Laboratory for Earth Surface Processes, Ministry of Education, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China; Key Laboratory for Environmental and Urban Sciences, School of Urban Planning & Design, Shenzhen Graduate School, Peking University, Shenzhen 518055, China.
Key Laboratory for Environmental and Urban Sciences, School of Urban Planning & Design, Shenzhen Graduate School, Peking University, Shenzhen 518055, China.
Sci Total Environ. 2021 May 15;769:144297. doi: 10.1016/j.scitotenv.2020.144297. Epub 2020 Dec 24.
Understanding the impacts of climate change and human activities on vegetation is of great significance to the sustainable development of terrestrial ecosystems. However, most studies focused on the overall impact over a period and rarely examined the time-lag effect of vegetation's response to climatic factors when exploring the driving mechanisms of vegetation dynamics. In this study, we identified key areas driven by either positive or negative human activities and climate change. Taking the three karst provinces of southwest China as the case study area, a Leaf Area Index (LAI)-climate model was constructed by quantifying the time-lag effect. Then the associated residual threshold was calculated to identify the vegetation change areas dominated by human activities and climate change. The results showed that, during the implementation period of ecological restoration projects from 1999 to 2015, positive impact areas of human activities were mainly distributed among the implementation areas of ecological restoration projects, accounting for 5.61% of the total area. For another, the negative impact areas were mainly distributed across the mountainous area of Yunnan Province, accounting for 1.30% of the total area. Karst landform had the greatest influence on the areas dominated by positive human activities, whereas both topography and karst landform significantly affected the areas dominated by negative human activities. Urban development level had the greatest impact on the areas dominated by climate change. The outcomes of this study provided scientific supports for the sustainable development of ecological restoration projects in China's karst region.
了解气候变化和人类活动对植被的影响，对于陆地生态系统的可持续发展具有重要意义。然而，大多数研究都集中在一段时间内的整体影响上，很少在探索植被动态的驱动机制时，研究植被对气候因素的响应的时滞效应。在本研究中，我们确定了由人类活动和气候变化驱动的关键区域。以中国西南三省的喀斯特地区为例，构建了一个叶面积指数（LAI）-气候模型，通过量化时滞效应来量化其对植被的影响。然后计算相关的剩余阈值，以识别主要由人类活动和气候变化驱动的植被变化区域。结果表明，在 1999 年至 2015 年生态恢复项目实施期间，人类活动的积极影响区域主要分布在生态恢复项目的实施区域内，占总面积的 5.61%。而另一方面，消极影响区域主要分布在云南省的山区，占总面积的 1.30%。喀斯特地貌对积极人类活动主导区域的影响最大，而地形和喀斯特地貌都显著影响了消极人类活动主导区域。城市发展水平对气候变化主导区域的影响最大。本研究的结果为中国喀斯特地区生态恢复项目的可持续发展提供了科学支持。
