The beneficial effects of sustainable farming on multitrophic biodiversity are amplified under harsh and less predictable environmental conditions

The expansion and intensification of agricultural lands are major contributors to the global biodiversity loss. Alternative sustainable management practices, such as integrated and organic farming, have emerged as tools to mitigate this loss, and make food production and nature conservation compatible. Multiple studies have assessed how transitioning from conventional to more sustainable farming promotes the diversity and abundance of accompanying organisms; however, there is significant variability in the findings. This variability can be driven by both local environmental contexts, and the metrics used to assess biodiversity responses. In this study, we compiled climatic and edaphic data from 55 studies and 101 study cases investigating differences in species richness and abundance across conventional, integrated, and organic farming practices. We also explored the relationship between biodiversity metrics and climatic or soil conditions and compared trends among types of sustainable management (i.e., organic vs. integrated). Overall, species richness and abundance consistently increased under more sustainable farming practices. However, while organic farming had a positive effect on both abundance and species richness, integrated farming only enhanced richness. The positive effects of sustainable farming generally increased in locations characterised by lower fertility and more alkaline soils and less predictable climates, indicative of harsher environmental conditions. Our study highlights the importance of implementing environmentally friendly management strategies to mitigate the ongoing biodiversity crisis, particularly under environmentally challenging conditions. Moreover, it emphasizes the need to apply adaptive management strategies that consider the environmental variability of farming regions to maximize these positive outcomes on biodiversity.