Introduction: The vegetation at the Sichuan-Tibet Interface (STI) in China serves as a core element in maintaining the ecological barrier function of the Qinghai-Tibet Plateau, playing a crucial role in safeguarding the ecological service functions of Southwest China.Methods: Based on normalized difference vegetation index (NDVI) data in August between 2001 and 2023, this study investigates the spatiotemporal variations in vegetation coverage during the peak growth period across adjacent administrative boundaries (STI-Tibet and STI-Sichuan), analyzes the time-lag effects of major climatic factors on it with Pearson’s correlation, and explores the driving factors by dream optimization algorithm-random forest model and Optimal parameter geographic detector.Results: The research has found that the average NDVI value in STI regions was between 0.6 and 0.8 with a growth rate of 0.009 per decade, and 68.41% of areas showed higher mean NDVI from 2012–2023 compared to 2001–2011. STI-Sichuan displays higher proportions of both medium-low and high vegetation coverage and lower proportions of middle-high vegetation coverage compared to STI-Tibet, but STI-Sichuan showed higher proportions of non-significant increase, significant increase, and extremely significant increase compared to STI-Tibet. The NDVI shift in STI-Sichuan occurred approximately 2 years earlier than in STI-Tibet, with greater magnitude and coverage. NDVI response lags to growing-season temperature, precipitation, and solar radiation are 2 months, 1 month, and immediate, respectively. Elevation significantly impacts NDVI across both regions; however, temperature exerts greater influence in STI-Sichuan, while precipitation predominantly affects STI-Tibet. Dual-factor interactions generally enhance explanatory power, reflected by increased q-values.Discussion: These findings provide valuable insights for transboundary vegetation management and conservation. Further research could encompass a broader range of ecological elements, and formulate targeted ecological restoration strategies.

The primary factors controlling regional gully distribution in mountainous areas are poorly understood. To investigate the spatial characteristics and controlling factors of mountainous gullies at the regional scale, kernel density (KD) estimation, semivariogram, and Geodetector methods were used based on 11 environmental factors of gullies in the Yuanmou dry-hot valley. The results show that (a) gullies are widely but unevenly distributed in the valley, with an average KD of 1.155 km/km², and gully distribution displays spatial autocorrelation with environmental factors over diverse scales; (b) relief amplitude (Ra), landform type, and slope are the primary factors controlling gully distribution, and land use type, precipitation, and elevation are also important factors; and (c) a high risk of gully erosion occurs in areas with an elevation of more than 1437 m, slope greater than 15°, and Ra greater than 173 m, with grassland vegetation or luvisols and cambisols soil types. These results will not only help to understand the spatial pattern and formation mechanism of gullies at the macroscopic scale but also provide a scientific reference for regional gully management.