Identifying the impacts of natural and human factors on ecosystem service in the Yangtze and Yellow River Basins

The Yangtze River Basin (YZRB) and Yellow River Basin (YRB) are important ecological regions in China. In recent decades, intense climate change and human activities have altered the natural landscapes of both basins and degraded their ecosystem functions. This study focused on clarifying the major factors influencing the ecosystem services (ESs) in different regions of China, which will be key to manage ecosystems sustainably. Five ESs, including water yield, carbon storage, soil conservation, water purification and habitat quality were selected for mapping. The geographical detector model was used to analyze the independent and joint effects of driving factors, and the spatial changes in driving factors were expressed using geographically weighted regression model. Results showed that (1) all five ESs decreased from southeast to northwest in the YRB but had an irregular distribution in the YZRB. (2) Precipitation and woodland proportion were dominant factors for total ecosystem services in both basins, followed by temperature, slope, and human activity intensity in the YRB, and temperature, human activity intensity, and population density in the YZRB. The combined effects of the driving factors were much higher than the individual effects in both basins (3) Natural factors (e.g., precipitation, slope, and woodland proportion). exerted positive effects in most areas of both basins. Human factors (e.g., GDP, human activity intensity, and built-up land proportion) had negative effects, with an uneven spatial distribution. Overall, natural factors promoted the formation and spatial distribution of ESs, and their direct impacts on total ecosystem services were insignificant in the short term. The impact of land-use changes played a leading role in joint impacts. In the YRB, the increase of woodland had a positive effect on ESs; the continuous growth of build-up land led to the degradation of ESs in the YZRB. Accordingly, adhering to the program of Grain for Green and changing the mode of economic development are crucial for future development. A comparative analysis of the driving factors of ESs in different regions provides a scientific basis for understanding and optimizing management policies.