根据太行山低山丘陵区苹果树主要生长季节冠层太阳总辐射(Q)与净辐射(Rn)的实测资料,在回归分析的基础上,从分形理论的角度,进一步揭示Q与Rn 的关系特征,探索果树冠层净辐射的计算方法。结果表明:1)Rn与Q具有很好的线性相关关系,回归拟合关系式为Rn =0.7408Q - 32.436 ,相关系数r可达0.9811(n =26279) ,Fcal=343 665.2 >>F0.01 2677=6.63;2 )Q与Rn分形曲线均存在2个无标度区,二者无标度区拐点的界限时间分别为453、441min ,且分形维数均很接近,第1标度区分别为1.1126、1.1319,第2标度区分别为1.9136、1.8834,说明Q与Rn 的分形特征非常相似。因此,可以利用苹果树冠层太阳总辐射推算净辐射。
以科尔沁沙地草地植被不同恢复程度的6个群落类型为对象,研究植被恢复过程中克隆植物的分布及其对群落结构和功能的影响。研究表明:在植被恢复过程中,克隆植物(主要是密集型克隆植物)对群落环境的改变和群落生态功能的维持起主导作用,但克隆植物在群落中过高的优势度有可能导致群落物种丰富度和物种多样性的下降。恢复梯度上密集型克隆植物的重要值始终高于游击型克隆植物,说明密集型克隆植物对环境的适应能力和对群落环境的改造能力更强。
采样分析常绿阔叶林、马尾松林和人工杉木林不同层次土壤的活性有机碳含量。结果表明:常绿阔叶林土壤微生物量碳和易氧化态碳含量高于马尾松与杉木林土壤,杉木林土壤水溶性碳含量相对较低。从不同层次看,土壤微生物量碳、易氧化态碳含量均随着土层深度加深而递减。水溶性碳、微生物量碳和易氧化态碳占总有机碳的比率分别波动在0.31%~1.18%、0.90%~2.51%和7.03%~29.52%之间,其中,土壤水溶性碳占总有机碳比率为马尾松林>常绿阔叶林>人工杉木林,易氧化态碳占总有机碳比率常绿阔叶林明显高于马尾松林和杉木林。不同土壤水溶性有机碳占总有机碳比率随剖面从上到下均表明出上升趋势,而易氧化态碳占总有机碳比率随剖面加深有规律地下降。土壤有机碳总量与各活性碳之间以及各类活性碳之间相关性均达到极显著水平。
运用趋势面分析方法,在arcinfo的支持下,采用统一网格样点采样法,通过对不同森林类型的演替阶段定量化,对吉林省汪清林业局金沟岭林场的森林景观要素沿环境梯度分布的趋势进行研究。结果表明:在金沟岭林场范围内,水平地理位置对景观要素空间分布的影响极为有限,景观要素空间格局更多地受地形特征和干扰格局的综合控制;研究地区海拔、坡向和坡度是控制景观要素空间分布格局的主要因素;在不同海拔带上,坡向和坡度对景观要素空间分布的作用在方向和强度上都有明显差别。
为研究Spot5、IKONOS及Quickbird等高空间分辨率遥感图像进行森林资源规划设计及调查的方法与技术,需进行遥感图像与实地位置的精确配准。对这3种遥感图像,地面控制点的精度应分别高于2.5m、1m及0.5m ,传统借助地形图选择校正点的方法很难满足精度要求。本文以满足Quickbird遥感图像几何精校正的精度为依据,在分析林区GPS控制网建立目的、精度要求及布设方法的基础上,结合目前GPS技术的发展现状,通过实例试验,详细探讨了林区快速布测GPS控制网的方法。
聚果榕与聚果榕小蜂有着种间专一的互惠共生关系。榕小蜂进聚果榕果内,结果表现为2方面:1)对长柱小花传粉受精后产生榕树种子,使聚果榕能正常进行有性繁殖;2 )在短柱花内产卵形成瘿花,产生榕小蜂后代,植食性,最后发育为聚果榕小蜂,并作为榕树传粉的媒体。对西双版纳地区2个样地内不同季节的聚果榕果进行了3年的连续解剖观察,统计了雄花期榕果内瘿花、种子、败育花的数量,比较了3年中旱季和雨季各种小花的比率。结果表明:不同季节,各种小花的比率不同。旱季的1月和11月,聚果榕产生的种子量最多,雨季末期的9—10月份次之,产生种子量最低的是3月份。旱季和雨季,瘿花的寄生比率没有显著差异,但不同月份之间差别较大,寄生率最高在旱季的1月份和雨季初期5月份,最低是在3月份。长花柱雌花和短花柱雌花的败育率,在气温最低的月份(1—2月)和雨量最多的月份(7—8月)结的榕果内最高,在雨季初期(5月)和旱季初期(11月)结的榕果内最低。造成聚果榕果小花败育的主要因素是低温、多雨的气候。除聚果榕小蜂外,榕果内还有造瘿类和重寄生2类非传粉小蜂,它们对聚果榕的种子形成具有一定的影响。
收集国内及日本大粒优质银杏核用品种29个,采用完全随机区组试验设计对核用品种的结实特性进行研究。2 0个品种高接换种后2~4年相继结实,但早实性品种间差异较大。平头接和分层接种实主要分布在树冠内膛。银杏幼年期相对较长,初果期结实量变异系数高达50%以上。不同品种平头接单核质量(g)、出核率(% )及单位树干横断面积种核产量(kg·cm-2 )均大于分层接。采用结实株率(% )、单株鲜果产量(kg)、单株种核产量(kg)、单位树干横断面积种核产量(kg·cm-2 )、单位树冠投影面积种核产量(kg·m-2 )、单位种植面积种核产量(kg·hm-2 ) 6个产量性状指标对20个品种系统聚类结果表明,“黄金丸”、“岭南”及“郯107#”属于高产品种。对银杏结实生物学特性进行了评价,对大粒、早实、丰产品种选育有重要意义。
通过温室中控制浇水量的方法,对12个美洲黑杨无性系间总生物量、长期水分利用效率(WUEL)的差异,及WUEL 差异与叶片稳定碳同位素组成(δ13C)的相关性进行研究。结果表明:水分胁迫下各无性系的总生物量均显著下降,而δ13C明显上升;同等水分处理下,无性系间总生物量、WUEL 差异显著, J2, J6, J7, J8, J9是生物量大、WUEL 高的优良无性系;δ13C的差异在水分处理间达到极显著水平,在无性系间也达到显著水平,均方的比较结果显示水分是引起δ13C差异的主要因素;同等水分处理下δ13C和WUEL 正相关,各水分处理下二者的相关系数都在0.70以上;同等水分处理下,δ13C是间接评估无性系间WUEL 差异的可靠指标。
以毛新杨无性系TB0 1×毛白杨无性系LM50的回交子代120株个体为作图群体,对控制叶片表型性状如叶长、叶宽、叶面积和叶柄长以及春季萌芽时间共5个性状的数量性状位点(quantitativetraitloci,QTLs)进行分析。运用AFLP标记技术结合拟测交作图策略构建了含有393个AFLP标记的毛白杨及毛新杨的遗传连锁框架图。毛白杨遗传图上共含有247个AFLP标记位点,连锁位点覆盖毛白杨基因组总长约3265.1cM ,而毛新杨遗传连锁图上共含有146个标记位点,连锁位点覆盖毛新杨基因组总长约1992cM ,这些连锁图的每一连锁群上含有的标记数为4~30个。在此基础上,利用区间作图软件共检测到控制叶片表型性状的QTLs14个,位于9个连锁群上;而对于春季萌芽时间共检测到3个QTLs,分别位于3个不同的连锁群上。在检测到的17个QTLs中,每一QTL可解释表型变异的7.6%~15.8%。此外,发现控制叶长、叶宽和叶面积等相关性状的QTLs位于相同的基因组区域,这些QTLs主要位于毛白杨遗传连锁图的TLG2和TLG11以及毛新杨连锁图的TBLG1连锁群上。据控制叶片表型和春季萌芽时间的QTLs所处的基因组区域,可推测叶片表型和春季萌芽时间这两类性状是由各自相应的基因控制。
以蒙古栎全分布区的8个天然群体为试材,对当年生枝的顶芽、叶、坚果、壳斗等15个表型性状进行比较分析,讨论群体间和群体内的表型多样性。结果表明,蒙古栎种内表型性状在群体间和群体内存在着极其丰富的变异。群体平均表型分化系数(VST)为0.5397,群体间变异(53.97% )略大于群体内变异(46.03% )。蒙古栎表型性状与地理气候因子相关分析表明,其种内群体表型变异呈梯度规律性,随着经纬度的增加,坚果逐渐增大,坚果形状由近球形向长椭球形变异;叶形由长倒卵形向宽倒卵形变异;随着海拔升高,坚果逐渐变小。蒙古栎表型性状(顶芽、叶、壳斗、坚果)间存在显著或极显著的相关关系。利用群体间欧氏距离进行的UPGMA聚类分析表明,蒙古栎群体可以划分为4类。
在白皮松天然林中采取分层取样,抽取10个群体2 10个单株。测定分析16种酶系统,得到31个酶位点。白皮松物种水平遗传多样性参数为:平均等位基因数AS=1 74 2 ,平均有效等位基因数AeS=1 4 9,多态位点百分率PS=5 4 8% ,期望杂合度HeS=0 16 2 ;白皮松群体水平遗传多样性参数为:平均等位基因数AP=1 39±0 11,平均有效等位基因数AeP=1 30±0 12 ,多态位点百分率PP=34 85 %±8 4 6 % ,期望杂合度HeP=0 0 99±0 0 4 9,观测杂合度HoP =0 0 95±0 0 4 2。白皮松遗传多样性在松属树种中属于中等偏下,群体间分化明显,遗传分化系数FST =0 133,群体间遗传距离 D =0 12 8,大于松属平均水平。根据Nei’s遗传一致度将10个群体分为3组。白皮松群体遗传多样性中心与资源分布中心和表型多样性分布中心吻合,适宜采取中心群体原地保护和多群体异地联合保存相结合的保护策略。
以开发富含α-亚麻酸新油源植物—接骨木为目的,通过分析证明,接骨木果含油量达36.7%以上,且质地优良,油中脂肪酸组成与常用食物油基本相同,唯功效成分α-亚麻酸含量高达22%以上。对接骨木果油的毒性实验和一些功能实验结果表明,接骨木果油无毒无害,可食用、药用、保健用。
对天然次生林下人工更新红松幼树的恢复过程进行研究。结果表明,在红松幼树生长的不同阶段进行适当的透光伐调整林分结构,有利于红松幼树的生长恢复。同时,研究中还利用大小比数(U)、混交度(M)和角尺度(W)等先进的林分空间结构参数,来分析不同经营阶段林下红松幼树的生长状况,以及红松周围相邻木的混交和分布状况,并将研究结果用数量化的形式表达出来。当红松幼树为优势木,周围相邻木为中度混交且呈随机分布时可表示为:U=0或U=0.25 ,M=0.5 ,W=0.5。
以湖北省建始县长岭岗林场15年生日本落叶松子代测定林为研究对象,研究了家系间优势高的生长变异,家系对树高生长模型参数影响的显著性检验,并构建了日本落叶松家系树高生长模型。研究表明,同一立地不同家系的树高—年龄关系为多形曲线,不仅渐近线存在显著差异,而且曲线的形状也发生改变,应采用不同的生长模式来描述其树高生长过程,优势高生长是环境差异和遗传变异的树木表现型的综合反映,树高生长潜力(立地指数)随着遗传改良材料的应用而增大:Schumacher和Richards方程对模拟日本落叶松幼龄阶段不同家系的优势高生长过程均能达到令人满意的效果:家系间优势高的差距随年龄而增大,且家系间连年生长速率也各不相同。
从2000年5月起在福建省东山县赤山林场临海风口干旱沙地进行3年试验研究,从7个参试无性系中选择惠1#、粤701#、东9801#等3个造林保存率达61.9%~69.5%的无性系,在此类特殊困难立地防护林植物材料选择方面取得突破。通过对风口沙地前沿高地和后沿低洼地2种微地形条件木麻黄无性系造林效果的比较分析,后者造林保存率提高约5% ,且林木生长较快。2种微地形条件林木根系生长状况,风口前沿高地林木根系分布深、数量多、结构密集、吸收根系网络发达,有助于逃避大气干旱和土壤干旱。并揭示根系分布深度、数量、密集程度、网络结构与土壤含水率大体呈负相关的趋势。研究揭示,风口干旱沙地造林成活的机制,是由于林木形成发达、庞大的根系网络的生理和形态特性,以适应干旱生境和保证造林成活。不同造林方式的试验结果表明,丛状、团状等植生组造林方式可提高保存率约10% ,在生产实践上有推广应用价值。
对携带两个外源抗虫基因(部分改造的BtCry1Ac基因和慈菇蛋白酶抑制剂基因API)的白杨杂种74 1杨的抗虫性、生长特性、木材品质、结实特性及适应性进行多年连续观测。结果表明,3个转双抗虫基因74 1杨株系对杨扇舟蛾、舞毒蛾、美国白蛾等鳞翅目食叶害虫具有高抗虫性,幼虫死亡率均在80%以上,并且还能抑制存活下来的昆虫幼虫的发育,使其发育速率减缓,不能正常结茧,连续4年饲虫试验未发现其抗虫性有规律下降的趋势。转基因受体741杨具有生长速度快,特别是胸径和材积生长在生长后期具有明显的速生优势,单株材积生长量平均超出对照40%以上;741杨木材品质优良,木材密度、纤维特性及各项力学性质均优于毛白杨。连续3年观测表明,741杨为高度败育雌株,果穗小、数量少,成熟开裂前70%~90%脱落,基本不飞絮。转基因741杨没有发生明显变异,生长未受影响,可在毛白杨适生区推广应用。建议采用适宜的栽培模式,控制害虫抗性发展。
加拿利海枣和丝葵萎缩病发生于厦门的行道树和苗圃,病树基部的茎干内变黑腐烂;从发病部位分离纯化获得根串珠霉。将此菌回接于苗圃和盆栽的加拿利海枣,产生相同症状并重新分离到该病原真菌。因此,通过柯赫法则证实该病的病原物为根串珠霉,本文对病害症状和病原形态特征进行了描述。
1999—2001年对山西太谷地区综合防治枣园与常规防治枣园天敌昆虫的群落结构及其多样性的研究结果表明:在综合防治枣园中发现有8个目、25个科、58个种和5009个天敌的个体数,而在常规防治枣园中发现有8个目、18个科、27个种和1911个天敌的个体数。方差分析结果表明综合防治枣园天敌的科、种及个体数显著大于常规防治枣园(P<0.05 )。枣园中天敌的优势种是枣盲蛇蛉、七星瓢虫、晋草蛉、桃小甲腹茧蜂和蚧金小蜂。在综合防治枣园中,主要天敌昆虫的优势度显著大于常规防治枣园(P<0.05 )。天敌昆虫各群落的生态优势集中性在两区不同生育期基本上趋于一致,综合治理区主要类群的优势集中性几乎总是大于常规防治区;综合治理区天敌昆虫群落和捕食性亚群落的多样性与均匀度较常规防治区有明显(P<0.05 )的提高;在综合治理区,影响群落多样性的主要成分是种类丰富度,在常规防治区,影响群落多样性的主要成分既有种类丰富度,又有均匀度和个体数。
2001年6月—2002年5月间,采用系统样地方法,对四川平武王朗自然保护区和黄羊熊猫观测站采伐和未采伐基地中大熊猫活动区域和非活动区域植被群落结构变化进行调查。结果表明:未采伐区大熊猫活动区域的物种数、物种丰富度、竹子更新能力、竹子密度、最大胸径的平均值均高于未采伐的大熊猫非活动区域;采伐区大熊猫活动区域的物种丰富度、物种优势度、物种多样性、单株竹生物量、竹子密度、样地平均竹子盖度、均高度、平均胸径、最大胸径的平均值均高于采伐后大熊猫非活动区域。森林采伐导致大熊猫栖息地物种丰富度、物种优势度、物种多样性、竹子密度、样地平均竹子盖度等因子下降,对大熊猫的适应性程度及生境质量产生了一定程度的影响。
对重要人工经济林树种核桃、枣木、银杏、板栗、樟树和橡胶等木材解剖、物理力学、化学性质进行研究。结果表明:核桃、银杏、樟树生长速度较快、材质好,是培育经济和用材两用林的优良树种,枣木和板栗材质好、生长慢,可以选择经济林果用为主、材用为辅的培育方式;核桃、橡胶、樟树和银杏的密度和力学强度较大,板栗和枣树木材的密度和力学强度很大;樟树、银杏和橡胶木材的纤维素含量与杨木接近,木质素含量界于杨木和马尾松之间,且纤维形态特征符合造纸用材的要求,树干和加工剩余物可以用于造纸;人工经济林枣木基本密度、核桃木材纤维长度可以通过生长轮年龄来预测,且预测效果显著。
分析导热与导电间某些属性的相似性,应用类比法推出导热系数具有导电系数的某些属性,可用导电系数类似的定义式定义导热系数,即木材导热系数等于木材单位长度单位截面的热阻的倒数。根据木材微观细胞形态,选用圆柱形模型推导木材横纹导热系数的理论计算式。应用该公式计算20种木材的横纹导热系数,理论值的最大误差14.1% ,平均误差7% ,理论值与试验值较为吻合,为理论研究木材热学性质提供一种可适用的方法。
运用高阶剪切理论对竹木复合空心板的弯曲性能进行分析与研究。结果表明:在跨高比较小时,横向剪切效应对板的弯曲性能有显著影响;预测的变形与一阶剪切理论基本相当;预测的强度能够反映出横向剪切效应的影响,其影响只与载荷大小有关,而与跨高比无关;描述横截面上的应力分布与一阶剪切理论显著不同,尤其是剪应力,不仅在跨中截面上存在较大差异,而且还随截面的位置而变。
将冷冻处理前后的日本柳杉边材在400℃下进行炭化,得到了木醋液、木焦油和木炭。与没有处理相比,虽然处理过边材的木焦油的收率几乎不变,木醋液的收率显示增加倾向,但是木炭的收率有减少迹象。用毛细管气相色谱法对得到的木醋液中的11种成分进行了定量分析。与无处理相比较后,发现处理过边材木醋液中的甲醇、脂肪酸及糠醛(呋喃甲醛)的收量有了变化,但是5 -羟甲基糠醛、麦芽酚、苯酚、邻苯二酚及愈创苯酚的收量几乎没有变化。
