2000—2019年中国南方竹林区水分利用效率时空特征及驱动机制  

Spatiotemporal patterns and driving mechanisms of water use efficiency in bamboo forest areas in southern China from 2000 to 2019

作　　者：梁家凤 赵银兵 栾军伟 刘世荣[4] 倪忠云 周国李 陈馨熠 罗宇豪 LIANG Jiafeng;ZHAO Yinbing;LUAN Junwei;LIU Shirong;NI Zhongyun;ZHOU Guoli;CHEN Xinyi;LUO Yuhao(College of Tourism and Urban-Rural Planning,Chengdu University of Technology,Chengdu 610059,China;State Key Laboratory of Urban and Regional Ecology,Research Center for Eco-Environmental Sciences,Chinese Academy of Sciences,Beijing 100085,China;Institute of Resources and Environment,International Center for Bamboo and Rattan,Key Laboratory of National Forestry and Grassland Administration/Beijing for Bamboo&Rattan Science and Technology,Beijing 100102,China;Key Laboratory of Forest Ecology and Environment,China′s National Forestry and Grassland Administration,Institute of Forest Ecology.Environment and Protection,Chinese Academy of Forestry,Beijing 100091,China)

机构地区：[1]成都理工大学旅游与城乡规划学院,成都610059 [2]中国科学院生态环境研究中心城市与区域生态国家重点实验室,北京100085 [3]国际竹藤中心竹藤资源与环境研究所国家林业和草原局/北京市共建竹藤科学与技术重点实验室,北京100102 [4]中国林业科学研究院森林生态环境与自然保护研究所国家林业和草原局森林生态环境重点实验室,北京100091

出　　处：《生态学报》2023年第12期5150-5161,共12页Acta Ecologica Sinica

基　　金：十四五重点研发计划课题“典型森林生态系统碳汇提升经营技术与增汇潜力”(2021YFD2200405);国家林业和草原局/北京市共建竹藤科学与技术重点实验室开放基金(ICBR-2020-16);城市与区域生态国家重点实验室开放基金(SKLURE2022-2-6);四川省社科重点研究基地国家公园研究中心项目(GJGY2022-ZD004)。

摘　　要：水分利用效率(Water Use Efficiency,WUE)是深入理解生态系统碳、水循环及两者耦合关系的重要指标,然而我国重要森林类型之一的竹林的WUE时空格局及其驱动机制研究不足。通过MODIS净初级生产力(NPP)和蒸散(ET)数据得到竹林区WUE,采用线性趋势法计算WUE年际变化率表征变化趋势,并应用地理加权回归(GWR)模型分析了WUE与气候和地形等10个驱动因子的关系,探究了中国南方竹林区近20年间(2000—2019)WUE驱动机制。结果表明:(1)2000—2019年中国南方竹林区WUE多年均值为0.89 gC m^(-2)mm^(-1),呈显著下降趋势,下降速率为0.0028 gC m^(-2)mm^(-1)a-1,ET上升速度大于NPP上升速度是造成WUE下降的主要原因;WUE呈南高北低的空间分布格局,83.5%区域的WUE呈下降趋势。(2)基于GWR模型的WUE驱动力分析发现,WUE变化最强的驱动因子是CO_(2)浓度和年降水量,而海拔、坡度等地形因子的驱动作用较弱,人类活动因子在大部分区域对WUE存在较小的正向驱动作用。明晰了我国竹林区近20年间对气候与环境变化的响应规律,为制定竹林适应性管理措施,并更好地发挥竹林在缓解气候变化方面的作用提供科学依据。Water use efficiency(WUE)is an important index to deeply understand the ecosystem carbon and water cycle and their coupling relationship.However,as one of the important forest types in China,the research on the WUE spatio-temporal pattern and its driving mechanism of bamboo forest is insufficient.In this study,we obtained WUE in bamboo forest areas from MODIS net primary productivity(NPP)and evapotranspiration(ET)data,used the linear trend method to calculate the interannual rate of change of WUE to characterize the change trend,and applied the geographically weighted regression(GWR)model to analyze the relationship between WUE and 10 driving factors,including climate and topography,to explore the WUE driving mechanisms in bamboo forest areas in southern China in 2000—2019.The results showed that:(1)the multi-year mean value of WUE in the bamboo forest areas of southern China was 0.89 gC m^(-2)mm^(-1)from 2000 to 2019,showing a decreasing trend,with an average annual decrease of 0.0028 gC m^(-2)mm^(-1),because the rising rate of evapotrans piration was greater than that of net primary productivity;WUE showed a spatial distribution pattern of high in the south and low in the north,with 83.5%of the area showing a decreasing trend.(2)The analysis of WUE drivers based on the GWR model showed that the strongest drivers of WUE were CO2 concentration and annual precipitation,while the topographic factors such as elevation and slope had a weaker driving effect,and human activities had a smaller positive driving effect on WUE in most areas.This study clarifies the response patterns of bamboo forests to climate and environmental changes in China,and provides a scientific basis for the development of adaptive management measures for bamboo forests,and for better utilization of bamboo forests in mitigating climate change.

关 键 词：水分利用效率 气候变化 MODIS时序数据 地理加权回归模型 地貌分区 

分 类 号：S718.5[农业科学—林学]