长江中下游平原区生态保护红线的划定——以江苏省为例

科学划定生态保护红线（Ecological Protection Red Line，EPRL）并严格保护是中国政府建设生态文明的重要战略举措，对国土空间可持续发展具有重要意义。通过解析生态保护红线制度的内涵、目标与划定标准提出生态保护红线的4项基础性问题。针对长江中下游平原面临的生物多样性减少、生境斑块破碎化以及农业与生态空间冲突等问题，考虑生态保护红线的区域差异性，以江苏省为研究区，结合区域特征利用生境维持、气候调节、水源涵养、粮食供给、土壤保持5项生态系统服务功能，基于生态安全格局研究框架探讨了相应的生态保护红线划定方法。研究结果表明：①江苏省生态源地主要由区域内河流、湖泊、滩涂与林地构成，各项生态系统服务功能空间格局差异化显著，限于农田覆盖范围广泛与水系网络结构发达，源地斑块破碎化现象严重。②江苏生态保护红线主要由湿地、林草地、农用地等地类构成，红线核心区以湿地为主，廊道与节点则以农用地为主。生态保护红线可根据源地景观规模分为3级，其中I级EPRL占比达72.87%，可基本代表核心红线图斑。③生态廊道与生态节点的设置有助于提高生境图斑的连通性，江苏省生态廊道共47条，包括33条关键生态廊道与14条潜在生态廊道，总长度分别为1296.27km、1726.33km。研究结果可为长江中下游平原的生态保护红线划定创新思路，并希冀对生态保护红线制度约束下的国土空间管控与管制制度改革具有借鉴价值。

Reflection on delimiting ecological protection red line (EPRL) in Middle-Lower Yangtze Plain: A case study of Jiangsu Province

Scientifically delineating and strictly protecting the ecological protection red line (EPRL) are essential strategic measures for the Chinese government to construct ecological civilization. It is of considerable significance to promote the sustainable development of land space. This paper puts forward four fundamental issues of the EPRL by analyzing the connotation, objectives, and delimitation criteria of the EPRL system. Aiming at the problems of biodiversity reduction, habitat patch fragmentation, and conflict between agriculture and ecological space in Middle-Lower Yangtze Plain, the regional differences of the EPRL are considered. Taking Jiangsu Province as the study area, this paper discussed the corresponding EPRL delimitation method based on the framework of ecological security pattern, considering five ecosystem service functions of habitat maintenance, climate regulation, water conservation, food supply, and soil conservation. The results show that 1) eco-source areas in Jiangsu Province mainly compose of rivers, lakes, tidal flats and woodlands, and the spatial patterns of ecosystem services are significantly different. Limited by the extensive coverage of farmland and the developed network structure of the river system, the source patches are severely fragmented. 2) Jiangsu EPRLs are mainly composed of wetland, forest, and grassland, agricultural land, etc. The core area of the EPRL is mainly wetland, while the corridors and nodes are mainly agricultural lands. The EPRL can be divided into three levels according to the landscape size of eco-source, of which grade I EPRL accounts for 72.87% and can basically represent the core EPRL patches. 3) The establishment of ecological corridors and ecological nodes helps to improve the connectivity of habitat patches. There are 47 ecological corridors in Jiangsu Province, including 33 critical ecological corridors and 14 potential ecological corridors, with total lengths of 1296.27 km and 1726.33 km, respectively. The results can provide innovative ideas for the EPRL delimitation in Middle-Lower Yangtze Plain and hope to have reference value for the system reform of land space management and control under the restriction of the EPRL system.