对九曲溪生态保护区次生阔叶林、马尾松人工林、竹林和茶园4种类型林地土壤团聚体的分形特征进行分析,探讨分形维数与土壤平均质量直径和几何平均直径及理化性质的关系。结果表明:4种林地土壤团聚体的分形维数均为2.375～2.658(干筛)和2.627～2.863(湿筛),土壤团聚体分形维数在0～20、20～40、40～60 cm土层均表现为:阔叶林<竹林<马尾松林<茶园,且均随土层深度的增加而增大;4种林地干筛和湿筛条件下>0.25 mm的团聚体百分数和>5 mm的大团聚体百分数与土壤团聚体分形维数表现为相反的变化趋势,即阔叶林的最大,竹林和马尾松林次之,茶园的最低;而结构体破坏率与土壤团聚体分形维数表现为一致的变化趋势,0～60 cm土层为阔叶林(21.31%)<竹林(26.18%)<马尾松林(31.98%)<茶园(38.25%);土壤团聚体分形维数与平均质量直径、几何平均直径及土壤理化性质关系密切。次生阔叶林土壤疏松,持水能力强,土壤有机质及养分含量高,土壤结构稳定性好;竹林和马尾松林次之;茶园土壤结构稳定性最差。 The fractal characteristics of soil aggregates in four types of forest land in secondary broadleaved forest, masson pine plantation, bamboo forest and tea garden in Jiuquxi Ecological Reserve were analyzed. The fractal dimension, soil mean diameter, geometric mean diameter and physico-chemical properties Relationship. The results showed that the fractal dimensions of soil aggregates were 2.375 ~ 2.658 (dry sieve) and 2.627 ~ 2.863 (wet sieve), respectively. The fractal dimension of soil aggregates was 0-20, 20-40 and 40-60 cm The soil layer showed as follows: broadleaf forest 0.25 mm in 4 kinds of woodland dry sieving and wet sieving> 5 mm , And the fractal dimension of soil aggregates showed the opposite trend, which was the largest in broadleaf forest, followed by bamboo forest and masson pine forest, and the lowest in tea plantation. The failure rate of the structure and the fractal dimension of soil aggregates For the consistent trend of change, 0-60 cm soil layer was broad-leaved forest (21.31%)