Key Laboratory of Water Cycle and Related Land Surface Processes, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
Key Laboratory of Water Cycle and Related Land Surface Processes, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China.
J Environ Manage. 2023 Jan 1;325(Pt B):116576. doi: 10.1016/j.jenvman.2022.116576. Epub 2022 Oct 26.
Ecological engineering is an important measure to promote ecosystem adaptation and restoration to deal with environmental change and human disturbance. To assess the effectiveness of ecological construction and analyze the influencing factors of ecosystem changes in the Qinghai-Tibet Plateau (QTP), this study detected the spatial changes and dynamic hotspots of vegetation ecosystems in the ecological construction regions of the QTP (QTPE) and regions without ecological construction (QTPWE) using hot spot analysis and comprehensive dynamic degree model. Then the random forest (RF) model and geographical weighted regression model were used to study the degree and spatial heterogeneity of impacts of climate and human activities on normalized difference vegetation index (NDVI). Results showed that the vegetation restoration of the QTPE was obvious during 2001-2018 as the area of the increasing NDVI accounted for 74.15%. In addition, the effects of climate and human activities on NDVI of vegetation ecosystem showed significant spatial heterogeneity. The RF model showed that population density was the most significant factor affecting ecosystem vegetation in the QTPE, and its relative importance was between 26.1-32.6%, followed by downward shortwave radiation (7.9-16.8%). However, climate factors still had the greatest impact in the QTPWE, with the relative importance of precipitation and temperature being 45% and 15%, respectively. These findings provide a scientific basis for the restoration and management of vegetation on the QTP, and are of great significance for the deployment of future ecological engineering projects.
生态工程是应对环境变化和人类干扰、促进生态系统适应和恢复的重要措施。为评估青藏高原（QTP）生态建设的成效，分析生态系统变化的影响因素，本研究采用热点分析和综合动态度模型，检测了青藏高原生态建设区（QTPE）和无生态建设区（QTPWE）植被生态系统的空间变化和动态热点。然后，利用随机森林（RF）模型和地理加权回归模型研究了气候和人类活动对归一化植被指数（NDVI）的影响程度和空间异质性。结果表明，2001-2018 年 QTPE 的植被恢复明显，NDVI 增加面积占 74.15%。此外，气候和人类活动对植被生态系统 NDVI 的影响表现出显著的空间异质性。RF 模型表明，人口密度是影响 QTPE 生态系统植被的最显著因素，其相对重要性在 26.1-32.6%之间，其次是短波辐射（7.9-16.8%）。然而，气候因素在 QTPWE 中仍具有最大的影响，降水和温度的相对重要性分别为 45%和 15%。这些发现为青藏高原植被的恢复和管理提供了科学依据，对未来生态工程的部署具有重要意义。
