| 气象干旱对皖南山区碳汇影响的滞后效应与驱动因素 |
| 摘要点击 1052 全文点击 104 投稿时间：2025-07-02 修订日期：2025-09-07 |
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| 中文关键词 气象干旱 净生态系统生产力（NEP） 滞后效应 驱动因素 皖南山区 |
| 英文关键词 meteorological drought net ecosystem production（NEP） time-lag effects driving factors Mountainous Area of Southern Anhui Province |
| DOI 10.13227/j.hjkx.202507024 |
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| 中文摘要 |
| 全球气候变化加剧背景下，极端干旱事件频发对陆地生态系统碳汇功能构成严峻挑战. 以中国亚热带典型山地生态系统——皖南山区（2001~2020年）为研究对象，综合运用标准化降水蒸散指数（SPEI）、净生态系统生产力（NEP）、地形与气象数据，采用趋势分析、Pearson相关性系数、XGBoost回归模型与SHAP解释模型等方法，系统探究了气象干旱对NEP影响的滞后效应及其关键驱动因子. 结果表明：①研究区NEP空间分异显著，碳汇集中分布在山地丘陵区，而碳源主要集聚于适宜城市发展和农业开发的平坦区域；75.07%的区域NEP呈上升趋势，表明区域碳汇能力整体增强. ②NEP对气象干旱的响应存在滞后效应，滞后时长集中在0~3个月之间（面积占比93.01%），区域平均滞后期为1.86个月. ③降水和潜在蒸散发是主导滞后效应的核心气象因子；地形因子中，坡度对碳汇响应干旱的敏感性具有显著调节作用. 研究揭示了亚热带山地生态系统碳汇对干旱的非对称响应机制，可为理解其碳汇稳定性维持机制提供了新视角，并为区域生态安全格局优化、提升生态系统韧性及制定适应性管理策略提供了关键科学支撑. |
| 英文摘要 |
| Amid intensifying global climate change， the increasing frequency of extreme drought events poses severe challenges to the carbon sink function of terrestrial ecosystems. From 2001 to 2020， we focused on the mountainous area of Southern Anhui Province， a representative subtropical mountain ecosystem in China， and integrated the standardized precipitation evapotranspiration index （SPEI）， net ecosystem productivity （NEP）， topographic variables， and meteorological data. Trend analysis， Pearson correlation， the XGBoost regression model， and the SHAP interpretation framework were employed to systematically examine the lagged effects of meteorological drought on NEP and to identify the key driving factors. The results show that： ① NEP exhibited significant spatial heterogeneity， with carbon sinks concentrated in mountainous and hilly areas， while carbon sources were mainly distributed in flat regions suitable for urban development and agricultural cultivation. Approximately 75.07% of the area showed an increasing NEP trend， indicating an overall enhancement in regional carbon sink capacity. ② NEP responded to meteorological drought with a clear lag effect， with lag durations primarily ranging from 0 to 3 months （accounting for 93.01% of the area） and an average lag period of 1.86 months across the region. ③ Precipitation and potential evapotranspiration were the dominant meteorological factors driving the lag effect， while among topographic factors， slope played a significant role in modulating the sensitivity of carbon sinks to drought. These findings uncover the asymmetric response mechanisms of subtropical mountain carbon sinks to drought， provide new perspectives on the maintenance of carbon sink stability， and offer critical scientific guidance for optimizing regional ecological security， enhancing ecosystem resilience， and developing adaptive management strategies. |
