京津冀地区生态系统服务供需测度及时空演变

生态系统服务供需状况深刻影响地区生态安全与经济社会的可持续发展。以京津冀为研究区，选取产水、碳固持以及粮食生产3项生态系统服务，应用InVEST模型、ArcGIS空间分析模块，定量测度2005年与2015年京津冀地区生态系统服务供需水平，探索京津冀地区生态系统服务供需时空格局及类型演变特征。结果表明：（1）在2005年与2015年，京津冀地区产水服务处于供需赤字状态，碳固持服务和粮食生产服务处于供需盈余状态，且各项生态系统服务供需状态呈显著的空间异质性；（2）2005年与2015年京津冀地区生态系统服务综合供需状况呈赤字状态，主要赤字范围以京津为中心呈环状分布，并在此期间范围有所扩大。（3）基于生态系统服务供需状况，将京津冀各县区划分为生态涵养区、生态保育区、生态改良区、生态恢复区以及生态控制区，并针对各类型区生态系统供需状况及其时空演变规律，提出了相应的政策建议。

Supply and demand measurement and spatio-temporal evolution of ecosystem services in Beijing-Tianjin-Hebei Region

The supply and demand of ecosystem services has a profound impact on the regional ecological security and the sustainable development of economy and society. In this paper, Beijing-Tianjin-Hebei Region is taken as the research area. Relying on the selected three ecosystem services, that is, water yield, food and carbon storage, this paper conducts measurement for the supply and demand of ecosystem services in the Beijing-Tianjin-Hebei Region in 2005 and 2015 through using the InVEST model and ArcGIS spatial analysis tools. On this basis, it explores the evolution characteristics of supply and demand typological areas of ecosystem service in the Beijing-Tianjin-Hebei Region. The results show that (1) the ratios of supply and demand of water yield services in Beijing-Tianjin-Hebei Region in 2005 and 2015 were -0.65 and -0.59 respectively, indicating that the supply and demand of water yield services were in deficit in these two years. The ratios of supply and demand of carbon storage services in these two years were 0.34 and 0.12 respectively while the ratios of supply and demand of food supply services in these two years were 0.07 and 0.03 respectively, indicating that the supply and demand of these two ecosystem services were in surplus. Meanwhile, the spatial heterogeneity of supply and demand of various ecosystem services was significant from 2005 to 2015. These results prove that the status of carbon storage services and food supply services in Beijing-Tianjin-Hebei Region is excellent, but the status of water yield services is not optimistic. In the future, the water shortage situation in the Beijing-Tianjin-Hebei Region may become more obvious. (2) The comprehensive ratios of ecosystem services supply and demand in Beijing-Tianjin-Hebei Region in 2005 and 2015 were -0.09 and -0.16 respectively, indicating that the supply and demand of the Beijing-Tianjin-Hebei Region in these two years were in deficit. The main deficit range was in a circular distribution centered on the Beijing-Tianjin-Hebei Region, and the range was expanded during this period. It also indicates that the overall ecological supply and demand situation in Beijing-Tianjin-Hebei Region may further deteriorate. (3) Based on the supply and demand of ecosystem services, the counties in Beijing-Tianjin-Hebei were divided into ecological conservation area, ecological protection area, ecological improvement area, ecological restoration area and ecological control area, each type area has its own characteristics of supply and demand. According to the situation of supply and demand of each ecosystem type and the law of its temporal and spatial evolution, this paper puts forward the corresponding policies and suggestions.