Abstract: To understand the mechanism and process of taiga along the pyrogenic succession in Kanas, Xinjiang, we investigated topography, soil, fire disturbance and species importance value by typical sampling method. The types and characteristics of taiga communities, as well as the factors influencing species distribution pattern, were analyzed using canonical correspondence analysis (CCA) and multivariate regression trees (MRT). The results showed that there are 172 species, 125 genera and 43 families of vascular plant species in Kanas taiga. Based on life form, these species can be divided into 7 tree, 19 shrub and 146 herbaceous species. Elevation, total potassium concentration, fire severity and posfire time were the main factors affecting species distribution in Taiga forest along the pyrogenic succession. Communities can be classified into six categories using MRT in Kanas taiga: (1) Betula pendula+Picea obovate Vaccinium hirtum-Carex atrata+Elymus sibiricus community, (2) B. pendula+P. obovate-V. hirtum+Spiraea chamaedryfolia-C. atrata community, (3)Larix sibirica+B. pendula-V. hirtum+Rosa spinosissima-C. atrata+Eremosyne pectinata community, (4)Pinus sibirica+L. sibirica-V. hirtum+Linnaes borealis-E. sibiricus+E. pectinatacommunity, (5)L. sibirica-V. hirtum+Lonicera caerulea-Vicia tenuifolia+E. sibiricus community, and (6) L. sibirica+P. obovate-V. hirtum-E. sibiricus+C. atratacommunity. In conclusion, variation in species distribution of taiga along the pyrogenic succession was mainly determined by topography, soil and fire disturbance. Within the factors -related to topography, soil and fire disturbance, altitude, fire severity and postfire time were the key factors driving the formation and persistence of communities in Kanas taiga.

Key words: carbon source, carbon sink, net carbon emission intensity, Yangtze River Delta, spatiotemporal pattern.