少穗竹种质秆形结构建模研究

通过对少穗竹的胸径、竹高、枝下高、节间长等秆形因子进行了调查分析,结果表明:立竹胸径与竹高具有显著相关性,最佳拟合方程为H=0.1373D+2.1639 (R=0.976),H=0.4401D0.7726(R=0.979)；立竹胸径与枝下高相关性系数不高；尖削度最佳拟合方程为Y=0.0011X3-0.0246X2+0.0399X+1.0266 (R=0.997)；节间长随高度的增加先增大,后减小, 最大节间长出现在第9～11节处,节长与节间的最佳拟合方程为Y=0.006X3-0.3997X2+6.7965X+9.1536 (R=0.984).     

杉木人工林目标树经营技术参数的研究

对浙江省杉木Cunninghamia lanceolata主要分布区51个不同发育阶段杉木人工林典型样地调查,分析不同优势木高杉木人工林的径级结构,并利用126株优势木数据,建立杉木人工林优势木的胸径、树高、冠幅之间关系,得出胸径与树高相关关系的最佳回归方程为:Y=0.361 8X+4.497 9,模型的拟合度R^2=0.796 5(X表示胸径,Y表示树高);胸径和冠幅的相关关系的最佳回归方程为:Y=0.137 9X+0.858 9,模型的拟合度R^2=0.881 6(X表示胸径,Y表示冠幅)。通过对3株50年生杉木人工林大径级林分优势木的树干解析,研究大径级杉木人工林优势木的胸径、树高与材积的生长规律,结果显示生长率都呈现逐年降低趋势,树高较为明显。树高、胸径、材积生长率最大值出现在10年生时分别为5.278 7%,15.069%,25.895%;而50年生时仅为0.273 3%,0.186 9%,0.921 7%。研究提出杉木人工林目标树经营的发育阶段划分、合理密度、目标树数量等关键经营技术参数,为杉木人工林的目标树经营提供理论依据。     

华北落叶松人工林树高和胸径的坡位差异与坡面尺度效应——以六盘山香水河小流域为例

在六盘山香水河小流域选择了一个水平长398.2 m和生长33年生华北落叶松人工林的典型坡面,调查分析了华北落叶松胸径与树高的坡位差异及随坡面水平长度变化的空间尺度效应。结果表明:(1)林分的胸径和树高都存在明显的坡位差异,从坡顶向下均表现为先增加后减小的变化趋势。(2)林分平均胸径、平均树高、优势木平均高均存在坡面尺度效应,即平均胸径的坡面滑动平均值在离开坡顶的0~200 m和200~398 m的水平距离范围内每增加100 m时增大0.33 cm和减少0.21 cm;平均树高的滑动平均值在0~67、67~305、305~398 m的水平距离范围内每增加100 m时分别减少1.12 m、增大0.31 m、减少0.10 m;优势木平均高的坡面滑动平均值在0~250 m、250~398 m的水平距离范围内每增加100 m时增大0.42 m和0.07 m。(3)各样地的平均胸径、平均树高、优势木平均高与坡面加权平均值的比值(Y_1、Y_2、Y_3,小数)随离开坡顶相对水平坡长(X,小数)变化的数量关系为:Y1=-0.312 8X2+0.239 1X+0.986 4(R~2=0.56)、Y_2=-0.483 4X3+0.304 3X2+0.125 0X+0.959 2(R~2=0.43)、Y_3=-0.177 5X~2+0.230 8X+0.941 6(R~2=0.26),藉此可由特定坡位的样地调查值推算整个坡面平均值,实现树木生长指标从样地到坡面的尺度转换。     

苏云金杆菌对龙眼裳卷蛾敏感菌株的筛选试验

用鳞翅目比较敏感的4种苏云金杆菌菌液浸渍龙眼叶片,喂食3～4龄龙眼裳卷蛾幼虫,5 d后感染浓度与死亡机率值回归方程为Y1=1.063 5+0.451 5X,Y2=-1.447 0+0.813 0X,Y3=0.205 9+0.615X,Y4=3.002 6+0.117 9X;半致死中浓度LC50值分别为5.236 8×108、8.517 1×107、6.237 4×107和8.7648×1015cell/ml.以3×108cell/ml浓度感染4龄幼虫,其致死中时间LT50值分别为5.747 3、3.557 2、4.817 7、16.086 2 d.结果表明Bt(2)菌株对龙眼裳卷蛾毒力次于Bt(3),但致死中时间最短,可供农林业生产上应用于林间防治.     

