Influência da alteração de habitat na distribuição de lagartos na Caatinga, com ênfase em espécies relictuais

Abstract

Under the hypothesis that the change in habitat may influence the richness and abundance of lizards, the objective of this work was to evaluate possible variations in the richness and abundance of communities during the implementation of the Projeto de Integração do Rio São Francisco (PISF). This water development was installed in the semiarid region of Pernambuco on the left bank of the São Francisco sub-medium, extending in three ecoregions, the Depressão Sertaneja Meridional, Depressão Sertaneja Setentrional and a part of Raso da Catarina. Sampling methods were employed through active search and the use of a fall trap - Pitfall to obtain the data, in addition, the database provided by the Centro de Conservação e Manejo de Fauna da Caatinga of the University Federal do Vale do São Francisco was incorporated into the work, totalizing eight years (2012 to 2019) of monitoring the installation of the water infrastructure. Eleven areas directly affected by the project were investigated for which we used the Normalized Difference Vegetation Index (NDVI) to verify the change in the landscape over the years. Additionally, ecological niche modeling was used to predict the potential distribution of the endemic lizard with a disjunct geographic distribution (relict distribution) Tropidurus cocorobensis, which overlaps with part of the areas directly affected by the PISF. Lizard communities have shown similarity between areas, however significant differences in richness and abundance have been found over the years. The Depressão Sertaneja Meridional showed greater wealth (n = 17) and abundance (n = 38.320). Three species with disjunct distribution (Acratosaura mentalis, Psychosaura agmosticha and T. cocorobensis) were observed, one (T. cocorobensis) registered only in Raso da Catarina. The models indicated that the potential distribution of T. cocorobensis covers priority areas for conservation in the Caatinga, part of which are under the influence of the PISF, with a history of degradation due to the influence of human action. Identifying areas potentially suitable for the occupation of relicts species, as well as diagnosing variations in fundamental diversity parameters, reinforces the need to assess the impacts on lizards when setting up ventures. In addition, it can direct work plans and, consequently, impact mitigation measures.