Spider and scorpion assemblies in areas impacted by water reservoir construction in the brazilian semiarid

Abstract

The Brazilian Semiarid Domain (BSD) is characterized by low and non-homogeneous rainfall, high evapotranspiration, and constant occurrence of dry periods. Both vegetation and animals are adapted to avoid water loss. Inhabitants of the driest areas of BSD construct various types of water reservoirs to store rainwater throughout the rainy season, and this process results in environmental impacts on fauna and flora. In this context, invertebrates such as spiders and scorpions may respond to such impacts by altering their abundance and richness. We tested the hypothesis that the construction of the Negreiros reservoir, located in the municipality of Salgueiro, state of Pernambuco, Brazil, causes impacts on the abundance of soil-dwelling spiders and scorpions. Spiders and scorpions were sampled using pitfall traps for invertebrates from August 2022 to August 2023 over fifteen days, totaling two collections per month. A total of 448 adult individuals of spiders and scorpions were sampled in areas characterized as preserved and human-altered around the Negreiros reservoir. The preserved area exhibited a higher number of individuals and greater species richness compared to the human-altered area, supporting the tested hypothesis. Our results also contributed to the increase in data on the occurrence of the species found, their geographical distribution, and how human disturbances tend to affect the abundance of spiders and scorpions in the Caatinga area.