【作者】 卢军；

【导师】 李凤日；

【作者基本信息】 东北林业大学 ， 森林经理学， 2008， 博士

【摘要】 本研究利用帽儿山天然次生林区2007年所调查的30块标准地和176株解析木的数据,共获得样木4237株,剔除枯死木,剩余3628株;获得枝条3401个,其中标准枝694个。测量样木的胸径、树高、冠幅、坐标和活枝高度等因子,并对解析木分段进行了枝解析和叶量的收集。用2915株样木建立了单木冠长率模型,其余713株作为检验数据;用枝解析的数据建立了次生林各树种的枝条解析模型,分析枝条梢头的着生位置建立了树冠轮廓模型,根据叶量在树冠相对高度上的累积百分比建立了叶量模型。研究次生林内几种空间结构指标,并根据多样性混交度、聚集指数、竞争指数和树冠叠加指数建立了天然次生林择伐空间优化模型,采用数学规划的思想对其求解,并应用到现实林分中。研究的主要内容包括:1、根据次生林内树木的大小(SIZE)、竞争(COMP)和立地(SITE)3个方面因子组的分析,利用Logistic的形式来建立10个树种单木的冠长率模型,并用多重决定系数砰来判断各个因子组对模型的贡献率。参数的拟合结果表明,三个因子组中林木的大小和竞争对树木的冠长率影响较大,而立地条件相对较小。树种的冠长率随着胸径的增大而增大,与树木的冠幅之间也是递增的关系,也是与树木的年龄成正比的。各个树种的冠长率模型的检验结果表明,10个树种的预估精度都超过了91%,除了枫桦和色木,都通过了置信椭圆F检验。几种偏差值都较小,尤其是ME和MAE值很小。多数树种的相关系数R相对较低,只有白桦和枫桦较高,超过了0.9。2、用分段的多项式所建立的枝条基径的三种模型,得出基径和枝条的着枝深度、胸径、树高和冠长之间有密切关系:建立的三种枝长模型是以树木的着枝深度、胸径和树高为自变量的;弦长与枝长之间是极显著的线性关系,可用对数形式来描述;枝条的着枝角度与总着枝深度、树木胸径、实测树冠半径、树高等因子的关系可以用多元线性方程来表示;着枝角普遍都分布在20～50度之间,这个区间的分布比例一般都能达到枝条数量的60%以上,不同树种的比例不太相同。而小于20度的枝条一般在20%左右变化,大于60度的枝条非常少,70～80度之间的枝条十分稀少,大于80度的枝条可能是测量的误差。着枝角的分布与着枝深度有密切的关系,着枝角度在树冠的上层时一般都较小,而随着树冠深度的增加,中层的枝条的枝长开始增大,枝条的重量随着基径和枝长在增大,着枝角度会明显增大,因此在这个范围内的分布最广,占了大多数。而到了树冠的下层时,枝条的着枝角度也较大,但是数量较少。对基径、枝长和弦长模型进行了检验,检验的结果较好,有较高的相关系数和预估精度。3、本研究认为阔叶树种的树冠轮廓并不是简单的从梢头到冠底增加的,根据分层枝解析的结果,把树冠分成2个部分,上层和中层作为一部分,用三次反抛物线式来建立h高度处树冠半径与冠内相对高度的模型;把树冠的下层的枝条作为一部分,也是用抛物线的不同形式建立不同树种的树冠轮廓模型。这些形式能较好的用几何位置来表现阔叶树种的树冠轮廓。4、用传统的三参数Weibull分布等形式无法很好的说明阔叶树种的叶量分布特点,而对数正态分布能描述这种特点。本研究用“S”曲线的形式来建立树冠内累积叶量百分比CF%和树冠内枝条相对高度RPC的模型,效果良好。并且得出,每个树种在树冠内相对高度上的叶量的垂直分布是不同的,天然次生林阔叶树种的叶量在树冠的上部(0.3CL以下)所占比例很小,约占10%左右;在树冠的中部以及中下部(0.4CL～0.8CL),叶量所占比例最大,几乎集中了整个树冠60%～75%的叶量;而在树冠的下部(0.8CL以下),几乎占很少的叶量,大约10%左右。5、采用Hegyi竞争指数来表现次生林内林木的竞争关系,并且根据竞争圈的大小和林木在竞争圈内的分布位置、大小与距离来计算有效的竞争木,并不是传统意义上的全部竞争木;本研究提出用树冠叠加指数(Crown area overlap index)来表示林木与周围树木的树冠竞争情况,并采用等树冠投影面积法把树冠分为5级,这样计算的树冠叠加指数更加与现实林分相符。6、本研究基于乘除法的思想,用多样性混交度、聚集指数、竞争指数和树冠叠加指数构建了天然次生林择伐空间优化模型,设计了10个与林学意义相一致的约束条件,并采用0-1整数规划的思路,在LINGO9.0软件中使用了隐枚举法对目标函数求得最优解。7、以M702标准地为应用实例,具体计算出了每株采伐木,经过择伐后,目标函数值按模型设计的要求发生了极大的改变,增加了5倍多,说明了最后这个解的优良性,满足了设计的要求。径阶数、树种数都保持不变,Shannon-Weiner指数增加了3.5%。约束条件中的q值减小了约6.6%,次生林的多样性混交度和聚集指数分别增加了2.5%和4.1%,竞争指数和树冠叠加指数分别减小了19.99%和50.93%。采伐量是小于林分的总生长量的,林木的蓄积减少了27.03%。目标函数的10个约束条件在经过择伐优化模型的求解后,都得到了满足,目标函数值显著的增加,在符合了设计的要求的同时,也与林分的林学意义相一致。本研究首次建立了天然次生林冠长率的模型,研究了次生林内主要阔叶树种的枝条的特征,建立了多种适用于阔叶树种枝条解析的模型,并且首次尝试建立阔叶树种的树冠轮廓模型,这些都取得了较理想的模拟效果。提出树冠叠加指数来描述林木树冠之间的竞争关系,更好的解释并量化了树木对光环境的适应能力。最后,以应用实例来描述次生林空间结构的特点,确定了采伐木,优化了林分的空间结构。这些理论和实践相结合的思路为次生林的经营提供了科学、数量化的经营理念,是对继承与发展传统方法的一次有益尝试。更多还原

【Abstract】 This study utilized 30 permanent sample plots and 176 stem analysis trees in Mao’er Mountain experimental secondary forest area which was investigated in 2007 and obtained 4237 sample trees,the died trees and sub-arbor trees were eliminated then the sample trees remained 3628;also 3401 branches data were measured among which 694 standard branches were gained.In all plots,diameter at breast height,tree height,crown width,coodinates and height to living crown base etc.were measured,besides,the detailed analysis of branches and foliage collection were conducted with 1 meter per sections of stem analysis trees.The individual tree crown ratio models for 10 major species epending on 2915 sample trees and the remaining 713 were used for validation were designed.Moreover,the branches analysis models for 10 species in secondary forest were established by the data of branch attributes, established crown profile models by analyzing insert positions of branch tips,and,established foliage models by cumulative percent of biomass in the relative crown length.Several spatial structure indices were dealed with and according to