近20年新疆荒漠草地动态变化及其对气候变化的响应  

Desert grassland dynamics in the last 20 years and its response to climate change in Xinjiang

作　　者：陈宸 井长青[1] 邢文渊 邓小进 付皓宇 郭文章 CHEN Chen;JING Chang-qing;XING Wen-yuan;DENG Xiao-jin;FU Hao-yu;GUO Wen-zhang(College of Grassland and Environment Sciences,Xinjiang Agricultural University,Key Laboratory of Grassland Resources and Ecology of Xinjiang,Urumqi 830052,China;Urumqi Meteorological Satellite Ground Station,Urumqi 830011,China)

机构地区：[1]新疆农业大学草业与环境科学学院,新疆草地资源与生态重点实验室,新疆乌鲁木齐830052 [2]乌鲁木齐气象卫星地面站,新疆乌鲁木齐830011

出　　处：《草业学报》2021年第3期1-14,共14页Acta Prataculturae Sinica

基　　金：国家自然科学基金项目(41561021);中亚大气科学研究基金和新疆气象局高层次骨干人才培养计划(CAAS201917)资助。

摘　　要：荒漠草地是干旱半干旱区陆地生态系统的关键类型,具有重要的生态作用,对气候变化和人类活动敏感。通过确定新疆荒漠草地NDVI阈值,提取荒漠草地范围,结合归一化植被指数(normalized difference vegetation index,NDVI)、植被净初级生产力(net primary productivity,NPP)、气象因子等数据,利用一元线性回归模型、相关性分析等方法,从不同的时间和空间尺度对1999-2018年新疆荒漠草地的动态变化及其对不同驱动因子的响应进行研究。结果表明:1)新疆南北疆荒漠草地分布存在差异,研究期间总体面积减少明显,平均NDVI稳定,NPP呈上升趋势。2)全年及7-8月气象因子变化趋势不同,南北疆存在显著差异,全疆大部分区域呈现气温升高、降水增多趋势。3)从时间变化看,降水量、大型蒸发量和平均风速是新疆荒漠草地年际NDVI的重要影响因子,水分条件对生长季NDVI的影响更为明显;年蒸发量与荒漠草地NPP呈显著负相关关系,平均风速、降水量与荒漠草地NPP存在一定相关性。4)从空间相关性来看,气温、降水在空间上与荒漠草地NDVI、NPP呈正相关的面积较大,且降水影响面积更大。研究表明,新疆荒漠草地植被动态变化是多种气象因子综合作用的结果,气温、降水是主要的影响因子,其中降水影响更为明显,水分条件是荒漠草地动态变化的决定因素。Desert grassland is a key type of land ecosystem in arid and semi-arid areas.Desert grassland has an important ecological role and is sensitive to human activities and global change.In this paper,we studied the dynamic changes in desert grassland in Xinjiang and the responses to different driving factors on different time scales and spatial scales for the period 1999-2018.We first extracted the coverage of desert grassland in Xinjiang and determined the desert grassland threshold values for normalized difference vegetation index(NDVI).Then,we used a unitary linear regression model,correlation analysis and other methods to combine NDVI,net primary productivity(NPP),meteorological factors and other data to study the changes in area of desert grassland and their driving mechanisms.The results showed that:1)There were differences in the distribution of desert grasslands in the North and South of Xinjiang during the study period.Over all the area of desert grassland decreased significantly,while the average NDVI was relatively stable,and the NPP showed an upward trend.2)Meteorological factors over the study period showed different trends at different times of the year.In July and August there were significant differences between North and South Xinjiang.Temperature and precipitation in most regions of Xinjiang increased between 1999 and 2018.3)In terms of interannual changes,precipitation,high evaporation events,and average wind speed are the important factors affecting NDVI of desert grasslands in Xinjiang.The effect of water conditions on NDVI in the growing season is more obvious.There is a significant negative correlation between annual evaporation and desert grassland NPP,and average wind speed and precipitation have a correlation with desert grassland NPP.4)In terms of spatial correlation,the area where temperature and precipitation are positively correlated with the NDVI and NPP of desert grassland is larger than that dominated by other factors,and the area where the precipitation effect dominates is larger tha

关 键 词：荒漠草地 植被NDVI 气象因子 动态变化 响应 

分 类 号：S812[农业科学—草业科学]