基于生态系统服务与引力模型的珠三角生态安全与修复格局研究

随着我国城镇化的快速推进,大型城市群及周边区域的生态环境问题日益突显。为了促进区域生态保护、生态修复以及精细化生态管理,空间尺度上的区域生态安全和修复格局的识别必不可少。选取珠三角地区为研究对象。首先,基于InVEST生态模型计算区域关键生态系统服务,并根据SOFM神经网络模型识别以林地为主的36个生态源地,约占区域总面积的29.56%。其次,基于最小阻力路径模型识别141条关键生态廊道(1900 km),10个承接生态流流动的生态节点以及2776 km²处于生态过渡地段的高优先级生态修复区。最后,依据引力模型判定的生态廊道重要性,将重要生态源地及其辐射区域整合形成东北部、西北部、东南部、西部和南部5个生态区。由此,提出以生态源地为核心、以生态廊道为主轴、以生态节点为承接点、以生态障碍点为修复区的珠三角区域生态安全和修复格局,并对各类别生态要素提出相应生态修复与管理措施,有利于解决大型城市群跨区域的共性生态环境问题。

Ecological security and restoration pattern of Pearl River Delta, based on ecosystem service and gravity model

With the rapid urbanization in China, ecosystems and relevant ecological issues of large metropolitan areas have increasingly become a source of concern. To promote ecological protection, restoration, and refined management, it is necessary to analyze and identify regional ecological security and restoration patterns. Here, we used the Pearl River Delta region as the study area. First, six key ecosystem services were quantitatively modeled and mapped based on the InVEST ecological tool. Some parts with high ecosystem services were identified as ecological sources according to the self-organization feature map (SOFM) neural network model. Second, a resistance surface of ecological flow was developed by integrating the factors of surface land cover, landscape connectivity, and human activities. Subsequently, the minimum cumulative path model was used to identify the basic trend of the regional ecological corridor and the spatial distribution of ecological nodes. Based on this analysis, the gravity model was applied to classify the importance of ecological zones and ecological corridors according to the correlation between ecological sources and extract ecological obstacle points. Based on the above analysis, 36 ecological sources, mainly forest land, were identified, which accounted for approximately 29.56% of the total area. In addition, based on the least resistance path model, we identified 141 key ecological corridors (1900 km), 10 ecological nodes connected with ecological flow, and 2776 km² high-priority ecological restoration area. Finally, the key ecological sources and their radiating areas were integrated to form five ecological zones in the northeast, northwest, southeast, west, and south, according to the importance level of the ecological corridors determined by the gravity model. Therefore, this study proposed a regional ecological security and restoration pattern of the Pearl River delta, which took ecological source as the core, ecological corridor as the main axis, ecological node as the connecting point, and ecological obstacle point as the restoration area. Corresponding ecological restoration and management measures were also put forward for various ecological elements, which would be beneficial for solving regional ecological issues in large metropolitan areas.