赤水河下游紫色土不同形态钾含量与地形要素及毛竹林植物多样性指数的关系

研究了赤水河下游紫色土不同形态钾含量与地形要素及毛竹林植物多样性指数的相关规律。结果表明:1)紫色土不同形态钾含量在毛竹林不同类型及土层间差异不显著,随土层厚度增加,全钾含量增加、速效钾含量降低。全钾含量与土壤主要物理指标相关性不显著,速效钾含量与A (B)层土壤密度及孔隙度相关性显著,不同形态钾含量与不同土层土壤阳离子交换量、以及表层土壤有机质含量、全氮含量及有效磷含量相关性显著。2)毛竹林乔木层植物Margalef指数、Simpson指数、Shannon-Wiener指数和Pielou指数值随毛竹重要值降低而增加,灌木及草本层植物多样性指数值变化的趋势性各异。不同层内植物多样性指数相关性显著,不同层间植物Margalef指数、乔木和灌木层植物Simpson指数相关性显著。3)不同土层土壤全钾含量与乔木及草本植物多样性因子相关性显著,速效钾含量与地形及草本植物多样性因子相关性显著。土壤全钾含量与毛竹林乔木、灌木及草本层植物多样性指数间相关显著的直线和二次多项式指标对数量分别为50.00%、50.00%,土壤速效钾含量的相应值为13.89%、44.44%,表明土壤不同形态钾含量与植物多样性指数关系存在无关型、直线型和曲线型3种类型,印证了毛竹林植物多样性的土壤生态功能多样性。

Correlation of Purple Soil Potassium Contents with Terrain Factors and Plant Diversity Indices of Moso Bamboo (Phyllostachys pubescens) Forest at Downstream of Chishui River,Guizhou Province,China

Correlation of the contents of potassium at different forms in purple soil with terrain factors and plant diversity indices of moso bamboo (Phyllostachys pubescens) forest were studied in this paper at the downstream of Chishui river, Guizhou Province, China. The results showed that:(1) No significant variation has been ever found between the purple soil's contents of different forms of potassium in different types of moso bamboo forest and soil stratum, and as the soil thickness increases from surface to mother rock, the total potassium content is increasing and the available potassium content is reducing. The total potassium content is not significantly correlated with main physical indicators of soil while the correlation coefficient of the available potassium content and soil density and porosity of A (or B) stratum was significantly. The contents of different forms of potassium is significantly correlated with the cation exchange capacity of different soil stratum, and the content of organic matter, the total nitrogen content and the effective phosphorus content in surface soil; (2) Values of Margalef index, Simpson index, Shannon-Wiener index and Pielou index of tree layer in the moso bamboo forest increase with the reducing bamboo important values, and the plant diversity index values of shrub and herb layers are different. The plant diversity indices values of different layers are significantly related, and Margalef index values of different layers is correlated significantly with Simpson index of the tree and shrub layers; (3) The total potassium contents in different soil layers are significantly correlated with the plant diversity factors of tree and herbaceous layers, while the available potassium contents are significantly correlated with the factors of terrain and herb plant diversity. The linear and quadratic polynomial numbers of significant correlation between the soil total potassium content and plant diversity indices of tree, shrub and herb layers are 50.00% and 50.00%, respectively, and the corresponding values of the soil available potassium content are 13.89% and 44.44% in the moso bamboo forest. It showed that the relationship between different form of soil potassium contents and plant diversity indices includes 3 types, i. e., no correlation, straight correlation and curve correlation, which confirms the diversity of soil ecological function, which is embodied in moso bamboo forest plant diversity.