山西省辽东栎单株木生长模型研究

辽东栎(Quercus wutaishansea Mary.)是山西森林分布最广泛的阔叶树种之一,兼具生态价值和良好的经济价值。通过对山西省部分山区66株辽东栎进行树干解析,选取40株辽东栎生长数据作为建模样本,其余26株作为检验样本,选择常用的6个生长方程进行拟合。结果显示,Gompertz方程拟合辽东栎胸径生长,Richards方程拟合树高和材积生长效果最好。对所选模型进行独立样本检验,相应方程的拟合精度都在95%以上。利用模型绘制辽东栎生长曲线,得出山西省辽东栎在20-55年进入胸径生长的高峰期,9-33年进入树高生长高峰期,第51年时,材积的年生长量达到最高峰,当年生长量可达0.009m³。辽东栎在生长83年后,其材积的连年生长量开始小于年平均生长量,达到适宜采伐树龄。     

辽东山区蒙古栎天然次生林生长规律研究

以辽东山区蒙古栎天然次生林为研究对象,采用72株不同林龄的蒙古栎解析木数据构建胸径、树高和材积生长模型,并对其生长过程进行分析.结果表明:Korf方程拟合胸径和材积生长效果最好,Gompertz方程拟合树高生长效果最好,R2值分别为0.8810、0.8233和0.9025,使用未参加建模的解析木数据对最优模型进行t检验...     

用生长模型改算基准年龄树高的探索

本文从生物学原理出发,结合树木高生长过程中不同年龄树高绝对比关系,给出一种拟合基准年龄树高的简便易行又经济实用的新方法—高生长模型比率拟合法,并利用刺槐数据分别用解析木直线回归法和新方法拟合出基准年龄树高值,通过方差对比检验和平均数差异性检验认为两种方法的计算结果基本相同。另对青杨数据进行了类似计算,同样取得满意效果,从而认为新方法在拟合基准年龄树高方面具有普遍意义。     

毛红椿8年生人工林生长过程研究

为了解毛红椿人工林的生长动态,并对其制定合理的经营措施,以江西省南昌县毛红椿8年生人工林的树高、胸径调查数据为基础,分析毛红椿的生长过程,拟合毛红椿人工林的树高、胸径和材积的生长模型。结果表明, Logistic方程对毛红椿树高拟合程度较好,幂函数对胸径拟合程度较好,抛物线方程对材积生长过程的拟合较好,且均通过了显著性检验。本研究为一定区域内毛红椿人工林树高、胸径、材积的生长预测提供理论参考,同时也为毛红椿人工林定向培育提供现实依据。     

遗传算法对5种理论生长方程的最优拟合研究

利用北美林肯小区黄杉6个分期的数据,选择Logistic、Richards、Korf、Gompertz和Mitscherlich 5种生长方程建立胸径随年龄变化的生长模型.分别利用遗传算法和传统拟合方法确定参数,并对拟合效果进行对比分析.研究结果显示：遗传算法对于Richards和Korf方程的拟合精度要明显高于传统拟合方法,对于Logistic、Gompertz以及Mitscherlich方程的拟合精度几乎一致.通过将检验数据带入由遗传算法拟合的方程中,除拟合后不符合生物学意义的Korf方程外,发现由剩下4种方程计算得到的预测值与实际值无明显差异（P值均大于0.05）.最终表明遗传算法对生长方程的最优拟合较传统拟合方法更有优势.     

湖北高密度杉木人工林生长规律研究

为研究湖北省高密度杉木人工林生长规律,对鄂东南地区高密度杉木人工林进行标准地调查,获取61块样地数据和183株解析木数据,建立了杉木单木树高、胸径和材积生长模型,根据拟合优度及残差指标,高密度杉木单木胸径和树高生长的最优模型选择理查德模型,单木材积最优模型选择考尔夫模型,所选模型检验精度均较高,达到拟合效果;通过绘制杉...     

