China has experienced enormous changes in land use in recent decades, which are largely driven by its unparalleled economic development. We analyze changes in vegetation and soil carbon storage between 1990 and 2010 resulting from combinations of land-use category conversion and management. Results demonstrate a major decline in grasslands (−6.85%; 20.83 × 10⁶ ha) and large increases in urban areas (+43.73%; 6.87 × 10⁶ ha), farmlands (+0.84%; 1.48 × 10⁶ ha), and forests (+0.67%; 1.52 × 10⁶ ha). The total soil organic carbon pool has been reduced by approximately 11.5 Tg of carbon (TgC) year⁻¹, whereas 13.2 TgC year⁻¹ has accumulated in the biomass carbon pool because of land-use category change. Large carbon losses (approximately 101.8 TgC year⁻¹) have resulted from land management failures, including forest fires and insect pests. Overall land-use change and land management have contributed about 1.45 Pg of carbon to the total carbon released from 1990 to 2010. Our results highlight the importance of improving land-use management, especially in view of the recently proposed expansion of urban areas in China.

Twenty-six cities in the Yangtze River Delta urban agglomeration were taken as the research object, and this study comprehensively evaluated urbanization quality and ecological resilience from 2005 to 2020. On this basis, the spatiotemporal evolution characteristics and main influencing factors of the coupling relationship between urbanization and ecological resilience were systematically explored using a coupling coordination model and panel Tobit regression model. The results can be summarized as follows: (1) from 2005 to 2020, the quality of urbanization in the Yangtze River Delta urban agglomeration continued to grow, the level of ecological resilience grew slowly and fluctuated, and the development among municipalities tended to be balanced. (2) The overall coupling coordination degree of urbanization and ecological resilience showed a continuous increasing trend, and the coupling coordination type changed from basic coupling coordination to good coupling coordination. The number of cities with lagging urbanization quality decreased significantly; spatially, the gap in the coupling coordination degree between municipalities narrowed, and the cities with good coupling gradually clustered. (3) The results of the panel Tobit regression showed that the differences in the spatial evolution of coupling coordination mainly resulted from the interaction of drivers such as real utilized foreign capital, per capita GDP, carbon emission intensity, the proportion of science and technology expenditure to fiscal expenditure, the ratio of per capita disposable income of urban and rural residents, fixed asset investment in municipal utility construction, and the index of ecological land area ratio. In the future, the coupling coordination degree of urbanization and ecological resilience should be improved based on the type of coupling coordination according to local conditions, and the seven influencing factors should be carefully examined to accelerate the high-quality integrated development of the Yangtze River Delta.

Measuring the efficiency of construction land utilisation is important for optimising the allocation of regional resources and guiding the sustainable development of the regional society and economy. Based on municipal panel data on urban land use from 2009 to 2017 from a municipal perspective, this research built a slacks-based measure of a super-efficiency model (SE-SBM) to evaluate the temporal and spatial differentiation characteristics of the construction land-use efficiency of 41 cities in the Yangtze River Delta. Following this, the driving force of construction land efficiency was calculated using the Malmquist–Luenberger index. Finally, the entropy-weight TOPSIS (technique for order preference by similarity to ideal solution) model and the k-means clustering method were applied to evaluate an input–output model of the cities. The main conclusions are as follows: (1) The construction land efficiency of the Yangtze River Delta remains at a low level and presents a spatial differentiation pattern, with the efficiency being higher in the east and lower in the west. Due to undesired outputs, the mean value has dropped by 4.67%, and the regional imbalance has decreased. (2) The degree of efficiency loss is significantly positively correlated with the intensity of urban pollution emissions—the higher the pollution emissions, the greater the efficiency loss. (3) The total factor productivity of urban construction land is mainly driven by technological progress, while the promotion of technical efficiency is low and unstable. (4) The evaluation of construction land efficiency must include resource allocation or pollution emission factors to scientifically measure the input–output level. These research results will help to formulate reasonable land-use countermeasures.

With the rapid development of urbanization, the demarcation of the urban development boundary (UDB) is of great practical significance to curb the disorderly spread of urban land, avoid losing control of urban development space, and build a barrier to green development space. In this paper, we propose a method to support the demarcation of the UDB by combining the Maxent model and the cellular automata (CA) model. This approach comprehensively considers the relationship between urban construction suitability, neighborhood effect, spatial constraint, and random interference based on a spatio-temporal dynamic simulation. This contributes to the analysis of the driving mechanism and distribution pattern of urban expansion. According to the principle of scale expansion and centralization, the simulation result is modified to demarcate the UDB. The following conclusions are drawn: the Maxent-CA model can intuitively reflect the driving mechanism and accurately simulate urban expansion in specific cities, which contributes to demarcating the UDB. Considering that this method fully embodies the principle of combining top-down and bottom-up approaches in the demarcation of UDB, we argue that the Maxent-CA model is of vital importance for the sustainable development of the living environment and is of great reference value for territorial spatial planning.