Growing inequality of ecosystem service distribution in China’s urban–rural transition zones: implications for SDG 11.3

The United Nations Sustainable Development Goal (SDG) 11.3 emphasizes “strengthening inclusive and sustainable urban construction” and the urban rural transition zone (URTZ) is a key social-ecological frontier for land transformation and the redistribution of ecosystem services. However, as global urbanization continues to intensify, how urban expansion affects ecosystem services equality (ESs-equality) within URTZ remains unclear. This study employed satellite data from 2000 to 2020 to study the evolution characteristics and influencing mechanisms of ESs-equality within URTZ in different climatic zones of China, and obtains four key findings. First, we found that ESs-equality within China’s URTZ shifted from equality to inequality, with the ecosystem services Gini (ESs-Gini) coefficient (0 = equality, 1 = inequality) increasing significantly (0.245 to 0.370) ( p < 0.001). Second, we found that the proportion of ecosystem service inequality (ESs-Gini ≥ 0.3) within URTZ in humid climate zones was higher than that in arid climate zones, at 90.17%. Third, we found that human activities and natural factors have nonlinear impacts and threshold effects on ESs-equality, and the interaction of factors will accelerate trend of change. Fourth, by analyzing and comparing typical cities in different climate zones, we found that as the area of impervious surface increases, ESs-Gini continues to increase and ecosystem service inequality continues to intensify. These findings reveal new environmental justice challenges that accompany urbanization and suggest the need for more intentional urban development strategies in different climate zones. The ESs-Gini constructed in this study provides an equality perspective that helps guide the implementation of SDG11.3.