杨树溃疡病及松材线虫病对树体干部电指标的影响

对杨树溃疡病及松材线虫病对树木电指标的影响进行研究.结果表明:杨树溃疡病胁迫下,毛白杨扦插苗POD酶活性先增大后减小,PPO酶活性持续增大,树木干部电容和单位电容呈减小趋势,而树木干部阻抗呈增大趋势,最先表现出统计学差异性的指标是POD酶活性,其次为树木干部电容,之后为树体干部阻抗,最后是PPO酶活性;树木干部电容和单位电容与马尾松枯针率均有显著的正相关关系,同时利用树体干部电容0.5 nF为阈值,判断马尾松是否感染松材线虫的准确率可达89.26%.     

2种Y形整形方式对‘中梨1号’生长结果的影响

为了解Y形架不同整形方式对梨树生长结果的影响,研究了龙干式和二主枝2种Y形架整形方式下‘中梨1号’梨品种幼树树干直径、主枝直径、早期结果性能、果实品质等方面的差异。结果表明,龙干式整形的‘中梨1号’树干直径、主枝直径、40%以上节位结果枝条数、单株平均结果数等均显著高于二主枝整形的‘中梨1号’,表现出良好的幼树早期丰产性。但龙干式整形的树势相对中庸,果实平均单果质量略小于二主枝整形的‘中梨1号’。除了龙干式的果心占比稍大于二主枝‘中梨1号’,2种整形方式的‘中梨1号’果实在果形指数、果肉硬度和可溶性固形物含量等品质指标上并无显著差异。总体上,龙干式较二主枝式更容易整形,树势更中庸,幼树早期丰产性强,但需要强化水肥管理。     

红柳和柠条苗木电信号与苗木活力关系的初步研究

试验以2年生红柳和柠条为材料,通过晾晒、移栽和田间自然生长调查,测定其电阻、电压、电容的变化,探讨苗木活力与苗木电信号的关系。结果表明:苗木的活力与电阻变化成反比,与电压和电容成正比。     

Time series diagnosis of tree hydraulic characteristics

An in vivo method for diagnosing hydraulic characteristics of branches and whole trees is described. The method imposes short-lived perturbations of transpiration and traces the propagation of the hydraulic response through trees. The water uptake response contains the integrated signature of hydraulic resistance and capacitance within trees. The method produces large signal to noise ratios for analysis, but does not cause damage or destruction to tree stems or branches. Based on results with two conifer tree species, we show that the method allows for the simple parameterization of bulk hydraulic resistance and capacitance of trees. Bulk tree parameterization of resistance and capacitance predicted the overall diel shape of water uptake, but did not predict the overshoot water uptake response in trees to shorter-term variations in transpiration, created by step changes in transpiration rate. Stomatal dynamics likely complicated the use of simple resistance-capacitance models of tree water transport on these short time scales. The results provide insight into dominant hydraulic and physiological factors controlling tree water flux on varying time scales, and allow for the practical assessment of necessary tree hydraulic model complexity in relation to the time step of soil- vegetation-atmosphere transport models.     

染井吉野樱的引种栽培技术

介绍了染井吉野樱引种栽培技术和大树移栽技术：栽培环境选择以土层深厚、排水性能良好的沙性土壤为佳;栽植早期为尽快成景株距以4m为宜,树龄达8～10年后株距应保持在8～10 m;做好水肥管理和整形修剪,包括施足基肥和追肥,做好除萌等修剪;喷洒合适的杀虫剂防治病虫害;大树移栽采用B2活力素进行灌根处理.     

