20世纪90年代以来中国生态空间演化的时空格局和梯度效应

改革开放以来中国经济和城市化的快速发展促使生产和生活空间挤占大量生态空间,系统认识和评估我国生态空间演化的宏观格局和过程对于生态文明建设具有重要的理论和现实意义。为揭示全国生态空间变化的时空过程,在对生态空间内涵进行界定的基础上,结合全国尺度时序土地利用数据构建生态空间分类体系,并评估1990-2015年中国生态空间演化特征。结果表明：1990-2015年中国生态用地面积持续减少,主要向半生态用地转变,发生在重要的粮食生产区域及周边;半生态用地面积波动明显,前期主要表现为不断扩张,后期大量转换为弱生态用地,发生在主要城市群地区;弱生态用地持续扩张,与城镇化进程不断加速相关。中国生态空间演变过程表现出一定的区域差异和梯度效应,不同区域生态空间变化发生的拐点时间有所不同,呈现"自东向西、由南到北"的3级梯度特征,区域生态空间状况与经济发展战略及生态空间管控具有较强的相关性。本研究对于国家生态空间管控近远期战略方案制订具有一定启示,建议处于不同梯度的各地区应基于区域生态空间演化所处阶段和不同驱动机制,确定分区域生态空间安全红线目标和生态空间管控方案。

Pattern and gradient effects of ecological space changes in China since 1990s

With the rapid development of economy and urbanization in China since the Reform and Opening-up in 1978, the living and industrial spaces have been occupied by numerous ecological space. Therefore, it calls for an overall evaluation of ecological space changes in the background of ecological civilization construction. First, the ecological space classification was built and corresponded to the land use classification system referring to the definition of ecological space. Then, the spatio-temporal characteristics of ecological space changes between 1990 and 2015 were examined. The results indicated that the areas of ecologically-used land across China decreased continuously in 1990-2015, mainly transformed to semi-ecologically-used land, which occurred in major grain production areas and surrounding areas. The areas of semi-ecologically-used land fluctuated significantly, which was expanded in the early stage, then converted into weak-ecologically-used land in the latter stage. Relating to the acceleration of urbanization, weak-ecologically-used land continued to expand. The turning point of ecological space transformation showed certain regional differences, showing a three-level gradient from east to west and from south to north. As a result, regionally ecological space conditions shows a strong correlation with economic development strategies and ecological space governance. This study has important implications for the formulation of nationally ecological space control near-and long-term strategic plan. The study suggests that different regions within varied gradients should consider bottom line of ecological space security and its governance based on the transformation stage and its driving mechanisms.