摘要
采用逐步聚类分析方法 ,对西南桦容器苗的苗木分级标准进行了初步探讨。提出以苗高和地径作为该树种容器苗分级的质量指标 ,得出了以下分级标准 :Ⅰ级苗 :苗高 2 5 2cm ,地径 0 2 6cm ;Ⅱ级苗 :2 5 2cm >苗高 19 9cm ,0 2 6cm >地径 0 2 1cm ;Ⅲ级苗 :苗高 <19 9cm ,地径 <0 2 1cm。
Grading standard of container seedling of Betula alnoides was explored by using the analysis method of gradual clustering.The seedling height and diameter at ground were proposed as the quality index for grading of container seedling.The grading standard worked out was: Class I with height ≥ 25 2 cm and diameter at ground ≥0 26 cm; Class II with height <25 2 cm and ≥ 19 9 cm, diameter at ground <0 26 cm and ≥ 0 21 cm, Class III with height <19 9 cm and diameter at ground <0 21 cm.
出处
《云南林业科技》
2003年第2期17-21,共5页
Yunnan Forestry Science and Technology
