杉木拟赤杨混交林土壤肥力表征指标的研究

运用分形理论探讨了杉木拟杨混交林 6种不同模式土壤结构的分形特征 ,计算了土壤团聚体、策团聚体与机械组成的分形维数 ,并建立分形维数与 >0 .2 5mm水稳定性团聚体、土壤结构体破坏率、土壤结构系数、土壤分散系数、>0 .0 1mm水稳定性微团聚体及 >0 .0 1mm土壤机械组成等土壤肥力指标之间的回归模型。结果表明 :>0 .2 5mm土壤水稳定团聚体、>0 .0 1mm土壤水稳定性微团聚体含量越大 ,团粒结构的分形维数越小 ,土壤肥力越高 ;在 6种杉木杨混交林模式中 ,以杉木拟赤杨 3∶1与拟赤杨纯林培肥土壤能力最佳 ,杉木纯林最差 ;所建立的分形维数与各土壤肥力指标之间的模型均存在显著的回归关系 ,因此 ,分形维数可以作为表征土壤肥力的一个新指标 ,从而为山地土壤肥力的科学评价提供了有力的手段。

Study on Characteristic Index of Soil Fertility in Chinese Fir Plantation Mixed with Alniphyllum Fortunei

The frractal characteristic of soil structure under six different patterns of Chinese fir plantation mixed with Alniphyllum fortunei was discussed and the fractal dimension of soil aggregate structure,soil micro-aggregate struct ure and soil mechanical composition were calculated in this paper.Then,the telationships between soil fractal dimension ahd >0.25mm content of water stable aggregates,percentage of destroyed structure,disperse coefficient,structure coefficient,>0.01mm content of water stable micro-aggregates and>0.01mm mechanical composition were built.The results showe that the higher the>0.25mm content of water stable aggregates and >0.01mm water stable micro- aggregates in soil,the smaller the fractal dimension of soil aggregates,and the higher the soil fertility.The pattern of Chinese fir plantation mixed with Alniphyllum fortunei(3:1) and pure Alniphyllun fortunei plantation had a better fertilizing ability.The regression relationships of mine built models were all remarkable .Therefore,the fractal dimension of siol structure could be used as a index in characterizing the soil fertility and it also provided a scientific basis in evaluating the mountain soil rertility.