Can green scenarios improve water ecosystem services and mitigate the effects of climate change? A case study in a river basin in southeastern Brazil

Recent studies suggest that ecological restoration can enhance ecosystem services and mitigate the climate crisis, though research on these interventions' effectiveness, especially in restoring native vegetation, remains limited. This study evaluates the effects of different climate scenarios, called Representative Concentration Pathways (RCP) (RCP 4.5 2040–2069, RCP 4.5 2070–2099, RCP 8.5 2040–2069, and RCP 8.5 2070–2099), and land use and land cover (LULC) scenarios (economic, trend, and green) on water ecosystem services (WES) in a southeastern Brazil river basin. These scenarios were compared to the baseline (2019 land use data). The main objective was to determine whether green scenarios, based on native vegetation reintroduction, could enhance WES while mitigating climate change effects. Climate and biophysical models from the InVEST package simulated these scenarios' effects on sediment export and retention (erosion control service), total nitrogen (TN) and total phosphorus (TP) export and retention (water purification service), and quickflow (QF) and baseflow (BF) (water supply). Results indicated that climate change mainly impacted water supply services, while LULC changes more significantly affected water purification and erosion control. The green scenario, combined with climate scenarios, significantly reduced sediment and nutrient exports while mitigating the effects of climate change on water supply. This study's methodology effectively shows how climate and LULC changes influence WES, suggesting that increasing green areas can improve WES and mitigate future climate change effects.