摘要
通过旱冬瓜云南分布区的访问调查,在所确定的15个县的选优林分中,采用对比木法选出119株旱冬瓜初选优树,经对其初选旱冬瓜优树的8个性状作相关分析,确定以林木的材积作为旱冬瓜用材林优树的主要选择性状,采用数量化回归的方法得出材积与其林木胸径、树高、枝下高的回归方程:Y(材积)=0.055X胸径+0.021X树高+0.01X枝下高-1.406。分析表明,旱冬瓜林木材积的实测值与其理论值间差值的频率分布呈正态分布。故以其材积差值作为旱冬瓜优树选择的选择指标H,以差值平均值±标准差作为分级依据,制定了旱冬瓜用材林优树的选择标准。其标准为:(1)Ⅰ级优树,H≥差值平均值+标准差,即H≥0.066;(2)Ⅱ级优树,差值平均值+标准差>H>差值平均值-标准差,即0.066>H>-0.104;(3)Ⅲ级优树,H≤差值平均值-标准差,即H≤-0.104。Ⅰ级优树和Ⅱ级优树皆可入选,故在旱冬瓜云南分布区内共评选出旱冬瓜用材林优树104棵,占其初选优树的87.4%。
Through survey and investigation in Alnus nepalensis distribution area in 15 counties in Yunnan Province, we screened out 115 trees of Alnus nepalensis as preliminary targeted trees based on 8 relative characteristics. Among them, timber volume was treated as major character. We obtained a regression equation as： Y（v） = 0. 055XDBH＋0. 021XH＋0.01HXBB-1. 406 with diameter at breast （ DBH）, height of the trees （H）, and height below branch （HBB）. It was shown that there was a normal distribution between the actual and theoretical values of timber volume of Alnus nepalensis. Thus we took the D-value of volume as selecting indicator （H）, and average Dvalue＋standard deviation as level standard and made the standard for excellent tree level. The levels were： 1. LEVEL Ⅰ, H≥average D-value＋standard deviation, i.e. H≥0. 066; 2. LEVEL Ⅱ, D-value ＋ standard deviation 〉 H 〉 D- value-standard deviation, i.e. 0. 066 〉 H 〉-0. 104; 3. LEVEL Ⅲ, H≤ D-value-standard deviation, i.e. H≤ - 0. 104. LEVEL Ⅰ and LEVEL Ⅱ could be taken into consideration as excellent tree. According to this standard, among the 119 trees above, 104 trees could be considered as excellent tree, which was 87.4 % of all those trees.
出处
《西部林业科学》
CAS
2010年第1期6-10,共5页
Journal of West China Forestry Science
基金
国家林业公益性行业科研专项项目(200704041)
云南省技术创新人才培养计划(2006PY02-09)资助
关键词
旱冬瓜用材林
优树选择
选择标准
Alnus nepalensis forest for timber usage
excellent tree selection
standard
