The impact of urbanization and climate change on ecosystem services: A case study of the city belt along the Yellow River in Ningxia, China

Understanding the impacts of climate and land use changes driven by urbanization upon ecosystem services (ESs) has great importance in ES management and policy making. However, knowledge of their impacts on ESs correlation and bundles are still lacking. This study quantified five ESs in a spatially explicit manner for 1989-2017 in the City Belt along the Yellow River in Ningxia, China. Ten scenarios based on two Representative Concentration Pathway (RCP 2.6 and 8.5) and five urban expansion policies, were used to predict the potential change of ESs in 2017-2045. Temporal trade-off and synergy relations among ESs were analyzed using correlation analysis, while ES bundles were delineated and mapped through a self-organizing map. Results indicated that climate change has larger impacts on sand fixation and carbon sequestration, especially in mountain areas. In 2017-2045, RCP 8.5 would result in a larger increase in sand fixation (by 1.75 times to 2045) and a slight decrease in carbon sequestration (by 1.62%) than RCP 2.6. Land use change has a more substantial impact on the other three ESs than climate change, especially in the central plain. Specifically, cropland reclamation during 1989-2017 and urban expansion in 2017-2045 caused the most intense alterations in ESs. Reclamation can increase food production and nutrient retention, but reduce recreational opportunity, while urban expansion has the opposite impacts. Encouraging compact urban growth, creating riparian vegetation buffers and environment protection policies can effectively reduce the trade-offs and simultaneous losses among ESs. Specific recommendations are proposed for different sub-regions indicated by the ES bundle classification. Our results can provide references for urban planning to enhance ESs under future global warming.