锈色粒肩天牛卵期预测预报的研究

锈色粒肩天牛是我国森林植物检疫一类重要的钻蛀性害虫 ,幼虫蛀入木质部后 ,一切防治手段较难奏效 ,准确掌握卵期预报是防治成败的关键。通过 1 997～ 1 999年恒温、变温饲养测定 ,2种方法统计计算 ,卵的发育起点温度C =1 2 2 9± 3 1 0或C =1 2 2 6± 0 81或C =1 2 0 2± 1 57;有效积温K =1 64 63± 3 2 1 2或K =1 74 67± 9 0 2或K =1 75 52± 1 6 3 0 ,理论表达式为Y =1 2 2 9± 1 64 4 2X、r =0 .983 1 >r0 .0 1=0 .60 55或Y =1 2 2 6± 1 74 67X、r =0 .991 0 >r0 .0 1=0 .683 5或Y =1 2 0 2± 1 75 52X、r =0 .93 3 4 >r0 .0 1=0 4 487,其预测式N =1 64 .4 2± 3 2 .1 2T -( 1 2 .2 9± 3 .1 0 ) 或N =1 74 .67± 9.0 2T -( 1 2 .2 6± 0 .81 ) 或N =1 75.52± 1 6.3 0T -( 1 2 .0 2± 1 .57) 。其中以变温饲养更趋简便、实用 ;以变温加权法计算更趋合理、准确     

皱大球蚧产卵与卵期预测预报的研究

皱大球蚧是国槐等多种园林树木的重要害虫。准确预报其发生量与若虫孵化期是防治成败的关键。 1999年 5月对产卵末期虫体重、体长及产卵量的测定和室内恒温、变温饲养的研究表明产卵量与体重、体长相关方程式分别为 :Y1=- 2 0 0 7 6 782 + 76 85 1 3738X1,Y2 =- 12 4 2 6 0 813+ 2 6 99 16 6 4X2 ,卵发育起点温度C =13 5 1± 0 5 0℃或C =13 2 1± 0 0 9℃ ;有效积温K =187 4 7±8 79DD或K =192 4 8± 1 5 9DD。经 2 0 0 0年检验与实际符合     

贵州省撑绿竹竹材质量表的研究编制

对贵州省撑绿竹栽培区13个县(市)67个点342株样株胸径、株高、枝下高以及竹材质量的实测值,分别以胸径、株高、枝下高为自变量(x),以竹材质量(Y)为因变量,采用一元线性、二次函数、三次函数、幂函数、指数函数等数学模型分别拟合它们之间回归方程,并对方程进行差异显著性检验,经分析比较选择因变量竹材质量(Y)与自变量胸经(x)建立的回归模型Y=1.093-0.788X+0.315X2编制贵州省撑绿竹竹材重量表,在生产上具有可靠和简洁实用的优点。     

果桑叶面积指数与产量的关系

以种植于蒙自草坝农场果桑园的果桑大10品种为对象,对果桑的叶面积与叶长、叶宽的相关性、叶面积生长动态、叶面积指数与产量的关系进行了研究,结果表明:果桑叶面积与叶长、叶宽的相关回归方程分别为Y(叶长)=-100.799 2 16.7483X(R = 0.978 0)和Y(叶宽)=-75.983 1 18.118 6X(R = 0.971 5);果桑叶面积的生长动态在夏伐前后其叶面积指数由0逐渐增长8.30和5.28,至落叶又为0,叶面积生长呈上升趋势,最快的时期是2～4月.果桑采果时的最佳叶面积指数为6～9.     