diversity mingling,aggregation index, competition index and crown area overlap index,a spatial structure optimizing model of secondary forest stand selective thinning was developed which can be solved by mathematic programming and apllied to the realistic stand.The primary works are below:(1)According to the analysis of tree size,competition and site in secondary stand,crown ratio models were developed for 10 species in the form of Logistic equation,and multiple coefficient was used to determine each factor groups contribute to the models.The parameters estimate results pointed that tree size and competiton between neighbour trees effect crown ratio greatly,whereas,site of stand effects little.All species crown ratio increase with diameter at breast height,as well as it with crown width and age of tree.The validation for each species crown ratio model indicats that the precision of prognose are all exceed 91%,also pass the Ftest except Betula costata and Acer mono.The value of deviation was all small especially mean error(ME) and mean absolute error(MAE).(2)Based on piecewise polynomial to develope 3 models of branch,there is a resulting close reletivity between branch diameter(BD) and the branch deepinto the crown(DINC),DBH, HT,and crown length(CL);3 branch models according to DINC,DBH,and HT as independent variables were provided;there is a high significance between branch chord length and branch length,the relationship can be described by the form of logarithm;a multiple linear equation was used to express the relationship between branch angle of origin and total DINC, DBH,crown radius and HT.Branch angle of origin generally distributed between 20 degree to 50 degree which can reach more than 60%in quantity,different spcecies had different proportion.Origin angle of branch less than 20 degree took 20%,there were few branchs with origin angle more than 60 degree,and seldom with angle between 70 to 80,furthermore,the angle bigger than 80 degree maybe resulted in measurement error.The distribution of branch angle was corelated to DINC of branch,the branch angle distributed in upper layer of canopy were generally small and with DINC increase the branch length of middle layer of canopy began to proglong,simultaneously,the weight of branch increased with branch diameter and length,hence,the branch angle of origin increased obviously and took the majority proportion. Howerver,in down layer of canopy the degree of branch angle were big all the same,the proportion was the smallest.The resulting branch diameter,branch length and branch chord length models were evaluated and appeared to behave well with high correlation coefficient and prognose precision.(3)This study considers the profile of broad-leaved species are not simply enlarged from the apex to crown base,depending on the stratified clip of branches the crown was divided into 2 parts,the first part was consisted of the upper and middle layer which could be developed the profile models of crown radius and relative height in the crown at a height of h in the form of cubic parabolic curve.Took lower layer of crown as the second part and used the similar parabolic curve in different forms to develope the profile models.All these forms performed crown profile for borad-leaved species well by geometry position of branch tips.