不同气候情景下甘肃草地碳收支时空模拟与预测

在碳达峰、碳中和的背景下，草地碳汇是实现碳中和的关键路径.基于第六次国际耦合模式比较计划（CMIP6）气候情景数据，运用Daycent模型对甘肃草地2015~2100年碳收支进行模拟，并利用趋势分析法研究未来78 a草地碳收支的时空变化规律.结果表明，SSP245未来气候情景下，净生态系统生产力（NEP）呈不显著波动下降趋势，速率（以C计，下同）达-0.20 g ·（m² ·a）^-1，且该情景下草地碳汇处于下降状态；SSP585未来气候情景下，草地NEP以1.36 g ·（m² ·a）^-1的速率呈显著波动上升趋势，草地碳汇逐渐增加；草地碳收支的空间分布由西北向东南递增；SSP585气候情景下的温度和降水的增幅高于SSP245的气候情景，且草地碳收支与降水量的变动具有一致性，与温度的变化呈反向关系.研究明确了在不同气候情景下甘肃草地的碳汇强度，对有效固碳有参考和促进作用.

Spatiotemporal Simulation and Prediction of Grassland Carbon Budget in Gansu Under Different Climate Scenarios

Under the background of carbon peak and carbon neutrality, grassland carbon sinks are a key pathway to carbon neutrality. Based on the Coupled Model Intercomparison Project Phase 6 (CMIP6) climate scenario data, the Daycent model was used to simulate the carbon budget of Gansu grasslands from 2015 to 2100, and the trend analysis was used to study the spatial and temporal changes in grassland carbon budget in the next 78 years. The results revealed that, under the future climate scenario of SSP245, the net ecosystem productivity (NEP) indicated a non-significant fluctuating downward trend with a rate of -0.20 g·(m²·a)^-1(in C, the same below), and the grassland carbon sink was in a declining state. Under the future climate scenario of SSP585, the grassland NEP indicated a significant fluctuating increase trend with a growth rate of 1.36 g·(m²·a)^-1, and the grassland carbon sink gradually increased under this scenario; the spatial distribution of grassland carbon budget increased from northwest to southeast. The increase in temperature and precipitation under the SSP585 climate scenario was higher than that under the SSP245 climate scenario, and the grassland carbon budget strongly correlated positively with precipitation. However, a negative correlation was observed between grassland carbon budget and temperature. We identified the carbon sink intensity in Gansu grasslands under different climate conditions, which provides a reference for and contribution to effective carbon sequestration.