不同栽植代数杉木林土壤结构特性的研究

对杂木林及一代、二代、三代杉木人工林土壤颗粒、土壤团聚体组成以及土壤孔隙状况的比较分析，结果表明：杂木林受人为干扰少，土壤结构性能最好；一代杉木林取代杂木林炼山时，土壤结构性能出现一定程度的退化，属于较好类型；在一代杉木林基础上再度进行干扰，土壤结构退化较为严重；三代林由于林下植被大量生长，对林地土壤结构恢复有利，但二代和三代杉木林土壤结构性能均较差，属同一类型．

Soil Structure Characteristics in the Plantations of Cunning hamia Lanceolata on Different Rotations

Soil particle, aggregate composition and porosity distribution in the broad leaved forests and Cunninghamia Lanceolata stands of the first, the second, and the third rotation were studied comparatively. The results indicate that, the soil structure of broad leaved forest was the best because of low disturbance of human activity. With the controlled burning and planting,Cunninghamia Lanceolata plantation of the first rotation replaced broad leaved forest, the soil structure then degraded to some extent.The planting of Cunninghamia Lanceolata of the second rotation disturbed the soil again, the soil structure degraded seriously. As to the Cunninghamia Lanceolata stand of the third rotation, the greatly growing of the undergrowth vegetation helped improve the soil structure, but the soil structurewas still poor.The soil structures of the second and the third rotations belong to the same gype.