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采用稀释平板法和Biolog-ECO微平板检测法,以山杨天然次生林土壤为对象,研究了典型黑土区未经开垦干扰黑土0~150 cm土层范围内土壤微生物群落的垂直分布特征。结果表明:(1)土壤微生物总数、细菌和真菌数量随土壤深度增加呈减少趋势,以0~10 cm土层数量最高,分别为4.10×106cfu g-1干土、4.05×106cfu g-1干土和5.04×104cfu g-1干土;而放线菌数量随土壤深度的增加表现为先减后增的趋势,最高值出现在30~50 cm土层,可达0.94×104cfu g-1干土。(2)在培养168 h时,土壤微生物碳源平均颜色变化率(AWCD)的变化范围为0.09~1.21,并表现出随土壤深度增加而逐渐减小的趋势。(3)土壤微生物群落功能多样性指数同样表现为随土壤深度增加而逐渐减小的趋势,且丰富度指数、Shannon-Weiner指数、Simpson指数和McIntosh指数的变化范围分别为0~27、0.46~3.17、0.33~0.95和0.09~8.19。(4)初步确定氨基酸类、羧酸类和多聚物类碳源是未经开垦干扰黑土土壤微生物利用率较高的碳源类型。研究结果为科学评价典型黑土区土壤生境质量退化与恢复过程中微生物特征的变化提供了本底值参考。
By means of dilution plate method and Biolog-ECO microplate assay, the vertical distribution of soil microbial community in the 0-150 cm soil layer of black soil in typical black soil area was studied. The results showed that: (1) The total number of microorganisms, the number of bacteria and fungi in soil decreased with the increase of soil depth, and the highest amount was in 0-10 cm soil layer, which were 4.10 × 106cfu g-1 dry soil, 4.05 × 106cfu g-1 dry soil Soil and 5.04 × 104cfu g-1 dry soil. However, the number of actinomycetes decreased firstly and then increased with the increase of soil depth. The highest value appeared in 30-50 cm soil layer, reaching 0.94 × 104 cfu g -1 earth. (2) The average color change rate (AWCD) of soil microbial carbon source ranged from 0.09 to 1.21 after 168 h of cultivation, and showed a trend of decreasing with soil depth increasing. (3) The functional diversity index of soil microbial community also showed a trend of decreasing with the increase of soil depth, and the range of the richness index, Shannon-Weiner index, Simpson index and McIntosh index were 0 ~ 27,0.46 ~ 3.17, 0.33 ~ 0.95 and 0.09 ~ 8.19. (4) The preliminary determination of amino acids, carboxylic acids and polymer carbon sources is a type of carbon source which has no reclamation effect on the microbial utilization rate of black soil. The results provide a reference for the scientific evaluation of the changes of soil microbial biomass in the degradation and restoration of soil habitat in typical black soil areas.