根据原条量材设计赋权有向图优化理论数学模型,按标号法对有向图求解的思路编制了原条量材设计优化软件。该软件采用的用户界面是对话框类型,利用双向链表存储常见木材缺陷的信息,并把缺陷的判定作为一个函数来使用;利用数据库技术把原木价格表按树种分成若干个数据库存储起来,并使用ADO数据对象访问技术作为检索数据库的方法。该软件可在Windows9X、WindowsXP、Windows2000等操作系统下运行,速度较快,能够满足量材需要,并对改变目前靠经验量材的生产现状,使原条量材设计工作更加科学、合理,具有一定的指导意义。
尽管社会主义市场经济体制已建立多年,但我国的森林资源监督体制仍然带有明显的计划经济体制的特点,因此,出现对国有森林资源资产的监督失灵问题。探索适应社会主义市场经济体制的国有森林资源资产监督体制是实现国有森林资源资产有效运营的保证。在分析现行国有森林资源资产运营体制存在问题的基础上,本着既要符合国有森林资源资产特点,又要适应社会主义市场经济体制的要求,提出了“内部监督+外部监督+稽查”的三重约束的国有森林资源资产监督体制,并从立法、优化监督环境、提升森林资源管理和检测的现代化水平和健全森林资源资产运营监督考核指标体系等方面提出了该体制运行的对策。
以木材生产为核心的国有林区现行的林业微观建制已成为国有林区及国有林业可持续发展的主要制度性障碍,因此重构国有林区林业微观主体便成为我国国有林区能否尽快实现良性运转的关键。首先研究国有林区林业微观主体重构的现实基础和经济可行性,新的微观主体构建符合市场经济理念,可以节约交易费用,实现专业化分工,提高资源配置效率;其次研究国有林区林业微观主体重构的内涵与特征;第三,研究重构后国有林区林业微观主体的基本类型,分别界定了基础性林业企业和商业性林业企业的目标、特征和经营内容;第四,研究由现行的国有森工企业向新的林业微观主体过渡的主体路径,指出打破现行国有森工企业格局的深刻内涵和经济本质;随后对国有林区基本的运行主体在实际运行中的关系进行研究,指出其间可能出现的各种“一体化”的关系,从而也拓宽了国有林区林业微观主体的存在形态。
应用DTV技术和理论,采用丰富度指数Dma、多样性指数H、均匀度指数JSW 及随林分中抗虫或感虫木比率由高到低变化时林分多样性指数累加值DV,分析人工混交林的多样性测度阈值与光肩星天牛危害率的关系。研究表明,多树种的人工混交林具有明显的抵抗蛀干害虫为害的能力,但混交林的抗虫力与所选配树种的抗性、抗性树种在混交林中所占的比率有关。当给定混交林分的树种数后,光肩星天牛的危害率P<.i>Z 与林分的多样性指数累加值DV 的关系符合Logistic模型;该模型中的系数a是林分本身的多样性测度值的起始位置,随树种数的增多a值具有稳定的增长规律;系数rm 的新意是混交林分对光肩星天牛扩大危害的阻力、即潜在的抗虫能力,rm 随林分中树种数的增多具有显著增大的趋势。林分的最大多样性测度值KDMa 、Kh、KJsw 也具有相同的变化规律。在4~7个树种组成的系列混交林内,林分的多样性测度阈值DTV随树种数的增加而增高,但被害率极值Lvp反而降低。上述规律的意义还在于,随混交林中树种数的增加,设计或改造现有感虫林时选择树种的余地也增大。
植物抗性分为组成抗性和诱导抗性两种类型。组成抗性是植物的一种固有特性,取决于植物不同的基因型,始终存在于植物中并发挥作用;诱导抗性是一种类似于免疫反应的抗性现象,是植物的一种表型反应,只有在外源损伤的情况下才得以表现。本文主要综述了自1997年以来植物诱导抗性的最新研究进展,包括对诱导抗性特性的重新认识及一些新的证据,对诱导抗性中能量分配与植物防御效益之间的风险平衡,信号(特别是植食者的取食信号)在诱导抗性中的作用,一些新发现的防御机制以及植食者的适应性等。对植物诱导抗性在生产上的应用前景作了简要的讨论,展望了这一领域的研究方向和尚需深入研究的问题。
鹭科鸟类是湿地生态系统中重要的生物种类之一,也是环境质量评价的一类指示动物。为了保护和利用资源,本文对中国鹭科鸟类研究进行了简要总结。中国鹭类有9属20种,可分为树巢类和芦巢类2大生态类型。树巢型鹭类群落结构多样性受栖息地结构、植物物种多样性、林木的水平和垂直层次复杂性的影响。而芦巢型则栖息地结构简单,类群落结构多样性也较低。中国鹭类的地理分布,除紫背苇为古北界种类,海南、黑冠2种为东洋界种类外,其余种类为广布种,台湾有澳洲界种类斑鹭的记录,当属偶见鸟。
基于聚合物 蒙脱土纳米插层复合材料的研究成果,综述了插层复合方法的原理、工艺过程和产品性能,分析比较了单体插层原位聚合和聚合物直接插层等方法。从木材与蒙脱土的结构和组成特性出发,分析比较了木材与聚合物溶解、熔融性的不同,讨论了利用插层复合原理制备木材/蒙脱土纳米复合材料的基本构想,并进一步提出了相应的技术路线和工艺流程概念图。
为促进传统木材改性技术产生新的发展,将生物矿化概念导入到木材科学与技术的研究领域中。本文综述了生物体系中生物矿化作用的基本内涵,探讨了基于这些原理之上的木质基纳米材料控制合成的构想,即通过立木形成层细胞分生的有机分子和无机离子在界面处的相互作用来设置矿化位,调节微环境,建立饱和溶液、提供有机质、搬运离子、加入添加剂等来控制生物矿化作用的方向和过程,实现用活立木制备木材纳米结构复合材。
Miyun Reservoir provides more than 70% drinking water resources for Beijing, it is very important that to study the hydrological properties of canopy of water resources protection forests, which to help managing and cultivating the water resources protection forests. In this paper, the stands of Robinia pseudoacacia, Pinus tabulaeformis and Castanea mollissima were studied from 1999 to 2000. The total precipitation amount was 545 mm in the 2 main rain periods from 1999 to 2000, distribution in canopy interception, through-fall and stem-flow in the R.pseudoacacia stand were 97.73 mm, 434.78 mm and 12.49 mm, respectively, that in the P.tabuleaeformis were 131.54 mm, 397.98 mm and 15.48 mm, respectively, and in the C.mollissima stand were 110.73 mm, 422.07 mm and 12.20 mm, respectively. The canopy interception and stem-flow amount of P.tabulaeformis stand, the through-fall amount of R.pseudoacacia stand was the biggest among the three stand respectively. The elements content of N, P, K, Na, Ca, Mg, Fe, Zn, Cu and Mn were monitored for the precipitation, canopy interception, through-fall and stem-flow of the three forest types. The total amount of weighed average content of ten chemical elements in precipitation was 12.001 1 mg·L-1. The sequence of the chemical elements weighted average content of the precipitation is followed: Ca > N > K > Mg > Na > P > Fe > Zn > Cu > Mn. The concentration of chemical elements of through-fall and stem-flow varied in differently for three forest types in comparison with the precipitation's.
The characteristics of throughfall and stemflow over one growing season were studied in a dark coniferous forest in the subalpine of the Western Sichuan. The results indicated that: 1) The distribution of precipitation by canopy was more relative to the rainfall, the higher the rainfall was, the more the throughfall and stemflow were, and the less the interception was; 2) The relationships between throughfall (T) and total rainfall (P) could be described significantly by a linear function (T=0.744P-0.937, R2=0.954, p<0.001), while the reationship between crown interception (I) and total rainfall by a power function (I=0.759P 0.666, R2=0.763, p<0.001); 3) The average canopy interception accounted for 35.8% of total rainfall and the average throughfall for 64.2%, and the average stemflow for 0.01%; 4) High water_hold capacity of moss on the surface of tree trunk and low rainfall intensity were the main reasons that the stemflow of the coniferous forest in the subalpine of Western Sichuan was less than other forests.
Ginkgo biloba is one of most famous officinal plant in China. In the past, many varieties were selected and planted, but there is not still identification system for these varieties. This paper studied DNA fingerprints of the main G. biloba varieties cultivated all over the country using ISSR DNA marker. The results indicated ISSR marker was effective highly for identifying 13 varieties. Only using primer ISSR46 and ISSR44, 13 varieties were able to be identified based on 11 polymorphic loci (ISSR46-550,ISSR46-670,ISSR46-740,ISSR46-1000,ISSR46-1159,ISSR46-1359,ISSR46-1600,ISSR44-520,ISSR44-580,ISSR44-660,ISSR44-1750). In addition, we found ISSR marker was stable and repeatable highly compared with RAPD marker.
Some Chaetomium spp. Are capable of antagonizing several plant pathogenic fungi through production of antibiotics and mycoparasitism. Secretion of lytic enzymes, mainly including glucanases and chitinases, is considered the most important step in the mycoparasitic process. In this study, an about 110kDa exo-β-1,3-glucanase from C. spirale ND35 was detected both in culture filtrate and directly on PAGE and IEF gels, as well as chitinases, although protease was not detectable on Litmus milk agar plates. Coiling and penetrating the hyphae of host fungus Valsa mali were observed by scanning electron microscope (SEM), which may be related to the synergistic interaction between β-1,3-glucanase and chitinases. Β-1,3-glucanase activity of C. spirale ND35 varied considerably when C. spirale ND35 was grown in different carbon sources during various incubation time, and might be subjected to both induction by substrate and catabolite repression.
Factors were analyzed in details which affects wood landing location. Decision models of wood landing location in different logging system were proposed from the view of economic benefits. Based on MapInfo, a GIS-based decision system of wood landing location was designed using programming language MapBasic. The system was applied in the research area located in Hongqiao state-owned forestry farm, Yong’an.
