Seasonality and Long-Term Effect of Environmental Variables on the Orb Weaver Spider Community of a Tropical Dry Forest in the Balsas Basin, Mexico

Abstract

Spiders are significant predators in terrestrial habitats, with the highest diversity found in tropical ecosystems, but it is also where they are studied least. In this study, we analyzed the effect of seasonality and three environmental variables (precipitation, evaporation, and temperature) in the orb-weaver composition, richness, abundance, dominance, and diversity. In addition, the species turnover between three localities with differences in the vegetation composition and maintenance in the Sierra de Huautla, Morelos, Mexico, were evaluated. The collection methods used included beating vegetation and direct searches conducted over seven hours during daylight, once per month, between April 2013 and March 2014. A total of 17 species from 14 genera were registered. With the records, we compiled the first species inventory of araneids for the three localities, adding eight new species records for the state of Morelos. The predominant species were Neoscona oaxacensis (Keyserling, 1864) and Trichonephila clavipes (Linnaeus, 1767), but over 50% of the species that we recorded corresponded to a single individual. The Araneid community changed between the dry and rainy seasons in all three localities, with each locality responding differently to changes in environmental variables, with most variables maintaining a long-term effect on the spider community.