Multiscale assessment of the spatiotemporal coupling relationship between urbanization and ecosystem service value along an urban-rural gradient:A case study of the Yangtze River Delta urban agglomeration, China

Evolutions in land use in urban areas exert a growing influence on ecosystem service value (ESV). As a manifestation of spatial arrangement in mature urban growth, the ecological challenges within urban agglomerations and their surroundings deserve attention. Therefore, clarifying the interrelation within the ESV and urbanization is crucial to constructing sustainable progress-oriented cities. Previous researches on the coordination relationship between ESV and urbanization have been limited to the provincial and county levels, and insufficient consideration has been given to the differences across urban and rural areas at different scales. Utilizing the coupling coordination degree (CCD) model, the present investigation assesses the interplay between urbanization and ESV across various scales within the Yangtze River Delta urban agglomeration (YRDUA) region from 2000 to 2020, and explores the differences in their distributions throughout the urban-rural gradient, aiming to help the regional coordinated development. The findings indicate that from 2000 to 2010, with increasing intensity of land use, the ESV in YRDUA area decreased. But between 2010 and 2020, ESV increased. Moreover, the CCD in the YRDUA has a positive relationship across ESV and urbanization, and is in a status of primary coordination from 2000 to 2020, with a slow upward trajectory. Meanwhile, along the rural-urban gradient, ESV and CCD both are declining, and there is a significant plunge from suburban to urban. And the interactions between ESV and urbanization have obvious spatial heterogeneity, which tends to show the coordination at broader scales, such as provincial and county levels, while manifesting conflicts at finer scales, such as the grid scale. Our findings can help city planners and policy makers to minimize the adverse effects of urbanization sprawl on ecosystem services.