利用叶面积指数分析气候变化下阿尔泰山泰加林的生长稳定性及其影响因素  

Using leaf area index to analyze the growth stability and influencing factors of the Mount Altai Taiga under climate change

作　　者：唐缘 孙晗 王襄平[1,2] TANG Yuan;SUN Han;WANG Xiangping(School of Ecology and Nature Conservation,Beijing Forestry University,Beijing 100083,China;National Key Laboratory of Efficient Production of Forest Resources,Beijing Forestry University,Beijing 100083,China)

机构地区：[1]北京林业大学生态与自然保护学院,北京100083 [2]林木资源高效生产全国重点实验室,北京林业大学,北京100083

出　　处：《生态学报》2024年第18期8258-8268,共11页Acta Ecologica Sinica

基　　金：第三次新疆综合科学考察项目(2021xjkk0603,2022xjkk1205);国家自然科学基金(32201258,32271652)。

摘　　要：阿尔泰山泰加林是西西伯利亚泰加林的南缘,受到全球变化的影响日益加剧,然而在气候变化背景下影响泰加林生长稳定性的关键因子尚不明确。利用叶面积指数(LAI)遥感数据,采用LAI基尼系数作为表征生长稳定性的指标,分析了1982—2018年间阿尔泰山泰加林生长稳定性的变化,并建立多元线性模型分析了气候条件及变化状况、植被生产力、植被高以及植被类型等因素的影响。结果表明:(1)阿尔泰山地区近38年间潜在蒸散量(PET)所表征的热量条件年际增加趋势显著,稳定性较低,饱和水汽压差(VPD)表征的水分条件年际变化趋势较小,泰加林生长稳定性在气候方面主要受到PET的影响;(2)泰加林生长稳定性在高海拔地区较低,低海拔地区较高,且主要受平均叶面积指数(Mean LAI)所表征的植被生产力的影响,对密林(Mean LAI>2.091)而言,生产力越大、稳定性越低,对疏林(Mean LAI≤2.091)而言,生产力越大、稳定性越高,生物因素影响甚至大于气候因素。在气候变化的影响下,稳定性较低的高海拔地区泰加林未来的生长可能会衰退,而生产力较高的泰加林承担着更多的生态系统功能,稳定性降低将导致其面临的威胁也更大。阿尔泰山泰加林作为区域重要的生态安全屏障,未来的保护应当将重心倾向于高海拔及高生产力的泰加林,以减缓气候变化对区域生态安全的影响。The Mount Altai region marks the southern boundary of the West Siberian Taiga Forest,increasingly affected by global change.However,the pivotal factors influencing the growth stability of the Taiga Forest amidst climate change remain unclear.This study utilizes remote sensing data on Leaf Area Index(LAI)and the LAI Gini coefficient,a stability characteristic index,to assess growth stability changes in the Altai Mountain Taiga Forest from 1982 to 2018.A multivariate linear model is employed to analyze the impacts of climatic conditions,vegetation productivity,vegetation height,and vegetation types.Findings reveal that:(1)There was a significant interannual increasing trend in thermal conditions,characterized by Potential Evapotranspiration(PET),over the past 38 years,with low stability;conversely,interannual variation in water conditions,characterized by Saturated Water Vapor Pressure Deficit(VPD),exhibits minor trends,with PET primarily influencing Taiga Forest growth stability.(2)Growth stability in the Taiga Forest is lower at higher altitudes and higher at lower altitudes,primarily influenced by vegetation productivity indicated by average LAI.For dense forests(Mean LAI>2.091),the higher productivity correlates with lower stability,whereas for sparse forests(Mean LAI≤2.091),the higher productivity correlates with higher stability.Additionally,the biological factors′influence surpasses that of climatic factors.Amidst climate change,Taiga Forest growth in high-altitude areas with lower stability may decline,while Taiga Forest with higher productivity assumes more ecosystem functions,exacerbating threats due to decreased stability.As a crucial ecological security barrier,future Altai Mountain Taiga Forest protection should prioritize areas with high altitude and productivity to mitigate climate change′s impact on regional ecological security.

关 键 词：泰加林 气候变化 叶面积指数(LAI) 生长稳定性 基尼系数 

分 类 号：Q948[生物学—植物学]