四川长宁楠竹(Phyllostachys Pubescens)竹干形状规律及材积测定公式的初步研究

为更精确地评定竹干材积,研究了竹干形状的特性。形率按直径的分布趋于正态分布。胸高直径与形率的相关、胸高直径与形数的相关,直径与形高的相关都已作了研究,作为结论八个测定竹干材积的公式提了出来,划分为四个类型,其标准差都小于±5％。另一方面,对实积仔数也进行了研究、实积仔数随直径的增大而减小。竹产资源的计量单位,目前我国尚无统一的标准,有以重量为单位、有以株数为单位、也有以竹干材积为单位。就楠竹而论,由于竹干形体相差甚大,用株数计不能正确评定竹产资源和竹干材积,用重量计则又称量不便,加之含水率对竹干重量影响甚大,正确测定竹干含水率不是每一生产单位都很方便和可能的。比较一致的意见是赞同以材积作为评定单位较合理可行。为此有必要对楠竹干形及求积式进行研究。长宁是四川楠竹的主产区,历年来大量地提供国家建设所需的竹材。我们根据400余株标准竹和计算竹的实侧资料,对该地竹干形状进行探讨,在此基础上提出了八个竹干材积测定公式,供生产单位试用检验。

A PRELIMINARY STUDY ON STEM FORMS OF PHYLLOSLACHYS PUBESCEN AND MEASUREMENT FORMULAS FOR ITS CULM VOLUME

To estimate the bamboo resources accurately by culm volume the characteristics of stems have been studied. The distribution of form quotient at different diameters tends to approach the normal one. The relationship between diameter height and form quotient, between breast height diameter and form faetoor and betweendiameter and form height was studied. As a conclusion eight formulas for the moasurement of the stem have been worked out and divided into four types with a stan dard error less than 5％ in accuracy. The coefficient of actual volume has bee-n found to decrease as the diameter increases.