Influencia del uso de la tierra sobre la relación entre la diversidad de arañas y sus presas potenciales

Abstract

The factors that regulate the diversity of organisms through trophic webs have been widely studied, although the environmental component is not frequently considered. Within the framework of environmental changes caused by land use and its influence on biodiversity, it is essential to consider how these changes influence the regulation of food webs. Here, we set out to investigate the effect of the diversity and abundance of prey on the diversity of predators (spiders) in different environmental conditions given by land use. Plots were established on sites with soybean crops and forest plantations. Half of them were treated by applying attractive bait for potential spider prey and the rest untreated as a control. Potential preys were collected using sticky traps, and spiders using drop traps. The response of specific richness, functional diversity and particular traits of spiders to the type of land use and treatment with bait was studied by means of mixed generalized linear models including the interaction between factors. The specific richness of spiders was similar between land uses and treatment with and without bait, although its abundance was greater in soybean fields than in plantations. In the latter, the functional diversity was lower in the bait plots than in the controls. The different traits examined showed varied responses to the factors. Soybean crops and eucalyptus plantations seem to limit the specific richness of spiders in a similar way, but not the functional diversity, even in the presence of greater diversity of food resources.