四川桤木立木干材材积收获模型

根据 16 0株样木资料 ,以年龄 (X1)、胸径 (X2 )、树高 (X3 )、枝下高 (X4 )、冠幅 (X5)为说明变量 ,建立以立木干材材积 (Y)为基准变量的收获模型。     

基于无人机机载激光雷达的桉树蓄积量估测技术研究

桉树Eucalyptus spp.人工林蓄积调查是林业生产经营的重要工作,无人机机载激光雷达能够自动获取大面积桉树人工林的激光点云数据,为计算桉树蓄积量提供新的方法。研究通过试验样地实际数据,建立了桉树树高(X)与胸径(Y)的回归模型:Y=3.611 6e~(0.067) ~(4X),并结合激光雷达软件获取的株数、树高估算样地总蓄积量。比较激光雷达测量与实地测量结果发现,激光雷达测量的株数比实测株数少27.09%,平均树高高8.67%,平均胸径大8.25%,总蓄积量小22.68%。因此,对于大尺度获取桉树成熟林的总蓄积量V,可以使用V=V_0/(1-22.68%)对激光雷达测量的总蓄积量V_0进行修正。     

昆嵛山赤松纯林赤枯病特征及与林分因子的关系

【目的】解析和定量评价林分因子对赤松赤枯病发生(发病率和病情指数)的影响,为昆嵛山赤松纯林的营林措施和赤枯病的预防提供理论指导。【方法】在昆嵛山区域选取林龄相对一致(约34年)的赤松纯林为研究对象,调查林分密度、郁闭度、树高、枝下高、胸径和冠幅6个林分因子及赤枯病的发病率和病情指数,采用方差分析、相关性分析和多重比较分析各项林分因子与赤松赤枯病之间的关系,并通过冗余分析得影响赤枯病发生的关键因子。【结果】赤枯病在赤松林中普遍发生,发病样地占调查样地的96.3%。整体上,高密度林( 2 956 ~4 089株·hm -2 )的发病率和病情指数显著高于低密度林(688~1 822株·hm -2 )和中密度林(1 823~2 955株·hm -2 )的发病率和病情指数;疏林(郁闭度<30%)的发病率和病情指数显著低于中疏林(郁闭度30%~70%)和密林(郁闭度> 70%)的发病率和病情指数;在不同的树高、枝下高、冠幅和胸径分组中,发病率和病情指数均随着分组值的增大而减小。相关性分析表明:林分密度对赤枯病发病率和病情指数的影响均达到极显著正相关水平( r =0.761, P < 0.01;r =0.748, P < 0.01);赤枯病的发病率和病情指数也均受到郁闭度的极显著影响( r =0.509, P < 0.01;r =0.442, P < 0.01);二者与树高均呈极显著正相关( r =-0.443, P < 0.01;r =-0.362, P < 0.01);赤枯病的发病率和病情指数均随枝下高的增大而极显著减小( r =-0.460, P < 0.01;r =-0.419, P < 0.01);二者与胸径均呈负相关关系,且相关性极显著( r =-0.425, P < 0.01;r =-0.373, P < 0.01);随着冠幅的增大,林木发病率和病情指数均极显著降低( r =-0.345, P < 0.01;r =-0.381, P < 0.01)。冗余分析证明林分密度和枝下高对赤枯病发生的贡献最大。【结论】松赤枯病在昆嵛山区域发生较普遍但不严重,其发病率和病情指数在不同林分因子分组中均有差异,且均受各林分因子极显著影响。RDA分析证明,林分密度和枝下高对松赤枯病影响最显著,建议对昆嵛山区域赤松纯林赤枯病的防治工作要以重要因子为主要调控对象,进行合理修剪和间伐。     

云南松人工林分材积生长率预测模型初步研究

本文根据在四川盐源县棉垭林场收集的10块云南松林分解析标准地资料,采用多项式任意逼近的方法,分别不同地位等级建立以年龄、直径单因子为解释变量的云南松人工林分材积生长率预测模型。经收集检验样本检验结果,能在研究区内使用,开展云南松人工林森林资源动态监测、组织合理经营及检验经营效果提供了依据。 测定森林生长量是掌握森林资源动态情况和进行科学营林的一项重要的基础工作。建立林分材积生长率模型间接估测森林生长量是森林生长量的间接估测法之一,其实质是依据林分材积生长率与林分直径和年龄具有紧密的相关规律的理论。在估测总体中收集有代表性的资料,探索森林的生长规律,建立生长预估模型。它具有避免直接测定法重复直接取样的大量工作量和直接测定误差、节省人力和经费开支等优点。     

