The Shift from Energy to Water Limitation in Local Canopy Height from Temperate to Tropical Forests in China

Canopy height greatly affects the biomass stock, carbon dynamics, and maintenance of biodiversity in forests. Previous research reported that maximum forest canopy (Hmax) at global regional scales could be explained by variations water or energy availability, is, water- energy-related hypothesis. However, fundamental gaps remain our understanding how different drivers (i.e., energy) contribute to Hmax local scale. In this study, we selected eight dynamic plots (20–30 ha) across a latitudinal gradient (from 21.6° N 48.1° N) China measured structure using airborne light detection ranging (LiDAR) data. Based on LiDAR point cloud data, extracted tree 20 × m quadrat as proxy for height, topographic wetness index (TWI) digital terrain model-derived insolation (DTMI) were calculated proxies conditions. We used linear mixed model spatial simultaneous autoregressive error quantify TWI DTMI contributed found positive effect was stronger subtropical tropical forests, highlighting main factor drives pattern these regions. contrast, although effects can both negative, its relative contribution higher temperate than other types, supporting idea input is more critical Overall, study revealed directional change from limitation Our findings offer important insights into management, especially under climate Anthropocene.