采用碱液吸收法对湖南省会同生态定位站郁闭杉木人工林林地土壤CO2 释放量进行测定,并分析温度、水分和土壤C/N比对林地土壤CO2 释放量的影响。结果表明:郁闭杉木人工林林地土壤CO2 释放量在0.1052~0.5590g·m-2 h-1 之间变化,且具有一定的季节变化规律,总体趋势是夏季高,其他季节低;林地土壤CO2 释放量与林内气温、土壤各层(0、5、10、15、2 0cm)温度和土壤各层(0、10、2 0cm)含水量在一定范围内呈一元线性正相关,与土壤C N比也呈一元线性正相关;以林内气温、土壤各层(0、5、10、15、2 0cm)温度为依据得到的Q10依次为2.08、2.22、1.94、2.28、2.51、2.23;林地土壤CO2 释放量与林内气温的相关性最强,为极显著相关,偏相关系数为0.916 (p<0.01) ,与土壤各层(0、5、10、15、2 0cm)温度也是极显著相关,偏相关系数均在0.818以上(p<0.01) ,但与土壤C N比和土壤各层(0、10、20cm)含水量相关不显著,偏相关系数为0.452~0.612 (p>0.05 )
研究根系的数量、长度和生物量在植物篱-桑树-脐橙坡地复合经营系统中不同位置和层次的分布。结果表明:植物篱树种新银合欢根系主要在植物篱带垂直分布,深度超过1.0m ,分布于植物篱带的≥1mm粗根数量、根长密度和生物量分别占该树种粗根总数量、总长度和总生物量的62%、66%和86% ;套种在植物篱中的桑树的根系沿植物篱带分布,≥1mm粗根数量、长度和生物量分别占粗根总数、总长度和总生物量的50%、49%和91% ;脐橙根系较浅,主要分布在作物种植带中间上下0.6m的范围内,深度不足0.6m ,分布于作物带中央上下0.6m范围的≥1mm粗根数量、长度和生物量占总量的83%、83%和85 % ;新银合欢<1mm细根主要在植物篱带及其两侧0.6m内,分布于该范围的细根数量、长度和生物量分别占相应总量的73%、79%和72% ;桑树<1mm细根分布与新银合欢类似,分布于该范围的数量、长度和生物量分别占相应总量70%、85%和77% ;脐橙<1mm细根主要分布在其植株周围0.6m范围,其数量、长度和生物量分别占相应总量的70%、63%和64%。该农林复合经营系统中新银合欢植物篱和套种在其中的桑树根系分布重叠,有利于桑树充分利用新银合欢根系提供的养分;脐橙与新银合欢和桑树的根系在土壤剖面的水平和垂直分布上不重叠,生态位合理分离,减少了各组分之间的水分和养分竞争,该复合经营模式中4m的作物带宽度对种植脐橙可能是比较合理的
介绍由摄像机图像抽取林木直径的方法、步骤,将度量误差模型算法应用到参数的求解当中,提出适合于林业野外作业的内、外参数分离策略,最后对文中算法、策略进行实际验证。结果表明:1)从图像中重构林木直径是可行的;2 )由度量误差模型算法求解参数是一种很好的算法;3)将摄像机、内外参数分离,不仅减轻了繁重的林业野外作业,同时保证了三维重建精度;4 )单独考虑摄像机焦距,增加了实际操作上的灵活性
以吉林省汪清林业局金沟岭林场为例,提出一种基于森林资源二类调查数据的景观要素分类方法。选取优势树种(组)、海拔、坡度、坡向和太阳辐射强度作为分类因子,在GIS技术支持下,按分类因子分割林场森林景观空间为975 7个空间基本单元,建立起量化的、与植被和环境因子相关的森林景观空间基本单元数据库,在此基础上采用聚类分析方法把所有基本单元聚合为不同相似水平上的景观要素类型,结合生态特征和经营需要对聚类结果进行分析并最终确定了7种景观要素类型,生成了景观要素类型斑块图。斑块特征和空间格局分析结果表明:该林区森林景观中以小斑块要素比例最大,中、小斑块数占总斑块数的90%。针阔混交林具有最大的面积、平均斑块面积、斑块周长、最大生境面积和内部生境指数,是该地区受人为干扰相对较小、仍需要进行保护的景观要素类型。在森林经营中,应注意保护大型斑块的景观要素类型。
利用数码图像显微镜处理系统和稳定性碳同位素测定技术,对20世纪30—80年代不同年代不同植被区域内辽东栎叶片气孔密度及δ13C值的时空变异规律进行研究。结果表明,全国不同区域辽东栎气孔密度为535~800stoma·mm-2 ,平均值为703 stoma·mm-2 ,δ13C值为-28.47‰~-25.02‰,平均值为-26.83‰。从时间分布角度,由20世纪30—80年代,暖温带落叶阔叶林区域中辽东栎叶片气孔密度和δ13C值持续降低比较明显;亚热带常绿阔叶林区域中辽东栎叶片气孔密度呈增加趋势,而δ13C值呈降低趋势;青藏高原高寒植被区域中辽东栎叶片δ13C值呈增加趋势,但气孔密度几乎没有变化。从空间分布角度,30年代,暖温带落叶阔叶林、亚热带常绿阔叶林、青藏高原高寒植被3个区域中辽东栎气孔密度和δ13C值依次递减,说明水分利用效率(WUE)呈下降趋势;50年代,辽东栎气孔密度在4个植被区域之间产生波动,温带针阔叶混交林和亚热带常绿阔叶林2个区域中的辽东栎气孔密度比较接近,且高于气孔密度相差不大的暖温带落叶阔叶林和青藏高原高寒植被2个区域,4个植被区域类型之间辽东栎叶片δ13C值差异不大;80年代,辽东栎在由东到西分布的暖温带落叶阔叶林至温带草原区域,气孔密度和δ13C值均呈降低趋势。因此,从时空分布角度,除个别区域外,辽东栎在从20世纪30—80年代,由暖温带落叶阔叶林至亚热带常绿阔叶林、青藏高原高寒植被的时空分布上,气孔密度和δ13C值均呈降低趋势
在黄土高原半干旱区采用工程整地与生物措施相结合的方法,进行柠条灌木林建设与土壤水分消耗及调控恢复研究。结果表明:在半干旱区柠条生长前6年为幼龄期,6~14年为中龄期,14年后进入老龄期。幼龄期0~800cm土壤中未形成干层,中龄期土壤干层厚度为240~260cm ,老龄期干层为700cm。水平阶整地丰水年土壤水分盈余44.82mm ,对照亏缺51.5~79.6mm ;平水年亏缺53.91mm ,对照亏缺103.64mm ;干旱年亏缺102.87mm ,对照亏缺153.32mm。不同降水年份土壤水分的补偿深度为80~180cm ,对照为21~45cm。根据柠条主根、侧根和毛根的根量分布比例得出,土壤水分要恢复正常,丰水年需要13年,平水年需要16年以上,干旱年约需20年以上,而对照无论是丰水年、平水年还是干旱年均需20年以上
以始温80℃水浸种1~4d吸胀的刺槐种子视为不同硬实程度的种子T1 、T2、T3及T4,与第4天仍未吸胀的刺槐硬实种子(记作Tr)为试材对其种子活力差异性进行研究。结果表明:随着硬实程度的提高,即Tr>T4>T3>T2 >T1,种子的发芽势、发芽指数、活力指数、呼吸速率呈上升趋势;而电导率呈下降趋势。通过测定人工逆境(盐胁迫、低温、人工老化)处理种子的SOD酶活性和MDA含量,发现硬实种子具有较高的抗逆性,且其抗逆性随硬实程度的增高而增强,进一步证实了硬实种子具有较高的活力水平。指出硬实种子在生产上具有潜在的应用价值
日本落叶松日永10、日永69和日草34三个优株,将其未成熟种子和成熟种子的胚及成熟种子萌发的胚根、胚轴和绿色愈伤组织5种外植体进行体细胞胚胎发生的试验,其中只有未成熟胚诱导出胚性愈伤组织,筛选出1)胚性愈伤组织诱导培养基:S培养基+6-BA 0.5mg·L-1 +KT 0.5mg·L-1 +2 ,4-D 1.0mg·L-1 ;2 )胚性愈伤组织保持与增殖培养基:S培养基+6-BA 0.25mg·L-1 +KT 0.25mg·L-1 +2 ,4-D 0.1mg·L-1 ;3)成熟体细胞胚诱导培养基:S培养基+ABA 15mg·L-1 +PEG4000 100g·L-1。以上3种培养基均需附加蔗糖30g·L-1 ,谷氨酰胺450mg·L-1 ,水解酪蛋白500mg·L-1 ,凝胶(Sigma# ) 3g·L-1 ,pH5.8。4 )体细胞胚萌发培养基:S培养基,不加任何激素,附加蔗糖2 5g·L-1 ,凝胶(Sigma# ) 3g·L-1 ,pH5.8。
利用9年生黑杨派10个无性系试验林材料进行了生长与材性等14个性状的遗传分析及选择研究。方差分析、遗传参数估测表明,无性系间14个性状差异均达极显著水平,各性状无性系重复力在0.852~0.987。说明这些无性系在多个性状上存在广泛遗传差异,并且这种差异受较强的遗传控制,从中进行多性状遗传改良是可行的。经多性状主成分分析和聚类分析,选出卡帕茨、50杨、I-69三个综合性状表现优良的无性系,其中卡帕茨为新选无性系,在该试验林中生长量最高,材积超I-214杨69.7%、超中林46杨7.9% ,且材质优良,适宜推广应用
以广西壮族自治区的西南桦天然分布区为研究对象,调查了11个居群190个单株的12个表型性状指标,运用变异系数和巢式方差分析研究了居群间和居群内的表型变异;应用相关分析揭示了表型性状间及其与地理、气候因子间的相关性以及表型变异的地理格局;并且运用聚类分析进行了居群分类。结果表明,西南桦天然居群内的变异远大于居群间的变异,居群分化较小;侧脉数、叶片基部至最宽处距离与经度、纬度显著相关,叶片长与经度相关显著,种翅宽与海拔显著相关,存在较明显的地理变异趋势。而表型性状的Mahalanobis距离与地理距离间相关不显著。研究结果为西南桦的遗传改良工作奠定了基础,为制定西南桦育种策略和天然林持续利用对策提供了科学依据
以系统揭示云杉全分布区天然群体表型变异程度和变异规律为目的,以其全分布区10个有代表性天然群体,每个群体30个个体为试材,对针叶、球果、种鳞、种翅和种子等17个表型性状进行系统比较分析,采用方差分析、多重比较、相关分析和聚类分析等统计分析方法,讨论了群体间和群体内的表型多样性。结果表明:云杉种内表型性状在群体间和群体内存在极其丰富的遗传差异。云杉球果、针叶、种鳞、种翅和种子5个表型性状的变异系数分别为19.14%、26.46%、13.58%、19.78%和17 40% ,种鳞性状稳定性较其他性状高。表型分化系数(VST)的变幅为2.09%~40.62 % ,群体间表型分化系数均值为30.99%。群体间变异(30.99% )小于群体内变异(69.01% )。17个表型性状间多数呈极显著或显著的正相关,球果长度、球果径、种鳞长度、种鳞宽度和种子千粒重为云杉易测定和重要的表型性状。云杉种内群体表型变异在空间分布上呈现以纬度为主的单向变异模式,利用群体间欧氏距离进行UPGMA聚类分析表明,云杉群体可以划分为5类
当前我国林业正处于全面调整、实施战略转折的关键时期,建立新的林业发展战略具有重大意义。本文以现代林业的新视角、从社会生态建设对林业的需求出发,提出并系统阐明建立以生态建设为主体的新林业发展战略的构想:以环境与发展为主题,从我国林业的实际出发,适应时代的要求,满足社会多种需求;以可持续发展理论为指导,全面经营森林资源,突出生态效益,综合发挥生态、经济和社会三大效益;以科教兴林为动力,建立林业的大经营、大流通、大财经体系,开展分类、分区、分块经营和重点工程建设,实现我国林业的跨越式发展。并对这一新林业发展战略进行了框架设计
以松材线虫rDNA -ITS2为靶区,建立松材线虫的TaqMan探针实时荧光PCR检测方法。对松材线虫大量DNA和单条线虫的检测结果表明,探针检测松材线虫和拟松材线虫时,前者产生明显的荧光信号,后者无荧光信号,表明探针具有高度的特异性;探针检测到最低模板浓度为1pg·μL-1 ,DNA测序结果与实时荧光PCR结果一致。
采用柱层析和高效液相色谱分离相结合,从松针褐斑病菌的PD培养液中分离提纯到一种致毒活性物质LA-I,该物质为无色油状物。紫外扫描显示LA-I的最大吸收波长为207nm。在365nm和254nm波长下LA-I无吸收。FAB-MS和HRFAB-MS分别显示该毒素物质的相对分子质量和分子式为162和C6H10O5;氢谱中的2个信号(δ1.26 ,δ4.22)表明该毒素物质存在—OCH(CH3)—基团。碳谱显示有3个碳信号(δ181.09,δ66.99,δ21.69) ,证明存在—COOH ,—CH ,—CH3基团。综合质谱、核磁共振谱分析确定LA-I为COOHCH(CH3)OCH(CH3)COOH(α,α′-二丙酸醚) ,红外光谱也证实了毒素的这一化学结构
以松材线虫的粉碎虫体免疫家兔制备抗血清,通过免疫印迹考察抗血清的特异性。利用固相松材线虫抗原和游离线虫抗原同线虫抗体相竞争,建立竞争型ELISA法用于疫木中松材线虫的分析。该方法可以直接检测出10mg的木屑中0.1μg微量的线虫蛋白,约7条线虫的存在。利用该方法对20个不同地区、树种及类型的松材样品进行检测,疫木中松材线虫的检出率为100% ,但拟松材线虫也呈现了一定的交叉反应。研究结果表明,以松材线虫抗原蛋白为指标的免疫学检测方法简便快速、灵敏度高,为松材线虫的快速检疫提供一种可能的途径
报道采自山东、江苏、浙江、福建,寄生梨圆蚧、核桃圆蚧和柑桔长白蚧的寄生蜂新种:长棒盾蚧跳小蜂(Coccidencyrtuslongiclavatus Xu sp .nov.)和采自山西、陕西,寄生枣大球蚧、草履蚧的寄生蜂新种:长柄麦厄跳小蜂,新种Mayrencyrtuslongiscapus Xu sp .nov .。对新种进行了详细描述,并给出我国盾蚧跳小蜂属3个种的检索表。
通过引入小波方法,对木材纹理进行了多尺度的频谱分解,并利用所得到的特征向量分析了水平、垂直和对角方向上的木材纹理频率分布特点,比较了针叶树材与阔叶树材、径向切面与弦向切面木材纹理的统计差异。并在试验基础上,提出了以小波分解子图像能量值的标准差进行木材纹理最佳分解尺度的筛选,探索出滤波长度取8、分解尺度取2对充分表现木材纹理特征最为适宜。同时还发现可将垂直中高频分量HL和低频分量LL的能量值作为木材纹理区别与归类的重要参数,将EHL/ELH值作为木材纹理的方向性量度
通过对日本人工林木材柳杉髓心方材进行系列高频真空干燥试验,掌握柳杉髓心方材的干燥特性及相应的高频真空干燥条件。结果表明:高频真空干燥前在常压下进行合理的蒸汽和过热蒸汽预处理,柳杉髓心方材可有效地提高干燥质量,尤其可防止开裂产生
利用锥形量热仪对磷酸铵盐处理的人工林杉木、杨木和马尾松木材的燃烧性能进行研究。结果表明:磷酸铵盐阻燃处理木材的引燃时间与阻燃剂量有关,对3种木材而言,阻燃剂量超过100kg·m-3,木材才不会被点燃;磷酸铵盐对降低木材的释热性能效果明显,释热速度降低,释热总量减少,气相燃烧放热降低,而且随着阻燃剂量的增加,降低程度更加明显;经磷酸铵盐阻燃处理,木材失重降低,这对保证结构外形的稳定性具有重要作用;磷酸铵盐阻燃剂的抑烟作用不理想,虽然降低了最强发烟过程的强度,但是也提高了最弱发烟过程的强度,而且随着阻燃剂量的增加,发烟量呈增加的趋势;在阻燃研究中,阻燃剂在木材内分布状态是一个不可忽视的影响因素,特别是木材这种非均质性材料,阻燃剂分布的不均匀性将会影响材料整体的耐火性能
以毛乌素沙地天然臭柏为材料,用实体解剖镜和光学显微镜研究观察臭柏的年轮形态特征,应用树干解析法研究毛乌素沙地沙丘顶部臭柏和滩地臭柏的径向生长和伸长生长动态。结果表明:沙丘顶部臭柏偏心生长明显,长径与短径比为140.36%,伪年轮发生频率为12.07% ;滩地臭柏偏心生长不明显,长径与短径比为105.22% ,伪年轮发生频率为1.80% ;根据年轮数推断,沙丘顶部臭柏群落的年龄至少有123 a以上,滩地臭柏年龄有50 a以上;沙丘顶部臭柏径生长缓慢,生长过程中没有明显的峰值,年平均生长量为0.94mm ,累积生长曲线的S型特征不明显;滩地臭柏的径生长高峰出现在35年,年平均生长量为1.51mm ,是沙丘顶部臭柏的1.6倍,累积生长曲线的S型特征也不明显;沙丘顶部臭柏的匍匐茎长度与年龄之间表现出指数函数关系,而滩地臭柏的匍匐茎长度与年龄之间存在着显著的线性相关关系
利用4 ,4′-二苯基甲烷二异氰酸酯(MDI) -脲醛树脂(UF)混合胶压制刨花板是一种能够显著降低游离甲醛含量的有效方法。本文借助差示扫描量热法(DSC)和板的力学性能测试等手段,重点研究了酸对混合胶固化和施胶方式的影响。试验中所用混合胶的比例为UF∶MDI=6∶1(UF施胶量为6% ,可乳化MDI施胶量为1% ) ,热压温度为175℃,压力3MPa ,热压时间6min。按照是否添加固化剂、分别施胶和混合施胶等情况进行压板试验,并利用DSC分析固化剂对混合胶反应过程的影响。结果都证明:酸性固化剂对MDI的固化是很不利的。在UF∶MDI=6∶1的条件下,添加氯化铵做固化剂时宜采取分别施胶方式,不加氯化铵时宜选择混合施胶方式。按刨花板性能优劣程度,施胶方式顺序为:UF与MDI混合后施胶,不加氯化铵>分别施加UF与MDI,UF里加氯化铵>分别施加UF与MDI,UF里不加氯化铵=UF与MDI混合后施胶,加氯化铵。混合胶刨花板的甲醛释放量可以降到9mg·(10 0g)-1 以下,符合E1级人造板标准的要求
探讨纳米SiO2 表面处理、加入方式、用量对纳米SiO2 脲醛树脂性能的影响。结果表明:采用KH-550硅烷偶联剂处理纳米SiO2 表面,用间歇式超声波震荡法将其加入脲醛树脂中,能有效改善树脂性能。当纳米SiO2 用量<15%时,用量越大,树脂的胶合强度越高,游离甲醛含量越低,粘度越大,固化时间不变。用纳米SiO2 (用量1% ) 脲醛树脂(F/U摩尔比1.2 )压制胶合板、刨花板、中密度纤维板,板的各项性能指标都超过国家标准要求,甲醛释放量达到E1 级水平。同时,通过红外光谱和X射线光电子能谱初步探索了纳米SiO2 对脲醛树脂的增强机制
选择火木层孔菌及5种木材降解能力较强的阔叶树上的白腐菌:粗毛盖菌、偏肿拟栓菌、三色革裥菌、冬拟多孔菌和血红密孔菌,采用国内外红外光谱分析的标准方法,用傅里叶红外光谱仪测定未腐朽材木粉和受6种白腐菌腐朽120 d后的腐朽材木粉试样的红外光谱图。刮取未腐朽的山杨木材样品和受6种白腐菌腐朽120 d时的山杨木材样品表层少许,在干燥条件下,分别放入KBr中,磨细,压片,然后在FTIR光谱仪上进行测定,得到经6种白腐菌降解120 d后的木材木粉和未腐朽材木粉其木材和木质素官能团谱峰位置和谱峰相对吸收强度的振动变化状况,进而分析腐朽后的山杨木材和木质素官能团的变化情况,以作为木材白腐菌对山杨材生物降解机制的进一步研究。结果表明,受6种白腐菌腐朽后的山杨木材和木质素官能团都受到一定程度的降解,但各自的变化情况有所不同。对木质素的降解主要是存在于侧链上,虽然苯环骨架变化不明显,但木质素苯环间的羰基、CH2 结构、紫丁香基和愈疮木基等侧链已部分被降解。从各吸收峰相对吸收强度的变化大小来看,血红密孔菌、冬拟多孔菌、三色革裥菌和偏肿拟栓菌对木质素降解的程度大于粗毛盖菌和火木层孔菌对木质素降解的程度
从森林对雾水的截留量、雾水对森林分布的影响及雾水的水文和化学效应方面,阐述国外在该领域的研究动态和取得的成果,以期推动我国在该领域的研究工作。国外的大量研究表明,雾水对于植物的生长、分布具有重要的生态意义,是森林生态系统水分平衡、养分循环不可忽视的输入项,其生态效应是多方面的。因而,进一步深入研究森林内雾水的水文和化学效应是必要的
介绍国内外林地土壤水分入渗模型、林地土壤水分运动方程、森林流域壤中流模型及其验证和应用,并对这些模型做对比分析,指出各自的优点和不足,阐述深入研究林地土壤水分运动的重要意义。同时,说明今后该领域的研究应结合退耕还林工程中的实际科学问题,针对森林土壤水分研究中的薄弱环节,探索变雨强、变容重和大面积流域的林地土壤水分动力学规律,从而使森林土壤水分的研究走向成熟和系统化的阶段,为森林流域水资源的合理利用和水分循环的计算提供科学依据
以森林历史、生态学、气候学、沙漠学研究成果为基础,综合研究森林、蒸散、气候、沙漠之间的关系。结果表明:森林、蒸散、气候、沙漠四者之间有着紧密的内在关系。因人为活动造成的中国森林的大面积减少,首先引起陆相蒸散量的降低,进而使中国北部气候逐渐趋于干旱化,最终表现为沙漠的扩张。4000年间,我国森林覆盖率由60%减至12.5 % ,作为主要原因使全国总年蒸散量减少146mm ,全国平均降水量减少约200mm ,沙漠化面积由占国土的10%扩大到17.6%。森林与沙漠是构成陆地生态系统的两极,是此消彼长的关系,连通两者联系的中介是水。中国从根本上防治沙漠化的途径是在“东南半壁”宜林地区大面积培育以提高蒸散为目的的“云根林”
