武夷山常绿阔叶林土壤氮素矿化过程的研究

Nitrogen Mineralization of Soil in Evergreen Broadleaf Forestson Mt.Wuyi

为研究武夷山常绿阔叶林土壤氮矿化过程的季节动态变化以及环境因子对其矿化作用的影响,采用野外顶盖埋管法估测氮素的矿化速率,并利用回归分析法分析其与环境因子的关系。武夷山常绿阔叶林土壤净矿化速率在低温时,随温度的升高而有所增加,当超过一定温度时,则呈下降趋势。净氨化速率的季节动态变化几乎可以代表总矿化速率的变化规律。土壤净矿化速率和土壤净氨化速率都与该地区降雨量的季节变化趋势一致。该区域干季硝化作用占优势,雨季氨化作用占优势。武夷山常绿阔叶林土壤中氨化作用起决定作用,降雨量是直接影响该地区的土壤矿化速率的重要环境因子之一。

Seasonal nitrogen mineralization of the soils in the evergreen broadleaf forests on Mt.Wuyi in Fujian was studied.The environmental factors affecting the process was investigated.The method of In-field Closed Tube Incubation was employed to estimate the mineralization rate.Data obtained were correlated by a regression analysis.At low temperatures,the net mineralization rate of the soil increased with rise of the temperature.After the temperature reached a high threshold,the rate began a downward trend.The seasonal change of the net ammonification rate basically paralleled that of the total mineralization rate.They were also similar in their responses to rainfall.In the region,the nitrification dominated during the dry season;while the ammonification in the rainy season.Ammonification played a determining role in the soil fertility of the evergreen broadleaf forests on Mt.Wuyi.And,rainfall was one of the important environmental factors directly affecting the soil mineralization.