Construction of green infrastructure networks based on the temporal and spatial variation characteristics of multiple ecosystem services in a city on the Tibetan Plateau: A case study in Xining, China

The construction of green infrastructure networks is an effective measure to guide orderly city expansion and ensure ecological security. However, limited research has been conducted to explore practical strategies for enhancing ecosystem services threatened by urban development, particularly in plateau cities with constrained natural resources. Xining, the largest and most densely urbanized city on the Tibetan Plateau in China, faces a significant conflict between urban expansion and ecosystem service conservation that is limited by an uninhabitable climate and mountainous topography. It is the only central city on the Tibetan Plateau, with a population of 2.47 million (2020). From 2000 to 2020, the urban area expanded by 37.42%; thus, reconciling the escalating demand for natural resources driven by urban development and promoting synergistic development between ecosystem services and urbanization remains a challenge. Here, we propose a modeling framework to reconstruct ecosystem service values using improved temporal ( p i ) and spatial ( d i ) difference indices, highlighting the temporal sensibility and spatial aggregation of multiple ecosystem services. The material quantities ( d i ) and monetary values ( p i ) of seven ecosystem services were estimated using experimentally verified local parameters as a case study in Xining from 2000 to 2020. The green infrastructure network and its interactions were identified based on the reconstructed ecosystem service value using the gravity modeling toolbox proposed in our previous study. The results illustrated that the identified green infrastructure network comprised 48 ecological sources and 96 corridors, covering an area of 162318.3 hm 2 ; while this includes approximately onefifth of the total study area, but it contributes to one-third of the overall ecosystem service value. The conservation priority and planning construction areas in the Xining City Master Planning (2021 -2035) outlines were then optimized based on the identified green infrastructure network. Overall, these optimized urban planning scenarios would reserve 59.3 million CNY of the reconstructed ecosystem service value encroached on by urban sprawl. The opportunity cost is transferring 14.7% of the planned construction area overlapping with the green infrastructure network. This study provides a distinctive example for establishing a green infrastructure network based on the spatiotemporal dynamic sensitivity of ecosystem services and provides a strong reference for sustainable development and ecosystem service conservation, particularly in plateau cities.