Forest Stages’s Phenology Across China's Thermal Zones: Implications For Carbon-Water Sustainability

Forest phenology profoundly influences ecosystem services, yet how developmental stages modify phenological responses across diverse climates remains unclear. Analyzing high-resolution forest age data across China's six thermal zones, we found overmature forests exhibit shorter growing seasons than younger stages in most zones, with greatest reductions in warm temperate (-32.77 days) and subtropical regions (-22.72 days). Young forests show heightened climate sensitivity, while topography controls plateau forest phenology. These patterns translate into distinct carbon-water trade-offs: overmature plateau forests excel in soil carbon retention; mature mid-temperature forests optimize carbon sequestration and soil moisture; tropical forests demonstrate superior carbon accumulation despite shorter growing seasons. Our findings reveal zone-specific carbon-water relationships across forest development stages, necessitating tailored management strategies to maximize sustainability in a changing climate.