全新世以来长白山区孤山屯泥炭地炭屑记录与古火演化历史

THE HOLOCENE FIRE EVOLUTION BASED ON CHARCOAL OF GUSHANTUN PEATLAND IN THE CHANGBAI MOUNTAIN, NORTHEAST CHINA

长白山拥有亚洲目前保存较为完好的温带山地森林生态系统,由于近年来无火事件发生而积累了大量可燃物,火灾隐患逐年增加,重建古火历史找出火事件发生规律有助于现代火灾的有效防控。本文以长白山区孤山屯泥炭剖面的68个样品为研究载体,选取炭屑作为主要指标反演了长白山全新世以来的火事件演化历史;并结合前人利用孢粉、植硅体等代用指标重建的古环境、古气候特征,分析了火事件的成因机制。在11 686-10 883 cal aBP、7 336-2 624 cal aBP、2 624-1 189 cal aBP,炭屑浓度较高,古火事件发生频繁,强度较大;在10 883-7 336 cal aBP、1 189 cal aBP至今,炭屑浓度较低,古火事件发生频率较小,强度相对较弱。气候和植被对于火事件的影响贯穿了整个全新世时期,火事件多发生在寒冷干燥气候时期且以区域性火事件为主;近千年以来,人类活动与火山喷发对火事件的影响显著,局域性火事件比例逐渐增多。

The Changbai Mountain forest ecosystem is currently one of the well-preserved temperate ecosystems in Asia.Recently,the fire risk caused by a large number of combustibles accumulation has increased year by year due to the occurrence of fire-free episodes.Reconstructing the historic fire episodes and explore their mechanism are beneficial to reduce the potential risk of modern fire episodes.In this paper,the charcoals as the main proxy were selected from 68 samples of the peat at the Gushantun profile to reconstruct the evolution history of fire episodes during the Holocene in the Changbai Mountain region,Northeast China.and other paleoenvironmental and paleoclimatic proxies were also adopted to analyze the mechanism of these fire episodes.The results showed the Holocene fire episodes in Changbai Mountain region occurred frequently and intensely during 11 686-9 827 cal aBP,7 773-2 560 cal aBP,2 560-800 cal aBP,while the intensity was relatively low during two periods:9 827-7 773 cal aBP,and 800 cal aBP to the present.The regional fire episodes which were affected by the cold and dry climate and vegetation throughout the whole Holocene.In contrast,the local fire episodes dominated the past millennium with the significant impact of the human activities and volcanic eruptions.