广德县古树树势与健康状况评价

在全面普查和专项补充调查的基础上,基于树形与生长方面的9个量化指标对安徽省广德县古树树势与健康状况进行综合评价。结果认为,全县古树总体上树势一般,呈中等健康水平,但不同的树种差别较大,其中生长缓慢的大乔木树种,凡处于中年阶段的古树,大多树势生长旺盛,健康等级高;乡土树种古树适应当地自然条件的能力较强,生长较好,健康等级较高;而速生树种或引入归化树种的古树,在处于生长的末期阶段,一般长势不佳,健康等级较低;具有量多面广的同一古树,树势旺盛,健康等级较高。不同保护级别的古树,树势和健康等级也各有差异,总的趋势是保护级别越高,树势越差,健康等级越低。生理老化、自然灾害、环境恶化、病虫危害、管护不善等则是当前影响古树树势和健康的主要因素。     

接种不同真菌菌株后黄栌生物电指标的变化

以黄栌枯萎病发病植株的根部所分离到的3种优势菌株作为供试菌株,利用新型电感电容表和电导率仪分别测定黄栌的树干电容、电阻和叶片电导率等生物电指标的变化,发现接种不同真菌菌株后黄栌的树干电容均值都呈现逐渐下降的趋势,树干阻抗均值、叶片细胞外渗液的相对电导率和叶片离子外渗百分率则都呈现逐渐增大的趋势。但接种Verticillium dahliae后黄栌出现枯萎病症状,且各项生物电指标均呈现更为显著的变化,其变化幅度较分别接种Fusarium sp.、Cylindrosporium sp.菌株后的电指标变化幅度大,而且树干电容和电阻在接种5 - 7天后表现出显著差异性,比病害症状出现提前7 - 10天;同时,受Verticillium dahliae侵染的植株和未受侵染植株在树体干部电容、阻抗和单位电容指标上差异显著,树干电阻与树干电容在植株受侵染后表现出更为显著的负相关关系。     

Decay susceptibility of wood in defoliated fir trees related to changing physical,chemical, and biological properties

Studies of the physical, chemical, and biological properties of wood from balsam fir trees indicated that as cambial electrical resistance increased in defoliated trees, the susceptibility of wood to decay appeared to increase. Increased susceptibility of wood to decay was associated with decreasing electrical resistance of wood as the tree lost its capacity to compartmentalize decaying wood.     

Five-year radial growth of red oaks in mixed bottomland hardwood stands

We studied the relationships among 5-year radial (diameter and basal area) growth of red oak (genus Quercus, subgenus Erythrobalanus) crop trees and predictor variables representing individual tree vigor, distance-dependant competition measures, and distance-independent competition measures. The red oaks we examined are representative of the commercially and ecologically important oak species of the bottomland hardwood forests of the southeastern US. The crown class score, a quantitative measure of crown class and tree vigor, performed best in accounting for the variability in tree diameter growth. Plot-level variables failed to account for a significant proportion of the variability in tree radial growth. The basal area of the first-order neighbors that were taller than the crop trees and located within 2.4 times the mean overstory crown radius had the highest negative correlation with crop tree 5-year radial growth. Red oaks were a major part of these competitors and likely exerted the greatest competitive pressure. However, crop tree radial growth was positively associated with the basal area of the red oaks which were indirect (second order) neighbors and which were taller than the crop trees. It is possible that indirect neighbors do not compete with the crop trees, but they likely compete with the direct competitors of the crop trees, thus having an indirect positive influence on crop tree growth. Such reasoning is consistent with previously observed spatial dependence up to four times the mean overstory crown radius. The findings may have implications for thinning hardwoods stands and crop tree management in that foresters need to take into account (1) oak intra-genus competition, (2) the negative competitive effect of direct neighbors, and (3) the potentially positive effect of the indirect neighbors, the competitors’ competitors.     

电阻测试法在立木腐朽检测中的应用研究进展

我国的木材需求巨大,但是木材利用率有待提高.木材无损检测技术可以很好地提高木材利用率,增加经济效益.电阻测试法对于立木早期腐朽变色具有良好的检测效果,而且使用方便快捷.介绍电阻测试法的基本原理,对针式探测法、四点检测法和断层成像法3种电阻测试法的研究进展进行分析和总结,在此基础上对电阻测试法在立木腐朽检测中的应用可行性进行探讨.     

