Post‐Drought Vegetation Shifts Lead to Divergent Carbon, Water and Energy Responses in a Savanna Ecosystem of Southwest China

ABSTRACT Increasing drought frequency and intensity affect biophysical functions of natural ecosystems. In tropical semi‐arid savannas, while immediate drought effects are well‐studied, the drought legacy effects on vegetation composition and associated ecosystem functions remain unclear. We used data of vegetation composition, net ecosystem CO 2 exchange, surface albedo and evapotranspiration (ET) in 2017–2022 from a savanna ecosystem, Southwest China, to investigate the legacy effect of an extreme drought event that occurred in 2019. Vegetation declined continuously for 3 post‐drought years. While tree numbers declined by 12%, shrub numbers dropped by 50% compared with pre‐drought levels, shifting vegetation dominance toward trees. This structural change caused sustained reductions in albedo and ET, which remained below pre‐drought levels, despite gross primary production recovering in the years immediately post‐drought. Vegetation shifts disproportionately impact ecosystem functions, with energy and water fluxes exhibiting greater vulnerability and potentially enhancing regional warming as droughts increase in Asian savannas.