全球林线动态和灌木扩张对气候变化响应的研究进展

摘要：

高纬度、高海拔地区是受全球升温影响最明显的地区之一.林线作为重要的生态界限,其过渡带上的灌丛和草甸以及苔原地区受温度、降水和强风的影响十分显著.近年来,林线移动和灌木生长的动态变化已经作为一个衡量全球气候变化的重要指标.大量研究利用重复摄影、长期监测和树木年轮学等的方法,证明环北极和高山地区林线上移和灌木覆盖增加.本文综述了:1)林线动态和灌木覆盖的现状;2)影响因素,包括气候因素和非气候因素;3)植被变化对气候的反馈以及对生态系统的影响.在全球,特别是环北极地区植物生产力都有不同程度的增加以及“绿化”的趋势,植被覆盖增加是这些现象最主要的原因之一.全球变暖导致积雪分布机制改变,永冻层土壤融化释放CO2,苔原火灾以及人类活动和草食动物的数量等都会影响林线移动和灌木覆盖.同时,林线移动和灌木扩张也会对能量流动、区域气候、土壤养分以及生态系统功能和结构产生重要反馈.为了更准确地预测气候变化对林线的影响,可以进一步开展不同形式林线(过渡型、突变型,岛型,高山矮曲林等)对全球变暖的响应及反馈.

High latitude and high altitude regions are the regions most affected by global warming.Treeline is a critical ecological boundary,the shrublands and meadows along the transition zone,and tundra areas are significantly affected by temperature,precipitation,and strong winds.In recent years,dynamic changes in treeline shift and shrub growth have become an important indicator of global climate change.Many studies have demonstrated that forest line upshifts and shrub cover increases in subarctic and alpine areas using repeated photography,long-term monitoring,and dendrology.This paper reviews:1)the current of treeline dynamics and shrub cover;2)the influencing factors,including climatic factors and non-climatic factors;3)the feedback of vegetation change to climate and its impact on the ecosystem.The increase in vegetation cover is one of the major reasons for increased plant productivity and thegreeningtrend globally,especially in the subarctic.Global warming resulting in changes in snow distribution,increased CO2 release due to permafrost soil melting,tundra fires,human activities and the number of herbivores affect treeline shift and shrub cover.At the same time,treeline shift and shrub expansion also have important feedbacks on energy flow,regional climate,soil nutrients,and ecosystem function and structure.In order to predict the impact of climate change on treelines more accurately,the response and feedback of different types of treelines(diffuse,abrupt,island,krummholz)to global warming could be further developed.

作者：

王晓春 杨婧雯 张秋良

Wang Xiaochun;Yang Jingwen;Zhang Qiuliang(School of Forestry,Northeast Forestry University,Harbin 150040,China;College of Forestry,Inner Mongolia Agricultural University,Hohhot 010018,China)

机构地区：

东北林业大学林学院 内蒙古农业大学林学院

出处：

《betway官方app 学报：自然科学版》 CAS 北大核心 2021年第6期1-10,F0002,共11页

Journal of Henan Normal University(Natural Science Edition)

基金：

国家自然科学基金(41877426) 中央高校基本科研业务费(2572017DG02).

关键词：

林线 灌木 气候变化 反馈

treeline shrub climate change feedback

分类号：

S718 [农业科学—林学]

全球林线动态和灌木扩张对气候变化响应的研究进展.pdf