Targeted tropical forest restoration can offset deforestation-induced water flux losses

Abstract

Tropical forest restoration is increasingly promoted as a nature-based solution for climate change mitigation, yet its capacity to reverse the hydrological impacts of deforestation remains unclear. Here we show forest gain increases evapotranspiration and precipitation more than forest loss reduces them. This hydrological asymmetry, driven by the rapid growth of young forests and enhanced moisture recycling, indicates that compensating for hydrological effects of deforestation requires restoring 43–63% and 53–83% of lost forest area in South America and Africa, respectively. In contrast, climatic conditions in Southeast Asia limit the potential of reforestation, underscoring the importance of forest conservation. Current climate models fail to capture these asymmetric responses, largely owing to poor representation of vegetation dynamics and age-dependent traits. Our findings call for reframing forest-based climate solutions through the lens of hydrological resilience, emphasizing the importance of spatially targeted, mechanism-informed restoration strategies to maximize ecosystem service co-benefits. The authors demonstrate asymmetrical impacts of forest gain and loss on evapotranspiration and precipitation: gain increases the processes more than loss reduces them. They highlight a need to better consider hydrological asymmetry in climate models and in planning of forest-based climate solutions.