【作者】 姜生伟；

【导师】 李凤日；

【作者基本信息】 东北林业大学 ， 森林经理学， 2009， 博士

【摘要】 本研究以不同年龄、不同密度及不同立地条件的落叶松(Larix olgensis Hengy)人工林作为研究对象,基于19块标准地中95株标准木的树干解析、枝解析及节子剖析数据,揭示了不同林分条件下林木的枝条数量及在树冠内的空间分布格局、生长发育规律;研究了不同大小树木的死枝和节子大小及其变化规律,分析了枝条的生长、被压、寿命和自然整枝过程,评价了节子大小和分布对木材质量的影响;以林分变量、林木变量和着枝深度等为自变量建立枝条生长和节子大小的动态预测模型;选择林分因子和林木的树冠因子作为竞争因子,用多元逐步回归的方法建立落叶松人工林与距离无关的单木生长模型,并根据研究地区选取的130株造材样木数据,建立了落叶松人工林最佳削度方程。在此基础上,分析了林地条件对落叶松干形的影响,在不影响林木生长前提下,合理地确定人工整枝的高度和相应抚育经营措施,控制树干上死枝和节子的大小,提高木材质量。研究结果表明:1、落叶松人工林活树冠内各轮生枝内枝条个数受遗传因素影响,与林木条件无关;总体上近似于正态分布,平均值为5个。树冠垂直方向上,相邻着生的枝条数量呈现“峰”“谷”相邻的状态,水平分布服从均匀分布;枝条着枝角的分布与着枝深度(DINC)有密切的关系,着枝角度随着树冠深度的增加明显增大,并且在树冠中层分布最广,数量也最多。而在树冠的下层时,枝条的着枝角度也较大,但是数量较少。2、落叶松人工林树冠总枝条数是胸径(DBH)的函数。林木的胸径(DBH)和树高(HT)变量可很好地反映不同大小树木的冠形变化。枝条的大小与着枝深度(DINC),以及胸径(DBH),树高(HT)有关。枝条基径,长度可用以这三个因子为参数的线性模型来描述。以Mistcherlich和Richards理论方程作为基本模型,引入林木的年龄、胸径和树高因子,可分别描述不同大小林木的枝条基径和枝长的动态生长3、落叶松人工林每轮死枝内节子的平均直径(KDmean)随着节子的着生高度的增加而持续增加,最大的节子分布在树干的中间部位约12m处。节子平均直径可以用以胸径(DBH),冠幅(CW)和节子高度(HK)为参数的舒马克生长方程来预测,用树木胸径(DBH)和冠长(CL)可对每轮节子平均直径的最大值及位置进行预测;健全节长度可用以节子着生高度(HK)、相对直径(RKD)、节子直径(KD)以及树木胸径(DBH)为参数的线性混合模型来预测,疏松节长度采用节子相对直径(RKD)和胸径(DBH)为自变量的可转化为线性模型的自然对数模型来预测;4、节子有四个生长发育时期:从枝条形成到生长停止(BC);从生长停止到死亡(CD);从死亡到包藏(DO);从形成到包藏(BO)。每个时期的:年轮数与相应时期的年轮宽度可作为独立变量用基于树木和节子因子的模型进行预估;5、以15处树干各相对高度的带皮直径数据建立的落叶松人工林最佳削度方程,提高了削度方程模拟各树种干形变化的精度,可很好地估计落叶松不同林木大小(胸径和树高)任意部位的去皮直径或任意小头直径时的材长。6、林木自身大小(D)和相对直径(RD)、林木的冠幅(CW)及立地质量(SCI)为参数建立的与距离无关的落叶松人工林的单木生长方程表明,立地质量越好的林地中,对象木自身的胸径与林分平均直径之比越大,林木自身的冠幅越大,进行光合作用的效率越高,其直径的生长量也越大。7、密度对落叶松松林木干形有一定的影响,密度越大,林木的干形相对来说越好。适宜的密度对落叶松林木干形有一定的改善作用。根据侧枝相对生长曲线法,落叶松人工林第一次修枝时间应该在15年左右,修枝强度应为树高的40%到50%。本项研究将在提高我国落叶松人工林林木生长量,干形控制和木材质量方面提供坚实的理论基础和经营方法,具有重要的理论和现实意义。更多还原

