Impact of Urban Land Expansion Efficiency on Ecosystem Services: A Case Study of the Three Major Urban Agglomerations along the Yangtze River Economic Belt

Abstract

The negative impacts of urban land expansion on ecosystem services have been confirmed by many studies; however, there has been a lack of studies examining the impacts of urban expansion on ecosystems from an efficiency perspective. China is increasingly emphasising the efficiency of development systems by maximising economic, social, and environmental benefits from limited land resources, which is a vital issue for high-quality urban development. Therefore, this paper aims to explore the evolutionary characteristics of urban land expansion efficiency (ULEE) and its impact on ecosystem services (ESs) to improve the ecological functions of urban systems. We first analysed the influence mechanism, based on efficiency and land use theory. Then, we used the Super-SBM and the InVEST model to measure ULEE and ecosystem service value (ESV). Finally, through regression analysis we explored the actual characteristics of the influence of ULEE on ESs. The results show: (1) ULEE positively influences ESs, and the influence mediators include three main aspects, i.e., land use structure, land use pattern, and land use quality. (2) The ULEE of the urban agglomerations exhibited a fluctuating downward trend from 2006–2020, and noticeable spatial differences were observed. (3) The AESV of the three major urban agglomerations showed a decreasing trend during the study period, with the UA-MRYR being higher than UA-YRD and UA-CY. Meanwhile, a certain degree of coincidence between the changing trend of AESV and ULEE was apparent. (4) A positive correlation was found between ULEE and the ESV of the three urban agglomerations. That is, the enhancement of ULEE was found to catalyse the improvement of ESs. The impact of ULEE on ESs exhibited a general decreasing trend from east to west. These results complement the study of the territorial system of the human–land relationship and have essential reference value for sustainable urban development and ecological restoration.