Effect of microenvironmental quantitative regulation on growth of Korean pine trees planted under secondary forest

Korean pine (Pinus koraiensis) and broadleaved mixed forest in Northeast China has been changed regressively into secondary forest with almost no conifers. Planting Korean pine trees under the canopy of secondary forest is a feasible approach for recovering Korean pine and broadleaved mixed forest. For establishing an effective growth promotion method for under-canopy planted young Korean pine trees, two stands were selected as the experiment plots, Stand A (planted in 1989) and Stand B (planted in 1982), and an experiment of microenvironment regulation was conducted relying mainly on Opening degree (K=1, K=1.5, K=2, CK) in 2004. The results were shown that the adjustment had promoted growth of diameter and height of Korean pine planted in Stand A and Stand B, and had a significant influence on the growth rate of basal diameter, diameter at breast height and height in the two growth stands. The four years periodic increment of mean diameter and height of Korean pine planted in 1989 and in 1982 after regulation in K=1 level were 63.4% (D₀) and 82.7% (H), 64.8% (D_1.3) and 69.7% (H) higher than that of control respectively. Quantitative regulation had significant influence on specific leaf area of Korean pine planted in 1989, and the current year specific leaf area (SLA) was lager than perennial year SLA. Quality indexes of natural pruning capacity, normal form quotient and crown size was not significantly changed but shown a positive tendency. The regulation scheme of Opening degree K=1 might be proper for adjusting the microenvironment of Korean pine trees planted under the canopy of secondary forest when the Korean pine trees were in the growth period of 15 to 26 years old in the experiment region.     

幼树不同直径对立木材积和生物量解释能力研究

利用马尾松幼树的样木实测数据,分析不同直径与立木材积和生物量模型确定系数之间的关系.结果表明:不同高度处直径对材积和生物量变动的解释能力并没有显著差异,但相对而言胸径的解释能力一般都要好于地径;对于材积模型而言,胸径仍是最合适的解释变量,而对于生物量的解释,0.5 m处直径可能比胸径更合适.     

14年生火炬松优良家系选择

在福建省漳平五一国有林场,对美国引进的火炬松第1代种子园25个家系试验林进行测定,以湿地松、马尾松为对照。结果表明:火炬松早期生长较易感染松针褐斑病,保存率较低;14年生火炬松家系总体生长优于湿地松、低于马尾松;各家系在树高、胸径和材积等性状上有着显著差异;综合各性状共选择出4个优良家系(21、9、18、13号),14年生树高、胸径和单株材积的平均值分别为12.6 m、20.4 cm、0.1981 m3,比湿地松增长9.2%、25.9%、71.1%,遗传增益达8.9%、24.7%、67.9%。     

Improving harvester estimates of bark thickness for radiata pine (Pinus radiata D.Don)

Harvesters estimate bark thickness primarily from diameter over bark (DOB) and use it to estimate log volume and value. Harvester bark thickness estimation errors can reduce returns through poor bucking optimisation and out-of-specification logs. Radiata pine bark thickness data from harvested logs and permanent sample plots (PSP) were analysed to determine best-fit coefficients for current and potential future harvester bark thickness models. The most suitable current harvester bark thickness model for radiata pine is: double bark thickness = b ₀ + b ₁*DOB (the ‘DOB model’). This describes a straight line, whereas radiata pine bark relative to DOB is thicker near the stem base and consistent over the remainder. PSP data set coefficients for this model overestimated upper stem bark thickness and underestimated lower stem values. The harvester model for Scots pine bark fitted better than the DOB model for diameters <400 mm but performed poorly for larger logs, as it is restricted to trees with a diameter at breast height <590 mm. Two better models were identified: (1) a model using relative height to account for bark thickness changes with height, and (2) implementing separate DOB models for the bottom 10% and top 90% of the stem split by relative height. These approaches require approval by the StanForD committee to be implemented. Prior to approval, the upper 90% model coefficients could be applied to the entire stem to improve upper 90% stem volume and value predictions at the expense of the lower 10%. Further research will determine if this approach produces acceptable results when optimising bucking. Increasing variability of bark thickness estimates with increasing DOB in the PSP data set may reflect manual measurement errors with thicker bark or may show that additional explanatory variables are needed. Efforts to identify new variables would need to be weighed against additional returns and probable reductions in numbers of larger trees by as the clearfell age is reduced.     

