基于通径分析的纯林结构特征对土壤养分的影响研究

Effects of Stand Structure Characteristics on Soil Nutrients in Pure Plantations Based on Path Analysis Method

以湖北省京山县太子山林场内马尾松、柏木和杉木3类人工纯林为研究对象,运用通径分析法研究了林分各结构因子与表层土壤养分之间的直接和间接作用。结果表明,凋落物现存量、平均胸径和草本层盖度通过直接作用和间接作用共同成为影响土壤有机质与全氮含量的主导因素,影响土壤全磷含量的主要因素依次为叶面积指数(LAI)、林分年龄和林分密度,林分密度、凋落物现存量和LAI是影响土壤全钾含量变化的主导因素;所选定的8个结构因子对土壤有机质、全氮、全磷和全钾的决定系数分别为0.973、0.907、0.859和0.878,说明8个结构因子能表达影响土壤养分含量众多因素中60%以上的信息。

Direct and indirect effects of stand structure characteristics on surface soil nutrients were investigated through path analysis in three types of pure plantations （Pinus rnassoniana, Cupressus funebris, and Cunningharnia lanceolata） in Taizishan Forest Farm, Hubei Province. The results showed that the content of soil organic matter and total nitrogen were determined largely by litter amount, herb coverage and average diameter at breast height, which were leading structure factors influencing the content variation of soil organic matter and total nitrogen. Leaf area index （LAI） of canopy, stand age and stand density were three main factors affecting the content of soil total phosphorus. The content of soil total potassium was determined by stand density, litter amount and LAI. The determinative coefficients, which reflect compli- cated extents of the influences of 8 stand structure factors on the content of soil organic matter, total nitrogen, total phosphorus and total potassium, were 0. 973,0. 907,0. 859, and 0. 878, respectively. The result also indicated these 8 stand structure factors could expressed more than 60% factors that influenced the content of soil nutrients.