城市生态用地需求测算研究进展与展望

Research progress and prospect on measuring urban ecological land demand

作为城市地域自然生态系统服务供给的基本载体,生态用地基于土地利用/土地覆被的内在关联将人类社会发展与自然生态演替耦合关联在一起,已成为统筹解决城市建设扩展与自然生态保护矛盾的重要综合途径;城市生态用地的需求测算直接决定供需均衡分析结果,是城乡统筹生态用地规划与管理的关键环节。本文在系统梳理生态用地概念内涵的基础上,对比分析了生态需求与生态用地需求的概念异同;提出基于空间与功能的城市生态用地需求测算概念框架,并据此将已有测算方法归并为经验判定法、生态系统服务法、空间格局法3大类,从综合性、代表性、阈值与规模、位置等方面对比分析了法定定额法、历史趋势预判法、生态足迹法、碳氧平衡法、生态安全格局法等具体方法的基本特征及其优缺点;最后将下一步研究的重点趋向概括为基于土地生态功能的城市生态用地分类、基于土地生态格局的城市生态用地效益综合测算、基于多目标情景的城市生态用地功能综合权衡、基于生态用地供需平衡分析的城市生态腹地识别4个方面。

As a fundamental supplying carrier of natural ecosystem services in urban areas, ecological land couples human social development and natural ecological succession based on the inherent correlation between land use and land cover. Thus spatial optimization of ecological land has gradually become a vital and comprehensive approach to address the conflicts between urban development and ecological conservation. The measurement of urban ecological land demand can directly determine the equilibrium between supply and demand for ecological land, which is a significant step in overall planning and management of urban ecological land. After a systematic review of the concept of ecological land, the similarities and differences between ecological demands and ecological land demands are discussed in this paper. Then a conceptual space-function framework for measuring urban ecological land demand is proposed. Within this framework methodologies of measuring urban ecological land fall into three categories, namely experimental predication, ecosystem services and spatial patterns. In details, the category of experimental predication includes legal quota and historical trend methods. The methods of ecological footprint and carbon-oxygen equilibrium belong to the category of ecosystem services, while the method of ecological security pattern is included in the spatial patterns category. By methodological principles analysis, the advantages and disadvantages of these methods are comparatively discussed and summarized in terms of comprehensiveness, representativeness, threshold and area, and location. Finally, four key directions of future research are presented： urban ecological land classification related to ecological functions, comprehensive efficiency measurement on urban ecological land focusing on spatial patterns of ecological land, functional tradeoff of urban ecological land using multi- target scenarios, and urban ecological hinterland recognition based on ecological land supply- demand balance analysis.