土壤养分因子对蒙古栎林优势木生长的影响

Effects of Soil Nutrient Factors on the Growth of Dominant Trees in Quercus mongolica Stands

为研究土壤因子对优势木生长的影响,以60块蒙古栎林样地为研究对象,运用6种曲线模型和多元线性回归的方法建立了以表层土壤养分因子为自变量,以样地内优势木树高、胸径、材积为因变量的优势木生长模型。结果表明,优势木平均胸径和树高间相关关系不显著,而与土壤因子中的p H值、有效磷、全钾质量分数显著相关,并得到优势木平均胸径与土壤因子的3个曲线方程。运用多元逐步回归方法,仅土壤有效磷质量分数进入模型。综合曲线模型和线性回归模型发现,胸径生长与土壤养分质量分数相关关系呈现分段趋势;当胸径大于27cm时,土壤有效磷对胸径的影响明显减小。

We selected 60 Quercus mongolica stands to establish the growth model of dominant trees with 6 curve models and multiple linear regression using soil nutrient factors in the surface layer as independent variables and the height,DBH,volume of dominant tree as dependent variables. There was no significant relationship between DBH and height of the dominant trees,while DBH had significant correlations with soil pH,available P and total K,and we got three curve equations,respectively,between DBH and soil factors. Soil available P was the only nutrient factor in the multiple linear regression model. The relationship between DBH and soil nutrients indicated a segmented trend,and the influence of available P on DBH decreased significantly when the DBH was larger than 27 cm.