都市生态农地空间分布特征、类型及保护模式研究——以广州市为例

为应对快速城市化带来的生态保护压力,有必要界定“都市生态农地”概念。都市生态农地是指在都市系统中由农用地构成的生态性空间,一般仅限于都市区内,以较大规模和连片的空间形态融入都市功能组团。论文根据城市空间重构过程,推演出两个假设：1）都市生态农地存在圈层分布模式;2）都市生态农地生态价值与农地丰度、区位表征的供需关系相关。以广州的镇街为空间单元进行实证,结果表明：1）从区位上看,广州都市生态农地基本可分为核心圈层、过渡圈层和外围圈层,验证了假设;2）基于区位和丰度差异,将都市生态农地分为三大类12级,为制定保护政策提供分类指导;3）农地生态功能是公共产品,但在政府与市场双失效下产生了租值消散。论文在总结核心圈层的国有化模式、外围圈层的区域协调模式后,建议在过渡圈层通过设立农地发展权进行保护。

Research on Spatial Distribution,Types and Conservation Modes of Urban Ecological Land:Case Study of Guangzhou City,China

To relieve the ecological conservation pressure resulting from the rapid urbanization, it is necessary to define the concept of “urban ecological land”. Urban ecological land refers to the ecological space composed of agricultural land in the urban system, which is generally confined to the urban area, merging into the urban function group with large scale of space. According to the urban space reconstruction process of Chinese urbanization, we deduce two assumptions of urban ecological land: 1) the distribution of urban ecological land is in circular mode; 2) the ecological value of the urban ecological land depends on the relationship between demand and supply, which can be characterized by the location and abundance ratio of the ecological land. The empirical study was implemented by taking the administrative towns and streets of Guangzhou City as the minimum space unit, and the results showed that: 1) From the perspective of location, the urban ecological land in Guangzhou can be divided into the core circle, the transition circle and the outer circle, which proved the hypothesis of “circular distribution mode”. 2) The urban ecological land can be divided into three categories and twelve levels according to the indicators of location and abundance ratio, which provided the reference for making effective conservation policy. 3) The ecological functions of farmland is a public product, but its ecological rent is in the dissipation situation due to the dual failure of the government and the market. Finally, after summarizing the nationalized mode in the core circle and the regional coordination mode in the outer circle, the paper proposed to protect the transition circle by establishing farmland development right.