Spatial heterogeneity of urbanization impacts on ecosystem services in the urban agglomerations along the Yellow River, China

To maintain the coordinated development between human and natural ecosystem, it is essential to understand the spatial heterogeneity of urbanization impacts on ecosystem services (ESs). The Yellow River Basin (YRB) in China, with a fragile ecological environment, is experiencing large-scale and rapid urbanization. To fill the research gap and meet current needs, we estimated the comprehensive urbanization level (CUL) from four aspects in the YRB and the five key ESs using material value methods. Then, we examined the correlations between ESs and CUL by Pearson correlation analysis, and explored the spatial heterogeneity of urbanization impacts on ESs by geographically weighted regression. The results indicated that: (1) CUL increased remarkably from 0.2283 in 2000 to 0.3722 in 2015, with the subindexes ranking of DUL (demographic) > SUL (social) > EUL (economic) > LUL (landscape); (2) grain production (GP), carbon sequestration and oxygen production (CSOP), and water yield (WY) increased, whereas soil retention (SR) and habitat quality (HQ) decreased. The five ESs exhibited an overall pattern of low values in the northwest and high values in the southeast; (3) on the whole, CUL had positive and significant relationships with GP (0.4150), CSOP (0.1635), and WY (0.2475). The impacts of ULs on ESs had significant spatial heterogeneity. CUL has strong positive impacts on GP, CSOP, and WY in the central regions but negative ones on the northwestern and eastern regions. Specific recommendations are proposed for optimizing human activities and protecting the ecological environment.