In this paper, the regularity and changes of the forest landscape along the major rivers, namely, Nuomin River,Bila River and Zhawen River in Daxing'an Mountains, Bilahe Forestry Bureau based on the interpretation of TM data were studied. The results showed that the regularity has changed a lot due to the gradually stronger human intervention on forest landscape. The most obvious change was the cultivated lands had been expanding alongside the major rivers. With the increasing of population, the only way to satisfy the increasing needs of the local people for subsistence is by expanding cultivated lands because of the backwardness of agriculture productivity. The regularity of conifer distribution along rivers of 1997 has changed in the diverse direction of that of 1988. The proportion of conifer gradually increases with 1 000 m further away from the major rivers. That is due to the favorable availability of conifer alongside river bank, the most populated area in the forest region.
The seedlings of Vernicia montana derived from seeds soaking with water (the first group)or 300 mg·L-1 mixed nitric-acid rare earth solution (the second group) were treated with various concentrations of mixed nitric-acid rare earth solution by foliage spraying. The results showed that the seedling heights sprayed with 100 和 1 000 mg·L-1 of the first group and with 50 和 100 mg·L-1 of the second group were significantly higher than the controls, and the diameter at ground level sprayed with 300 mg·L-1 of the second group was significantly greater than the control, being 26.92% more than the latter; except for spraying with 0 mg·L-1 and 700~1 500 mg·L-1 of the second group, the seedling dry weight above ground of others was 29.13%~73.91% greater than the control, whereas the seedling dry weight under ground of others was 20.78%~116.88% greater than the control; the contents of chlorophyll a and chlorophyll b for all spraying seedling were 91.67%~191.67% and 87.5%~306.25% greater than the control, respectively, and soluble proteins and soluble sugars were 16.00%~179.78% and 10.73%~105.65% greater than the control, respectively. Compared with the control, the activity of SOD tended to increase, whereas the contents of MDA decreased. These indicated that spraying leaves with optimum concentration of mixed nitric-acid rare earth solution could markedly promote the growth of seedlings and improve resistance ability of V. montana seedlings to bad environment. On the whole, the effects of spraying the leaves of seedling with 50~500 mg·L-1 mixed nitric-acid rare earth solution, which were derived from seeds soaking with 300 mg·L-1 mixed nitric-acid rare earth solution, were good.
The test site was located in Jincheng Town, Lin'an City, Zhejiang Province. The leaves, culms and rhizomes of two-year-old and three-year-old flowering individuals or non-flowering individuals were taken from the same bamboo (Phyllostachys praecox f. prevernalis) forest. The culms and rhizomes of one-year-old flowering or non-flowering were also taken from the same bamboo forest. Based on analysis of the content of endogenous hormones, amino-acid and nutrition in flowering stage of bamboo, the results showed that abscisic acid(ABA) had main effect on accelerating its flowering and the increase of cytokinin(CTK) was also one reason for bringing flower, but indole-3-acetic acid(IAA)antagonized on its flowering. Total amino-acid in the non-flowering bamboo was 23.01% higher than that in flowering bamboo. Aspartic acid (ASP) could delay flowering. Protein, especially protein in leaves had main effect on senescence procedure. Increase of phosphorus content in flowering bamboo could accelerate metabolizing, and therefore promote senescence of bamboo.
Immature zygotic embryos of Quercus variabilis were as explants to induce somatic embryogenesis. Several factors influencing somatic embryogenesis have been assayed. Somatic embryos can be induced in MS and WPM basal medium, but there was more quantity, big size and high induction rate in MS medium. Induction rate was not significant cultured in light and dark condition. Zygotic embryos, collected in middle of July, gave higher rate of somatic embryogenesis than those collected on the earlier or later date. By adding 6-BA in medium individually, somatic embryogenesis appeared directly on the zygotic embryos without detectable callus. Secondary embryogenesis appeared in medium with 2,4-D individual or combined with 6-BA or TDZ. High induction frequency of 90% was achieved in MS medium supplemented with 0.5 mg·L-1 6-BA and 2,4-D, whereas the rate in hormone-free medium was only 16.7%. The genotypes of mother trees had an great impact on the inducing rate. Zygotic embryo surgery treatments were not favorable to embryogenesis. It was best to inoculate with entire zygotic embryos. The hypocotyl was a crucial part on somatic embryogenesis for Q. variabilis.
Embryonic axis and cotyledon of immature and mature embryos were induced as explants for embryogenesis in Ginkgo biloba. Results showed somatic embryos could be induced only through embryonic axis and cotyledon of immature embryos. MK + NAA 1 mg·L-1 + 6-BA 1 mg·L-1 was the best medium for somatic embryogenesis from embryonic axis, and somatic embryogenesis rate was 45.28%. MK + NAA 1.5 mg·L-1 + 6-BA 1 mg·L-1 was the best medium for somatic embryogenesis from cotyledon, and somatic embryogenesis rate was 12.9%. The growth and development of somatic embryos were promoted by adding 10% coconut milk into MK, and 34.48% somatic embryos could develop into plants.
Genetic relationships between Ziziphus jujuba and Ziziphus spinosa populations were studied using RAPD data in population genetics. 275 loci were gained among which 249 loci were polymorphic by 22 primers. The polymorphic loci percentage was 89% among Z.spinosa population while that of Z.jujuba population was 56%. 31 specific RAPD markers were detected on 3 Z.jujuba varieties and 15 Z.spinosa forms. Cluster analysis showed: when λ=12, the forms tested were divided into 2 groups. One included Z. jujuba cv. Zanhuangdazao, Yudichuangan, Yuanshichuangan, Xiaochuangan, Qiantai No.1, Luzhuangchuangan; the other included Z. jujuba cv. Zilingdan and 26 Z. spinosa forms. All above indicated that Z. jujuba and Z.spinosa should be regarded as two separate species.
The article describes the phase result of Tibet natural forest resource protection projects on the basis of the investigation.It is analyzed that the projects were short of investment,the forests were protected difficultly,it is difficult for the forestry enterprises to manage,replying energy resources were developed slowly in the natural forest resource protection projects.The article puts forward that how to guarantee the science and technology with the matter and to deal with the relationship between the natural forest protection and sustainable development combining with the actual situation.Structural reform should be deepened.The mechanism should be renewed.While the natural forest protection is strengthened,the resources will be used scientifically and reasonably.The new forestry economic growth point can be bred positively in the project areas.The people's consciousness of environment protection should be advanced.The forest vegetation must be protected strictly.
Public welfare forest is the most important model of vegetation restoration in the Conversion of farmland to forests in Sichuan Province. It can well represent and reflect the characteristics and laws of vegetation restoration in hillside fields. Therefore an Alnus cremastogyne forest community developed via converting hillside fields to forest, was investigated by contrast with a weed community on abandoned hillside fields. The results indicated that: 1) In Sichuan Basin and surrounding regions of it, vegetations restored so rapid that the average DBH (diameter at breast height), tree height of A.cremastogyne tree crown density, ground vegetation coverage respectively reached 5.2 cm, 6.1 m, 0.7 and 100 percent for 3 years and after converting hillside fields to forest. 2) With vegetation restoring, community gradually developed mosaic spatial pattern and vertical stratification, simultaneously distribution of plant population changed from regular to clumped, and spatial heterogeneity of community increased. 3) Community biodiversity remarkably increased in the process of vegetation restoration in hillside fields. During the period, species richness of both commnuities changed from 20 to 39, Shannon-Wiener diversity index was 4.205 and 5.021 respectively, while Pielou equitability index dropped little. 4) Plant species frequently and dramatically altered, which mainly showed that therophytes declined rapidly from 16 to 10, while perennial ones dramatically increased from 2 to 26, and 8 of them are phanerophytes. 5) The pathway of community development approximately was from annual herbs to shrubs + perennial herbs to trees + shrubs and herbs + perennial herbs, finally to natural mixed forests, such driving force was mainly from interspecific competition.
