中国生态用地研究：内涵、分类与时空格局

Study of ecological land in China: conception,classification,and spatialtemporal pattern

生态用地具有重要的生态系统服务功能,是衡量一个地区国土生态环境质量好坏的"晴雨表"。在综述生态用地概念内涵基础上,划分生态用地类型、构建生态用地分类体系,基于全国土地利用变更调查数据对我国生态用地开展评估。研究表明:(1)生态用地内涵在区域尺度上主要有"生态要素决定论"、"生态功能决定论"和"主体功能决定论"3种观点,生态功能主体性应作为界定生态用地的基本准则。(2)基于生态系统服务主体功能,生态用地分类体系包括湿地、森林、草地和其他生态土地4个一级类型、19个二级类型。其中,湿地、森林、草地可统称为基础性生态用地,其他生态土地为保全性生态用地。(3)2008年我国生态用地总量7.64×106km2,约占陆域国土面积的80%,其中基础性生态用地约为5.31×106km2;基础性生态用地总量和人均基础性生态用地面积在空间上均呈现出"东南低、西北高"的特点;2002年至2008年间,我国生态用地总量与基础性生态用地面积均呈逐年下降态势,年均分别减少0.55×104km2和0.18×104km2,部分地区生态安全状况不容忽视。

As the idea and theory of sustainable utilization of natural resources has developed over recent years, research on the classification and evaluation of the ecological services of ecological land have become increasingly more important. Meanwhile, ecological land conservation has become the focus of land use research and ecological construction. Along with other important ecosystem services, such as water conservation, soil conservation, wind sheltering, sand fixation, climate regulation, environment purification and biodiversity protection, ecological land is an indicator of the eco-environmental quality of a region. With rapid economic development and accelerating urban expansion in China, the demand for land has increased, causing the loss of large areas of ecological land or land with special ecological value, such as wetlands. Consequently, it will accelerate the situation of a fragile ecosystem, and result in many environmental problems. Therefore, in order to change the trend of ecological land loss caused by blind economic development, it is necessary to re-examine the concept and meaning of ecological land and study the rational allocation of the quantitative structure and spatial patterns of ecological land, which can maximize the ecological benefit of land resources. At present, ecological land has various meanings, and is not an independent land type in existing land classification. In this study, the formation and meaning of ecological land was reviewed, a classification system was proposed, and the status and change in trend were evaluated based on national land use survey data. The conclusions were as follows ： （ 1 ） Major ecosystem services should be the basic principle used in the definition of ecological land at a regional scale, differing from other criteria, such as ecological elements or comprehensive ecological functions. （2） Based on major ecosystem services, ecological land can be classified into four types （wetland, forest, grassland, and other ecological land） and 19 sub-types. Among them, wetland, forest and grassland should be collectively referred to as fundamental ecological land and others as preserved. （3） The total area of ecological land in China was 7.64 × 106 km^2 in 2008, which occupied about 80% of the entire land surface, with fundamental ecological land of 5.31 × 10^6 km^2. Both the gross amount and per capita possession of fundamental ecological land were the same： descending from northwest to southeast in China. From 2002 to 2008 the area of ecological land and fundamental ecological land gradually reduced, with average annual reductions of 0.55× 10^4 km^2 and 0.18×10^4 km^2, respectively. Among 356 prefecture-level cities in China, 104 increased and 251 decreased in terms of fundamental ecological land. In some regions in north and east China, the ecological security situation should not be ignored. In addition, the total amount of fundamental ecological land per capita showed the same spatial distribution characteristics with high levels in the northwest and low levels in the southeast, which correlated well with Hu＇s Line of population. The eco- security status in some regions was facing serious challenges. For example, the density of fundamental ecological land was lower than 0.4 in most areas of eastern North China and Northwest China, with the former caused by increased human development and construction activities, while the latter reflects the vulnerability of the local natural ecological environment background.