中文摘要：

对胡桃楸人工林进行控制火烧，利用摄像机记录火烧情况，对火烧前后土壤pH值、全氮、速效氮、速效磷、钾、钙、镁等化学性质的变化及其与林火能量释放指标的相关性进行了分析。结果表明，火烧使胡桃楸人工林土壤肥力总体增加。火烧后土壤pH值、速效磷、钾、钙、全氮、速效氮增加，镁变化不显著。火烧对土壤各主要化学性质影响的程度与点烧时的能量释放有关，其中全氮、速效氮、速效磷的绝对变化值与样地总能量释放呈负相关，镁的绝对变化值和钙的相对变化值与单位面积能量释放呈正相关，而pH值和钾与这两个能量释放指标都不相关。上述所有化学性质的变化与林火强度都不存在线性相关关系，以林火强度为依据划分的轻度地表火和低度地表火对土壤各化学性质变化程度没有影响。同时对林火烈度与林火能量释放诸指标的关系进行了讨论。

英文摘要：

A controlled burning experiment was conducted in Manchurian walnut plantation using video camera to record the burning process. Analysis was made on the changes of pH, total nitrogen（ TN）, available nitrogen（ AN）, available phosphorus （AP） , Potassium, Calcium and Magnesium in soil after burning and also on the correlation between the changes and the energy release in the burning. Results indicate that fire causes the Soil more fertile with pH, AP, K, Ca, TN and AN increased and Mg not changed. The changes of TN, AN, and AP are negatively correlated with total energy release. The change of Mg and percentage change of Ca are positively correlated with unit area energy release. The changes of pH and K are correlated neither with total energy release nor unit area energy release. All the changes of these soil properties are not correlated with fire intensity. The light surface fire and low intensity surface fire classified by fire intensity have no significant effect on the changing extension of these properties. The relationships between fire severity and energy release indexes were also discussed.