植物生态学报 ›› 2023, Vol. 47 ›› Issue (1): 51-64.DOI: 10.17521/cjpe.2021.0500

所属专题: 遥感生态学 青藏高原植物生态学:遥感生态学

• 研究论文 • 上一篇    下一篇

青藏高原植被绿度变化及其对干湿变化的响应

朱玉英1, 张华敏2, 丁明军1,3,*(), 余紫萍1   

  1. 1江西师范大学地理与环境学院, 南昌 330022
    2江西省自然资源政策调查评估中心, 南昌 330025
    3鄱阳湖湿地与流域研究教育部重点实验室, 南昌 330022
  • 收稿日期:2021-12-31 接受日期:2022-05-12 出版日期:2023-01-20 发布日期:2022-07-15
  • 通讯作者: *丁明军(dingmj@jxnu.edu.cn)
  • 基金资助:
    第二次青藏高原综合科学考察研究项目(2019QZKK0603);中国科学院战略性先导科技专项(A类)(XDA20040201)

Changes of vegetation greenness and its response to drought-wet variation on the Qingzang Plateau

ZHU Yu-Ying1, ZHANG Hua-Min2, DING Ming-Jun1,3,*(), YU Zi-Ping1   

  1. 1School of Geography and Environment, Jiangxi Normal University, Nanchang 330022, China
    2Natural Resources Policy Investigation and Evaluation Center of Jiangxi Provincial, Nanchang 330025, China
    3Key Laboratory of Poyang Lake Wetland and Watershed Research, Ministry of Education, Nanchang 330022, China
  • Received:2021-12-31 Accepted:2022-05-12 Online:2023-01-20 Published:2022-07-15
  • Contact: *DING Ming-Jun(dingmj@jxnu.edu.cn)
  • Supported by:
    Second Tibetan Plateau Scientific Expedition and Research (STEP) Program(2019QZKK0603);Strategic Priority Research Program of Chinese Academy of Sciences(XDA20040201)

摘要:

青藏高原是全球气候变化的敏感区, 特殊的自然环境孕育了极端脆弱的植被及其生态系统, 已成为研究植被对气候变化响应的一个理想区域。植被易受气候变化的影响且响应可能因季节和植被类型而异。该研究将标准化降水蒸散指数(SPEI)和MODIS归一化植被指数(NDVI)分别作为干湿度和植被绿度指标, 采用Sen’s斜率估计、BFAST模型和相关分析, 分析了2000-2018年青藏高原植被绿度变化的时空格局特征, 并探讨了植被绿度对干湿变化的响应。结果表明: 2000-2018年青藏高原植被绿度呈上升趋势, 但变化速率空间差异显著。大部分高原地区植被绿度于2012-2015年间存在突变, 突变后普遍呈上升趋势, 以藏北地区最为突出。青藏高原植被生长季NDVI与不同时间尺度SPEI整体呈正相关关系, 且在生长季的中后期相关性逐渐增强。青藏高原植被对SPEI的响应表现出一定的年内周期性, 草本植被(草甸和草原)区尤为显著。相对于森林和灌丛植被, 草本植被对SPEI响应更为敏感, 且在生长季的不同阶段对不同时间尺度的SPEI的响应存在明显差异。

关键词: 青藏高原, 归一化植被指数, 标准化降水蒸散发指数, 植被类型, 响应

Abstract:

Aims The Qingzang Plateau is highly sensitive to global climate change. The unique natural conditions lead to extremely vulnerable vegetation and its ecosystem, making this region ideal for analyzing responses of vegetation to climate change. However, different types of vegetation may have different responses to seasonal variability. This study explores and analyzes vegetation changes on the Qingzang Plateau and the response characteristics of different vegetation types to moisture variations (i.e., dry and wet conditions) during the growing season.
Methods The standardized precipitation evapotranspiration index (SPEI) and the normalized difference vegetation index (NDVI) were used here as indicators of dry humidity and vegetation greenness, respectively. Sen’s slope estimation, BFAST model and correlation analyses were used to quantify the spatiotemporal variability of vegetation greenness and its response to drought-wet variations on the Qingzang Plateau from 2000 to 2018.
Important findings Results show that vegetation greenness on the Qingzang Plateau generally increased over the time period analyzed. Additionally, the rate of spatial variation reveals striking regional differences. The breaks of vegetation greenness occurred in most regions during 2012-2015, after which there was general upward trend after the breaks, the various trend is most apparent in northern Qingzang Plateau. Positive correlations between NDVI and multi-time scale SPEI were observed in most regions during the growing season, and gradually increased in the middle and latter part of the growing season. The responses of each vegetation type to SPEI also showed a distinct periodicity during the year. Meadow and steppe areas were more sensitive to multi-time scale SPEI than forest and shrub areas, and this response differed significantly during different stages of the growing season and for different time scales of SPEI.

Key words: Qingzang Plateau, normalized difference vegetation index (NDVI), standardized precipitation evapotranspiration index (SPEI), vegetation type, response