Effect of rural abandonment on multi-trophic biodiversity in Aragón

Abstract

In the current process of widespread depopulation in Mediterranean rural ecosystems, agroecosystems are undergoing a process of passive rewilding due to the abandonment of agricultural practices. This study evaluates the effect of the factors involved in multi-trophic biodiversity changes associated with the rewilding process. A network of paired plots (areas abandoned more than 20 years ago and controls with no history of cultivation) in 40 municipalities in Aragon that have lost population in recent decades was used. Specifically, the effect of environmental factors, at local and regional scale, on the diversity of primary producers (plants), herbivores (orthoptera) and predators (spiders) measured in these plots was evaluated. Agricultural abandonment did not have a significant effect on species richness, although it did modulate the effect that environmental factors had on it. Each trophic group showed different responses to the environment, with local (soil) factors being more important for plants and spiders, and regional factors (human population) being more important for orthoptera. The study suggests that both local and regional factors influence the process of multi-trophic rewilding, highlighting the complexity involved in managing the consequences of depopulation on the natural environment.