The reproduction characteristics of Aprostocetus prolixus, which is a new parasitioid on Apriona germarii, were studied. It demonstrated that the female adult can generate offspring by either sex reproduction or parthenogenesis, but all the offspring were male if they were from the mode of parthenogenesis. The sex ratio, with investigating in nature, was 2.38∶1. The environmental conditions had notable influence on sex ratio, survival ratio and fecundity. Its sex ratio increased to 3.48∶1 by feeding complementary nutrition that adding with 20% honey. The temperature has great effect on Aprostocetus prolixus in terms of system research, of which adult longevity decreased with temperature from 17.5 ℃ to 35 ℃ and its ability of reproduction increased between 25 ℃ and 30 ℃ but the acme at 27.5 ℃. Without the feeding complementary nutrition, on the other hand, the female adult will both lose the ability of fecundity at the temperature below 17.5 ℃ and over 35 ℃. With humidity increasing from 40% to 80%, its fecundity increased significantly. It also showed that there was no significant influence of temperature on fecundity between the 4 ℃ to 8 ℃ when cold storage( I.e. the matured larvae for 90 d, the adults for 10 d and the host egg for 40 d).
The termite baits were maded by the handmade molding instrument,and the crackle degree of termite baits was regarded as the evaluation index. The shaping craft of the termite bait was studied by orthogonal method.The results of the experiment showed that the best shaping craft of the termite bait of the cane powder was:the thin cane powder,10% adhesive, 5 s of crush time and 200% water;while the best shaping craft of the termite bait of the pine fritter was:the thin pine fritter,10% adhesive,5 s of crush time and 100% water.
Soil animal communities of Pinus koraiensis broad-leaved mixed forest were studied.The purpose was to discuss the dynamic characteristic of soil animals and relationship with environmental factors.The ecosystem geography distribution law of soil animals, soil animals’role and function in ecological system were revealed.In June,August,October each year,three plots were selected. In each plot, four layers were sampled(litter layer,0~10 cm,10~20 cm & 20~30 cm),adding up to 72 soil sample.The area for large_sized soil animals was 50 cm×50 cm,and the area for middle_small_sized soil animals was 10 cm × 10 cm.Separated soil animals through adopting hand_picking method and Tullgren method respectively.Sampled the soil animals in two continuing years.Shannon_Wiener index was adopted to analyze the diversity of soil animals.Monad liner regression was used to search the relationship between soil animals and environmental factors.The dominant groups were Oribatida, Isotomidae.There were relatively great changes in groups and individual numbers of dominant groups and rare groups when the reason changed.The individual numbers of dominant groups and the groups of rare groups changed.The number of individual and group was the most in August.Obviously it correlated with climatic factors in middle temperate zone.The evenness was low and dominance was high. The diversity index was not most.Among the annual fluctuating there was a increasing trend. The evenness was low and dominance was high.The diversity index was low.It conformed with the law of reason change.The correlation between soil animals and atmospheric temperature,rainfall,ground temperature and sunlight showed the correlation with rainfall and soil temperature was the most significant.
In this paper, CIRAD-Foret method and strain gauge method were used to measure the longitudinal surface growth strains released from fallen woods. Comparison was also done between two methods for measurements at the same point (sawing grooves inside the position pins)and at two points. Results showed that the values obtained from the CIRAD-Foret method were bigger than those from strain gauge method. The former was 1.3 times as high as the latter for the measurement at two points, and it was 2.0 times as high as the latter for the measurement at the same point. There was no distinct difference in the longitudinal surface growth strains from strain gauge method with measuring way at the same point and two points. However, the differences were obvious for the strains from CIRAD-Foret method with two measuring ways. They indicated that there was little effect on the values from strain gauge method with measuring way at the same point or at two points, and that the measuring way would influence measured result when CIRAD-Foret method was applied. In general, in comparison with CIRAD-Foret method, strain gauge method was more stable.
对樟子松人工林群落结构和土壤水分动态进行研究。结果表明:13年林龄的樟子松人工林300cm深层的土壤水分已基本耗竭,而且整个生长季还在持续减少,土壤水分不能得到有效补给;林木生长衰弱,平均高仅3.59m ,平均胸径5.77cm ,并出现大量枯梢;林木生长已受到土壤水分亏缺的严重制约,林分开始衰败;林下草本层发育良好,盖度较高。研究指出,干旱半干旱地区人工林在不适宜的密度下造成群落结构与环境条件不相适应,存在着由乔木植被向草本植被演替的规律,对人工林群落的稳定性进行分析,指出通过密度控制、树种选择等措施可以进行调整,延缓土壤水分的耗竭速度,提高林分的稳定性。要建立稳定性更高和维持时间更长的人工林,从根本上改变草本植被代替乔木植被的规律,需要借鉴天然稀树草原植被的乔木密度,大幅度降低人工林的密度。在有地下水存在和植物可以利用的情况下,人工林的稳定性可以维持一个世代甚或更长。
福建三明格氏栲天然林及在其采伐迹地上营造的33年生格氏栲人工林和杉木人工林粗木质残体现存量与季节动态、C库及养分库的研究表明,格氏栲天然林、人工林和杉木人工林粗木质残体现存量分别为1.32、0.46和0.23t·hm-2。3种林分粗木质残体现存量的季节变化模式均为夏季>冬季>秋季>春季。格氏栲天然林粗木质残体C贮量为0.78t·hm-2 ,分别是格氏栲人工林和杉木人工林的4.11倍和7.09倍;格氏栲天然林粗木质残体C库与2种人工林间差异显著(P<0.05)。格氏栲天然林、人工林和杉木人工林粗木质残体养分贮量分别为14.16、2.90和0.95kg·hm-2 ;格氏栲天然林粗木质残体中各种养分贮量均最高。与人工林相比,天然林粗木质残体现存量、C和养分贮量均最大。
生态足迹是某地区生产消费的粮食和纤维、维持能源消费以及建筑用地的总和。应用生态足迹分析,共和县2002年人均生态足迹供给12hm2 ,即生态承载力值为1.056hm2。该地区的人均生态足迹为1.662hm2 与生态承载力比较,生态赤字0.606hm2 。共和县荒漠化发展是生态足迹扩大的结果之一,另一方面荒漠化扩张减小了共和县的生态承载力,因此荒漠化发展对共和县生态赤字起到两个方面的作用。提出共和县减少生态赤字,走可持续发展道路的政策措施。引入产量因子的地区修正因子,使Wackernagel因子更符合中国不同地区的实际。
在海南东北部农村周边植物调查过程中,发现了分布在这一区域的青梅林。基于与海南其他热带雨林的植物区系成分和群落结构的比较,认为此青梅林是海南东北部原有森林的幸存者,与海南现有的典型热带雨林属一个类型,是海南北部地区热带雨林幸存的活证据,所不同的是次生性强,优势种明显。
紫茎泽兰是一个典型的外来入侵植物。利用便携式光合测定系统,对分布于四川省凉山州德昌市郊(27°28′36″N,102°12′28″E)的紫茎泽兰的气体交换特性进行测定,并与本地8个伴生种和其他12个分布于我国不同地区和日本的入侵种和本地种进行比较。目的是探讨气孔调节在日变化过程和长期干旱与湿润生境上的差异及其对紫茎泽兰入侵能力的影响。研究发现:紫茎泽兰光合午休现象明显,气孔调节和非气孔调节共同控制了紫茎泽兰的光合日进程模式,而以气孔调节最为重要。非气孔调节主要是通过羧化效率的降低,从而影响表观量子效率或其他光合过程来实现的,而气孔调节主要是通过降低胞间CO2 浓度,提高气孔限制值来实现的,这与其他种的差异不大。经过长期的野外不同湿度环境适应后,气孔调节出现了一定的弹性变化。在气孔导度相差不大的情况下,土壤有机质、土壤pH值和土壤有效氮含量差异不明显,湿生生境的光合速率和蒸腾速率显著高于干生生境,并导致了叶片含氮量显著提高。气孔在调节紫茎泽兰水分利用效率方面有别于所测定的其他20种植物,在湿生生境下随气孔导度下降,水分利用效率下降,而在干生生境下则显著升高。因此,紫茎泽兰同时兼有“省水”植物和“费水”植物的双重特点,这一灵活水分利用特点保证了它在不利环境中的生存和有利环境中的扩展,对于其在侵入区的生长发育有一定的意义。
选择相同年龄(12年生)、起源(实生)和立地条件下的东北东部山区主要树种水曲柳、紫椴、蒙古栎、核桃楸、黄菠萝和红松幼树,采用ICT-2000TE自动监测系统同步测定其树干液流密度、耗水量及其主要环境因子。在生长季晴天,各树种的树干液流密度日变化基本呈单峰曲线(但黄菠萝有3次为双峰曲线) ,日峰值主要出现在10:00—14:00。黄菠萝、红松、紫椴、水曲柳、蒙古栎和核桃楸最大树干液流密度分别为234.00、286.21、507.93、516.36、625.93、945.83cm3·cm-2 h-1 。除黄菠萝之外,树干液流密度日变化主要受光合有效辐射(PAR)和蒸汽压亏缺(VPD)的影响,它们对树干液流变异的贡献率波动在60%~74%。整个生长季中核桃楸、紫椴、水曲柳、红松、黄菠萝和蒙古栎的耗水量分别为3840、2820、2710、2120、1470和1390kg·株-1。
铝胁迫下龙眼幼苗铝吸收特性试验表明:龙眼铝吸收特性取决于介质中铝的浓度,介质浓度≤0.370mmol·L-1 时,龙眼铝吸收主要受代谢控制,属于主动吸收;介质浓度>0.370mmol·L-1时,则主要受非代谢因素影响,即为被动扩散。铝胁迫下,龙眼吸收的铝主要集中于根系,根的铝含量是茎的3.54~5.66倍,是叶片的3.60~5.80倍,其积累量占全苗铝总积累量的58.85%~75.07%,且随铝浓度的提高根中铝含量、铝积累量均大幅度增加,根吸收的铝转移到地上部的比例随介质铝浓度的提高而减小。铝在龙眼叶片细胞中主要分布在细胞壁,铝胁迫下龙眼叶片细胞壁中的铝含量占86.20%~88.58%,依次是细胞质、叶绿体、线粒体,核蛋白中最小。
采用农杆菌介导的遗传转化方法,将来自枯草杆菌的果聚糖蔗糖转移酶基因(SacB)导入银腺杨,以提高杨树对水分胁迫的抗性。以来自无菌培养的叶片为外植体,通过大约1000个叶盘与农杆菌LBA4404共培养,将植物双元表达载体pKP中SacB基因导入银腺杨基因组,经卡那霉素筛选后,共获得102株卡那霉素抗性植株。经PCR特异性扩增和Southern点杂交分析,证明其中97株再生植株基因组DNA中整合了SacB基因。对其中的62个无性系进行RT-PCR分析,结果表明SacB基因在其中的50个无性系中获得表达。温室生长观察表明,转基因无性系外部形态与对照相比没有稳定的显著差异,少数部分转基因无性系的生长明显受到抑制,其他转基因无性系生长正常。这些转基因无性系的获得为培育抗旱转基因杨树奠定了基础。
用0~-2℃低温和不同水平的PEG预处理石楠种子,可提高种子的活力指数,增加可溶性蛋白、煮沸稳定蛋白的含量,提高SOD、CAT活性,降低MDA含量与POD活性;SDS PAG电泳图谱表明:15%PEG预处理的种子,在萌发的第4天,分子量分别为40.27、42.5、44.5、46.2、50.8kD的5条多肽带的染色比未处理种子的深。
设计3种磷水平的水培和土培试验,研究马尾松5个不同种源酸性磷酸酶(Apase)活性和分泌性Apase活性以进一步阐明造成马尾松不同种源对磷肥反应差异的适应机制及与磷效率等关系。结果表明,低磷胁迫会刺激马尾松根系Apase向根际的分泌,其中福建武平和广东信宜种源根系分泌性Apase活性较强,浙江淳安、江西崇义种源较低,仅为福建武平种源的50%左右。在磷饥饿的诱导下,生长高峰期马尾松种源根系和针叶的Apase活性显著提高,表现出与磷素水平的负相关,根系的Apase活性在总体上高于针叶。统计分析发现,低磷水平下马尾松不同种源根系和针叶Apase的活性存在显著的遗传差异,以福建武平和广东信宜2种源的活性最高。结合这2种源具有较高的光合速率和磷效率,可以认为福建武平和广东信宜乃耐低磷型优良种源。测定结果还发现,马尾松幼苗Apase的活性在生长高峰期过后将急剧下降,不同种源间未显示出明显的差异。
以厦门植物园引种的5 6种棕榈科植物为材料,应用相关分析、通径分析、决定系数分析等方法,分析原产地的经纬度、海拔、植物的生态学特性、定植时间等因素对引种结果的影响。结果表明:影响厦门地区引种棕榈植物的3个关键成败因子是原产地的纬度、海拔和引种定植时间;分布于南北纬20°以上的中纬度棕榈植物、分布于高海拔的种较易获得引种成功;引种定植时间宜于初春之后到秋季之前进行;棕榈植物原产地的经度以及内陆或沿海适应性,对引种棕榈植物影响较小。
