dry areas. However, most of the Brejos de Altitude have not yet had their herpetofauna inventoried, resulting in insufficient knowledge about this group in the Atlantic Forest of high altitude of the Northeast. Moreover, considering that abiotic factors have great influence on communities, including lizards and snakes, the present study aimed to inventory the taxocenosis of lizards and snakes of the Refugio de Vida Silvestre Matas do Siriji (RVSMS), a Brejos de Altitude located in the State of Pernambuco, Northeastern Brazil, as well as analyzing the influence of local environmental variables on it. Three environments were selected in the area and the methods used to record the animals were limited transects by time, pitfall traps, occasional encounters and third-party reporting/registration. Environmental variables (abiotic and vegetation) were collected through plots distributed in each environment. Only those species recorded by time-limited transects, pitfall traps and occasional encounters were used to analyse the influence of environmental variables. Thirteen lizard species and twenty five snake species were recorded, but the collector curve did not reach the asytonate. The number of sightings and the richness of the three environments did not differ significantly. Rainfall was negatively related to the number of sightings (r= -0.556; p= 0.061) and richness (r= -0.506; p= 0.093), but not significant. The set of variables that correlated with richness and composition in each environment was different, and some of these variables differed significantly between wetter and less rainy periods. Thus, rainfall directly and indirectly affected some local environmental variables, and these, in turn, influenced the structure of taxocenosis. The RVSMS has 35.51% of the lizard and snake species in the State of Pernambuco, occupying the fourth place in number of species in the State. Taking into account the category of extinction risk, the level of information and geographic distribution, ten species deserve greater attention: S. torquatus, E. cephalomaculata, E. cephalostriata, B. bilineatus, L. muta, D. atlantica, A. arenensis, M. lemniscatus, X. rhabdocephalus and D. variegata. The RVSMT has a rich and still underestimated fauna that is threatened by agriculture and hunting, activities that directly and indirectly affect local biodiversity, and it is urgent to apply appropriate protection measures to conservation units, which have been neglected.