中文摘要：

研究了马尾松次生林在轻度、中度、强度和无火干扰情况下林地土壤化学性质5年内的动态变化规律。结果表明：除有机质以外，火干扰对土壤pH值、土壤CEC、全N、碱解N、全P、全K和速效K的影响持续期不长，大多在两年左右恢复到火烧前的水平；随着火干扰强度的增大，土壤有机质损失越大，全P含量下降，速效P升高；火干扰强度对I层有机质、速效P含量和Ⅱ层速效P含量的影响极显著（P〈0．05），不同时间点I层有机质和Ⅱ层速效P含量随火干扰影响的趋势有明显的差异（P〈0．05），分别拟合了轻度火干扰、中度火干扰和强度火干扰下有机质和速效P含量随时间变化趋势模型。

英文摘要：

The dynamic rules of soil chemical properties of Pinus massoniana were studied under different intensities of fire disturbance from year 2001 to 2005. The results showed that the duration of fire disturbance affecting soil pH value, CEC, total N, hydrolysis N, total P, total K and available K was not long except organic matter. For most of the nutrients, it took about 2 years to restore to the level before fire. With the fire intensity increasing, organic matter lost more seriously and total P contents decreased, but available P content increased. The influence of fire disturbance on organic matter, available P in the first layer and available P in the second layer was extremely remarkable （P〈0.05）. The influence tendency between different sampling time on organic matter in the first layer and available P in the second layer of different time was changing obviously （P〈0.05）, then the model of organic matter and available P was fitted separately for slight fire disturbance, intermediate fire disturbance, intense fire disturbance.