对1 0种国产木兰科玉兰属(原木兰属玉兰亚属)植物辛夷挥发油成分及其含率进行分析和研究,其中腋花玉兰、河南玉兰、椭圆叶玉兰、舞钢玉兰、两型玉兰、罗田玉兰和鸡公玉兰7种植物为首次测定。结果表明,10种植物共检测出84种成分,每种植物为36~56种成分,鉴定出6 2种化合物,其含率占挥发油的98.4%。有17种成分为10种植物所共有,含率达72.9%,以单萜类化合物为主,占64.8%,其余为倍半萜类化合物,占8.1%。主要共有成分为桉油醇、香桧烯、β-蒎烯、月桂烯、a -松油醇,其中桉油醇的含量最高,通常在20%以上,最高达35.5%。5种成分在玉兰属植物挥发油中为首次报道,其中1种共有成分:1羟基- 1 ,7-二甲基- 4 -异丙基-环癸二烯,其平均含率2.72%;4种非共有成分:α-姜烯、大根香叶烯B、β-倍半水茴香烯和四甲基环癸二烯异丙醇。根据不同植物挥发油成分及其含率差异,提出河南玉兰与椭圆叶玉兰的亲缘关系较近,可能为同一杂种起源。玉兰属挥发油成分月桂烯与四甲基环癸二烯异丙醇具有重要的分类学意义,据此可把10种玉兰属植物分为2类,一类为朱砂玉兰、玉兰、舞钢玉兰、两型玉兰、罗田玉兰和鸡公玉兰,其月桂烯含率在6.0%以上,四甲基环癸二烯异丙醇含率在1 %以上;另一类为望春玉兰、腋花玉兰、河南玉兰和椭圆叶玉兰,其月桂烯含率在20%以下,不含四甲基环癸二烯异丙醇。
中国竹类资源现主要分布在秦岭和淮河以南地区。然而,根据考古材料和历史文献的研究表明,5000年来,我国竹类的古今分布区产生了显著的变化。唐代以前,黄河流域有较多的竹类分布,竹类自然分布区北界可达北纬39—40°,而今天为北纬35°,往南退缩了4~5°。竹类分布区退缩的原因,主要受气候变冷、变干的影响。竹类植物对气候的变化相当敏感,可作为研究气候变迁的指示物种。当代气候变暖,在我国北方扩大竹类的栽培面积是十分有利的。
采用LandsatETM +多时相影像,在地类光谱特征分析的基础上,用分层分离的方法,提取出沙化土地信息。以全国沙漠化普查地类划分标准中的植被覆盖度为确定沙化土地程度的依据,通过建立NDVI和实测植被覆盖度的回归模型,确定不同程度沙化土地对应的植被覆盖度与NDVI的对应关系,用NDVI阈值进行划分,得到沙化土地程度图。
通过嫁接病皮和病枝传病的方法,在河北唐县试验地内对壶瓶枣、蛤蟆枣、婆枣、马牙枣、砘子枣、长红枣6个枣树品种和1个酸枣品种,以及从婆枣中选择的4 6个抗性单株的抗病性进行试验研究。经过1996年以来的多次传病测定结果表明:壶瓶枣和蛤蟆枣无一发病,表现出强的抗病性;长红枣、马牙枣、酸枣、婆枣和砘子枣表现为感病,发病率分别为66.6%、78.6%、80.0%、100%、100%。筛选的46个婆枣单株的平均发病率为81.1%,单株间抗病表现差异明显,有4个单株经过6年6次传病而一直没有发病,说明其对枣疯病有很强的抗性,用DAPI荧光显微镜观察,尤其是PCR技术检测,基本上能在嫁接接种后未发病的抗病单株上检测到植原体的存在,说明其体内已携带了低浓度的植原体,暗示抗病材料对植原体繁殖可能有抑制作用。对酚类物质在2个层析系统进行的薄层层析分析中发现某些抗病材料与感病材料存在不同特异性的荧光斑。在对枝条组织切片自发荧光观察中,在抗病的2个婆枣材料和1个壶瓶枣材料的韧皮部至表皮区域的薄壁细胞内中发现了较多的金黄色亮斑点。
采用林间定期调查取样的方法,测定白蜡窄吉丁幼虫的龄数以及各龄的龄期;分别测量不同发育阶段幼虫的体长、体宽(第7腹节最宽处)、前胸背板宽、口缘宽、尾叉长和尾叉前缘宽等6项指标,以期找出区分和判定幼虫虫龄的最佳形态特征及指标。结果表明:白蜡窄吉丁幼虫有4龄,尾叉及其长度可作为理想的分龄特征和分龄指标;幼虫的口缘宽度也可作为指标之一;体长、体宽、前胸背板宽和尾叉前缘宽变异较大,不宜用于分龄。研究还发现:幼虫尾叉内侧的形态特征是区分幼虫虫龄的简洁而方便的方法。利用种群众数龄期法测定各龄的平均龄期分别为:1龄18.1d ,2龄11.2d ,3龄10.7d ,4龄261.2d ,幼虫期共为301.3d。
以小叶杨和北京杨的材性测定值(导管分子长度或木纤维长度或导管腔径)作为因变量,以年轮数作为自变量,建立材性成熟非线性模型,以此为依据讨论成熟龄问题,并对幼龄材在树体内的分布进行分析。导管分子长度、木纤维长度和导管腔径的成熟龄模型为应用分段回归分析方法拟合的二次方程和定数函数结合的非线性方程,方程的决定系数在0.857~0.991之间,并在0.1%水平上达到显著。以导管分子长度作为材性指标,应用这个非线性模型分析的结果表明:材性成熟龄及幼龄材半径因树种、立地的灌溉条件不同存在差异。无灌溉北京杨6~10年达到成熟,幼龄材半径为52mm左右;无灌溉小叶杨24~29年达到成熟,幼龄材的半径为90mm左右;灌溉小叶杨13~15年左右达到成熟,幼龄材的半径为85mm左右。
对聚合物稳定沙土的作用机制从分子间作用、聚合物性质和界面作用等3个方面进行研究。结果表明:干燥状态下阴离子基团与沙土颗粒的结合作用为化学键形式,强于非离子基团的氢键结合;但阴离子基团含量过高会降低聚合物处理后沙土的水稳定性。合适的高分子沙土稳定材料应该具有良好的水分散性、较高的平均分子质量、合适的阴离子和非离子基团含量以及较伸展的分子构象。提出了干燥状态下聚合物与沙土颗粒之间存在粘接作用,聚合物性质与其沙土稳定效能之间的关系也可以用粘接原理进行解释。
应用DSC分析中的等温扫描和等速升温扫描,研究异氰酸酯与不同含水率纤维素反应机理。等温DSC研究揭示含水纤维素与异氰酸酯反应时,存在无规成核机理、扩散机理和相界面机理等多种情形,水分迁移作用和异氰酸酯与水反应速率较快是致使异氰酸酯与含水纤维素的反应机理复杂的关键。通过等速升温DSC研究,找到一种能够描述异氰酸酯与不同含水纤维素等速升温反应的机理函数。
开发基于线阵CCD植物活体微根系图像监测分析系统,消除面阵CCD图像桶形畸变,实现微根系生长无损原形监测。环形微根系扫描结合纵向深度位移,系统实现微根管内微根系全景图像扫描。通过基于分形理论的计算机微根系图像处理系统完成所采集图像的分析,系统可自动完成基于像敏单元的定量化获取微根系生长关键特性值及其生长动态特性计算。本系统可应用于农林行业苗木培养、作物生长模型研究等领域。
探讨漾濞泡核桃壳作木材胶粘剂原料的化学背景。化学分析结果表明:漾濞泡核桃壳中含(硝酸法)纤维素33.25%、多戊糖26.72%、木素60.94%、灰分1.19%;核磁共振氢谱、紫外和红外光谱的分析结果表明:核桃壳木素以愈疮木基-紫丁香基木素为主,属GS型木素,且G型木素的含量大于S型木素。利用G型阔叶材木素的化学性质可以合成得到与普通酚醛树脂胶合性能相当的核桃壳木素-苯酚-甲醛共聚树脂。
激光雷达是近年来国际上发展十分迅速的主动遥感技术,在森林参数的定量测量和反演上取得了成功的应用。激光雷达具有与被动光学遥感不同的成像机理,对植被空间结构和地形的探测能力很强,特别是对森林高度的探测能力,具有其他遥感数据无法比拟的优势。介绍激光雷达遥感的基本原理、大光斑和小光斑激光雷达系统的特点,对它们在林业上的应用现状进行评述,重点分析激光雷达反演森林参数的方法,对激光雷达的林业应用前景进行分析和展望。
介绍了一种可在植物转基因中应用的新型筛选方法—磷酸甘露糖异构酶(PMI)法,与传统筛选体系不同,它以甘露糖为筛选剂对转化细胞进行正筛选。PMI能将甘露糖- 6 -磷酸转化成果糖- 6 -磷酸,使转化细胞以甘露糖为唯一或主要碳源而正常生长;非转化细胞由于不能利用甘露糖而停止生长。该筛选体系受基因型、培养基中其他糖和磷酸根离子浓度及培养条件等因素的影响。目前已应用于多种模式植物和经济作物的转基因筛选,在木本植物甜橙上也首获成功。其检测方法多样,除了常规转基因检测方法外,还可对酶活性进行检测,其中氯酚红法简单可靠,且无需昂贵试剂。安全评估结果表明PMI基因对人体健康和环境无害。PMI/甘露糖筛选体系有望成为植物转基因的又一有效筛选手段。
青枯菌引起许多植物及林木青枯病。该菌侵染植物根部,首先在根皮层细胞间隙等处定殖,然后入侵维管束,在木质部导管内扩展危害;细菌在导管及相邻组织内迅猛增殖和广泛散布,由此产生输水管道的阻塞和破坏并最终导致植物枯萎。胞外多糖(EPSI)、细胞壁分解酶(主要是果胶质酶和纤维素酶)、Ⅲ型Hrp分泌系统产物是主要的致病因子,其中EPSI尤为突出,它在保护细菌、促进细菌移动和定殖以及堵塞和破坏寄主导管方面都起着重要作用。而上述致病因子的协调作用则由一复杂的调节系统控制,这一系统由随细菌密度变化而变化的3 -羟基棕榈酸甲基酯水平作为信号,以PhcA调节基因的启动和转录为核心,自动而精密地调节病菌有关致病基因的表达及关闭,并由此控制细菌的生长状态。
植物蛋白酶抑制剂是除Bt之外又一个愈来愈研究较多的抗虫基因资源,其分布广泛,在豆科、茄科、禾本科、葫芦科及十字花科等植物中存在较多。植物蛋白酶抑制剂抗虫基因主要通过2种途径获得并在多种植物中进行转化,获得抗虫转基因植株。植物蛋白酶抑制剂在林木抗虫基因工程中的应用刚刚起步。本文在总结我国林木病虫害防治现状的基础上,阐述植物蛋白酶抑制剂在林木抗虫基因工程中的应用前景,同时也探讨植物蛋白酶抑制剂在林木害虫防治应用中存在的问题及解决途径。
弄清楚不同化学药剂处理过程中木材细胞壁分子结合构造的变化与化学流变学特性之间的关系,对于开发新的木材改性技术,丰富木材化学流变学基础理论具有十分重要的意义。在归纳化学处理过程中木材的分子构造变化研究现状的基础上,提出几点研究构想。
尺度选择是科学研究的重要环节。本文评析传统森林经营单元的时空尺度选择特征及其局限性,指出为了实现森林可持续经营与发展,应该引进新的尺度观念,扩展森林经营单元的基本时空尺度。在简析景观管理与一般可持续发展研究关系基础上,从镶嵌体稳定和动态整体优化、对生物多样性保护工作的融合、生态服务功能表现的尺度依赖特征、采伐等行业实践的景观尺度影响、与其他景观尺度土地可持续管理工作的协调等角度重点论证景观尺度对于设计、管理以及度量森林可持续经营的独特价值;同时提出并初步讨论流域生态区、生态周期以及与景观相对应的世代尺度等时间尺度在森林可持续经营与发展中的应用。
The concentrations of N, P, K, Ca and Mg in different organs of Phyllostachys pubescens with in sequence of age and the amount of soil nutrients were analyzed. The results showed that the content of four nutrition elements(N, P, Ca, Mg) in different organs were in the order as: leaf > branch > stem; while for K: leaf >stem >branch. The abundance of different elements in leaf, in branch and in stem respectively ranged as: N>K>Mg>P>Ca, K>N>Mg>P>Ca and K>N>Mg>Ca>P. The nutrition elements in various organs of P. pubescens were interrelated one another at some extent, significant(P<0.05) or great significant correlation (P<0.01)existed between eleven pairs nutrient elements contents out of total thirty pairs of nutrient elements. The productivity of the woods in on-year was much higher than that in off-year, while the content of N, P and K in leaf was much higher in off-year. The nutrition in bamboo were generally correlated to nutrients of soils, eg, nitrogen content in leaf had a significant relationship with organic matter, total nitrogen, available nitrogen and available potassium in soil, phosphorus content in leaf had a strong relationship with organic matter and available nitrogen in soil, however, only good relationships in stem were found between nitrogen content and organic matter, available potassium in soil. Potassium content in branch were negatively correlated to organic matter, total nitrogen and available nitrogen in soil.
Xingyuangtong handhold forest inventory instrument is a microcomputer-based Hi-tech product integrating remote sensing、mobile GIS and GPS, which is developed by 3S research center of Shenzhen Polytechnic. It can be used in forest resource inventory, area calculation on map, area survey on the spot, compartment and sub-compartment mapping and editing based on remote sensing images or scanned relief maps, interactive query and amendment between graphics and its attributes, etc. On the basis of theory analysis of area survey principle, the practical area survey precision of nine different-sized plots in different period of time and under different interfered conditions is analyzed in order to study the possible precision of area survey on the spot by using this product. It is demonstrated that Xinyuantong handhold forest resource inventory instrument can meet the precision needs of returning the grain plots to forestry, acceptance check of forestation land, area survey of compartment and sub-compartment, etc. This product can be widely used in forest resource inventory.
In order to improve the resistance of Euonymus japonicus, its ability of adventitious shoots regenerating from inter-node stem-segment were researched on MS medium in vitro. The effect of both plant growth regulators and carbon resources in media on adventitious shoots differentiating was studied. Regenerating system of E. japonicus was established successfully. Adventitious shoots were highly obtained from inter-node explants inoculated on MS media supplemented with 6-BA 1.7 mg·L-1+IBA 0.005 mg·L-1 or 6-BA 1.9 mg·L-1 + IBA 0.03 mg·L -1. The regenerating ratio reached to 52.4% and 46.7% respectively. Media for inducing adventitious roots were 1/2MS+ IAA 0.5mg·L-1. Adventitious shoots originated from surface tissue of inter-node stem-segment.
Harvested Prunus persica fruits cv. Dajiubao and cv. Bayuecui were immersed in 0, 0.1 or 0.3 g·L-1 salicylic acid (SA) solutions for 15 minutes,then stored at room temperatures (22~25 ℃) for 14 days or low temperatures (0~2 ℃) for 30 days. The results showed that after SA treatment,the activity of lipoxygenase (LOX) was inhibited significantly,contents of malondialdehyde (MDA) in the fruits also decreased.The immersion of fruit in the solutions of SA was helpful for maintaining the flesh firmness.The cell membrane electrolyte leakages of SA treated fruits,compared with control,were high during early days and low at the subsequent days.
