摘要:评估气候变化及生态恢复对碳酸盐岩风化碳汇（CS）的复合影响机制是当前喀斯特生态系统碳循环及气候变化研究领域的一个重要任务。基于碳酸盐岩热力学溶蚀模型估算了1992-2017年中国西南喀斯特槽谷碳酸盐岩风化碳汇通量（CSF），利用Lindeman-Merenda-Gold模型定量评估了气候及生态恢复因子对槽谷CSF的相对贡献率。研究结果表明：（1）槽谷整体年均温及年降雨量均处于持续升高的趋势，增速分别为0.06℃/a及12 mm/a，进入21世纪之后，增速均有一定程度的放缓，年蒸散发在21世纪以前为增加的状态，2000年以后整体表现为减少的趋势；（2）槽谷植被覆盖度增加速率为0.004/a，其增加区域的面积占比达到了95.07%，槽谷生态系统恢复效果显著；（3）槽谷的年均CSF约为9.42 t C km^-2 a^-1，研究期间处于增加的状态，其年均增长速率约为0.2 t C km^-2 a^-1，CSF增加区域的面积占比约为89.28%；（4）槽谷CSF受到气候因素（降雨、蒸散发、温度）及生态恢复2方面的影响，其中降雨、温度及生态恢复反馈因子FVC与CSF呈正相关关系，ET与CSF呈负相关关系，降雨对于研究区CSF的贡献率最大，达到了70.36%；（5）本研究揭示了气候变化及生态恢复对岩石风化过程的复合影响机制。



Abstract:Evaluating the coupling effects of climate variability and ecological restoration on carbonate rock weathering-related carbon sink (CS) is an important objective in current research on carbon cycle and climate change in karst ecosystems. In this study, we estimated the flux of CS (CSF) in the typical karst valley of Southwest China from 1992 to 2017 based on the thermodynamic dissolution model for carbonate rock. We extended our research by using the Lindeman-Merenda-Gold model to quantify the relative contribution rates of climate change and ecological restoration factors to CSF. We obtained the following results:1) annual average temperature and precipitation of the valley were both increasing continuously at rates of 0.06℃ per year and 12 mm per year, respectively, and after 2000, these rates of increase slowed down. The annual evapotranspiration increased before 2000, and decreased after that. 2) The increase rate of fractional vegetation cover (FVC) in the valley was 0.004 per year, and the proportion of increased area reached 95.07%, which indicated significant ecological restoration in the valley. 3) The annual average CSF in the valley was 9.42 t C km^-2 a^-1 with an increasing trend during the study period showing an average increase rate of 0.2 t C km^-2 a^-1, and the proportion of the area with increased CSF was 89.28%. 4) CSF in the valley was affected by climatic factors (precipitation, evapotranspiration, temperature) and ecological restoration factors (FVC); among these factors, precipitation, temperature, and FVC had a positive impact on CSF, whereas, evapotranspiration exerted a negative impact on CSF. The relative contribution rate of precipitation in the valley was the maximum among that of all factors, with a magnitude of 70.36%. 5) We revealed the coupling influence mechanism of climate change and ecological restoration on rock weathering process.





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