温度和湿度对长白山两种林型下土壤氮矿化的影响

在实验室条件下,将不同含水量的两种森林类型的土柱分别置于5,15,25,和35℃条件下培养30d,分析培养前后的NH^ 4-N和NO^-3含量,确定土壤的净矿化速率,结果表明,在温度为5－35℃范围内,N的矿化速率与温度呈正相关,在一定的含水量范围内（0．46－0.54kg.kg^-1),净矿化速率随湿度的增加而升高,当含水量超过该范围,净矿化速率则随含量而降低,温度和湿度对土壤的矿化和硝化过程存在较明显的交互作用,建立了二维的方程（T,θ）来描述温度和湿度对土壤N矿化速率的影响,阔叶红松林土壤N矿化的最佳条件是温度35℃,含水量0.51kg.kg^-1,云冷杉林土壤N矿化的最佳条件是35℃,含水量0.52kg.kg^-1.

Influence of temperature and moisture on soil nitrogen mineralization under two types of forest in Changbai Moun.tain.

The effect of temperature(t) and soil water content(theta) on soil nitrogen mineralization under coniferous-broadleaved and spruce-fir coniferous forests was evaluated by using laboratory incubation method. Based on the analysis of inorganic nitrogen in soil extracts before and after incubation, it was showed that the net mineralization rate of soil nitrogen was positively related to t(alpha < 0.001) from 5 degrees C to 35 degrees C, and to water content when water contents was low, but there was a decrease in net mineralization rate when the water content was above an optimum value. The result suggested the interactive effect of temperature and moisture on the mineralization of soil nitrogen. Two dimensional (t, theta) equations to describe the effect were drawn up.