基于生态安全格局的岩溶山地国土空间生态修复关键区识别——以贵州省关岭县为例

Identification of key areas for the ecological restoration of karst mountainous territorial space based on the construction of ecological security pattern:A case study of Guanling,Guizhou Province

为识别县域国土空间生态修复关键区,以滇黔桂石漠化片区的贵州省关岭县为例,选取2020年国土变更调查数据、“三区三线”划定成果、高程DEM等数据,利用MSPA、景观连通性指数、电路理论等方法,通过构建生态安全格局,识别生态夹点、生态障碍点等作为生态修复关键区。结果表明:(1)识别关岭县37块生态源地(449.78 km^(2)),其受不同石漠化程度影响呈现东西部集中成片、中部零星离散的空间分布特征;(2)提取74条生态廊道(140.775 km)有效连接零散分布的源地,等级较高的生态廊道多分布在石漠化程度较低区域。共识别36处生态夹点和14处生态障碍点作为国土空间生态修复关键区,构建出“三区、两轴、多点”的国土空间生态修复格局以提高生态修复成效;(3)确定生态夹点区的生态修复面积为757.84 hm^(2),主要分布在研究区中部的低阻力区域,确定的生态障碍点区的生态修复面积为364.48 hm^(2),主要集中在研究区中部的人类活动密集区,其分布范围受人类活动与大面积、深程度石漠化的双重干扰;(4)生态修复措施需结合实际石漠化治理成效及修复成本科学推进,并根据胁迫因子的差异性提出有利于关岭县生态修复与岩溶地区环境保护的规划布局。

As one of the most ecologically fragile regions in the world,the ecosystem in the karst area is characterized by low environmental bearing capacity,high vulnerability and acute conflicts between human and land use,and thus the karst area requires strict ecological protection and effective ecological restoration.Guanling Buyi Miao Autonomous County(hereinafter referred to as Guanling county)is located in Anshun City,Guizhou Province.The karst landform accounts for 83.83%of the total land area of this county.Guanling county is a desertification area of Yunnan,Guangxi and Guizhou,with the ecological protection red line area amounting to 25.10%of the land area of this county;therefore,Chinese government listed it as a key county receiving assistance for rural revitalization.The karst mountainous area of Guanling county is distributed with a wide area of severe rocky desertification,with prominent conflicts between human and land use,and at the same time a number of national ecological zones are located there.In recent years,ecological degradation problems have caused habitat fragmentation and poor capacity for ecosystem supply in this county.Therefore,the identification of key areas for ecological restoration of national territorial space is of great significance to the ecological security of the Beipan river basin and even the Pearl river basin.The objectives of this study are:(1)to determine the importance level of ecological source areas,and to identify these areas by combining multiple factors such as MSPA,ecological protection red line,landscape connectivity analysis,etc.;(2)to construct the ecological resistance surface by synthesizing the impacts of human beings and nature,and to construct the regional ecological security pattern by using the circuit theory to extract the ecological elements such as ecological corridors,ecological pinch points,ecological barriers,etc.;(3)to classify the ecological control area based on the regional ecological background,and to propose targeted ecological restoration measures for territorial space.The results of the study show that:(1)Thirty-seven ecological source areas(449.78 km^(2)),affected by different degrees of rocky desertification,in Guanling county have been identified.These areas are contiguously concentrated in the east and west,and scattered in the central part of the county.(2)Seventy-four ecological corridors(140.775 km)have been extracted,with important ecological corridors concentrated in the areas in a lower degree of rock desertification.At the same time,36 ecological pinch-points and 14 ecological barriers have been identified as key areas for ecological restoration of territorial space,and the ecological restoration effectiveness have been improved by the construction of an ecological restoration pattern of"three zones,two axes and multiple points".(3)The ecological restoration area of the identified ecological pinch-points covers 757.84 hm^(2),which is mainly distributed in the lowresistance area in the central part of the study area.The ecological restoration area of the identified ecological barriers covers 364.48 hm^(2),which is mainly concentrated in the central part of the study area with intensive human activities,and its distribution is subjected to the double interference of human activities and extensive and severe rocky desertification.(4)Ecological restoration measures need to be promoted scientifically in combination with the actual effectiveness of rock desertification management and the restoration cost.Besides,the planning conducive to ecological restoration and environmental protection of karst areas in Guanling county should be proposed according to the variability of stress factors.