Abstract
Integrated assessments of vegetation dynamics and ground thermal responses remain limited along warm discontinuous permafrost corridors on northeastern Qinghai–Tibet Plateau. This knowledge gap is particularly important for the compound G214-G0613 engineering corridor across the Bayan Har Mountains, where national highway and expressway construction jointly intensify anthropogenic disturbance to permafrost–ecosystem interactions. Here, we assessed vegetation and permafrost responses within a 10-km corridor buffer using Landsat-derived growing-season normalized difference vegetation index (NDVIgs; 2000–2020), mean annual ground temperature at the depth of zero annual amplitude from 16 monitoring sites (MAGTDZAA; 2010–2019), and modeled MAGT at 10 m depth (MAGT10m). Trend-free pre-whitening Mann-Kendall tests, Hurst analysis, segmented regression, and GeoDetector were used to quantify vegetation trends, disturbance thresholds, and dominant environmental controls. NDVIgs increased significantly across the corridor at 0.0045 a−1, while MAGTDZAA warmed at 0.012 °C a−1. Despite this regional greening, near-road vegetation degradation was concentrated within an acute disturbance zone extending 0.91 km from the corridor, with a broader transition zone reaching 2.13 km. GeoDetector results showed that annual precipitation and elevation were the dominant controls on NDVIgs variability, whereas elevation and soil type primarily governed MAGT10m patterns. Areas with high human footprint were the only class with a positive median MAGT10m (0.33 °C), indicating absent or actively degrading permafrost in warmer, lower-elevation terrain where engineering activity is concentrated. These results reveal a scale-dependent duality between corridor-wide greening and localized near-road degradation, a pattern that regional trend analyses may obscure. The study provides a quantitative basis for ecological buffer-zone design and permafrost-sensitive planning along compound engineering corridors in warm discontinuous permafrost regions.