The dynamic impact of landscape urbanization on ecosystem service multifunctionality in the Chengdu-Chongqing urban agglomeration: A panel VAR approach

Understanding the influence mechanism of landscape urbanization on ecosystem services (ESs) will provide useful guides for ecosystem conservation and urban sustainable management. However, the models used in existing studies tended to evaluate the various impacts of landscape urbanization on ES in the same period and fail to reveal the dynamic response of ES to landscape urbanization and the contribution of each impact variable, which is not conducive to the long-term planning and management of urban ecosystems. To fill the gap, based on the panel data of the 141 counties in the Chengdu-Chongqing urban agglomeration (CCUA) from 2000 to 2015, this study applied the panel vector autoregressive (PVAR) model to investigate the dynamic impact of different aspects (i.e., urban scale, density, shape, and compactness) of landscape urbanization on ES multifunctionality (ESM) and identified the key impact factors. The results showed that (1) the proportion of high-level ESM decreased by 9.13% in 2000-2010 and then increased by 19.14% in 2010-2015; (2) the ESM of the CCUA existed significant spatial agglomeration, and the high-level areas were concentrated in the southwestern mountains, while the low-level areas were mainly located in the central plains and urban areas; (3) There was a strong non-linear relationship between landscape urbanization and ESM, with variability in the intensity and direction of ESM's response to landscape urbanization shocks as time. Specifically, urban landscape scale and shape (i.e., percentage of landscape, largest patch index (LPI), and landscape shape index) were generally more influential on the ESM than urban landscape density and compactness (i.e., patch density and pacth cohesion index), with LPI making the greatest contribution. These findings will help to clarify the dynamic relationship between landscape urbanization and ESM, which could provide important guidance for ecosystem conservation and urban planning.