原始阔叶红松林土壤微生物特征研究

Study on Soil Microbial Characteristics of Primitive Broad-leaved Korean Pine Forest

以凉水国家级自然保护区内的云冷杉红松林、枫桦红松林、椴树红松林和蒙古栎红松林土壤为研究对象,分别采用稀释平板法与微平板检测法,研究了4种林型不同土层之间的土壤微生物特征。结果表明:4种林型土壤微生物总菌数变化范围在1.60亿~6.29亿cfu/g之间,且细菌含量的变化差异性最大;各林型间土壤微生物活性的差异达到显著水平(P<0.05);ECO微平板在恒温条件下培养的24h内,其平均颜色变化率呈现出随时间的延长而逐渐升高的一致性规律,直至168h上升速度趋于平缓。4种林型土壤微生物各类多样性指数均表现出随土层深度增加而降低的趋势,且相同土层不同林型间的差异显著(P<0.05);各林型土壤微生物均对氨基酸类碳源产生了较强的代谢能力,更加验证了红松的喜铵特性;由主成分分析(PCA)可知,各林型表层和下层土壤微生物对各类碳源的代谢能力在空间上表现出较为显著的差异,与AWCD值和各类多样性指数所得结论一致。

The soils of the spruce-red pine forest,the maple-brown pine forest,the eucalyptus red pine forest and the Mongolian pine-song pine forest in the Liangshui National Nature Reserve were studied.The dilution plate method and microplate method were used to study soil microbial characteristics between different soil layers of the four forest types.The results showed that the total microbial population of four forest types varied from 1.60 to 620 million cfu/g,and the difference of bacterial content was the largest.The difference of soil microbial activity among different forest types reached a significant level(P<0.05).The average color change rate of ECO microplates cultured under constant temperature for 24 h showed a consistent law of increasing gradually with time,until the rising speed of 168 h tended to be gentle.The diversity indices of soil microbes in four forest types showed a trend of decreasing with the increase of soil depth,and the differences among different forest types in the same soil layer were significant(P<0.05).The carbon source produced a strong metabolic capacity,which further verified the ammonium-promoting properties of Pinus koraiensis.From the principal component analysis(PCA),the metabolic capacity of various forest types and the underlying soil microorganisms on various carbon sources appeared spatially.The more significant differences are consistent with the AWCD values and the various diversity indices.