Vegetation structure as the main source of variability in scorpion assemblages at small spatial scales and further considerations for the conservation of Caatinga landscapes

Abstract

Even at the local scale, environmental changes due of anthropogenic actions represent a source of disturbance in terrestrial ecosystems, forcing species to respond according to their ecological plasticity. Thus, stenotopic species and those with low-dispersal ability will likely be negatively affected by landscape modifications that reduce environmental complexity. In this study, we identify and quantify the effects of biotic and abiotic factors related to habitat complexity on the variation in scorpion assemblages in terms of both species’ richness, abundance and composition across 18 transects covering Caatinga landscapes with different levels of degradation. Using ultraviolet flashlights, we sampled 269 scorpions, belonging to six species and two families. The results showed contrasting patterns of species richness and abundance that depend on the level of habitat complexity. More specifically, we reported that scorpion species richness could be predicted by the number of trees, while the coefficient of variation of the diameter at breast height of trees (cvDBH) is a predictor of scorpion abundance. These findings suggest that vegetation structure is deterministic for the maintenance of scorpion assemblages in Caatinga landscapes. In addition, the cvDBH and tree number may explain 39% and 40% of the variability observed amongst scorpion assemblages in terms of richness difference and species composition, respectively. This study provides insights concerning the development of conservation strategies, clarifying the role of habitat complexity for the preservation of low-dispersal animals in neglected environments, such as those within the Caatinga domain.