塞罕坝林场华北落叶松人工林生长模型的研究

对塞罕坝林场华北落叶松人工林标准地的平均木和优势木进行树干解析,通过11m、13m、15m地位指数级的72株平均解析木和36株优势解析木资料,对华北落叶松人工林的胸径、材积与年龄之间的生长过程利用6种数学模型进行拟合,从中选出最优模型,并对模型进行检验,得出结论:在建立生长模型时应分别不同地位指数级进行;不同的生长因子须选择不同的生长模型拟合才能达到最佳效果;通过适应性检验,各回归方程拟合良好。     

美丽异木棉苗期生长节律

利用Logistic方程对美丽异木棉(ceiba speciosa)1年生容器实生苗的苗高、地径年生长节律进行拟合,结果表明,Logistic方程拟合效果显著。一年中,苗木的高生长有2次生长高峰,地径生长有1次生长高峰。采用有序样本聚类分析对美丽异木棉容器苗苗期日生长率进行分析,将苗木生长划分为生长初期、速生期、生长后期3个阶段,并根据不同阶段的生长特性提出相应的育苗措施。     

豫南杉木生长过程表的编制

收集豫南杉木不同立地指数级标准地资料,利用Richards等经典方程拟合豫南杉木生长的基本模型．编制生长过程表。并对树高、蓄积量等生长方程进行了检验,为豫南地区杉木经营活动提供了理论依据。     

长白山区3种天然阔叶林分生长规律研究

从吉林省红石林业局森林资源调查小班中筛选出天然柞树纯林、慢阔和中阔等3种林分类型,利用各林分类型的森林资源调查小班数据,对4种符合“S”型生长曲线的林分生长模型进行了构建,并对各林分类型的生长规律进行了研究。结果表明:所拟合的各林分生长模型检验精度均大于98%,拟合结果较好。其中柞树纯林和中阔以模型(4)拟合最优,慢阔以模型(2)拟合最优。3种林分中最早达到最大连年生长量和平均生长量的为中阔,其次为慢阔,最晚为柞树纯林,其数量成熟龄,分别为50,56,64a。柞树纯林、慢阔和中阔的林分生长速生期分别为27—70a,24—64a,24—54a。     

不同地理种源鹅掌楸幼苗生长适应性比较

研究了南方６省７个不同地理种源鹅掌楸幼苗在南京地区阳生生境中的生长表现，测定了２年生幼苗生长量差异和光合日进程中净光合速率差异。结果表明，就光生理而言，盐津、金平和资源等种源在南京地区的阳生生境中生长状态良好，铜鼓种源则生长较差。     

植物生长调节剂对林木生长的控制

用植物生长调节剂处理樟子松。丁香幼苗。实验表明,经处理后的幼苗。高径生长提高１５％￣３０％。樟子松小苗造林成活率平均提高１９．８７％。     

理论生长方程研究概述

理论生长方程能对林木的生长及分布作出科学合理的描述。通过对几种主要理论生长方程的起源、应用发展现状及方程间错综复杂的关系予以了较为全面的阐述,旨在使人们对理论生长方程有个清醒的认识并科学、合理地使用之,进而拓宽其应用研究领导以及推动理论生长方程的深入发展。     

EFFECT OF FERTILIZATION ON THE GROWTH OF LARCH SEEDLINGS

The primary purpose of fertilization in nursery soils is to assure production ofhigh—quality planting stock. Therefore,the appropriate information on fertilizers and their use aswell as their effects on seedling growth is important to nursery managers in their nursery practice.Inthis paper,larch seedling growth response to six fertilizers are discussed based on the results ofthree—year studies which were carried out at Dailing Forest Nursery in 1987.     

Larch and white birch growth stresses’ experimental investigation and analysis

In this paper, the equations of tree growth stresses are given by using thick-walled cylinder theory under the assumption that tree trunk is considered as a homogeneous orthogonal anisotropic cylinder. Through a lot of calculation of the experimental data, some figs of growth stresses’ distributions are given, and growth stresses distributions are analyzed.     

