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通过对亚热带3个地区地带性阔叶林和杉木林土壤活性有机质的比较,分析森林类型变化及杉木连栽对土壤有机碳和养分含量的影响.结果表明:地带性阔叶林转变为杉木林后,土壤总有机碳含量下降27.8%～52.1%、腐殖酸碳下降32.2%～52.8%、胡敏酸下降36.4%～59.0%、富里酸下降29.7%～50.0%;杉木连栽也使土壤总有机碳和腐殖质含量下降.森林类型改变和杉木连栽对土壤活性有机质的影响更明显.杉木林取代阔叶林后,土壤微生物生物量碳、微生物生物量氮、可溶性有机碳和可溶性有机氮含量的最大降幅分别为61.8%、38.2%、43.3%和69.0%;与第1代杉木林相比,第2代杉木林土壤微生物生物量碳、微生物生物量氮、可溶性有机碳和可溶性有机氮含量的最大降幅分别为34.7%、29.3%、30.4%、18.4%.经相关性分析,除冷水浸提有机氮外,土壤活性有机质与养分含量之间具有密切的相关关系.
Through the comparison of active soil organic matter in the broadleaved forest and Chinese fir plantation in three subtropical areas, the effects of forest type change and continuous plantation of Chinese fir on soil organic carbon and nutrient content were analyzed. The results showed that the broadleaved forest changed into Cunninghamia lanceolata , Soil total organic carbon content decreased 27.8% ~ 52.1%, humic acid carbon decreased 32.2% ~ 52.8%, humic acid decreased 36.4% ~ 59.0%, fulvic acid decreased 29.7% ~ 50.0% Total organic carbon and humus content decreased.Changes of forest types and Cunninghamia lanceolata plantation had more significant effects on soil active organic matter.The soil microbial biomass C, microbial biomass C, Compared with the first generation of Chinese fir plantations, the soil microbial biomass carbon, microbial biomass nitrogen, dissolved organic carbon and soluble organic nitrogen in the second generation Chinese fir plantation were the largest declined by 61.8%, 38.2%, 43.3% and 69.0% The maximum decrease was 34.7%, 29.3%, 30.4% and 18.4% respectively.According to the correlation analysis, besides the organic nitrogen extracted by cold water, the soil active organic matter had a close correlation with the nutrient content.