亚热带几种林分类型的土壤肥力评价研究

以江西省大岗山地区的天然次生林及其更新后的杉木林、马尾松林、马褂木林和马褂木-桤木混交林为研究对象,分析和比较了不同林分下土壤理化性质以及土壤脲酶、过氧化物酶、多酚氧化酶的活性及其动力学参数,通过主成分分析法对5种林型下土壤肥力的整体水平进行了评价。结果表明:天然次生林更新后土壤理化性质、酶活性以及土壤酶促反应动力学参数都表现出不同程度的变化;除多酚氧化酶和过氧化物酶的Km值外,其他各项酶指标都具有一定的土壤肥力评价意义;天然次生林的更新会导致土壤肥力降低,各林型土壤肥力由高到低依次表现为:天然次生林马尾松林马褂木-桤木混交林杉木林马褂木林。

Evaluation of soil fertility in subtropical forests

One natural secondary forest and four regenerated forests, i.e., Cunninghamia lanceolata, Pinus massoniana, Liriodendron chinense and Alnus|Liriodendron forests, were selected in the Dagang mountains, Jiangxi Province to study physical and chemical soil properties, the activity and corresponding kinetic parameters of soil urease, peroxidase and polyphenol oxidase. Furthermore, we evaluated soil fertility of these five forests using principal component analysis. The results show that physical and chemical soil properties, as well as the activity of soil enzymes and kinetic parameters of enzyme reactions changed in different manners after the regeneration of natural secondary forests. All parameters, except the Km of polyphenol oxidase and peroxidase, had significant effects on the evaluation of soil fertility. The regeneration of natural secondary forests led to a decrease of soil fertility in the following decreasing order: natural secondary forest > Pinus massoniana > Alnus|Liriodendron > Cunninghamia lanceolata > Liriodendron chinense forests.