中亚不同植被生产力对干旱事件的敏感性  

Vegetation sensitivity analysis of different vegetation productivity to drought events in Central Asia

作　　者：吴光明 姜亮亮 刘文利 李奇锦 WU Guangming;JIANG Liangliang;LIU Wenli;LI Qijin(School of Geography and Tourism,Chongqing Normal University,Chongqing 401331,China;Chongqing Key Laboratory of GIS Application,Chongqing Normal University,Chongqing 401331,China)

机构地区：[1]重庆师范大学地理与旅游学院,重庆401331 [2]重庆师范大学地理信息系统应用研究重庆市高校重点实验室,重庆401331

出　　处：《生态学报》2024年第24期11331-11346,共16页Acta Ecologica Sinica

基　　金：国家自然科学基金(42201124);重庆市自然科学基金创新发展联合基金项目(CSTB2024NSCQ-LZX0064);中国博士后科学基金(2023M740433);重庆市研究生科研创新项目(CYS240366)。

摘　　要：在全球变暖背景下,干旱事件频发。亚洲中部干旱区的干旱事件频发引起植被退化问题日益严重,对实现联合国土地退化“零增长”目标构成了严峻挑战。然而,中亚植被生产力对干旱事件敏感性仍缺乏了解。基于此,使用土地利用数据、ERA5-Land和干燥指数等数据,利用游程理论、敏感性计算以及提升回归树(BRT)模型等方法,研究中亚植被生产力对干旱事件的敏感性,揭示了SPEI3—12间干旱事件的基本特征以及干旱事件期间植被异常的时空变化,使用BRT模型量化了干旱基本特征对植被敏感性的相对重要性。研究结果表明:(1)随时间尺度增加,除干旱间隔和干旱次数减少外,其他干旱特征均逐渐增加,尤其在半干旱、半湿润地区发生了更频繁,严重程度更高的干旱事件,干旱严重度在SPEI12时高达25.11;(2)随时间尺度变化,植被初级生产力(GPP)异常值在SPEI12时低至-30,其中在半干旱、半湿润地区的哈萨克斯坦西部、中亚中东部及南部土库曼斯坦东部,受影响更明显。而GPP异常值在箱型图SPEI3—12间存在差异,耕地出现异常负值中位数最低值,稀疏植被GPP异常值波动变化最大;(3)不同植被对干旱事件的敏感性随时间尺度增加而逐渐减少,在中亚半干旱和半湿润地区,尤其是耕地和稀疏植被表现出更高的敏感性。BRT模型表明,干旱严重程度是影响植被变化最重要因素,在模型中,草地和林地对SPEI3—12间干旱严重度的敏感性均值分别达到37.41%和31.70%。因此,了解植被生产力对干旱事件的敏感性,尤其在生态脆弱地区,将有助于为植被退化的防治提供决策参考。In the context of global warming,the frequency of drought events has increased.Frequent droughts in arid regions of Central Asia have intensified vegetation degradation,presenting a considerable challenge to meeting the United Nations“zero net land degradation”objective.However,the sensitivity of vegetation productivity in Central Asia to drought events remains poorly understood.To tackle this issue,the study utilized land use data,ERA5⁃Land data,and the aridity index.The sensitivity of vegetation productivity to drought events in Central Asia was investigated through methods including run theory,sensitivity calculation,and the Boosted Regression Tree(BRT)model.The fundamental characteristics of drought events over SPEI3—12 periods and the spatiotemporal variations of vegetation anomalies were identified.The sensitivity of different vegetation types to drought events was assessed and the relative importance of drought characteristics on vegetation anomalies was quantified based on the BRT model.Findings indicate that with an expanding time scale,drought characteristics generally worsen,with the exception of intervals and frequencies of drought events.Particularly in semi⁃arid and sub⁃humid regions,drought events occurred more frequently and the severity remained high,with drought severity(SPEI12)reaching up to 25.11.With the time scale variation,the negative anomalies of Gross Primary Productivity(GPP)dropped to-30 in SPEI12 in semi⁃arid and semi⁃humid areas,notably impacting western Kazakhstan,central and eastern portions of Central Asia,and eastern Turkmenistan.There were differences in GPP anomalies between SPEI3 and SPEI12,with cropland showing the lowest negative median anomalies,and sparse vegetation exhibited the greatest fluctuation in GPP anomalies.The sensitivity of different vegetation types to drought events gradually decreased as the time scale expanded.In the semi⁃arid and semi⁃humid regions of Central Asia,croplands and sparse vegetation were more sensitive.The BRT model indicat

关 键 词：植被敏感性 干旱事件 不同植被类型 游程理论 中亚 

分 类 号：Q948[生物学—植物学]