Spatial–Temporal Interaction Relationship between Ecosystem Services and Urbanization of Urban Agglomerations in the Transitional Zone of Three Natural Regions

Clarifying the spatial interaction relationship between urbanization and multiple ecosystem services (ESs) is a prerequisite for reducing the impact of urbanization on the ecological environment and coordinating urbanization and ecological environmental protection. Urbanization is especially significant for ecologically fragile areas, where ecosystems are particularly sensitive to changes in urban patterns. This study considered the Lan–Xi (LX) urban agglomeration in three natural transitional regions using socio-economic, ecological environment, and other data, through a variety of methods, to supersede administrative boundaries and to explore the relationship between urbanization and ESs on a grid scale. The results revealed a significant negative spatial correlation between the levels of urbanization and comprehensive ESs, indicating that rapid urbanization has led to a decline in regional ESs. However, with the rapid urbanization trend from 2010 to 2018, the ESs in the LX region showed an upward trend because the implementation of ecological protection and restoration projects greatly offset the decline in ESs caused by urban expansion. We found a positive correlation between nutrient purification and the levels of urbanization among various ESs and four principal types of spatial–temporal interactions between ESs and urbanization levels. Among them, the high–high cluster areas occupied the smallest proportion, and the low–low cluster areas occupied the largest proportion.