闽北典型毛竹林土壤微团聚体分形特征研究

Fractal Features of Soil Micro-aggregates under Typical Phyllostachys edulis Forests in Northern Fujian Province

以中亚带常绿阔叶林和杉木林为对照，对闽北典型竹林土壤微团聚体分形维数变化特征及其与土壤物理性质、化学性质、土壤酶活性及微生物数量的关系进行了研究，结果表明：〉0．25mm和0．05～O．01mm颗粒含量越高,0．25～0．05mm，0．005-0．001mm和〈0．001mm颗粒含量越低，分形维数越小。土壤肥力与土壤分型维数有显著的相关性，土壤微团聚体分形维数与上述颗粒含量之间存在极显著或显著的回归关系；分形维数还与20个土壤肥力指标（土壤理化性质和生物活性指标）中的11个指标存在极显著负线性相关，与土壤容重极显著正相关，与毛管孔隙度、水解氮含量和过氧化氢酶活性之问存在显著的线性关系。说明土壤微团聚体分形维数能很好地表征试验林分的土壤理化性质和土壤生物活性，可作为评价土壤肥力的一项综合性定量指标。

The changes of soil micro-aggregates fractal features and the relations between fractal dimension of soil micro-aggregates and soil physical properties, soil chemical properties, soil enzyme activity and soil microbiology quantity were studied under Typical Phyllostachys edulis forests in north of Fujian Province were studied by regarded Evergreen broadleaved forest and Cunningharnia lanceolata forest as contrasts. The resuits showed that the more the contents of the cluster 〉0.25 mm and 0.05-0.01 mm and the less the contents of the cluster 0.25-0.05 mm,0. 005-0. 001 mm and d0. 001 mm,the less the fractal dimension of soil micro-aggregates and there is an obvious correlation between fractal dimension of and soil fertility, i.e. there existed highly significant or very significant relationship between the fractal dimension of soil micro-aggregates and above contents of soil cluster. There also existed highly significant negative quantitative relationship between the fractal dimension of soil micro-aggregates and 11 indexes among 20 soil fertility indexes of soil physical and chemical properties and soil biological activity indexes. The fractal dimensions were in highly significant positive correlation with the soil bulk density, and in very significant negative quantity correlation with the soil capillary porosity, the content of soil hydrolysable nitrogen and the activity of soil catalase. Obviously, the fractal dimension of soil micro-aggregates could objectively reflected the soil physical and chemical properties and soil biological activity, so it can be used as a comprehensively quantitative index to evaluate the soil fertility.