Fire has emerged as a critical disturbance agent in the boreal forest ecosystems of Northeast Asia

Boreal forests in Northeast Asia serve as critical global carbon sinks and biodiversity hotspots, yet their long-term disturbance dynamics—particularly across the politically complex China–Russia border—remain significantly understudied. To address this gap, this research presents a comprehensive 37-year (1986–2022) transboundary assessment of forest disturbances using an integrated framework combining Landsat time-series analysis (LandTrendr) with machine learning (Random Forest). Our analysis identified 26561.34 km² of disturbed forest, representing 16.93% of the total forest cover in the region. The results revealed significant heterogeneity in disturbance drivers: while logging constituted the most extensive agent in cumulative terms (accounting for 64.00% of total disturbances), fire has emerged as a critical and intensifying disturbance agent, particularly after 2000, accounting for 23.08% of the total disturbed area and driving episodic peaks (e.g., in 2003). Anthropogenic disturbances (e.g., infrastructure expansion) accounted for the remaining 12.92%. Notably, non-fire disturbances (logging and anthropogenic) exhibited a marked decline after 2008, reflecting the effectiveness of enhanced forest protection policies and land-use adjustments. In terms of post-disturbance dynamics, we observed a counterintuitive pattern where vegetation spectral recovery rates following high-severity disturbances exceeded those of low-severity events, likely driven by improved light availability and the rapid establishment of fast-growing pioneer species. Furthermore, recovery trajectories varied distinctly by agent, with logging sites demonstrating the highest recovery potential, whereas permanent anthropogenic disturbances imposed the most persistent constraints on regeneration. These findings provide novel insights into the cross-border connectivity of disturbance-recovery processes and underscore the pressing need for adaptive, transboundary forest governance in the face of escalating climate-driven fire risks.