根据５ａ长期定位观察结果,本文应用两模型参数ｔ检验、弹性分析及边际分析法,探讨年时间序列对炼山与对照的杉木人工幼林养分流失的效应。ｔ检验表明,不同处理在年时间序列上的铵态氮、亚硝态氮、硝态氮、磷酸盐、钾、有机质流失模型的Ｂ、Ａ参数存在显著差异。弹性分析和边际分析表明,年时间对不同处理的上述养分效应呈负效应,在炼山条件下,上述养分流失的弹性系数分别为－１．２１５％、－１．２１４％、－１．２１５％、－１．２１５％、－１．２４１％、－１．２１４％,上述养分流失的边际量分别为－０．３９４ｋｇ、－０．０３３ｋｇ、－０．３６５ｋｇ、－０．０２３ｋｇ、－３０．０１０ｋｇ、－５９．４２１ｋｇ。在不炼山处理下,上述养分流失的弹性系数分别为－０．８４２％、－０．８５１％、－０．８４４％、－０．８５４％、－０．８４５％、－０．８４１％,上述养分流失边际量分别为－０．１５９ｋｇ、－０．０１０ｋｇ、－０．０８５ｋｇ、－０．００６ｋｇ、－１２．０２４ｋｇ、－１７．７６７ｋｇ。

On the basis of the results of a long term fixed location observation of 5 years, this paper uses the two model parameter t test, the elasticity analysis and the marginal analysis for exploring the effects of the annual time series on the nutrient losses of controlled burning and the the constractive young Chinese fir plantation.The t test shows that the B and A parameters of the loss models of amoniacal nitrogen, nitrous nitrogen, nitrate nitrogen,phosphate, potassium and arganic matter on the annual time series are quite different under different treatments. The elasticity analysis and marginal analysis show that the effects of annual time on the above mentioned nutrients under different treatments are negative. Under the controlled burning conditions, the elasticity coefficients of the above mentioned nutrient losses are-1.215%, -1.214%, -1.215%, -1.215%,-1.214% and-1.214%respectively,and their marginal amounts are-0.394 kg,-0.033 kg-0.365 kg, -0.023kg, -30.010 kg and -59.421 kg respectively. Under the treatments without controlled burning, the elasticity coefficients of the above mentioned nutrient losses are -0.842%,-0.851%, -0.844%, -0.854%, -0.845% and -0.841% respectively, and their marginal amounts are -0.159 kg, -0.010 kg, -0.085 kg, -0.006 kg, -12.024 kg and -17.767 kg respectively.