Climate change and non-climatic drivers jointly enhanced the NDVI of alpine grassland in the Source Region of the Yellow River (2000–2022)

The source region of the Yellow River (SRYR) is a vital water conservation area with substantial spatial heterogeneity in grassland vegetation. Yet the respective contributions of climate change and non-climatic drivers s to that variability remain unclear. This study quantified the relative impacts of climate and non-climatic factors on alpine grassland vegetation dynamics in Maqin County, a typical pastoral area in the SRYR, from 2000 to 2022. Multiple linear regression and residual analysis were used to disentangle climate change and non-climatic drivers to the changes in the Normalized Difference Vegetation Index (NDVI). The results showed that grassland NDVI exhibited a significant positive trend from 2000 to 2022 ( P < 0.05), with 72.84% of the study area showing improvement. Spatially, NDVI displayed a “southeast-high and northwest-low” pattern, driven by differential responses to temperature and precipitation, with temperature being the dominant climatic factor. Climatic change and non-climatic influences jointly dominated vegetation dynamics (affecting 74.67% of the area), with their combined effect exceeding those of either factor alone. Climate change accounted for 51.86% of the variation in NDVI, slightly higher than that explained by non-climatic drivers (48.14%). Overall, a warming and wetting climate has promoted the restoration of alpine grassland, while sustained human interventions (e.g., ecological projects) have become an essential role. These findings provide a promising scientific basis for adaptive management in ecologically sensitive pastoral regions.