Abstract: [Objective]This study aimed to classify forest communities, and quantitatively analyze the spatial distribution of forest communities and its relationship between environmental factors and fire disturbance factors, so as to provide the scientific guidance for conservation of species diversity and sustainable taiga forest management of Kanas in Xinjiang.[Method]The pyrogenic succession taiga forest community in Kanas was taken as the research object. Based on the survey of 149 forest community sample plots and the occurence time and severity of fire disturbance, the Two-way indicator species analysis (TWINSPAN) method was used to classify the forest communities at different successional stages in the scientific experimental area of Kanas National Nature Reserve. The redundancy analysis (RDA) method was used to rank the forest communities, the interrelationship among the distribution of forest community, environmental factors and fire disturbance factors was analyzed, and the effects of environmental factors, fire disturbance factors and its interactions on the spatial distribution of forest communities were quantitatively separated.[Result]The 149 survey plots were classified into sixteen types of forest communities by TWINSPAN. The results of the RDA ordination clearly reflected the relationship between the forest community formation and environmental factors and fire disturbance. The altitude, slope position, aspect, soil organic and total potassium content in environmental factors played an important role in the distribution of forest community. Among them, altitude, location, slope position and aspect were significantly correlated with the first RDA axis (P<0.01), soil organic and total potassium content were also significantly correlated with the first RDA axis (P<0.05). In terms of fire interfering factors, fire disturbance severity also affected the distribution of forest community. There was a highly significant correlation between fire severity and second RDA axis (P<0.01). Factor segregation showed that among the factors affecting the formation of the community, 21.96% were explained by environmental factors, 1.80% by the fire disturbance factors, 49.82% by the interaction between the above two factors, and 26.42% were not determined.[Conclusion]There are sixteen forest communities in the experimental area of Kanas National Nature Reserve. The forest community distribution is collectively controlled by environmental factors and fire disturbance factors, and the interaction between them is particularly prominent as well. Fire disturbance is an indispensable and important factor for the conservation of species diversity and the sustainable forest management of Kanas in Xinjiang.

Key words: taiga, forest community, fire severity, TWINSPAN, RDA