Could agroforestry restore ecosystem services in arid lands? An analysis through the weight of the evidence approach

Abstract

Degradation is limiting the ability of arid lands to provide ecosystem services. Agroforestry Systems can supply several of these ecosystem services. In this context, we carried out a systematic review of literature, to find the ecosystem services provided by Agroforestry Systems in arid lands irrigated by rainwater harvesting systems in worldwide. The ecosystem services most mentioned (soil quality, productivity increase, carbon sequestration, biodiversity conservation, cultural values, water regulation and purification, and pollination), that were provided by the four Agroforestry Systems (protein banks, intercropping, windbreaks and homegardens) were used to apply the Weight of Evidence Approach. The regions where Agroforestry Systems practices were carried out, the species most used and their multipurpose were also evaluated. Most of the experiences were documented in Africa (42%) and Asia (37%). We registered 82 species, being the Fabaceae and Chenopodiaceae families were the most used. These species (49% shrubs) were mainly integrated in Agroforestry Systems by homegardens (43%), intercropping (40%), and windbreaks (23%). The most evaluated species uses were medicine (58%), food (28%), and forage (27%). We found several positive evidence of Agroforestry Systems in all ecosystem services evaluated. We also found some evidence that Agroforestry Systems can cause drawbacks such as salinization, or species invasion.