The role of sustainable agroforestry practices and food consumption to prevent tropical deforestation and increase ecosystem services

Abstract

Tropical forests harbor most of global terrestrial biodiversity and provide essential ecosystem services, although they have been largely replaced by agricultural activities. Amazon is the largest tropical forest remaining, and cattle ranching and soybean cultivation are by far the greater drivers of deforestation, that together with other few commodities constitutes the main products responsible for the imported deforestation caused by European countries. Agroforestry systems and sustainable intensification are pointed out as solutions to conciliate food production with environmental conservation, thus reviewing the results of studies comparing these practices against conventional ones are needed. We performed a systematic review of papers assessing the effects of cattle ranching and soybean cultivation on Amazon deforestation as well as performed a meta-analysis on the effects of sustainable practices on different ecosystem services. Our results highlight the negative impacts of cattle ranching and soybean crops on the ecosystem dynamics and functionality of the Amazon biome, also due to speculative economical mechanisms. Our meta-analysis indicated a huge gap of knowledge of empirical studies comparing sustainable and conventional practices, with just 13 studies meeting the requirements for inclusion. The overall model comparing the ecosystem services provided in conventional land-uses and those adopting sustainable practices indicated a non-significant effect. Such result was due to the negative effect found on the few studies assessing crop yield and herbage biomass, a pattern also found in a European meta-analysis. However, livestock productivity, soil organic carbon, soil fertility and woody biomass were positively affected, indicating a wider beneficial effect. Our review also shed light on the responsibilities in the consumption of many food products that are the cause of tropical deforestation. In conclusion, we discuss challenges and opportunities to advance research into the real effects of sustainable practices to conciliate agriculture and tropical forests conservation.