What is the Spatiotemporal Relationship between Urbanization and Ecosystem Services? A Case from 110 Cities in the Yangtze River Economic Belt, China

Rapid urbanization has altered landscape patterns and ecological functions, causing a decline in ecosystem service and generating many ecological and environmental issues. Studying the spatiotemporal interaction between urbanization and ecosystem service (ES) can provide effective supports for regional sustainability and policy formulation. This research utilizes the Yangtze River Economic Belt (YREB) as a case to analyze the spatiotemporal interaction between multi-urbanization indicators and multi-ESs over a large-scale region. The results show that the urbanization process in the YREB evolves from a rapidly growing state to a steady state with a slower rise. The urbanization level of the Yangtze River Delta urban agglomeration is relatively higher than the other regions. The distribution pattern of urbanization shows an overall characteristic of lower urbanization in the west and higher in the east. From 2009 to 2016, ecosystem service value (ESV) in the YREB decreased first and then increased, ESV in 2016 showed a reduction of 12.768 billion yuan compared with the 2009 level. ESV increases gradually from highly urbanized areas to those with lower levels of urbanization. Areas with high ESV levels are distributed at the middle reaches of YREB. There is a U-shaped curve relationship between urbanization and ESV, the ESV sharply increased when the urbanization index exceeded 0.6 in 2012. Land urbanization has the greatest impact on ESV among the four subtypes of urbanization indicators. Urbanization and ESV show the synergy relationship mostly in the eastern region, accounting for 18.18% of the total 110 cities. By contrast, they present the trade-off relationship in northern, southern and central regions, occupying 47.27% of the total observations. This study is helpful to provide scientific suggestions regarding the development of new urbanization, the protection of ESV, and the issue of how to achieve synergistic and sustainable development between them.