Abstract: A great volcanic eruption with the characteristics of Plinian eruption was happened in Changbai Mountains 800 years ago. This eruption was classified into two large scale eruption periods and the thenceforth several small scale eruptions. Great amount of volcanic particles was released at the time of the outbreak. These particles were blown to the east by the strong deflective west wind, and mainly deposited on the eastern slope of Changbai Mountains, making the vegetation in this area experience extinction several times. The vegetation type on the eastern slope was larch (Larix olgensis) forest, which differed greatly from the vegetations on the other slopes, possibly due to the devastating damage of volcanic eruption to the vegetation on the eastern slope. In this study, the original vegetation on the eastern slope before volcanic eruption was reverted through identifying the pollen spore and carbonized wood. The relationships between historical changes in vegetation and volcanic activities were analyzed, aimed to demonstrate the changes in vegetation on the eastern slope before eruption and the impacts of volcanic eruption on the evolution process of vegetation. It was suggested that larch forest is the transitional community established after the volcanic eruption.

Key words: Alkaline phosphatase(ALP), Succinate dehydrogenase(SDH), Hyphae, Mycorrhizal colonization, Growth