A merchantable volume system for major pine species in El Salto,Durango (Mexico)

A compatible volume system for the major pine species in El Salto, Durango (Mexico) was developed from data corresponding to 1930 destructively sampled trees. Several well-known taper functions were evaluated and compared against the model selected in a previous study of these pine species in the same area. Appropriate statistical procedures were used in model fitting to account for the problems of autocorrelation and multicollinearity that are associated with the construction of taper functions. A compatible segmented model best described the experimental data and was found to be better than the previously selected model. It is therefore recommended for estimating diameter at a specific height, height to a specific diameter, merchantable volume, and total volume for the five species analyzed. The non-linear extra sum of squares method indicated differences in species-specific taper functions. A different taper function should therefore be used for each pine species.     

山西太岳山油松人工林群落结构研究

油松是我国北方人工林重要的造林树种,是我国人工林种植中使用较早的一种树种。本文调查的油松人工林是山西沁源县马泉林场宋家沟。通过在太岳山马泉林场宋家沟设立标准样地,并进行调查、取样,旨在研究人工油松林的群落结构,包括油松林下的植物种类,及科、属、种的统计,同时计算油松林下植被的重要值及多样性指数,揭示油松林下植被多样性情况。同时,针对油松密度与林分平均胸径、平均树高的关系进行研究,找寻油松最佳的种植密度。寻求最佳的解决人工林生长、经营、管理问题的一些途径。     

Genetic effects on total phenolics, condensed tannins and non-structural carbohydrates in loblolly pine (Pinus taeda L.) needles

Carbon allocation to soluble phenolics (total phenolics, proanthocyanidins (PA)) and total non-structural carbohydrates (TNC; starch and soluble sugars) in needles of widely planted, highly productive loblolly pine (Pinus taeda L.) genotypes could impact stand resistance to herbivory, and biogeochemical cycling in the southeastern USA. However, genetic and growth-related effects on loblolly pine needle chemistry are not well characterized. Therefore, we investigated genetic and growth-related effects on foliar concentrations of total phenolics, PA and TNC in two different field studies. The first study contained nine different genotypes representing a range of genetic homogeneity, growing in a 2-year-old plantation on the coastal plain of North Carolina (NC), USA. The second study contained eight clones with different growth potentials planted in a 9-year-old clonal trial replicated at two sites (Georgia (GA) and South Carolina (SC), USA). In the first study (NC), we found no genetic effects on total phenolics, PA and TNC, and there was no relationship between genotype size and foliar biochemistry. In the second study, there were no differences in height growth between sites, but the SC site showed greater diameter (diameter at breast height (DBH)) and volume, most likely due to greater tree mortality (lower stocking) which reduced competition for resources and increased growth of remaining trees. We found a significant site?×?clone effect for total phenolics with lower productivity clones showing 27-30% higher total phenolic concentrations at the GA site where DBH and volume were lower. In contrast to the predictions of growth-defense theory, clone volume was positively associated with total phenolic concentrations at the higher volume SC site, and PA concentrations at the lower volume GA site. Overall, we found no evidence of a trade-off between genotype size and defense, and genetic potential for improved growth may include increased allocation to some secondary metabolites. These results imply that deployment of more productive loblolly pine genotypes will not reduce stand resistance to herbivory, but increased production of total phenolics and PA associated with higher genotype growth potential could reduce litter decomposition rates and therefore, nutrient availability.