Terrain gradient variations in the ecosystem services value of the Qinghai-Tibet Plateau, China

The Qinghai-Tibet Plateau is an important ecological function area in the world, but its ecosystem is very fragile owing to the alpine environment. Owing to varying landforms exhibiting significant spatial differences in terms of temperature, light, soil and water conservation capacity, topography largely determines the spatial distribution of ecosystem services in areas with complex natural conditions. Studying the impact of topography on ecosystem services is important for efficient land use and ecosystem management. However, the effects of topography on ecosystem services have rarely been studied in the Qinghai-Tibet Plateau. In this study, using land use data from 1980, 1990, 2000, 2010, and 2020, the ecosystem services value (ESV) of the Qinghai-Tibet Plateau was estimated, and its spatiotemporal variation characteristics were analyzed using the ESV equivalent factor method. Spatial autocorrelation was introduced to analyze the spatial dependency between ecosystem services and topography. The results showed that the ESV of the Qinghai-Tibet Plateau decreased from $1,700,028 million in 1980 to $1,656,0 38 million in 1990 and then steadily increased to $1,678,294 million in 2020. Moreover, the spatial distribution of the average ESV was mainly characterized by high values in the southeast region and low values in the northwest region. The ESV exhibited different geographical distributions and temporal variation characteristics across the topographic gradient, and a significant spatial dependence was observed between the average ESV and topography. Hence, priority should be given to the ecological protection of high-altitude areas, such as high mountain valley regions of the plateau.