无性系木麻黄人工林生长规律研究

利用项目研究中设置的系统抽样样地,选择不同径阶的无性系木麻黄标准木各3株作为解析木材料,测定木麻黄的生长规律研究。结果表明:木麻黄的胸径、树高生长快速期都出现在早期,均在12a生前达到最快生长;胸径的连年生长量与平均生长量曲线在第11~12a生时相交,树高的连年生长量与平均生长量曲线在11~12a生时相交;12a生以后胸径、树高生长均逐渐减弱。木麻黄材积的连年生长量在3~12a生一直呈现较快的增长趋势,12a生以后增长很慢,在15a生时达到最大值;而材积的平均生长量一直表现为平稳的增长趋势。     

Effects of competition on growth of Amur linden plantation

IntroductionCompetitionorinterf6renceisimportantinfOrestgrowthandstandstructure(Weiner1982,1984).ForexampIe,thesizeofindividuaIcrownsanddiametersisaffectedbycompetition.Mbstint6rferencestudieshavefocusedonthemeanperformance0fplantsinreIationtodensity(Harper1977)andneighbouringdistance(Martinetal.1977;Weiner1984,Bigingeta[1992).Theyuseddistance-dependentcompetitionindices(Cl)todescribeinfluencefOrindividuaItreesthatincIudesaIIcompetitorsinthezoneofinfIuenceandprovidebettercorrelationswit…     

Evaluation of non-destructive methods of measuring growth stress in Eucalyptus globulus: relationships between strain, wood properties and stress

High levels of growth stress are implicated in causing end splitting of logs, deflection during sawing and deformation of boards as stresses are released during sawing operations. Level of stress is a function of strain and the elastic modulus of the wood (MOE). Levels of peripheral strain can be measured on standing trees and, if the MOE is known, stresses can be estimated. The validity of using peripheral strain measurements relies on underlying theoretical models that relate strain to expected patterns of stress distribution and levels of board deflection. This study evaluates these theoretical relationships by determining relationships of stress and strain with board deflection, end splitting and a range of wood properties.

Peripheral strain levels were extremely variable within the bottom log and little evidence was found for consistent patterns of variation, although measurements generally increased with increasing height above ground. Sampling on two sides of the standing tree at breast height appeared to be a suitable strategy, with the mean for these strain readings having a correlation (r) of 0.86 with the average strain in the bottom log.

Growth strain was not a reliable predictor of board deflection and cannot be recommended as a non-destructive sampling method. Overall there was a poor relationship between growth strain and board deflection. No consistent relationships were found between a range of wood properties and growth strain or board deflection across both sites. Stress levels were calculated for each tree as the product of growth strain and modulus of elasticity and the relationship between calculated stress and mean board deflection determined. No relationship was found at either site with correlations being very close to zero.

The underlying theoretical relationships between stress and strain were examined and several questions raised about the validity of such models.     

杨树新无性系苗期生长节律研究初报

1999年引进35杨、74杨、7号杨3个杨树无性系，对其生长节律进行了观测和分析，结果表明，3个杨树无性系在扬中地区都能正常完成年生育周期，对本地的土壤、气候均能适应，7，8，9月为生长高峰期。     

Cultural characters and growth of Cylindrocladium quinqueseptatum isolates1

Isolates of Cylindrocladium quinqueseptatum (CQ), which cause leaf blight of Eucalyptus in Kerala, differed significantly in growth and cultural characters on nine different agar media. Malt extract agar and yeast malt agar and yeast malt agar were the best media for discerning differences among the CQ isolates. Of the 11 carbon (C) and 13 nitrogen (N) sources evaluated in liquid media for their differential utilization by the five selected CQ isolates, five each of C and N sources differentiated them from each other. In general, organic N sources supported better growth and micro-sclerotia production over inorganic, and hexose and disaccharide over trisaccharide and polysaccharide.