Multilevel driving difference of nature’s contributions to people in achieving SDGs in the arid and semi-arid zones of China

Nature’s contributions to people (NCPs) are a crucial component in facilitating the realization of the United Nations Sustainable Development Goals (SDGs). However, the cross-scale effects of the intervention factors affecting the coupling between NCPs and SDGs remain a research gap, particularly in the ecologically vulnerable arid and semi-arid zones of China (ASZC). Here, we selected ASZC as the study area, comprising 65 cities, and assessed the spatiotemporal patterns of association between NCPs and SDGs using the coupling coordination degree model from 2000 to 2020. The NCPs included habitat maintenance (NCP1), climate regulation (NCP4), water quantity regulation (NCP6), and soil conservation (NCP8). The SDGs included SDG 2.1, SDG 8.1, and SDG 15.2, which relate to grain production as well as to economic and ecological development. We then identified the intervention factors influencing the relationship between NCPs and SDGs using a structural equation model across cities and explored the scale dependence of these intervention factors through a hierarchical linear model between provincial and city scales. Results revealed that the spatial coordination relationship between NCPs and SDGs was high in eastern cities and low in northwestern cities of the ASZC. GDP, precipitation, forest and grassland area promoted the coupling of NCPs and SDGs, while population and aridity contributed to their decoupling in most of the cities. The cross-scale mediation is the pathway from city GDP and population to regional vegetation, which in turn mediates the coupling between NCPs and SDGs. Understanding the cross-scale effects of the intervention factors influencing the relationship between NCPs and SDGs could help identify measures to advance the coordinated fulfillment of SDGs.