Simulating the Effects of Future Urban Expansion on Ecosystem Services: A Spatial Spillover Analysis

ABSTRACT Changes in landscape patterns and ecosystem services (ESs) in urban agglomerations profoundly influence regional ecological security and the quality of human settlements. Although extensive research has examined the direct impacts of urban expansion on ESs, the spatial spillover effects on neighboring areas under future scenarios remain insufficiently explored, especially in trans‐provincial, polycentric urban agglomerations. This study integrates the Patch‐generating Land Use Simulation with the Spatial Durbin model to investigate the direct and indirect effects of landscape pattern changes on ESs in the Chengdu–Chongqing urban agglomeration under four different scenarios by 2030. Results indicate that high values of the proportion of urban land (PUL), patch density (PD), and proportion of like adjacencies (PLADJ) are mainly concentrated in the urban cores, while high values of the interspersion ‐ juxtaposition index (IJI) occur in the mountainous areas. By 2030, PUL will continue to increase, while PLADJ will show slight upward changes, PD will decrease, and IJI will remain relatively stable. ESs show significant positive spatial autocorrelation (Moran's I > 0.7), with a high‐periphery and low‐center spatial pattern. The indirect effect of PUL on ESs is stronger than the direct effect. Under the four scenarios, a 1% increase in local PUL corresponds to declines in neighboring ESs of 0.218%, 0.199%, 0.172%, and 0.213%, respectively. Moreover, the effects of landscape metrics on ESs demonstrate significant spatial nonstationarity. These findings suggest that urban planning strategies should account for the spatial spillover effects of landscape patterns on neighboring ESs and their spatiotemporal heterogeneity.