黄河上游甘蒙柽柳生长对极端旱涝的响应  

Growth responses of Tamarix austromongolica to extreme drought and flood in the upper Yellow River basin

作　　者：方欧娅 张永[2] 张启 贾恒锋 FANG Ou-Ya;ZHANG Yong;ZHANG Qi;JIA Heng-Feng(State Key Laboratory of Vegetation and Environmental Change,Institute of Botany,Chinese Academy of Sciences,Beijing 100093,China;Key Laboratory of Land Surface Pattern and Simulation,Institute of Geographic Sciences and Natural Resources Research,Chinese Academy of Sciences,Beijing 100101,China;and 3University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院植物研究所植被与环境变化国家重点实验室,北京100093 [2]中国科学院地理科学与资源研究所陆地表层格局与模拟院重点实验室,北京100101 [3]中国科学院大学,北京100049

出　　处：《植物生态学报》2021年第6期641-649,共9页Chinese Journal of Plant Ecology

基　　金：国家自然科学基金(31700412);第二次青藏高原综合科学考察研究项目(2019QZKK0301)。

摘　　要：青藏高原黄河上游河岸带是典型的生态脆弱区,然而近年来气候变暖加剧了该地极端旱涝事件的频繁发生,高原河岸带生态脆弱区植被是否能够应对极端旱涝事件的干扰成为流域生态环境管理工作所关注的重点问题。为了研究黄河上游河岸林中主要树种对极端旱涝的响应,该研究选取青海省同德县和兴海县3处河岸林中的47株甘蒙柽柳(Tamarix austromongolica),分别从树干面向邻近山体一侧及与之垂直的一侧分别获取1根树轮样本,分析其历史生长。通过对比两个方向上的生长速率判断甘蒙柽柳是否受到地质灾害影响从而将其划分为受伤组和对照组,分析两组甘蒙柽柳在过去63年中径流极值年的抵抗力状况及两个方向的生长差异。研究发现,甘蒙柽柳对干旱和洪涝均有着很强的抵抗力,河岸带多样化的水分来源有助于甘蒙柽柳在极端干旱环境中较好地生长;但洪涝伴随泥石流等地质灾害的频发使甘蒙柽柳面向山体侧面受到严重的生长抑制,表现出显著的方向性差异,从而影响甘蒙柽柳的形态。较长的创伤恢复期带来的遗留效应可能造成甘蒙柽柳对外界干扰的较高敏感性。研究黄河上游甘蒙柽柳生长对极端旱涝的响应,将有助于评估生态脆弱区生态弹性过程,同时为高原河岸带生态建设和恢复提供科学依据。Aims The riparian forests in the upper reaches of the Yellow River are typically fragile ecologically.However,the frequent extreme hydrological events induced by climate warming may pose increasing threats to ecological stability and security of this fragile ecosystem type.The ecological resilience and adaptation of riparian forests to extreme hydrological events are of key considerations in eco-environmental management of river basins.This paper aims to determine how Tamarix austromongolica,a major tree species in riparian forests of the upper Yellow River basin,responds to extreme drought and flood and explain the resistance and morphology of these riparian plants against environmental stresses.Methods We selected 47 Tamarix austromongolica trees from three sampling sites along the upper reaches of the Yellow River.Two mutually perpendicular cores were taken from the trunk of the each sampling tree for estimation of the past annual growth,one from the direction facing the slope and the other along the contour of the nearby mountain.We compared the tree-ring growth between cores from the two sides and grouped them according to whether the growth was strongly affected by geohazards.We analyzed the resistance of the two groups to extreme hydrological events during the past 63 years.The statistical growth difference between two sampling directions from each group was performed by using paired test.Important findings Tamarix austromongolica trees were found to be very resistant to extreme drought events.The diverse sources of water in riparian zones attributed to their stable growth,which helps enhance their tolerance to hydrological drought events.But the trees injured by geohazards appeared to be more severely affected by droughts.The legacy effect in trauma-associated recovery might initiate high sensitivity to interferences.Moreover,T.austromongolica trees are adapted to a wide range of water conditions and their growth did not appear to be substantially affected by flooding.Well-watered condition along with ful

关 键 词：生态弹性 抵抗力 生态脆弱区 干旱 洪涝 气候变化 甘蒙柽柳 

分 类 号：S793.5[农业科学—林木遗传育种]