Habitat quality is an important indicator for assessing biodiversity and is critical to ecosystem processes. With urban development and construction in developing countries, habitat quality is increasingly influenced by landscape pattern changes. This has made habitat conservation to be an increasingly urgent issue. Despite the growing interest in this issue, studies that reveal the role of land use change in habitat degradation at multiple scales are still lacking. Therefore, we analyzed the spatial and temporal variations of habitat quality of the Three Gorges Reservoir area by the InVEST habitat quality model and demonstrated the responses of habitat quality to various landscape dynamics by correspondence analysis. The result showed that the habitat quality score of this area increased from 0.685 in 2000 to 0.739 in 2015 and presented a significant spatial heterogeneity. Habitat quality was significantly higher in the northeastern and southwestern parts of the reservoir area than in other regions. Meanwhile, habitat quality improved with altitude and slope, and increased for all altitude and slope zones. The habitat quality of >1000 m and >25° zone exceeds 0.8, while the habitat quality of <500 m and <15° zone is less than 0.6. Habitat quality significantly varied among landscape dynamics and was extremely sensitive to vegetation recovery and urban expansion. The vegetation restoration model of returning farmland to forest is difficult to sustain, so we suggest changing the vegetation recovery model to constructing complex vegetation community. This study helps us to better understand the effects of landscape pattern changes on habitat quality and can provide a scientific basis for formulating regional ecological conservation policies and sustainable use of land resources.

Land use planning usually increases the uncertainties of the ecosystem structures and functions because various human demands usually bring both positive and negative ecological effects. It is critical for estimating various land use changes and their ecological effects, but the previous studies have failed to decouple the respective and the combined effects of different land use changes on ecosystem services. Net primary productivity (NPP) could be used to indicate many ecosystem services such as carbon sequestration and storage. Here, we employed a light use efficiency model to estimate the spatial and temporal dynamics of NPP in the Three Gorges Reservoir (TGR) area from 2000 to 2015, and designed four scenarios to analyze the relative roles of afforestation, urbanization and storing water on NPP dynamics. Our results documented that terrestrial NPP of the TGR area increased from 547.40 gC•m−2 to 629.96 gC•m−2, and carbon sequestration capacities were 31.66 TgC (1Tg = 1012g) and 36.79 TgC in 2000 and 2015, respectively. Climate change and land use change both could contribute to carbon sequestration with 4.08 TgC and 1.05 TgC. Among these land use changes, only afforestation could sequester carbon with 2.04 TgC, while urbanization-induced and impoundment-induced emissions were 0.12 TgC and 0.32 TgC, respectively, and other land use changes also could release 0.55 TgC of carbon. This finding suggested that although positive and negative environmental effects happened simultaneously over the past decades, green infrastructure could effectively offset the carbon emissions from urbanization and storing water in the TGR area, which provides some fundamental supports for further ecological restoration and contributes to empowering land use policies towards carbon sequestration and storage at the regional scale.

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Urbanization has become one of the hot issues of global sustainable development, and is mainly characterized by urban population growth and construction land expansion. However, the inharmonious development of urban expansion and population migration has brought serious challenges to urban planning and management. China is the largest developing country in the world, and the urbanization process has accelerated over the past decades. In this paper, decoupling analysis was used to demonstrate the spatio–temporal relationship between urban expansion and population growth in 321 prefecture–level cities in China, providing a reference basis for sustainable development. The results showed that China’s population, total GDP, and construction land area increased from 1990 to 2018. The rate of construction land expansion was larger in the eastern coastal and western regions than in the northeastern and central regions, but the population growth rate was not significantly different among these regions. According to the decoupling analysis, the relationships of population–GDP, construction land–GDP, and population–construction land were mainly weak decoupling, indicating that both the population growth and the construction land expansion lagged behind the economic development, and the population growth lagged behind construction land expansion. In addition, the results were analyzed based on China’s four economic regions. Population and construction land area changes in the northeastern provinces experienced a shift from weak decoupling to expansive negative decoupling, then presented a strong decoupling. The decoupling state of population–construction land in the west region was relatively stable. The relationship between population and construction land in the central regions was mainly weak decoupling, and some cities developed into strong decoupling. The relationship between population and construction land in the east region experienced a shift from strong decoupling to weak decoupling, then demonstrated expansive negative decoupling, mainly manifested in the Beijing–Tianjin–Hebei, Yangtze River Delta, and Pearl River Delta urban agglomerations. Therefore, the northeast region should take measures to promote regional population growth while reasonably controlling the expansion of construction land, the west region should focus on ecological protection and moderately attract population, the central region should control their population development and reasonably allocate land, and the east region should pay attention to and solve the citizenship problem of migrant workers in second–tier and third–tier cities when promoting new urbanization.