退化红壤区不同重建模式森林土壤微生物碳氮特征研究

以地处江西省泰和县的退化红壤区不同植被重建模式的森林为研究对象,采用氯仿熏蒸浸提法测定不同植被重建模式森林土壤微生物量C、N的季节变化,结果表明:不同的植被重建模式对土壤微生物量C、N的影响均达到极显著(P<0.001),微生物量N大小依次表现为:阔叶林(33.67mg/kg)、针阔混交林(30.64mg/kg)、无林荒草地(28.09mg/kg)、针叶林(23.46mg/kg);微生物C量大小依次表现为:阔叶林(181.67mg/kg)、针阔混交林(162.75mg/kg)、无林荒草地(139.68mg/kg)、针叶林(136.57mg/kg)。季节对微生物量N的影响差异为极显著(P<0.001),对微生物量C的影响差异为显著(P<0.05),微生物量C、N均表现为夏、秋季高于春、冬季。微生物量C、N均与土壤全N、全C呈显著相关,能有效地反映土壤的肥力状况。综合来看,不同植被恢复模式中阔叶林最好,其次为针阔混交林、无林荒草地和针叶林。

A Study on Microbial Biomass C,N Characteristics in Different Rehabilitating Forests on Degraded Red Soil

The rehabilitated forest of different models in a degraded red soil region located in Taihe County,Jiangxi Province was taken as the object of the study. The season variation of soil microbial biomass C,N was investigated by chloroform fumigation extraction method. The results are described as follows: (1)The soil microbial biomass C,N were significantly affected by different rehabilitating models(P<0.001). The soil microbial biomass N in the forests was ranked: broad-leaved forest(33.67 mg/kg)、coniferous-broadleaved mixed forest(30.64 mg/kg)、grassland(28.09 mg/kg)、coniferous forest,and the microbial biomass C was ranked:broad-leaved forest(181.67 mg/kg)、coniferous-broadleaved mixed forest(162.75 mg/kg)、grassland (139.68 mg/kg)、coniferous forest (136.57 mg/kg).Seasons significantly affected the soil microbial biomass N(P<0.001) and had a notable effect on the soil microbial biomass C(P<0.05). The soil microbial biomass C and N were higher in summer and autumn than in spring and winter.The soil microbial biomass C and N were notably associated with the total nitrogen in soil and could effectively reflect the status of soil fertility. In general,broadleaf forest was the best model in the different rehabilitating forests,followed by coniferous-broadleaved mixed forest,grassland and coniferous forest.