Fire is a major disturbance agent in the boreal forest, affecting the structure, dynamics and biogeochemical cycles in this biome. In the Asian section of boreal forest, the records of long-term fire history are few that limits our understanding of factors forcing regional fire dynamics. We presented an annually-resolved 352-year (1666–2017) fire chronology based on fire scars of Scots pine (Pinus sylvestris L.) and Siberian larch (Larix sibirica Ledeb) from the Transbaikal area in the southeastern Siberia. Fire activity showed an increasing trend from 1720 to 1929 (R² = 0.80, P < 0.0001), and a significant decreasing trend from 1920 to 2010 (R² = 0.62, P < 0.001). We assessed the potential relationships between drought (as represented by the Palmer Drought Severity Index, PDSI, and the Monthly Drought Code, MDC), ocean-atmosphere circulation and forest fire by Superposed epoch analyses, cross-wavelet analysis and Granger causality analysis. Increased fire activity was associated with stronger drought from previous winter to current summer of fire event years and positive Arctic Oscillation (AO) before and during major fire season (February and April to May), as revealed by superposed epoch analysis. Granger causality pointed to the significant role of drought in driving forest fires. Our findings provide insights into the climate drivers of forest fire activity and its prediction in the Transbaikal region.

火是北方森林中的主要干扰因素，影响该生物群落的结构、动力学和生物地球化学循环。在北方森林的亚洲部分，长期火灾历史的记录很少，这限制了我们对区域火灾动态因素的理解。我们根据来自西伯利亚东南部外贝加尔湖地区的苏格兰松 ( Pinus sylvestris L.) 和西伯利亚落叶松 ( Larix sibirica Ledeb) 的火痕，提出了每年解决的 352 年（1666-2017）火灾年表。1720—1929年火灾活动呈增加趋势（R ²  = 0.80，P  < 0.0001），1920—2010年呈显着下降趋势（R ²  = 0.62，P < 0.001)。我们通过叠加纪元分析、交叉小波分析和格兰杰因果分析评估了干旱（由帕默干旱严重程度指数、PDSI 和每月干旱代码 MDC 表示）、海洋-大气环流和森林火灾之间的潜在关系。叠加时代分析显示，火灾活动的增加与火灾事件年份从前一个冬季到当前夏季的更严重的干旱以及主要火灾季节（2 月和 4 月至 5 月）之前和期间的北极涛动 (AO) 呈正相关。格兰杰因果关系表明干旱在引发森林火灾中的重要作用。我们的研究结果提供了对森林火灾活动的气候驱动因素及其在外贝加尔湖地区的预测的见解。