Quantitative Evaluation of Ecological Stress Caused by Land Use Transitions Considering the Location of Incremental Construction Lands: The Case of Southern Jiangsu in Yangtze River Delta Region

With their significance in connecting socio-economic development and related eco-environmental consequences, land use transitions have gradually become the focus of land change science and sustainability science. Although various research studies have determined the ecological effects of land use transitions and provided suggestions to regulate them, few studies have investigated the different ecological stress of construction lands from the perspective of their spatial locations in ecologically differentiated regions. Taking economically developed and highly urbanized southern Jiangsu in Eastern China as an example, we developed a process-based method to indicate the spatial heterogeneity of ecological suitability and divided southern Jiangsu into five-level ecological zones accordingly. Considering that construction lands in ecological zones with higher ecological suitability levels cause greater ecological stress, we evaluated the ecological stress levels of incremental construction lands at different stages after 1990. Then, we carried out the calculation of county-level ecological stress and county-level zoning based on both the area and ecological stress level of their incremental construction lands. Results indicated that ecological zones with the highest to lowest ecological suitability levels accounted for 49.85%, 25.73%, 15.56%, 6.51%, and 2.34%, respectively. The majority of the incremental construction lands had the highest and moderately high ecological stress levels, and they were mainly distributed in areas along the Yangtze River and around Taihu Lake. The general ecological stress level of southern Jiangsu was at a relatively high level at each stage, but the county-level patterns of ecological stress levels were spatially different. As determined from the relationship between the amount of incremental construction lands and the average stress level associated with these lands in each unit, four types of zones, i.e., H-H, H-L, L-H and L-L zones, were identified, and targeted suggestions on land use regulations were proposed. We conclude that the spatial distribution of incremental construction lands significantly affects their ecological consequences from the perspective of maintaining ecosystem integrity. Both construction lands and ecological suitability are location specific, so the location-oriented evaluations could provide an effective approach for determining the spatial patterns of land use transitions based on spatially differentiated ecological consequences. It is essential to propose location-specific policies to carry out spatially precise ecological restoration and the redistribution of incremental construction lands.