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2007—2008年,采用氯仿熏蒸浸提法测定了落叶松和水曲柳人工林土壤微生物生物量,研究施N肥对土壤微生物生物量碳、氮,以及细菌、真菌和放线菌数量季节变化的影响.结果表明:落叶松林地土壤微生物生物量碳、氮两年平均值分别比水曲柳林地低13.8%和18.3%,但两种林分土壤微生物生物量碳、氮具有相同的季节变化规律:5月最低,9月最高;表层(0～10cm)土壤微生物生物量碳、氮及微生物数量均高于亚表层(10～20cm)土壤.但细菌、真菌和放线菌数量的季节变化格局与生物量不同.施肥降低了两种林分的微生物生物量碳、氮,以及细菌、真菌和放线菌数量,其中,落叶松林地微生物生物量碳和氮分别降低了24%和63%,水曲柳分别降低了51%和68%.说明施N肥限制了土壤微生物生物量,改变了土壤微生物的群落结构.
2007-2008, the soil microbial biomass of Larix gmelinii and Fraxinus mandshurica plantations were determined by fumigation with chloroform. The seasonal variation of soil microbial biomass carbon, nitrogen, and bacteria, fungi and actinomycetes were studied. The results showed that the mean values of soil microbial biomass carbon and nitrogen in larch forest were 13.8% and 18.3% lower than those in the wood of Fraxinus mandshurica respectively, but the soil microbial biomass C and N had the same seasonal change The law was the lowest in May and the highest in September. The soil microbial biomass carbon, nitrogen and microbial biomass in surface layer (0 ~ 10cm) were higher than that in subsoil (10 ~ 20cm) soil, but the seasonal changes of bacteria, fungi and actinomycetes The pattern was different from that of biomass. Fertilization reduced the microbial biomass C and N, as well as the number of bacteria, fungi and actinomycetes in the two stands, in which the microbial biomass C and N decreased by 24% and 63% , Manchurian ash decreased by 51% and 68% respectively, indicating that application of N fertilizer limited soil microbial biomass and changed the community structure of soil microorganisms.