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草业学报 ›› 2021, Vol. 30 ›› Issue (3): 1-14.DOI: 10.11686/cyxb2020143

• 研究论文 • 上一篇    下一篇

近20年新疆荒漠草地动态变化及其对气候变化的响应

陈宸1(), 井长青1(), 邢文渊2, 邓小进1, 付皓宇1, 郭文章1   

  1. 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
  • 收稿日期:2020-03-25 修回日期:2020-05-07 出版日期:2021-03-20 发布日期:2021-03-09
  • 通讯作者: 井长青
  • 作者简介:Corresponding author. E-mail: jingchangqing@126.com
    陈宸(1994-),男,山东聊城人,在读硕士。E-mail: sdaucc@126.com
  • 基金资助:
    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)

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

Chen CHEN1(), Chang-qing JING1(), Wen-yuan XING2, Xiao-jin DENG1, Hao-yu FU1, Wen-zhang GUO1   

  1. 1.College of Grassland and Environment Sciences,Xinjiang Agricultural University,Key Laboratory of Grassland Resources and Ecology of Xinjiang,Urumqi 830052,China
    2.Urumqi Meteorological Satellite Ground Station,Urumqi 830011,China
  • Received:2020-03-25 Revised:2020-05-07 Online:2021-03-20 Published:2021-03-09
  • Contact: Chang-qing JING

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。

关键词: 荒漠草地, 植被NDVI, 气象因子, 动态变化, 响应

Abstract:

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 than that driven by temperature. It was concluded that the dynamic changes of desert grassland in Xinjiang were the result of the combined effects of multiple meteorological factors. Temperature and precipitation were the main factors of influence, and of these the impact of precipitation was more obvious. Water status is the decisive factor driving dynamic vegetation change in desert grassland.

Key words: desert grassland, vegetation NDVI, meteorological factors, dynamic change, response