Impact of expanded built-up land on ecosystem service value by considering regional interactions

During rapid economic development and urbanisation, land expansion in built-up areas is China's dominant land-use change type, resulting in the loss of ecosystem service value (ESV). Economic development is China's main driving force for built-up land expansion. Under the trend of the spatial separation of production and consumption, expanded built-up land embodied in trade flows between regions as a scarce land resource. Through trade, a region can indirectly use built-up land from outside areas, which may affect land use within the user and provider regions. Regional ESV loss may be affected by outer regions, although previous studies have seldom considered it. Accordingly, this study quantified ESV for the whole of China in high resolution and determined ESV loss caused by expanded built-up land for each province and ESV loss flows embodied in interregional interactions. The results found that China's total ESV of terrestrial ecosystems was 37.44 trillion yuan in 2015, and the expanded built-up land resulted in a loss of 13.7 billion yuan in ESV. Due to the north–south differences in natural and economic levels in China, there was significant spatial heterogeneity in ESV and ESV loss caused by built-up land expansion, with the high-value areas mainly in the southern coastal areas. With regional interaction, the leading regional flow direction of built-up land and ESV loss was from north to south, mainly from economically developing regions to economically developed regions. However, there was a discrepancy between the actual users of the built-up land and the ESV loss-bearers. Evident regional inequalities existed in several provinces with regional interactions. Overall, this study provides a reference for developing China's interregional economic and ecological harmony strategies in the context of sustainable development.