The positive effect of Nature-based Solutions for achieving the Sustainable Development Goals in Mediterranean agroecosystems: a meta-analysis

The increasingly frequent impacts of climate change in the Mediterranean region challenge the resilience and sustainability of the region's agroecosystems. In this context, Nature-based Solutions (NbS) emerge as a sustainable strategy to address climate change adaptation and mitigation. Extensive literature focuses on the analysis of NbS to address this problem, although no analysis discriminates against the individual and combined effect of NbS in agroecosystems. In this work, we capitalize on state-of-the-art results and present a random-effects meta-analysis of NbS. Our analysis focuses on a cohort of 80 NbS for agricultural land management, such as conservation tillage practices, soil-improving cropping systems, organic amendments and fertilizers, and landscape solutions. We used response ratios as effect sizes to determine the most suitable NbS for improving soil health. We built a database with field-scale data from 70 published case studies comparing NbS and conventional agricultural management practices in agroecosystems in 12 countries with a Mediterranean climate. Our analysis results from a literature selection of 988 scientific articles published from 2019 to 2022. We have analyzed the combined effect that NbS have on soil's ability to retain water, organic matter, and carbon and to reduce soil loss. To further understand the influence of abiotic factors, we also analyze the impact of precipitation, soil texture, and irrigation systems on the effects of NbS. These results shall contribute to leveraging climate change adaptation in Mediterranean agroecosystems, addressing land and water-related Sustainable Development Goals (SDGs).