17:15 〜 19:15
[ACG39-P08] Assessment of fire disturbance and post-fire recovery in Siberian vegetation
キーワード：山火事、シベリア、植生のダイナミクス、気候変動
Siberian forests have long been considered a crucial carbon sink. However, increasing exposure to severe fire disturbances may have significantly altered their carbon dynamics. Quantifying the impact of fire on Siberian vegetation is essential for understanding regional carbon fluxes. In this study, we analyze annual leaf area changes from 2001 to 2022 using MODIS and VIIRS observations. Our results show that during this period, vegetation increased significantly across 42.7% of the region, while 6.3% experienced a decline, predominantly in wildfire-affected areas. We find that non-forest vegetation, despite having lower total leaf area, exhibited a greater annual increase (1.38 Mha per year) compared to forests (1.06 Mha per year). Fire disturbances led to a total reduction of 11.45 Mha in leaf area across Siberia, with forests experiencing the most significant loss (10.82 Mha), followed by shrublands and savannas (2.54 Mha). Notably, fire reversed the regional greening trend, having a more pronounced impact on forests than on other vegetation types. Further analysis of post-fire vegetation recovery reveals that forests not only experience a more substantial decline in LAI but also take longer to recover compared to shrublands and savannas. LAI shows a sharp decline immediately after fire, continuing to decrease in the first post-fire year. Subsequently, a rapid recovery phase is observed. Among the vegetation types, shrublands recover to 50% of their pre-fire LAI within approximately three years, followed by savannas in five years, while forests require seven to eight years for recovery. Our findings highlight the vulnerability of Siberia’s forests, shrublands, and savannas to climate-driven disturbances, raising concerns about the long-term stability of the region’s carbon sink.