云南红豆杉萌枝类型的划分、生长特征及其异速生长

Classification,Growth Characteristics and Its Allometric Growth of Taxus yunnanensis Sprouts Types

利用主导萌枝结构特征的云南红豆杉分类方法,探明不同类型幼树生长特征及其异速生长现象。以4年生云南红豆杉幼树为研究对象,通过比较3组成对萌枝特征指标(萌枝高度与萌枝相对高度,最大萌枝基径与平均萌枝基径,最大萌枝长与平均萌枝长)间及其与生长特征间的相关性,构建萌枝结构特征指标体系。采用通径分析方法确定主导萌枝结构特征并划分不同萌枝类型,比较不同类型生长差异,并采用标准化主轴分析法分析其异速生长关系。结果表明:3组成对萌枝结构特征指标间均呈极显著正相关;构建了萌枝相对高度、平均萌枝长度、平均萌枝基径、萌枝数量的指标体系。萌枝相对高度是云南红豆杉的主导萌枝结构特征,并依此划分3个不同类型(低位类型:萌枝相对高度0~0.33;中低类型:萌枝相对高度0.33~0.67;高位类型:萌枝相对高度0.67~1.00。)。不同类型幼树树高、地径、冠幅、材积指数、单株生物量等生长性状均存在显著差异,且随类型的萌枝相对高度上升而持续减小。除低位类型的树高与地径、冠幅与树高、地径与个体大小间为等速生长外,幼树的其他生长特征间、生长特征与个体大小间呈极显著的异速生长关系。类型间冠幅与树高,树高、地径、冠幅与个体大小间异速生长指数差异显著。不同类型的树高与地径具有共同异速生长指数。不同萌枝类型间云南红豆杉幼树生长特征及其异常生长关系差异显著。

A classification method of sprouts Taxus yunnanensis based on the dominant sprout structure characteristics was proposed,andthe growth characteristics and its allometric growth of T.yunnanensis saplings of different types were explored in this paper.Taking the 4-a sprout T.yunnanensis saplings as the research object,the index system of sprouts structure characteristics was constructed by compared the correlation of between three groups paired sprouts indicators(such as sprout height and sprout relative height,the maximum and average sprouts base diameter,the maximum and average sprouts length),the correlation between three groups paired sprouts indicators and growth characteristics.The dominant sprouts structure characteristics were determined by using path analysis method,and then the sprouts types were divided.The differences of saplings growth characteristics of different types were compared,and the allometric relationship was analyzed by standardized major axis analysis.The three groups paired sprouts indicators of T.yunnanensis saplingswere significantly positively correlated,so it was necessary to screen characteristic indicators,and then the index system of T.yunnanensis sprouts structure characteristics were constructed with the sprout relative height,the average sprouts length,the average sprouts basal diameter and the sprouts number.The sprout relative height was the dominant sprouts structure characteristics of T.yunnanensis,and the saplings were located at three types which classified based on the sprout relative height as follows:low type,middle type and high type,which had a sprout relative height of 0-0.33,0.33-0.67 and 0.67-1.00,respectively.There were significant differences in tree height,ground diameter,crown width,volume index and biomass per plant of saplings among different types,and showed continuous decreased with the type sprout relative height increased.In addition growth relationships between tree height and ground diameter,crown width and tree height,ground diameter and individual size of low type was isometric,growth relationships among other growth characteristics and between growth characteristics and individual size showed extremely significant allokinetic growth.There were significant differences in allometric exponent index between crown width and tree height,tree height,ground diameter,crown width and individual size among different types.The tree height and ground diameter of T.yunnanensis different sprouts type of saplings exhibited a common allometric exponent.There were significant differences in the growth characteristics and itsallometric growth of T.yunnanensis saplings among different sprout types,it showed that the method and system for types classification was scientific and effective.There is no consistency allometric growth relationship among different sprouts types,it represents the growth and adaptation strategies of different sprouts types saplings.It was suggested that low type should be adopted to develop the raw material forest.