| In this paper, taking the burned area of Larix gmelini forest in Greater Xing'an Mountains as the research object, the different management (clear-cutting, non-cutting) burned area which occurred in 2003 was selected as plots, and the non-burned area in the same site condition as a control. Samples were collected in 2014 from May to October. The soil microbial biomass carbon and soil enzyme activities was measured by biochemical methods, and the correlation of all the above parameters and soil nutrient was analyzed. The diversity of soil bacteria and fungi was analyzed by DGGE method. Therefore, current studies aimed at revealing the soil microbial characteristics under different management mode of burned area in Greater xing'an mountains, further to provide theoretical basis data for scientific management and forest regeneration after fire. The results showed as follow:1. It showed a significant monthly dynamic changes in microbial biomass carbon and nitrogen in each plots.The microbial biomass carbon and nitrogen content was high in July and August at the stage of plant growth, peaked in July, and low in May, June and September, and there were a slightly rising trend in October when the surface of soil will be frozen. And in the same month, there were significant differences in microbial biomass C and N between clear-cutting and non-cutting plots. Overall, during the growing season, the soil microbial biomass carbon and nitrogen of non-cutting plot were significantly higher than clear-cutting and control plot.2. It showed a significant monthly dynamic changes in the soil enzyme activities in each plots. The activities of urease and invertase were higher in July and August, lower in September, catalase activity was high in May and June, lower in September. In the same month there were differences between each plots. Respectively in May and June, the catalase activity of burned area was lower than that of control semple; in vigorous plant growth season, the ureasa activity of non-cutting plot was higher than the control samples, the invertase activity was lower than the control sample, the urease and invertase activities of clear-cutting plot were lower than the control sample, and catalase activity was higher than control sample.3. There was no significant correlation between the soil microbial biomass carbon, nitrogen and the soil physical and chemical factors in each plots. The microbial biomass carbon and nitrogen of burned area was impacted by soil invertase activity, there was a significant negative correlation between microbial biomass carbon, nitrogen and soil invertase in non-cutting plot (P<0.05). In addition, the microbial biomass carbon were significantly correlation with catalase (P<0.05).4. In the sane month, there were differences between richness (S),diversity index (H), evenness (E) of soil bacteria and fungi, and in a few months reached a significant differences (P<0.05). Overall, the richness (S), diversity index (H), evenness (E) of non-cutting plots soil bacteria and fungi was higher than clear-cutting plot, but changes irregularly between non-cutting and control plot, which was that richness of soil bacterium (S) showed control plot>non-cutting plots>clear-cut plots; diversity index (H) and evenness (H) of soil bacterium showed non-cutting plot>control plot>clear-cutting plots. And richness (S) diversity index (H) of soil fungi showed non-cutting plot>control plot>clear-cutting plots; evenness (E) showed control plot>non-cutting plots>clear-cutting plots. According to the results of main strip homology comparison, Actinomycetes was the dominant bacteria species, and Ascomycota was the dominant fungi species in burned soil. |
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