土壤粒径分形维数与土壤水分亏缺度和补偿度相关性分析

Correlation Analysis of Soil Particle Size Fractal Dimension and Soil Water Deficit and Compensation Degree

土壤水分亏缺度与补偿度是人工林水分管理的重要依据,对林分结构与密度调控具有指导意义。为了探寻更简便的指标表征土壤水分亏缺度与补偿度,笔者选择黄土高原最常见的刺槐林地、油松林地、侧柏林地,通过计算不同土层深度的土壤水分亏缺度与补偿度、土壤颗粒组成与分形维数,分析了土壤粒径分形维数与土壤水分亏缺度和补偿度之间的相关性。结果表明,刺槐林地、油松林地、侧柏林地的土壤水分亏缺度均超过63%,土壤水分严重亏缺;而土壤水分补偿度均较小,分别为4.79%,19.48%,31.12%.不同林地土壤水分亏缺度之间差异较小,且与气候、土壤颗粒组成有关;而不同林地的土壤水分补偿度之间存在显著差异,且与土壤颗粒组成的相关性较大。分形维数不仅可以很好地表征土壤粒径分布特征,也能够相对准确地衡量土壤水分亏缺度和补偿度。

Soil water deficit degree and compensation degree are important bases for water regulation of artificial forest,which have a certain guiding significance to regulate the structure and density of forest.In order to explore a simple indicator to characterize the soil water deficit degree and compensation degree,Robinia pseudoacacia,Pinus tabulaeformis,and Platycladus orientalis forestland,which were the most common forest types in the Loess Plateau area were selected as the experimental plot.Soil water deficit degree,compensation degree,soil particle distribution,and soil particle size fractal dimension of different soil depth were calculated.And then the correlation between these soil physical characteristics was analyzed.The results showed that the soil water deficit degrees of all the three kinds of forestland were more than 63%,which meant the soil water deficit was serious.While the soil water compensation degrees of the three kinds of forestland were 4.79%,19.48%,and 31.12% respectively.The difference of soil water deficit degree between different forestlands was small,and it was related to climate and soil particle composition.While there were significant differences in soil water compensation degrees among different forestlands,and it had a great correlation with soil particle composition.Fractal dimension could not only characterize the characteristics of soil particle size distribution well,but also could measure the soil water deficit degree and compensation degree relatively accurately.