Carbohydrate transfer through root grafts to support shaded trees

We investigated whether root grafts between lodgepole pine (Pinus contorta var. latifolia Dougl. ex. Loud.) trees can transfer sufficient carbohydrate reserves from a source tree to a grafted sink tree to affect the vigor of trees growing in a light-limited environment. Eleven plots were established in early spring and two grafted tree pairs and two independent non-grafted trees were selected at each plot. One tree in a grafted pair and one non-grafted tree were shaded at each plot, whereas the remaining trees were non-shaded during the experimental period. Shaded trees had significantly lower carbohydrate reserves and smaller crowns than non-shaded trees following one growing season. Grafted shaded trees had significantly higher root total nonstructural carbohydrate concentrations than non-grafted shaded trees, indicating that root grafts partially offset the effects of shading. Also, large root grafts transferred proportionately more carbohydrates to the shaded trees than small root grafts. Carbohydrates transferred through root grafts could allow grafted trees to persist under conditions where non-grafted trees would be removed by competition.     

西南桦优树选择技术研究

以胸径、树高、材积为数量评价指标,结合干形、冠高比和分枝粗细形质指标,采用5株优势木对比法开展了西南桦人工林的优树选择技术研究。通过对西南桦人工林10 21年生不同林龄阶段的优树选择标准的总结,提出了优树选择标准,即优树胸径、树高、单株材积分别大于5株对比优势木平均值的9%11%、5%7%、26%31%以上,形质指标综合得分大于7.5,共选择出西南桦优树37株,入选率为33.9%。西南桦优树的选择标准在实际应用中可根据林分状况适当调整,选优即要考虑其生长性状,同时注意材性、抗性的选择以保证西南桦育种群体的遗传多样性。     

树木抗风能力测试新方法

介绍一台由我国自行研发的树木抗风能力测试装备与方法，基于树木力学原理，通过将角传感器合理布置在树干上实时监测树干角度变化，结合实时风速，利用树木抗风能力预测分析系统，可测算该树能够承受的最大风速或最大风力等级。以2株樟Cinnamomum camphora为研究对象，采集了樟在风载荷作用下树干形变的角响应信息，测得樟能够承受的最大风速和临界断裂的破坏方式及断裂位置。本方法可为树木在大风或台风来临前是否需要防护提供科学依据，同时可为抗风性树种选择提供理论支撑。     

转录组和代谢组在林木真菌病害防御反应中的应用研究进展

真菌病害是林木的主要生物胁迫之一，严重影响林业生态安全和经济效益。近年来随着组学技术的突破，转录组技术和代谢组技术已成功应用于林木真菌病害研究，主要包括致病和抗病关键基因的挖掘、林木防御物质的动态合成、抗病分子育种等方面，但林木如何抵御真菌病害及其两者间的互作机制仍是今后研究的热点与难点。文中通过对林木遭受真菌侵染后的转录组信息和代谢组信息进行探讨，包括类黄酮物质合成途径、植物激素信号转导、林木防御关键基因和关键代谢物、关键防御机制及功能网络等，将在理论上丰富林木响应真菌病害侵染的过程，为林木和真菌病害的互作研究奠定基础，并为林木抗性育种和化学防治提供参考；此外，基于目前转录组和代谢组在林木真菌病害防御反应方面的研究，对林木基因组研究、多组学联合研究以及病原菌组学研究等进行展望，以期为林木真菌病害研究提供新思路。     

失叶对油松抗赤松毛虫的影响及其防治策略

本文研究了不同失叶量、不同季节失叶、不同叶龄对油松(Pinus tabulaefo-rmis)叶的光合、蒸腾、叶绿素、淀粉、可溶性糖及油松生长与抗性的影响,还研究了油松的贮藏营养物质。结果表明:30％失叶量能提高树势与对赤松毛虫的抗性;油松的贮藏营养是脂肪,主要贮存于叶内,新叶的营养制造与贮存大于老叶;油松失新叶后所抽的梢比失老叶后的短,光合、蒸腾及树势与抗性更弱;为增强树势与抗性,新叶是应重点保护的对象;赤松毛虫(Dendrolimus spectabilis)幼龄幼虫主要危害新叶,取食新叶死亡率低,体重增长率大,为保护新叶与树势,应抓紧对幼龄幼虫的防治。     