(4)The tranditional three parameter Weibull distribution and others had no capability to describe the foliage distribution of broad-leaved species in secondary forest,other than Lognormal distribution.The cumulative distribution of foliage percent(CF%) and relative height into the crown(RPC) was found to follow a sigmoid shape from the crown base to the top of the tree in the study and performed well.The result pointed out that the vertical distribution of foliage for each species was different,however,generally speaking,the foliage in upper crown (0.3CL) for broad-leaved species in natural secondary forest took a small percentage,about 10%;in middle or middle lower of the crown(0.4CL to 0.8CL) the branches here took the majority percentage of whole foliage,almost 60%to 75%;but in lower crown(0.8CL),there was about 10%of whole foliage.(5)The interspecies competition of trees in secondary forest was expressed by Hegyi competitioin index,and the active competitor was calculated by the competition zone radius and the tree position,DBH,and distance in the zone,it was not all competitors in tranditional calculation.The study introduced crown area overlap index to describe the crown competition between subject tree and its competitors,furthermore,the crown area was classified into 5 levels with a method of equal crown projection area,therefor,the resulting crown area overlap index showed more realities of existing stand conditons.(6)Based on the theoretics of multiply divide,the spatial strcture optimizing model of secondary forest stand selective thinning was developed by diversity mingling,aggregation index,competition index and crown area overlap index,also designed 10 constraint conditions which were related to forestry meanings,the objective function was solved by the implicit enumeration method with LINGO 9.0,using 0-1 integer programming.(7)The model took M702 sample plot as an application example to specific every felled trees,and the value of objective function was changed quite significant which was increased more than 5 times after selective thinning,these proved that it satisfied the requirement of model design.Diameter class,species remained their steadiness while Shannon-Weiner index increased 3.5%.The value of q in constraint conditions decreased 6.6%,as the competition index and crown area overlap index decreased 19.99%and 50.93%respectively,howerver, the diversity mingling and aggregation index increased 2.5%and 4.1%respectively.The yield from felling less than the increment of stand and the volume decreased 27.03%.10 constraint conditions were all satisfied after the objective function solved which value increased obviously,these result reached the model design requirement as well as accorded with forestry meanings.This study,for the first time,established crown ratio models for natrual sencondary forest, besides,established branch analysis model acceptable for broad-leaved species by research branch attributes of major species in secondary stand,furthermore,the crown profile models for these trees were attempted to be developed,eventually,the results of these models obtained really good simulation.The study found out the crown area overlap index to describe the competition between crowns,these efforts quantified the ability to adapt light environment of broad-leaved species.Finally,the felled trees were determined and the spatial structure of stand was optimised in the application of example plot which showed characteristics of secondary forest in detail.The combination of forestry theories and practice will provide scientific,quantitative ideas for secondary forest decision-making,it is aslo a useful attempt to succeed and develope the tranditional forest management.更多还原