基于生态安全格局的城市大规模绿化方法——北京百万亩平原生态造林

A MILLION MU OF AFFORESTATION IN BEIJING PLAIN AREA BASED ON ECOLOGICAL SECURITY PATTERN

为改善北京市的生态和环境,北京市政府提出在2012—2016年五年内营造百万亩生态林工程。在土地有限,农业、城市建设和生态用地矛盾非常突出的情况下,在什么地方造林和造什么样的林子,才能有效发挥大规模造林的综合功能,变成为一个核心的问题。文章分析了北京以绿化隔离带为主要特征的传统造林绿化方式的不足,其核心问题是无法发挥绿地应有的综合生态系统服务功能,并提出基于生态安全格局的三种绿化造林模式,即以北京市生态安全格局为本底,构建保证关键生态过程的生态廊道网络;建立以居民游憩为核心目标的游憩绿道网络;形成与农业生产和未来城市发展相结合的农田林网。再根据土地利用特征,结合三种模式,以土地斑块的形式落实在北京小平原区,从而实现了具有生产、调节、生物多样性保护和文化及游憩等综合生态系统服务功能的生态基础设施。

In order to improve the ecological environment of Beijing, the municipal government proposed a project to build one million mu of forest in the next five years. Under the conditions of limited land and serious conflicts among agriculture, urban construction, and ecological conservation, where and how to afforest in order to bring role of large scale afforestation into full play becomes the key issue. This paper points out the shortcomings of the conventional strategies of afforestation and greening, mainly the green buffer, in Beijing, by proving that it is ineffective in improving the ecological situation. And then it presents three types of large scale afforestation based on ecological security pattern that aiming at achieving comprehensive ecosystems services: the overall ecological corridors based on the regional ecological security pattern in the plain area of Beijing, the greenway network that focuses on fulfilling the recreational need of the residents and tourists, and the agroforestry network that integrates agricultural production and potential urban expansion of the future. According to the characteristics of land use, combined with above three models, it will be implemented in the small plain area of Beijing in the form of land patches, thus realizing the ecological infrastructure with integrated ecosystem services such as production, regulation, biodiversity conservation, as well as culture and recreation.