Responses of Water and Carbon Variables to Fire, Tropical Cyclone and Drought Across Southern Guangxi, China

ABSTRACT The water‐carbon cycles and ecosystem resilience across regions are impacted differently by various disturbances. However, how these cycles respond to disturbances, as well as the major variables influencing these responses, remain poorly understood at regional scales. In a coastal tropical region of southern Guangxi, China, we evaluated the effects of fire, tropical cyclone (TC) and drought on evapotranspiration (ET), gross primary production (GPP), leaf area index (LAI) and water use efficiency (WUE). We quantified resistance, recovery time and dominant environmental controls for each disturbance using random forest and satellite‐derived ET, GPP and LAI products. Resistance and recovery varied among disturbance types, with drought having the shortest impact and fire having the longest (ET recovered within 3 to 4 years in 69.77% of the burned area), and with forests exhibiting higher tolerance to drought and TC but the lowest resistance to fire when compared with croplands. Importantly, the analysis showed a shift in ecosystem controls: following TC and drought, ET, LAI and WUE became mostly energy‐limited, whereas GPP remained water‐limited throughout all disturbances. A geographical disparity in the dominant control of WUE during drought, with VPD controlling forests and savannas and precipitation controlling grasslands and croplands, further demonstrated this disturbance‐specific reconfiguration of constraints. Our results from this tropical coastal region indicate that the type of disturbance, rather than just the current climate, determined the primary limitation on ecosystems. These findings provide insights for forecasting post‐disturbance trajectories in areas with climatic extremes.