城市生态用地的空间结构及其生态系统服务动态演变——以常州市为例

生态用地是城市社会-经济-自然复合生态系统重要的组成部分,为城市提供多种显著的生态系统服务。应用遥感、地理信息系统技术和生态系统服务评估等方法,针对城市生态用地的空间结构与服务功能演变科学问题,通过对常州市区1991、1996、2001和2006年4个时段遥感图像的处理与比较分析,揭示了常州市区15a来城市空间景观格局的演变规律,评估了由城市生态用地改变所导致的生态系统服务的变化。研究结果表明,1991-2006年间,常州市区生态用地占市区面积的比例由89.2%降低至65.1%。1991-2001年,林地、农田和水体的面积都呈不同程度的下降趋势。2001-2006年,林地面积增加基本回到1996年水平。常州市区生态用地主要为城市提供了农林产品生产、气候调节、涵养水源、水土保持、生物多样性保护等生态系统服务。在过去15a间,由于城市化占用生态用地,常州市区生态用地生态系统服务的经济价值总体降低了19.3%。其中,农田的生态服务价值减少最大,减少了32.3%。研究结果表明,常州城市空间景观格局演变与生态系统服务变化之间存在着密切相关性,研究可为城市生态系统服务强化、城乡土地利用规划与管理、城市可持续发展等提供科学方法与决策参考。

Spatial structure of urban ecological land and its dynamic development of ecosystem services: a case study in Changzhou City, China

Ecological land is one of the most important components of urban Social-Economic-Natural Complex Ecosystem, it can provide various important ecosystem services for urban areas. Using Remote Sensing, Geography Information Science technology and landscape index analysis software, focusing on the scientific problem of urban ecological land and ecosystem services, on the basis of analyzing four-phase remote sensing images of Changzhou in 1991, 1996, 2001 and 2006, we got the evolution of landscape spatial structure of Changzhou during the past 15 years and assessed changes of ecosystem services generated by urban ecological land. The results show that the ecological land proportion of land-use decreased from 89.2% to 65.1%. During 1991 to 2001, the areas of forests, fields and water had a decreasing tendency. During 2001 to 2006, the areas of forests turned back to that of 1996. Ecological land in Changzhou have provided ecosystem services including agricultural and forestry production, climatic regulation, conservation of water resource, soil and water conservation, biodiversity protection, etc. During 1991 to 2006, the value of ecosystem services provided by ecological land has reduced 19.3%. The decrease of ecosystem services value provided by agricultural lands was the largest of all and it decreased 32.3%. The results showed strong correlation between landscape spatial structure and ecosystem services of Changzhou city. This paper can provide scientific methods and decision making for strengthening of urban ecosystem services, land use planning and management, urban sustainable development, etc.