Understanding how to manage ecosystem services (ESs) in urban agglomerations is crucial for sustainable land use planning under rapid urbanization. We assessed the spatiotemporal distributions of multiple ESs based on the land use in Beijing-Tianjin-Hebei (BTH), Yangtze River Delta (YRD), and Pearl River Delta (PRD) urban agglomerations of China from 1980 to 2017. The urban hierarchy extends from city proper level to metropolitan region level and then urban agglomeration level. Using correlation and regression analysis, we examined the relationships between pairs of ESs and identified the dominant influencing factors of ESs. An integrated framework was also proposed to enhance the critical ESs by developing the optimal land-use scenarios at different levels.
Results/Conclusions
The expansion of developed lands and the decrease of croplands have led to the declines in most of ESs except water yield in three urban agglomerations. The provisioning services had tradeoffs with regulating and cultural services in three urban agglomerations. As the spatial extent extends, the relationships between food production and most of the ESs were more negative and weaker, while the relationships of nitrogen retention and soil retention with other ESs were more positive and stronger. The influencing factors become more diverse at higher urban hierarchy level. Socioeconomic factors were the key ES drivers at lower level, while natural factors become the key drivers at higher level. Different levels of urban hierarchy should implement different land-use optimal strategies to effectively enhance the critical ESs. At the city proper level, the intensive utilization of developed lands and barren lands would be the optimal land-use strategy; at the metropolitan level, agroforestry intercropping scenario can reduce the tradeoffs between provisioning services with other ESs; at the urban agglomeration level, the forest conservation practices would be an effective ecological engineering measure. The scale-dependent strategies for ESs protection in this study can provide references for land use policy and regional sustainability in China.