基于2017年广东省第九次森林资源连续清查马尾松77块固定样地数据,采用主成分分析和聚类分析方法评价马尾松立地质量。结果表明:砾石含量、土壤厚度、地貌、坡位、腐殖质层厚度、坡度和枯枝落叶层厚度等7个主成分的累计贡献率达到86.32%,对马尾松立地质量综合影响较大;阈值为0.081时77个样地可以聚为4类,Ⅰ、Ⅱ、Ⅲ、Ⅳ类型单位面积蓄积分别为59.41,45.38,80.07,73.48m³/hm²,Ⅲ和Ⅳ类型明显高于Ⅰ和Ⅱ类型,砾石含量、土壤厚度、腐殖质层厚度和枯枝落叶层厚度等立地因子对马尾松立地质量影响较大。

Based on data from 77 fixed plots of Pinus massoniana in the 9th consecutive forest inventory data in Guangdong Province in 2017,principal component analysis and cluster analysis methods are used to evaluate the site quality of Pinus massoniana in this study.Research results showed that according to the principal component analysis method,the cumulative contribution rate of the seven principal components including gravel content,soil thickness,landform,slope position,humus layer thickness,slope and litter layer thickness reached 86.32%,and the overall impact is great.The cluster analysis method shows that when the threshold value is 0.081,77 plots can be grouped into 4 types,and the unit area accumulation of type Ⅰ,Ⅱ,Ⅲ,and Ⅳ is 59.41m³/hm²,45.38m³/hm²,80.07m³/hm² and 73.48m³/hm²,types Ⅲ and Ⅳ are significantly higher than types Ⅰ and Ⅱ.Site factors such as gravel content,soil thickness,humus layer thickness and litter layer thickness have a greater effect on the site quality of Pinus massoniana.