江汉平原楸树无性系不同密度幼林龄生长分析

Growth Performance of Catalpa bungei Clones With Different Density in Jianghan Plain

在江汉平原的典型立地区域潜江市开展了24个楸树无性系造林测定试验,对两种密度(4.0 m×1.5 m、4.0 m×3.0 m)下,不同无性系2 a生和3 a生幼树的胸径和树高生长量进行了比较分析。结果表明:密度为4.0 m×1.5 m时,参试无性系2 a生和3 a生的胸径和树高平均生长量均高于密度4.0 m×3.0 m下的生长量,且不同密度、不同无性系在不同林龄时胸径和树高生长量均存在极显著差异。同时,4.0 m×1.5 m密度下2 a生和3 a生胸径及树高的重复力都大于4.0 m×3.0 m密度下的重复力。以胸径和树高为指标,采用加权系数选择指数法对不同无性系进行排序评价,发现不同林分密度间不同林龄各无性系选择指数排序结果不一致。

The growth of DBH and height of 2-year-old and 3-year-old of 24 Catalpa bungei clones with two densities were compared and analyzed in Qianjiang city,the typical area of Jianghan Plain.The results showed that the average growth of DBH and height of 2-year-old and 3-year-old clones with the density of 4.0 m×1.5 m was higher than that under the density of 4 m×3 m,and there were significant differences between different densities and clones at different forest ages.And the repeatability of 2-year-old DBH and height,3-year-old DBH and height under 4.0m×1.5m density was greater than that at 4.0 m×3.0 m density.Taking DBH and height as indexes,the selection index method of weighted coefficient was used to rank and evaluate different clones,the results showed that the ranking results of growth performance of all clones with different densities and different ages were inconsistent.