Based on the principal component analysis and the cluster analysis of phenological observation data from 70 meteorological observation stations for 8 years (1994—2002), which were located in all the distribution regions of Melia azedarach in China, the distribution regions of Melia azedarach in Chinese were divided into 11 phenological areas. It will provide a scientific basis for seedling rational allocation and germplasm resources conversation for Melia azedarach; and the phonological isophene map will be a guidance for agriculture and forestry production in the most parts of southern China.
In this article, the growth dynamics of Davidia involucrata population was studied in Sanjiang, Wolong Natural Reserve. The seed dispersal range was limited in a circle of 0~10 meters away from the mother tree, which changed with the terrain where the trees grow. The survival percent of seedlings germinated from seeds was very low, and few seeds germinated in 2002. About 3 percent of seeds germinated in 2001 grew up and became seedlings. Considering the various diameter classes of Davidia involucrata forests, only a small part of trees was germinated from seeds, most of trees were sprouted from the base of the fall trees. In natural, the regeneration of Davidia involucrata population was difficult and had difficulty to spread. The seedlings and juvenile trees were so lack that the Davidia involucrata population has been declining. We should devote major efforts to protecting them.
Centred around 371 indexes including natural environment,human activities,condition of society,economic situation,forest resources,forestry organizations,technology,management and administration,we have investigated 105 counties(cities,districts) in Hunan Province. Eighty three counties out of them were designated for our research objects. For each county,we selected 28 indexes which had directly bearing on our social forestry project such as natural environment,social economy,forest resources.Then through Cluster Analysis and Factor Analysis,we used a social science statistical analysis software(SPSS) to analyze the impact of natural,environmental,social,economical and forest resources’ factors on community forestry activities.Based on such work,we have established a set of indexes system for Hunan provincial social forestry project’s regional evaluation.According to the cluster analysis results and the current situation of the project implementation,Hunan provincial social forestry project could be divided into five types,the results will provide a scientific basis for Hunan provincial social forestry project’s implementation.
We reported in this paper the results of our test of four insecticides used through cover spray for controlling the Asian longhorned beetle, Anoplophora glabripennis (Motsch.). The four insecticides were ASTRO (A. I. 36.8% permethrin) by FMC Corp., AllPro DURSBAN 4E (A. I. 44.9% chlorpyrifos) by Sureco Inc., ORTHENE 75 S (A.I.75% acephate) by VALENT USA Corp., and SEVINXLR PLUS (A. I.44.1% carbaryl) by Rhone_Poulenc AG Co. (now part of Bayer CropScience). The insecticides were sprayed onto 1.5 years old poplar (Populus sp.) trees until insecticide run-off from twigs. Twigs were collected from treated trees once every 3 d until the 21st day after insecticide application to feed caged adult beetles. Adult mortality was recorded once every day for 3 d. Leaf and twig samples of treated poplar were collected from each treatment 3, 6, 9, 20, 40 d after spray to determine the levels of insecticides in these parts of trees. Although all insecticides showed promise for short term efficacy (>95% 3 d mortality for adults feed on twigs collected 1 after application), permethrin (concentration 920 mg·kg-1) was the best among the 4 tested insecticides for longer residual activity with 3 d cumulative mortality>95% for adults feed on twigs collected within 15 days after application. Chlorpyrifos (2 245 mg·kg-1) was the least effective with 3 d cumulative mortality around 60% for adults feed on twigs collected within 6 d after application, while the mortality was around 90% and 75% for acephate (7 500 mg·kg-1) and carbaryl (17 640 mg·kg-1), respectively. However, high concentrations of acephate and carbaryl are not feasible for controlling adult beetles, especially in urban areas. In general, levels of insecticides were higher in leaves than in twigs for the 4 insecticide. Levels in leaf 3~9 d after application was 0.9~4.1 mg·kg-1 for permethrin,2.5~1.6mg·kg-1 for chlorpyrifos,2.6~2.3 mg·kg-1 for acephate, and 35.2 ~49.6mg·kg-1 for carbaryl. Residual levels 20~40 d after application were 2.8~1.9 mg·kg-1 ,1.4~1.2 mg·kg-1 , 1.9~1.4 mg·kg-1 and 40.9~39.7 mg·kg-1 for permethrin, chlorprrifos, acephate, and carbaryl. Based on the relationship of the mortality of adult beetles and residual levels of insecticides, mortality may reach 95% when the level of permethrin reaches 4 mg·kg-1 in leaf, 1.4mg·kg-1 in twig. For acephate, a level of 2.5 mg·kg-1 in leaves or 2.1mg·kg-1 in twigs will achieve 90% mortality of adult beetles.
The ultra_morphology and chemical composition of waxes secreted by the scale insect Physokermes shanxiensis (Homoptera: Coccidae) was researched with the techniques of scanning electron microscope (SEM), infrared absorption spectra (IR) and gas chromatography/mass spectrometry (GC/MS). The result indicated that the scale insect secreted wet wax in its nymph stage. The wet wax coagulated into translucent wax covering on the body surface. However, the female adult secreted its wax secretion with white color and long thread form. According to the infrared absorption spectra characteristic of the waxes, it can be known that the both waxes either from male nymph or female adult were composed by a series of saturated and unsaturated long carbon chain compounds. But the two waxes have different in the chemical functional groups kind and numbers that composed the compounds, because of the differences in absorption peaks numbers and forms which appeared in the two infrared spectra from the wave number 1 800cm-1 to 1 000 cm-1. Through detected with GC/MS, 14 compounds with carbon atom number form C13 to C13 were obtained form the wax of the male scale insect. These compounds included 5 saturated higher fatty acids, 1 unsaturated higher fatty acid, 1 saturated higher fatty alcohol, 1 unsaturated higher fatty alcohol, 1 unsaturated ester, 1 saturated aldehyde, and 4 saturated alkane compounds.
Under the microwave,the activated carbon from bamboo shavings was prepared with the phosphoric acid according to orthogonal tests.The optimum conditions were obtained.The results of the experiment showed that the bamboo shavings could be producted good activated carbon by the method of microwave-phosphoric acid.The iodine number reached 836 mg·g-1 The decolorizing capacity of metylene blue reached 13 mL·(0.1g)-1 The decolorizing capacity of caramel adsorption reached 113%.The addition of sulfuric acid or hydrogen peroxide could also significantly improve its adsorb function.
湿地功能一般可分为水文功能、生境功能和生物地化学循环功能3种类型,3类功能各包括若干子功能,各子功能的强弱由可以量化、相互独立、能够表示其本质特征的评价指标表示,指标总和即为湿地功能评价指标体系。湿地功能所具有的模糊属性决定了模糊数学方法在湿地功能评价中具有广泛的应用前景。运用模糊数学理论和方法进行湿地功能评价的实质就是确定待评价湿地属于哪个事先划分好的模糊集合,或描述它属于某个集合的程度。两级模糊模式识别模型的原理是通过确定评价对象对最优、最劣2种状态的隶属程度,从而定量判断评价对象的优劣状况。对于任意一块待评价的湿地,以其原始状况下指标最大可能特征值作为最优标准值,以其在人类干扰下指标可能达到的最小特征值作为最劣标准值。运用模型对黑龙江三江平原洪河国家级自然保护区不同年份(1980,1988和2002年)湿地功能进行了评价,结果表明该区湿地功能对最优状态的隶属度在1980、1988和2002年分别为0.9743、0.8573和0.7030,呈明显下降趋势。
应用稳定氢同位素技术对四川卧龙巴郎山亚高山暗针叶林不同降水条件下3群落类型中降水、林冠穿透水和壤中流的变化动态进行跟踪研究。结果表明:降水δD与降雨量负相关显著(R2=0.456,p=0.043),降雨氢同位素存在显著的雨量效应。降水δD与林冠穿透水δD差异不显著(p=0.863)。壤中流δD与降水δD有明显差异(p=0.049),表明壤中流补给来源是降水,但不一定是当日当次降水直接补给。降水量的升高或降低引起壤中流δD升高或降低。当降水量0~10mm时,影响在降雨后第4天发生;当降水量在10~20mm时,影响在降雨第2~3天后发生;当降水量在20~30mm时,影响在降雨1~2天后发生。显示出亚高山暗针叶林对壤中流有显著的调控作用。降水δD与林冠穿透水δD的差值(用ΔδD表示)在3个不同群落中随着降雨量的增大呈现偏正态分布,当降水量在4.91~25.25mm时,ΔδD>0;当降水量<4.91mm及>25.25mm时,ΔδD<0;当降水量为12.65mm时,δD最大,这主要是林冠层蒸散过程和大气降水过程相互作用的结果。
