武夷山常绿阔叶林土壤微生物量氮的动态变化

Microbial Biomass Nitrogen in Soil of Mt.Wuyi Evergreen Broad-leave Forest

以武夷山常绿阔叶林不同土层土壤为研究对象,研究土壤微生物量氮(SMBN)、全氮(TN)动态变化特征。结果表明:常绿阔叶林土壤SMBN含量的变化表现为夏、秋季较高,春、冬季较低;而TN含量的季节变化不明显。SMBN在0～10cm表层土壤含量高于10～30cm,差异极显著(P<0.01);10～30cm土层之间差异不显著,但均表现为自上层向下显著递减的趋势。土壤微生物量氮与土壤全氮、土壤微生物量碳(SMBC)和有机碳(SOC)之间表现出极显著相关性(P<0.01),表明土壤有机质是影响土壤微生物量的重要因素。

Seasonal changes and distributions of the soil microbial biomass nitrogen （SMBN） in different layers of soil in the main areas of evergreen broad-leave forest in Mr. Wuyi were studied during 2010 and 2011. The correlations among SMBN, total nitrogen （TN）, organic carbon （SOC） and microbial biomass carbon （SMBC） in the soil were examined. The environmental factors affecting the results were identified. It was found that （a） SMBNs were higher in summer and autumn than in spring and winter; （b） the seasonal changes of TN was not significant; （c） SMBN of G1 （0--10 cm） soil were higher than Gz （10--20 cm） and G3 （20--30 cm） ; （d） SMBN was not significantly different between Gz and G3 ; （e） SMBN decreased from top to lower layers; and （f） SMBN, STN, SOC and SMBC in 0--30 cm soil showed a significant correlation （P（0. 01）. The results suggested that SMBN was significantly affected by the organic matters presented in the soil.