中文摘要：

采用样方法调查了秦岭山地5种典型次生林——油松林、锐齿栎林、红桦林、云杉林和华山松林幼苗的更新特征.结果表明：不同次生林木本植物幼苗物种分化明显,除锐齿栎林和华山松林外,其余次生林幼苗物种相似性系数均较低;油松林和锐齿栎林木本植物幼苗数量、物种丰富度指数、Simpson优势度指数及均匀度指数均较高,红桦林均最低;云杉林和华山松林幼苗数量及物种多样性指数基本一致.不同次生林幼苗和幼树所占比例存在明显差异,除红桦林幼树数量的比例较大外,其余林分幼苗的比例较大,为云杉林〉油松林〉锐齿栎林〉华山松林.不同林分幼苗萌生比例差异明显,为华山松林〉云杉林〉红桦林〉锐齿栎林〉油松林.锐齿栎林和油松林乔木幼苗比例最高,分别占木本幼苗总种数的68%和51.4%,群落处于演替中期,持续更新能力较强;云杉林、华山松林乔木幼苗比例分别为40%和15%,处于演替后期,更新能力较差;而红桦林中幼苗很难发育成幼树,持续更新能力欠缺.

英文摘要：

By using sampling plot method,an investigation was conducted on the regeneration characteristics of woody plant seedlings in five kinds of typical secondary forests（Pinus tabulaeformis,Quercus valiena var.acuteserrata,Betula albo-sinensis,Picea asperata,and Pinus armandii） in Qinling Mountains.There was an obvious species differentiation of woody plant seedlings and saplings in the forests.Except for Q.valiena var.acuteserrata and P.armandii forests,the similarity coefficient of the seedlings and saplings species in the forests was lower.The seedlings and saplings quantity,species richness index,Simpson dominance index,and evenness index were higher in P.tabulaeformis and Q.valiena var.acuteserrata forests,the lowest in B.albo-sinensis forest,and basically the same in P.asperata and P.armandii forests.The percentages of the seedlings and saplings in the five forests had significant differences（P0.05）.Except in B.albo-sinensis forest where the percentage of the saplings was higher,the percentage of the seedlings in the other stands was larger,and in the order of P.asperata forest P.tabulaeformis forest Q.valiena var.acuteserrata forest P.armandii forest,respectively.The sprouting percentage of the seedlings in different forests had significant difference（P0.05）,and was in the sequence of P.armandii forestP.asperata forest B.albo-sinensis forest Q.valiena var.acuteserrata forest P.tabulaeformis forest.In Q.valiena var.acuteserrata and P.tabulaeformis forests,the percentage of tree seedlings was the highest,occupying 68% and 51.4% of the total number of woody seedlings,respectively,and their communities were in the medium succession period,with a stronger persistent regeneration capability;in P.asperata and P.armandii forests,the percentage of tree seedlings was 40% and 15%,respectively,and their communities were in the late succession period,with a rather poor regeneration capability;while in B.albo-sinensis forest,the seedlings were difficult to develop into saplings,and thus,its continuous persistent