不同栽杉代数土壤抗蚀性的变化

THE CHANGE IN SOIL ANTIERODIBILITY IN DIFFERERNT CHINESE FIR ROTATIONS

采用标准地定位研究方法对杂木林及１代、２代、３代和４代杉木人工林土壤颗粒、土壤团聚体组成进行比较分析，结果表明：杂木林受人为干扰少，土壤颗粒及土壤团聚体组成较好，抗蚀性最好；但１代、２代、３代和４代分别是在杂木林及前１代林的采伐迹地上经再度干扰建立起来的，土壤结构破坏率加大，土壤团聚体稳定性减小，因而随着杉木林取代杂木林及杉木连栽代数增加，土壤抗蚀性减弱。

Through a comparative analysis on soil particle, soil aggregates in broad_leaved forest and Chinese fir plantation of the first , the second,the third and the fourth planting, using long_term located research, the result indicated that, owing to less artificial disturbance, soil particle and soil aggregates composition was quite good and the antierodibility was the best in broad_leaved forest; Contrarily, due to repeated disturbance by etasblishment on the cut_over area of the former rotation, decompose ratio of soil structure increased, and stability of soil aggregates declined in the Chinese fir plantation of first, second, third and fourth planting. Along with the substitution of Chinese fir, plantation for broad_leaved forest and then the continuously planting Chinese fir, soil anticrodibility impaired, which accounted for the increasing of soil and water loss and was disadvantageous for avoiding flood calamity.