Multilevel driving factors affecting ecosystem services and biodiversity dynamics on the Qinghai-Tibet Plateau

Understanding the driving factors of ecosystem services and biodiversity (ESB) is necessary for sustainable ecosystem management. Previous studies have analyzed many individual factors affecting ESB on the Qinghai-Tibet Plateau (QTP). However, there is limited knowledge on the scale dependence of the driving factors at different levels. In this study, we selected and assessed vegetation carbon uptake reduction (VCR), water supply index (WSI), and mean species abundance (MSA) on the QTP during 2000–2020, which can represent carbon sequestration, water yield ecosystem services, and biodiversity intactness, respectively. Then, we unutilized the hierarchical linear model (HLM) to determine the impacts of natural factors at the eco-functional zone level and socioeconomic factors at the city level on the three indices. The results showed that the spatial distribution of VCR and WSI had a generally gradual declining trend, and MSA had an increasing trend from the southeast to the northwest from 2000 to 2020. At the eco-functional zone level, degradation of forest and grassland had the greatest, most negative effects on carbon uptake and MSA. Potential evapotranspiration rather than precipitation had the strongest and most positive influence on the WSI. At the city scale, rural per capita net income, GDP, and meat production dominated the decrease in VCR, WSI, and MSA, respectively. The eco-functional zone was nested into the city, population, and economic controlled ESB mainly through its effect on land use, especially grassland. VCR and MSA were mainly affected by natural factors, while WSI was affected by socioeconomic factors. Overall, our study provides a reference for analyzing the multilevel factors that affect the sustainability of ESB.