闽楠容器苗评价指标及分级标准研究

Quality Evaluation and Grading of Phoebe bournei Container Seedling

采用主成分分析和聚类分析方法,对1.5年生的闽楠(Phoebe bournei)容器苗苗木的质量评价和苗木的分级标准进行了探讨。结果表明:闽楠容器苗的质量主要取决于地上生物量、地下生物量、单株生物量,苗高、基径和质量指数也是重要指标,含水率、高径比、根冠比、侧根数为辅助参考指标综合评价;建立以苗高和地径为质量指标的闽楠苗木分级体系,获得苗木3级分级标准,即Ⅰ级苗木苗高≥42.51 cm,地径≥0.54 cm;Ⅱ级苗木,42.51 cm>苗高≥28.70 cm,0.54 cm>地径≥0.46 cm;Ⅲ级苗木苗高<28.70 cm,地径<0.46 cm。

In this paper,the quality and the standard of 1.5 years old seedling grading of Phoebe bournei was studied by using the methods of principal component analysis and cluster analysis.The results showed that the seedling quality might be determined by dry weight of the seedling.Moreover,some indices such as stem diameter and height at soil surface also very important.Seedling height and basal diameter were proposed as the main indexes of quality for seedling grading of this species.The following standards were produced for seedlings of the first to third grades.The seedlings with the height of 42.51cm or above,basal diameter of 0.54cm or above were classified as grade one,those with height lower than 42.51cm but higher than or equal to28.70cm,basal diameter lower than 0.54cm but higher than or equal to 0.46cm were classified as grade two,those with height lower than 28.70cm and basal diameter lower than 0.46cm were classified as grad three.