Rivers increase drought resistance and resilience of forests in the Northern Hemisphere

Abstract

Under climate change, increasingly frequent and severe droughts pose a significant threat to forests. Rivers play a dual role, as they not only influence local hydrological cycles but also serve as essential water sources to support forest growth. However, it remains unclear whether there is a distinct variation in drought response between forests growing in areas with rivers and those without. In this study, we investigated the influence of river density on drought resistance and resilience in forests across the Northern Hemisphere. We found that drought resistance and resilience of forests showed a significant increase with the increasing river density. In addition, the river-induced enhancement in drought resistance and resilience was significantly greater in dry regions than in humid regions. We further observed a notable increase in evapotranspiration, precipitation, soil moisture with the increase in river density. These suggest that dense river networks can significantly increase drought resistance and resilience by influencing local hydrological cycles. The observed rivers-induced shifts in drought resistance and resilience are crucial for developing effective ecosystem management strategies in the face of increasing drought frequency and intensity under climate change. Our results highlight the vital role of rivers in sustaining the stability of forest ecosystems in the face of frequent drought events under climate change.