## 4 Discussion
The study of the spatial change drivers of the ecosystem service values of water bodies, broad-leaved forests, artificial wetlands, and scrublands will provide a scientific basis for revealing the relationship between the geographic characteristics of the riverine and terrestrial intertwined zones, the spatial distribution of land use types, and the ecosystem service values, as well as the impacts of human activities on the value of ecosystem services [44]. Within levels 1-4 of the river section, because of the large distribution of mountainous areas and favorable climate, broad-leaved forest ecosystems have the highest per capita service value and perform ecosystem service functions such as water conservation; the terrestrial ecosystem service values decrease as the distance from the lower reaches of theXijiang River shrinks and gradually transitions to aquatic ecosystems; after the fifth level of the river section, with the increase in human activities and the need for land-use type construction and economic development, the mean land service value of broad-leaved forest and scrub ecosystems gradually declines, and the mean land service value of water bodies and artificial wetland ecosystems gradually dominates; within levels 5-6 of the river section, there is a staggering point between the mean land service values of water bodies and broad-leaved forest ecosystems due to the plains areas exceeding the mountainous areas, the expansion of the water bodies area, and the increase in water use for urban construction, and the mean land service value of the water bodies ecosystems then exceeds that of the broad-leaved forests; within levels 7-10 of the river section, the mean land service value of the artificial wetland ecosystems is second only to that of water bodies, providing mainly provisioning and cultural services; within the eighth level of the river section, the mean land service value of water body ecosystems is at its peak, providing about 124% of the value of the provisioning services and 59% of the value of the regulating services. The GWR model fitting results of the Guangdong section of the Xijiang River Basin obtained from the study show that the driving relationship between each driving factor and the ecosystem service function in the study area is not a simple linear relationship. When referring to relevant research [45], the constraint lines between vegetation coverage, water production, and soil conservation services are all in the form of an open downward parabola. That is, after vegetation coverage reaches a certain threshold, there is a constraint effect on the value of ecosystem services, which is consistent with vegetation coverage. The driving relationship happens between the degree factors and ecosystem service functions in the study area. Its specific analysis needs to be further deepened in subsequent research. Among the driving spatial characteristics, temperature, humidity, rainfall, the share of the primary industry, the share of the secondary industry, and the share of the tertiary industry have obvious regional and small patchy driving characteristics for the ES in the study area. Vegetation cover, slope, total consumption of electric power, the emissions of industrial exhaust gases, and the emissions of industrial wastewater in the study area showed obvious region characteristics, and the spatial differences in the impact of elevation and annual consumption of electric power energy by industrial enterprises above the national scale were not obvious. Among the driving intensity characteristics, humidity, rainfall, and the share of the three major industries showed small-scale, patchy, and intense heterogeneity; GDP, population density, lighting during the night, and evapotranspiration were too low in intensity, and the rest of the factors were shown to be blocking the driving characteristics. The differences in topography, geomorphology, and socio-economic development of the Guangdong section of the Xijiang River Basin determine the above spatial differentiation phenomenon.