Analysis of the evolution of ecosystem service value and its driving factors in the Yellow River Source Area, China

The Yellow River Source Area (YRSA) functions as an ecological barrier within the Yellow River Basin, playing a significant role in providing indispensable ecosystem services. Analyzing the ecosystem service value (ESV) of YRSA holds great significance in establishing ecological protection awareness and promoting ecological actions. In this study, we reveal the spatial and temporal characteristics of ESV in YRSA from 2000 to 2020 based on the land use change and equivalent factor method, and explore the driving mechanisms behind ESV heterogeneity using geographical detector. The results showed that from 2000 to 2020, ESV in the YRSA increased significantly, with an average increase rate of 9.12 x 10(21)seJ/5a, showing a spatial distribution pattern of low in the northwest and high in the southeast, and this imbalance is gradually weakening. The average annual contribution of grassland ESV reached 45 %, followed by water bodies (23 %). Ecosystem services in the YRSA are mainly dominated by regulating services, among which hydrological regulating services are dominated, with an average annual contribution rate of more than 40 %. Supply and regulation, support and cultural services both form a strong correlation synergy. Climate factors are the main drivers of spatial heterogeneity in ESV, further illustrating the sensitivity of the YRSA to climate change. Moreover, our results accentuate the integral role of the YRSA in furnishing ESV to the broader Yellow River Basin, which provides a theoretical basis and reference for decision makers to assess the ecological security of the ecological barrier zones.