以内蒙古大兴安岭不同龄组兴安落叶松林为研究对象,分析土壤养分含量及化学计量特征的动态变化。结果表明:1)土壤有机碳(SOC)与土壤总氮(TN)、碳磷比(C:P)、氮磷比(N:P)具有极显著正相关关系;土壤TN与C:P,N:P呈极显著正相关关系;土壤铵态氮(${NH_{4}}^{+}$-N)与土壤硝态氮(${NO_{3}}^{-}$-N),C:P,N:P呈极显著正相关;土壤C:N与C:P呈显著正相关;土壤C:P与N:P呈极显著相关。2)随林龄的不断增加,土壤SOC,TN含量及C:N,C:P,N:P表现出先升高而后降低的趋势,近熟林达到最高;土壤总磷(TP)含量呈先降低后升高的趋势,中龄林最低;土壤铵态氮与土壤硝态氮的含量无显著变化规律;而土壤养分含量逐渐降低。3)土壤容重随林龄的增加表现出降低的变化趋势,各龄组土壤容重之间差异均不显著。土壤TP与土壤容重无显著相关关系,土壤SOC,TN与土壤容重具有显著相关性。

The dynamic changes of soil nutrient content and stoichiometric characteristics of Larch forest in different age groups in Greater Khinggan Mountains of Inner Mongolia were analyzed.The results showed as follows:1) Soil organic carbon (SOC) was significantly positively correlated with soil total nitrogen (TN),C:P ratio (C:P),N:P ratio (N:P);Soil TN was positively correlated with C:P,N:P.Soil ammonium nitrogen (${NH_{4}}^{+}$-N) was significantly positively correlated with soil nitrate nitrogen (${NO_{3}}^{-}$-N),C:P,N:P.Soil C:N and C:P were significantly positively correlated.The correlation between soil C:P and N:P was extremely significant.2) With the increase of stand age,soil SOC,TN and C:N,C:P,N:P showed a trend of increasing first and then decreasing,and reached the highest in the near mature stand.The content of total phosphorus (TP) in soil was firstly decreased and then increased,and the content of TP in middle aged forest was the lowest.There was no significant change in the contents of ammonium nitrogen and nitrate nitrogen in soil.The soil nutrient content decreased gradually.3) Soil bulk density decreased with the increase of stand age,and there was no significant difference in soil bulk density among all age groups.Soil TP had no significant correlation with soil bulk density,while soil SOC and TN had significant correlation with soil bulk density.