摘 要 ：本文用离子交换树脂袋法(lon exchange resin bag method)，测定了鼎湖山马尾松人工林土壤硝态氮和铵态氮动态情况。结果表明，鼎湖山马尾松林土壤硝态氮和铵态氮均具有明显的季节性变化，以春季最高和夏季最低。硝态氮在0～10cm和10～20cm两土层的年平均值分别为1.722和1.429μg．d-1·g-1干树脂，铵态氮在0～10cm和10～20cm的年平均值则分别为19.137和14.696μg·d-1·g-1干树脂。硝态氮和铵态氮在试验的大部分季节表现出显著的直线相关关系(P<0.05)，表明了铵态氮供应是调节硝化速率的一个重要因子。
Abstract:The dynamics of soil NH4+-N and NO3--N in a pine forest of Dinghushan were investigated using ion exchange resin bag method. Soil NH4+-N and NO3--N both exhibited significantly seasonal variations, with the highest in spring and the lowest in summer. In the soil at 0～10 cm and at 10～20 cm depth, the mean values of soil NO3-N were 1. 722 and 1.429 μg·d-1· g-1 dry resin, respectively. However, in the soil at 0～10 cm and at 10～20 cm depth, the mean values of soil NH4+-N were 19.137 and 14.696 μg·d-1· g-1 dry resin, respectively. NO3--N was positively correlated with NH4+-N at both soil depths for most seasons (P<0.05) ,indicating the importance of ammonium supply in regulating nitrification rates.