SPATIAL AND TEMPORAL VARIABILITY OF ECOSYSTEM SUPPORT SERVICES AND DRIVERS IN METROPOLITAN AREAS BASED ON THE INVEST MODEL

Abstract. With the rapid economic growth since the turn of the 21st century, the fast-degrading environment has emerged as a significant factor limiting the continued development of megacities such as Beijing and Shanghai. It has also placed unprecedented pressure on ecosystem services. Therefore, the present study uses the morphological spatial pattern analysis model and the index of connectivity (IIC) and possible connectivity (PC) indices to analyse changes in the spatial pattern of Beijing and combines the carbon sequestration module and habitat quality module of the InVEST model to evaluate the supporting functions of Beijing’s ecosystems from 2000 to 2020, to investigate the characteristics of spatial and temporal changes and the drivers of these changes, and to provide a scientific basis for urban ecosystem management. The results show that between 2000 and 2020, the overall area of green space in Beijing decreased, and the IIC and the index of PC decreased, indicating that the overall spatial connectivity of green space decreased and fragmentation increased. During this period, the carbon stock within the Beijing city area decreased by a total of about 2.94 Tg, and the habitat quality index decreased from 0.71 to 0.67, indicating a trend of degradation. This paper suggests that the expansion of urban and rural land use is a major factor in the decline of ecosystem support services, while the spatial pattern of the landscape also has an impact on habitat quality, which is generally higher in areas with better landscape connectivity.