Dynamics of transpiration, sap flow and use of stored water in tropical forest canopy trees

In large trees, the daily onset of transpiration causes water to be withdrawn from internal storage compartments, resulting in lags between changes in transpiration and sap flow at the base of the tree. We measured time courses of sap flow, hydraulic resistance, plant water potential and stomatal resistance in co-occurring tropical forest canopy trees with trunk diameters ranging from 0.34-0.98 m, to determine how total daily water use and daily reliance on stored water scaled with size. We also examined the effects of scale and tree hydraulic properties on apparent time constants for changes in transpiration and water flow in response to fluctuating environmental variables. Time constants for water movement were estimated from whole-tree hydraulic resistance (R) and capacitance (C) using an electric circuit analogy, and from rates of change in water movement through intact trees. Total daily water use and reliance on stored water were strongly correlated with trunk diameter, independent of species. Although total daily withdrawal of water from internal storage increased with tree size, its relative contribution to the daily water budget (approximately 10%) remained constant. Net withdrawal of water from storage ceased when upper branch water potential corresponded to the sapwood water potential (Psi(sw)) at which further withdrawal of water from sapwood would have caused Psi(sw) to decline precipitously. Stomatal coordination of vapor and liquid phase resistances played a key role in limiting stored water use to a nearly constant fraction of total daily water use. Time constants for changes in transpiration, estimated as the product of whole- tree R and C, were similar among individuals (~0.53 h), indicating that R and C co-varied with tree size in an inverse manner. Similarly, time constants estimated from rates of change in crown and basal sap flux were nearly identical among individuals and therefore independent of tree size and species.     

元宝枫等3个树种枝干水容特征

对元宝枫、油松、侧柏等3个树种枝条和树干水容特征进行了研究.结果表明:3个树种枝条水容值的日变化均表现为自6:00开始先行递减,12:00或14:00后缓慢回升,直至18:00上升至一定数值,其季节变化为雨季大于旱季;3个树种树干水容值的日变化也表现为先降后升,但其季节变化为雨季小于旱季;树干水容要大于枝条水容,而且上部枝干水容的日变化较中下部的变化明显.树体枝干水容特征能很好地反映林木与环境水分的关系,对蒸腾耗水具有一定的调节作用.     

树木抗病的生理生化学研究进展

对树木受病原物侵染前后体内生化物质及其变化状况和诱发产生的多种生理生化代谢差异在寄主抗病性中作用的研究现状进行了概述，指出，目前关于树木抗病性的研究多集中在相关因素的比较分析上，有关抗病的分子机制和抗病基因定位等研究是今后深入探讨的重要方面。     

林木遗传工程及木质素的生物合成调节(英文)

林木遗传工程有利于保存林木遗传资源，改善全球气候，减轻自然林的过度采伐和满足人类日益增长的林木产品需求。控制林木真菌、病毒病、虫害和杂草的遗传工程方法正被广泛地研究和应用。尽管转基因林木的历史不长，种类不多，但它有广泛的应用前景。目前，抗除草剂基因、抗虫基因以及和木材质量相关的基因已被分离并应用于林木遗传工程。植物分子生物学和基因组学中的新技术使得高效林木遗传改良成为可能并将促进这些技术的商业化应用。木质素的应用已有一百年的历史，但木质素生物合成的全过程并不完全清楚。有关松树自然突变体和转基因林木的最新研究结果表明，木质素的生物合成是一个可以调节的过程。这些发现对完善木质素的生物合成途径、加深对木质素前体生物合成途径的理解和通过遗传工程改善木材质量有促进作用。本文综述了林木遗传工程在这些领域中取得的一些进展。     

板栗树皮电阻值与枝干病害的关系

利用万用电表对板栗枝干病害的病情程度与树皮电阻值的关系进行了研究。结果表明：在不同的植株间,树皮电阻值随着病情的加重而增加;在同一植株上,树皮电阻值随着树体的高度增加而增大;在树干基部、主枝和梢头三个部位中,电阻值差异比较显著．诙研究为今后板栗乃至其他林木枝干病害研究提供了一种简便易行的新方法。