Abstract:
The Qilian Mountains in Qinghai Province serve as a vital ecological barrier in northwestern China. Alpine meadows, as the dominant vegetation in the Qilian Mountains, play a significant role in the local ecology, production, and life. A comprehensive understanding of the overall status and dynamic changes of these alpine meadows is of great significance for their protection, restoration, and utilization. This study aims to characterize the long-term, continuous spatial changes in the fractional vegetation cover (FVC) of alpine meadows in the Qilian Mountains. Based on simple linear regression and residual analysis, a classification system adaptable to the long time series of changes in the FVC of alpine meadows was established, reflecting the stability, change amplitudes, and change trends of the FVC of alpine meadows. The results indicate that the established classification system effectively reflected the changes in the FVC of alpine meadows in the study area. The alpine meadows of various change types exhibited pronounced spatial distribution characteristics consistent with terrain variations. From 1989 to 2022, the FVC of alpine meadows remained stable overall in the study area, with areas with slight variations in FVC larger than those undergoing significant changes in FVC. Under the influence of a warm and humid climate, the FVC of alpine meadows increased significantly in high-altitude, sparsely populated areas. In contrast, the decrease in FVC resulted from the combined effects of topography, climate, and human activities.