【摘要】 为了探讨阔叶红松林演替与原始阔叶红松林稳定性中存在的Ｎ素机制作用，１９９１年７月、在长白山（北坡）自然保护区（海拔７４０ｍ），应用近几年建立的化学和生物化学分析方法．通过分析土壤Ｎ素及有效形态ＮＯ_３－Ｎ、ＮＨ_４－Ｎ的供应和林木的Ｎ素吸收利用状况，对原始阔叶红松林及破坏后形成的两个不同龄级的杨拌林中优势树种林木的Ｎ素营养状况及树种间Ｎ素营养关系进行了研究。结果表明：１．各样地土壤中Ｎ素及其有效形态ＮＯ_３－Ｎ、ＮＨ_４－Ｎ的含量和ＮＯ_３－Ｎ、ＮＨ_４－Ｎ的转化关系和其植被组成、土壤含水率以及ｐＨ值关系较大，特别是根层土壤Ｎ素和其上、下层土壤Ｎ素关系较密切；２．原始阔叶红松林优势树种林木在Ｎ素吸收利用和土壤供应状况上一致，且树种间在Ｎ素营养上存在着缓和竞争的关系，这是其稳定的一个重要原因；３．当更新或更替树种的幼苗、幼树对Ｎ素的吸收利用适应其所处的生态环境及其Ｎ素变化时，它们才能很好地生长、更新或更替其它树种而使群落发生演替。更多还原

【Abstract】 In July of 1991,at the elevation of 740m of the Changbai Mountain Natural Reserve,we studied the N nutrient situation and relation of the dominant tree species in deciduous Koraien pine forest and two different aged poplar-birch forests to find out the nitrogen mechanism for the climax stability and community succession. Using Modern Chemical and Biochemical analysis methods,we analyzed N contents and available Nitrate(NO3-) and Ammonia(NH4-) as well as the exchange relationship between NO3- and NH4-,i.e.the nitrate reductase activity in the soil,and the N are situation and relation of the,dominant tree species.Conclusions are as follows:1.The dominant tree species in deciduous koraien pine forest to absorbt N responses with the N in soil situation,furthermore,they are some nourishment in the utilization of N among them,but they have not strong competition with each other.It is one of the major reason why the deciduous koraien pine forest is stable.2.The seedlings or saplings, absorb and utilize the N adaptation with the ecological conditions in order to survive well or to make the species alternation in the community succession.更多还原