林火对森林生态系统氮素循环影响(综述)

本文综述了火烧对森林生态系统氮素循环的影响,阐明火烧时氮素受热挥发（>200℃）,并随温度的升高挥发量增加,火烧后土壤氮素的有效性增强,但由于雨水和径流的浸提、搬运等引起氮素流失。其损失程度与土壤可蚀性、降雨侵蚀力及火烧后植被恢复状况及所采取的营林措施有关。并着重指出在北方林内采用低强度火烧能够加速氮素的矿质化过程,在我国南方应采取有效措施控制由于炼山引起的氮素损失。

Effect of Forest Fire on Nitrogen Cycling in Forest Ecosystems

Effect of forest fire on nitrogen cycling in forest ecosystems is comprehensively expounded. It is shown that nitrogen is volatilized by heat (>200℃ ) during a fire, and that nitrogen volatilization increases with temperature rises, nitrogen availability increases after fire, but is carried away by rainfall and rainwash, the extent of loss being dependent on the erodibility of soil, the rain eroding force, condition of vegetation recover after fire and of cultivation measures. It is emphatically pointed out that the low fire intensity would accelerate the mineralization of nitrogen in the north. And it is suggested that the available measures of controling the nitrogen loss be adopted after controlled burning in the south.