【Abstract】 Based on the data of stem analysis,branch analysis,and knot characteristics from 95 sample trees in 19 sample plots for Larix olgensis Hengy plantations with different age, different stand density,and different site,the total number,spatial distribution and development process of branches in crown under different forest conditions were discussed in this paper. Dead branches or knots in different sizes of tree was studied and different branch development phases of growth,suppression,death and self-pruning was analyzed to evaluate the effect that knot size and distribution impact on timber quality.Branch and knot dynamic models were developed using stand and tree variables.Based on multipleunit stepwise regression method, the individual tree growth model was established using forest and crown factors as the variable. The best taper equation model of Larix olgensis was bucking data of 130 sample trees selected in the studied area.The effect of forest condition on step form was analyzed and proper pruning heightand relevant management measures were determined to control dead branch and knot size along the stem and improve timber quality.The results are followed:1.The branch numbers in every whorl does not relate with forest conditions and they are affected by genetic factors.It obeys normal distribution with average value is 5.There is a adjacent peak and valley of branch number in the vertical distribution of primary branches and uniform distribution was appropriate to reflect branching pattern around the bole.Branch angle is related with the depth into crown(DINC).It increased with the increseament of DINC. There are large branch angles in the middle of crown with smaller value and few in the lower crown with larger value.2.The total number of branch is the function of DBH.And the variables of DBH and HT can reflect the diversity of crown structure.Branch size is mainly related with its depth of crown(DINC),DBH and HT.The linear model with variables of DINC,DBH and HT can predict the branch diameter and length.Based on the Mistcherlic and Richards theory growth equation,the variables of AGE,DBH and HT were introduced to established branch dynamic models to predict the growth of branch diameter and length.3.The average value of knot diameter(KDmean) increased with the increasing of knot height and the biggest knots were located in the middle of stem,which is about 12m.The Shumacher equation can predict KDmean with the variables of HK,DBH and crown.The tree diameter at breast height(DBH) and crown length(CL) can be used to predict the size and location of mean knot diameter in a whorl.A linear mixed model expressed as function of tree and knot variables such as HK、RKD、KD and DBH was used to predict sound knot length(KLsound),and a log-linear mixed model using RKD and DBH as variables was used to describe loose knot length(KLloose).4.A knot has four development phases:from the birth of a branch to its growth cessation (BC),from growth cessation to death(CD),form death to occlusion(DO) and form birth to occlusion(BO).The numbers of annual rings in four periods,as well as the stem width of respective zones were used as dependent variables predicted by models expressed as function of tree variables and knot attributes.5.Using the data of diameter out side bark of 15 relative heights along the step,the best taper equation for Larix olgensis was established.It can improve the precision of using taper equation to simulate the step form diversity.It also can predict the diameter inside bark of the trees or the timber length of the trees of different size.6.The individual tree growth model using the tree size(D),relative diameter(RD), crown width(CW),crown length ratio(CR) and site quality(SCI) as variables was established. The model showed that the trees with larger crown width in a forest with good site quality and the trees has large relative diameter,usually has large diameter increase for higher photosynthesis efficiency.7.The forest density has some effect on tree step form.The step form is good in the forest with larger density and the proper forest density can improve the step form.According to the method of branch relative growth curve,the first pruning of Larix olgensis is about 15 years and the intension is about 40%to 50%.6.The individual tree growth model using the tree size(D),relative diameter(RD), crown width(CW) and site quality(SCI) as variables was established.The model showed that the trees with larger crown width in a forest with good site quality and the trees has large relative diameter,usually has large diameter increase for higher photosynthesis efficiency.7.The forest density has some effect on tree step form.The step form is good in the forest with larger density and the proper forest density can improve the step form.According to the method of branch relative growth curve,the first pruning of Larix olgensis is about 15 years and the intension is about 40%to 50%.These results can provide theory base and management method for improving forest increment and timber quality which is of great significance.更多还原