Threats to Sustainable Ecosystem Services Provision for Different Sociodemographic Groups: A Case Study in Nanjing

Ensuring equitable and sustainable access to ecosystem services (ESs) is vital for achieving environmental justice. The distributive equity of ESs is often assessed at a single point in time, overlooking long-term threats to sustainable ESs provision for various sociodemographic groups. Taking Nanjing, China, as an example, we analyzed the threat level to the sustainable provision of 8 ESs (air purification, food production, flood mitigation, habitat quality, outdoor recreation, water retention, urban cooling, and water provisioning) using a framework that incorporated ESs supply trend, the ecological supply–demand ratio (ESDR), and ESDR trend. Spearman correlation and Wilcoxon tests were used to examine the threats faced by different sociodemographic groups. We found that (a) threats to food production, urban cooling, and water provisioning were particularly high, with most streets in Nanjing classified as undersupplied, endangered, or critically endangered. Air purification, flood mitigation, and habitat quality showed lower threats, with most streets classified as vulnerable or least concern. (b) Nearly half the streets fall within extremely high and high threat zones, mainly in central urban areas. (c) The proportions of nonlocal hukou holders and ethnic minorities were higher in high-threat regions, while the proportion of elderly residents declined from extremely low- to extremely high-threat areas. Our study highlights the substantial threats to sustainable ESs provision and the unequal exposure of vulnerable populations. Local mitigation strategies must address these imbalances and consider the needs of nonlocal hukou holders and ethnic minorities.