调查茂兰喀斯特森林林隙干扰特征,并对林隙特征、林隙的形成方式进行探讨。结果表明:1)林隙大小分布表现出以小林隙为主的偏正态分布,但在总林隙面积比例上,大林隙所占的比例较大;2)林隙大多数在20年前形成,估计林隙形成速率为0.55个·hm-2a-1,返回间隔期为270年;3)林隙密度约为20个·hm-2,林隙平均面积(69.7±45.71)m2,扩展林隙平均面积(152.7±79.43)m2,林隙和扩展林隙占所调查林分面积的比例分别为13.9%和30.6%;4)林隙形成方式以折干为主,但因地形差异,槽谷、坡地、漏斗的主要形成方式分别为干中折断、拔根倒和干基折断;5)大多数林隙由1~4株形成木形成,平均每个林隙的形成木为2.5株。大部分林隙形成木为森林建群种,常绿和落叶树种分别占61.5%和38.5%。林隙形成木以小径级为主,表明本地森林林隙干扰十分频繁。
根据朱春全提出的态势理论对更新生态位宽度和更新生态位重叠公式进行改进,分别以林隙大乔木和小径木的生态位作为更新生态位的态和势来计算动态的森林更新生态位。通过对长白山阔叶红松林固定样地林隙更新的调查,分析了林隙内主要树种的数量特征,研究了其更新生态位宽度及重叠的特征。结果表明:此改进公式不但保证了其数学上逻辑的一致性,同时增加了生态学的解释意义,提高了更新生态位测度的精确度。
选用5个对磷肥反应差异显著的马尾松种源,设计3种磷素水平的盆栽试验以研究马尾松磷效率的种源差异,确立种源磷效率的特异性指标。结果表明:马尾松磷效率的种源差异很大,尤以地处武夷山脉南端的福建武平种源最高,其磷效率高于70%,为最低磷效率种源的2倍左右,该种源在低磷胁迫下具有最大的磷素吸收和利用效率及最高的干物质积累量。在参试的3个南方种源中,广东信宜种源也具有相对较高的磷效率。低磷水平下马尾松种源磷效率与磷素利用效率有关,而与磷素吸收效率相关性较小,磷效率和磷素利用效率高的种源其干物质积累量较高。相关分析表明,低磷胁迫下马尾松种源磷效率与其根体积、侧根数、侧根总长和须根总数等呈显著正相关。结合已有水培和土培试验结果,初步认为侧根总长、侧根数、根体积等根系参数以及根系有机酸分泌物含量、酸性磷酸酶活性等可作为低磷胁迫下马尾松种源磷效率的特异性指标。
以1年生长白落叶松幼苗为研究对象,采用沙培方式,供给含不同浓度的硝酸铵或磷酸盐的营养液,着重研究氮磷供给水平对其叶绿素生物合成、叶片氮含量及光合速率的影响。结果如下:1)硝酸铵浓度1~8mmol·L-1时,5-氨基酮戊酸(5-aminolevulinicacid,ALA)合成速率增加,而当硝酸铵浓度达到16mmol·L-1时,与8mmol·L-1相比,ALA合成速率反而下降17%。在磷处理下,ALA合成速率变化与之相似。在氮磷处理下,氮磷浓度分别为8和1mmol·L-1时胆色原素(porphobilinogen,PBG)合成酶活性达到最大。2)叶绿素a、叶绿素b、总叶绿素以及类胡萝卜素含量在硝酸铵浓度为8mmol·L-1、磷浓度为0.5mmol·L-1时达到最大。叶片总氮含量随硝酸铵浓度增加而增加。3)磷浓度0.125~1mmol·L-1时,叶片总氮含量只有微量增加,且磷浓度增加到2mmol·L-1时,与1mmol·L-1相比,叶片总氮含量反而下降9%。硝酸铵浓度为1~8mmol·L-1时,叶片中可溶性蛋白含量总体上逐渐增加,硝酸铵浓度增加到16mmol·L-1时,与8mmol·L-1时相比,可溶性蛋白含量下降17%。在磷处理下,可溶性蛋白含量在0.25mmol·L-1时达到最大。4)当硝酸铵浓度为1~8mmol·L-1,总体上FvFm随硝酸铵浓度增加而逐渐增加,而在16mmol·L-1时反而下降。在磷处理下,FvFm的变化趋势与之相似。在硝酸铵浓度1~8mmol·L-1时长白落叶松幼苗净光合速率逐渐增大,但硝酸铵浓度为16mmol·L-1时净光合速率反而下降16%(与8mmol·L-1相比)。在磷处理下,净光合速率在1mmol·L-1时最大,磷浓度过量(2mmol·L-1)则导致光合速率降低。这些结果表明氮供给水平对长白落叶松幼苗叶绿素的生物合成过程中ALA合成速率和PBG酶活性影响较大,从而影响幼苗叶片中叶绿素和类胡萝卜素含量;同时氮供给水平也影响幼苗叶片总氮含量和可溶性蛋白,因而影响净光合速率。磷供给水平对长白落叶松幼苗叶绿素的生物合成过程中ALA合成速率和PBG酶活性影响较大,但对幼苗叶片中叶绿素和类胡萝卜素含量影响则小,同时对净光合速率的影响也小。
鉴于巨柏目前的濒危状况,通过对巨柏天然分布的3个居群(雅鲁藏布江朗县段、米林县、林芝县)进行野外观察和测量以及TTC法种子活力测定,研究了巨柏结实状况、种子形态特征、种实受害和种子活力、出芽率等与濒危的关系,结果表明:巨柏成熟个体有70%~80%不结实或结实极少,健康球果平均含种子58粒;树体大多受樵采危害,种实受病虫、鸟鼠危害严重,是导致巨柏濒危的主要外因;种子活力最高只有39.8%,平均只达到34.6%,远远低于红松、杉木等的种子活力;种子发芽率较低,平均只达到32.67%,是导致巨柏濒危的主要内因;种子品质和其所处生境的温湿条件不利于巨柏个体繁殖和种群扩散。
为利用侧芽进行泡桐人工接干提供理论依据,研究了自然状态下1年生泡桐侧芽萌发成枝接干规律。结果显示:1)在高密度粗放管理条件下,毛白33泡桐分枝习性表现为假二叉分枝,第2年不能接干的占42%,而58%的单株分枝特性表现为合轴分枝与假单轴分枝(近似顶芽接干的主轴分枝或单轴分枝),能够实现自然接干,这3种分枝类型可以统称为假轴分枝;2)第2年接干单株的接干形率均较大,但能不错位通直接干的仅占14%,86%的接干单株的错位状况需要2~3年后才能得到改善;3)在接干单株中,从接干的上侧芽向下数,越向下在干上分布的侧芽萌发成枝的长度、粗度越小,枯死率越高,但与主干上方夹角逐渐变大,第4对侧枝的分枝夹角最大,以下夹角减小,长度、粗度减小趋势变缓,并枯死。
以12年生日本落叶松自由授粉家系子代测定林为研究对象,对生长、干形和材性性状进行相关分析、通径分析及间接选择研究,利用综合选择指数法开展了日本落叶松纸浆材优良家系选择,并为湖北等亚热带高海拔山区筛选出一批生长、干形和材性兼优的家系,最后提出了日本落叶松纸浆材选育指标及优良家系利用途径。研究表明:生长性状与纤维长度之间存在显著正相关关系,与壁腔比之间存在显著负相关关系,与木材密度、1%NaOH抽出物、综纤维素含量间相关不显著;木材密度与主枝长之间,纤维长度与主枝长、主枝粗和新枝粗之间,晚材壁腔比与主枝粗、主枝长、皮厚、冠幅、新枝数之间,1%NaOH抽出物与主枝长之间存在显著正相关关系。各控制性状对单木材积直接作用的大小依次为:胸径、树高、主枝长、壁腔比、主枝粗、皮厚、冠幅、晚材纤维长和早材纤维长,其中胸径和树高2个性状对单株材积性状的直接作用占材积总变异的63%,虽然冠幅、壁腔比等性状对单木材积的直接控制作用很小,但这些性状通过胸径对单木材积具有很大的间接遗传控制作用,由这9个性状组成的控制系统可以说明单木材积变异的98.66%。
对6年生四川省桤木15个种源51个家系在湖北、江西、福建3个试验点试验林的单株生物质产量进行了研究,结果表明:桤木种源3个地点6年生的平均单株生物质产量为6.15kg。单株生物质产量种源间、种源内家系间差异显著。单株生物质产量具有极显著的地点效应,单株生物质产量种源×地点、家系×地点交互作用显著。3个地点单株生物质产量种源遗传力为0.27~0.75,家系遗传力为0.17~0.83,表明单株生物质产量受到中度到强度的遗传控制。材积(直接通径系数0.791)对单株生物质产量控制作用最大,其次为树高(直接通径系数0.396)和木材基本密度(直接通径系数0.256)。树高、胸径和冠幅通过材积对单株生物质产量的间接通径系数较大。四川省金堂盐井、盐亭、金堂淮口、沐川和邛崃5个桤木种源初选为工业用材林优良种源。
选取北京市永定河沙地4种不同土地利用类型(耕地、林地、荒草地、河滩地)作为试验地,对不同下垫面的起沙风速、下垫粗糙度、输沙量、风沙流结构、土壤机械组成、土壤风蚀量进行研究。结果表明:1)不同利用类型起沙风速及粗糙度大小顺序为:林地>荒草地>耕地>稀疏荒草地>河滩地;2)不同下垫面在相同风速时的输沙量明显不同,近地面0~20cm随高度增加输沙率逐渐减少,不同下垫面的风沙流结构垂直分布明显不同;3)河滩地和稀疏荒草地的机械组成主要以细沙为主;耕地、林地、荒草地主要由细沙、极细沙以及粉沙组成。4)不同利用类型在相同时间内风蚀量与风积量不同;5)建议对区域风沙治理主要从两个方面进行:提高未利用地的植被覆盖度;改变农业耕作技术措施。
木质素固沙材料是制浆废液经化学改性制备而成的一种新型固沙材料,具有见效快、可降解、成本低等优点,并可与植物固沙有机结合,促进沙化地区的植被恢复。经过3年在宁夏(半干旱地区)的木质素固沙与植被恢复相结合的研究,结果表明:1)木质素固沙材料溶液可以在1天之内快速形成沙结皮,起到固沙作用,比草方格固沙节约成本50%以上,当年植被便可恢复,经济、生态效益明显;同时使固沙的高度突破了12,达到了23的沙丘高度;使生物多样性明显增加。为干旱、半干旱地区的生态建设提供了一项新的技术措施。2)木质素固沙材料1%~2%的浓度和2.5L·m-2的剂量既可有效固沙,同时还可保持水分、减缓水分蒸发,对植物的发芽、生长及生物量积累均起到了良好的作用,是固沙与植被恢复的理想结合。3)木质素固沙材料是水溶性的,在半干旱地区木质素固沙材料的作用大约在8个月至1年,足以帮助植物的生长,但降水过多地区将使木质素的效能弱化。4)1年生草本与多年生的灌木植物组合配置,可持续性发挥固沙作用。
对TM遥感图像各原始及常用比值波段的信息量大小、相互间存在的多重相关性及其对郁闭度估测造成的不利影响进行分析研究。针对特定监测区域,对设置的遥感比值波段,采用平均残差平方和准则进行筛选,最终确定对郁闭度估测有一定影响的遥感波段,并形成可操作的软件系统。
以15块人工落叶松纯林演化后形成的落叶松云冷杉混交林为对象,间伐后12年观测结果,研究间伐对林分和树木生长、树种组成、物种多样性及土壤等因子的影响。间伐强度分为2级:中度(平均为20%)和强度(平均为30%)。结果表明:间伐促进了保留木生长的显著增加,但不同间伐强度间无显著差异。林分及单木的直径、断面积和蓄积生长率均表现相同的趋势即随间伐强度的增加而增加。但间伐没有显著地增加12年间的总收获量。伐后对照样地表现为较高的枯损,枯死木主要是落叶松和阔叶树。林分进界株数严重不足,进界的主要树种是云冷杉、阔叶树和红松,以耐荫树种为主。从枯损和进界看,如果能对红松和阔叶树进行保护,这种林分很可能逐渐演化为阔叶红松林。建议对红松和阔叶树进行保护,使林分向阔叶红松林方向发展。各林分的树种组成在12年间基本没有发生变化,即间伐没有显著地改变林分的树种组成,目前的树种组成即落叶松、其他针叶树(云杉、冷杉和红松)和阔叶树组成比约为6∶3∶1可能是相对稳定的群落。20%和30%的间伐强度没有显著地改变林分的物种多样性、灌草生物量和土壤物理性质,间伐样地的物种多样性略有提高;间伐样地的土壤物理性质有所改善,总孔隙度和毛管孔隙度都大于对照;林下灌草生物量有所增加。
采用随机区组试验设计,通过方差分析、多重比较及回归分析,研究不同配方基质性质与油松容器苗生长及生理特性的关系和对苗木生长的影响。结果表明:不同基质对油松容器苗的地径、高径比、单株鲜质量、地下干质量影响存在显著性差异,对苗木单株干质量、地上干质量、地上鲜质量的影响差异达极显著水平;不同基质的苗木在顶芽干质量、根系活力和体内碳水化合物含量上也存在明显差异;基质的密度、全磷和速效磷的含量是影响油松容器苗生长的主要因子;基质中碱解氮的含量是影响容器苗地上与地下部分比例关系的主要因子;在北方培育油松容器苗,基质配方以表土40%、黄色粘土15%、松林表土20%、腐熟粪肥20、炉灰渣5%的配方比例,质地为中壤土,密度10t·m-3,全磷含量达0.8g·kg-1,速效磷含量90mg·kg-1,速效钾含量260mg·kg-1,碱解氮含量112mg·kg-1,有机质含量34g·kg-1的微酸性土(pH=6.3)为佳。
根据统计数据和实际调查,论述天然林保护工程实施过程中,天然林区1998—2003年间职工的社会保障现状和存在的问题。分析得知,富余职工的安置工作取得进展,但天然林区富余职工的安置和职工的社会统筹保险等方面仍然存在问题。目前,天保工程区仍有9.84万下岗待安置职工,大部分单位没有给职工上医疗和失业保险,养老保险金拖欠现象严重。以黑龙江省大兴安岭呼中林业局为案例进行了分析研究,提出了解决天然林区社会保障问题的对策:1)建立完善的社会保障体系,保证参保人的权利,增大天保工程区职工参加社会保险的覆盖面;2)加强社会保障的立法,确保林区职工的最低生活保障、医疗保险和养老保险;3)减轻森工企业的经济负担,尽快解决养老保险金拖欠问题;4)发展替代产业创造再就业机会,实现转产分流、减员增效等。
根据《国家重点保护野生植物名录(第一批)》统计梅州现有国家重点保护野生植物21种,隶属于16科20属。本文对保护植物的生活型、分布特征及地理区域特点进行了分析,结果表明大多数的种类为热带亚热带区系成分,而且在保护区内分布最为集中,栖息地易受到人为活动的干扰,需加强保护。论文同时探讨了这些保护植物的价值,并就如何加强保护提出具体的建议,为研究和合理利用梅州地区保护植物资源提供基础材料。
研究了苦豆草生物碱对分月扇舟蛾幼虫拒食、生长和繁殖的影响。在选择性取食时,2.5mg·mL-1苦豆草生物碱即对分月扇舟蛾幼虫具有强烈的拒食作用,拒食率达62%~86%,而在非选择性取食时,拒食率仅为20%~29%;在选择性取食时,虫龄越大,拒食率越大,非选择性取食则未见此趋势。苦豆草生物碱对分月扇舟蛾幼虫的生长具有明显的抑制作用,表现在取食生物碱处理的食物后体重、体重增加量、相对生长率均显著降低。用浓度为10mg·mL-1的苦豆草生物碱处理后第2天,分月扇舟蛾幼虫相对生长率比对照下降了39.8%。对食物的消耗和利用效率均显著下降;取食量和排粪量分别是对照的57.7%和57.4%,近似消化率升高,而食物转化率和利用率均下降。此外,苦豆草生物碱处理后成虫的产卵量明显低于对照。讨论了利用苦豆草这一荒漠植物防治森林害虫的意义和前景。
采用SDS法提取线虫基因组DNA,分别选取了6种随机引物对部分地区的10株松材线虫和10株拟松材线虫进行随机扩增和亲缘关系比较。RAPD的结果可以明显区分松材线虫和拟松材线虫,与形态学分类相吻合。聚类分析的结果也表明,线虫种内和种间均存在差异,但种间差异明显大于种内差异,同种线虫在同一地区或临近地区的同源性明显高于其它地区,同一地区内寄主对线虫种类分布的影响较小。该方法具有所需样品量少、检测灵敏度高、结果准确等优点,为松材线虫种群的亲缘关系、传播途径及其检测防疫等方面提供一种灵敏、可靠的研究方法。
将来自Bacillusthuringiensissubsp.kurstaki的杀虫基因cryIAc通过综合质粒载体pEG601,整合到松树共生细菌B.cereus(Bc752)的染色体上,得到的工程菌对马尾松毛虫幼虫有明显的杀虫活性。此综合质粒含有能在营养期表达BtcryIAc基因的强启动子、cryIAc杀虫基因、四环素抗性标记基因tetr、8.0kb的EcoRI-NcoⅠB.cereus(O147)染色体片段。将综合质粒通过电击导入Bc752中,综合质粒与Bc752染色体发生同源重组,将BtcryIAc基因整合到Bc752的染色体上。通过对转化子的DNA酶切分析、PCR扩增、SDS-PAGE凝胶电泳检测、Westernblot、电镜观察、毒力测定,结果表明BtcryIAc基因已经整合到松树共生细菌Bc752的染色体上,并可高效表达。
给昆明种雄性小鼠口服印楝油氯仿提取物2g·kg-1d-1,连续1周,停药后第3周取材,研究了其抗生育作用。结果表明小鼠口服印楝油氯仿提取物后抗生育作用肯定;半数致死量为33g·kg-1;血清中转氨酶的活性在停药后的1~3个月升高,停药后的4~6个月基本恢复至正常,血清中睾丸酮含量在服药前后,无明显改变;流式细胞术研究结果表明:印楝油氯仿提取物引起睾丸组织生精细胞减少,细胞凋亡率升高;对变态期精子细胞核蛋白转换的影响表现为总碱性核蛋白含量减少47.11%,总组蛋白精核蛋白比值升高82.25%。研究表明,印楝油氯仿提取物有较好的抗生育作用,其作用机制主要是干扰精子核蛋白的转换,另外还可能与细胞免疫介导有关,对于控制鼠害有一定的意义。
应用人工神经网络建立热带森林火灾发生情况预测的多层神经网络模型,并将林火发生影响因子的历史数据作为样本值,输入模型进行训练。结果表明:利用所选取的输入因子作为样本的人工神经网络,可以对林火的发生发展作出准确有效的预测。文中还对模型的准确性和训练精度进行讨论,进而分析人工神经网络在林火预测中的可行性,证明人工神经网络在林火预测中的应用价值。
给出由木材内部结构参数确定其物理力学特征的神经网络设计与实现的方法—广义回归神经网络(GRNN)模型。该方法的实现,全面、准确地揭示出杉木微观结构参数与其物理力学特性的内在联系,并且达到理想的逼近精度(96.3%以上)。这一结果将为木材性质研究、木材性质形成机理、树木优质种质资源培育、树木转基因工程、定向培育材质改良的树木新品种提供强有力的科学依据及研究方法。
对毛白杨无性系测定林分内25个无性系150棵单株木芯试样的湿心材比例进行测定和遗传分析。结果表明:无性系间湿心材比例差异达到5%显著水平,湿心材比例的无性系重复力高达0.749,受中度遗传控制,在无性系间进行可获得良好效果;湿心材比例与木质素含量及与木材基本密度之间无相关性,对这3个性状可以进行单独选择;湿心材比例与胸径之间在1%水平上呈极显著的负表型相关性和显著的负遗传相关性,可联合选择;在所研究的25个无性系中,可选择1232#无性系,它的湿心材比例较低、木质素含量较低、材色较白,且胸径较大。
分析木材细胞结构形态,以长匣子形作为木材细胞模型,根据材料导热与导电规律的相似性,应用类比推理方法,从欧姆电阻定律推出材料导热的热阻公式;依据该细胞模型和热阻公式推导木材弦向导热系数的理论表达式,从而揭示木材弦向导热系数是木材孔隙率的函数。孔隙率越大的木材,导热系数越小,并实际计算了24种木材的弦向导热系数,与试验值比较,理论值的最大误差12.6%,平均误差小于6.4%。
采用FTIR显微分析技术,对FRW阻燃处理红松木材限制燃烧固相产物的结构进行分析;采用GC-FTIR联机分析方法,对经FRW阻燃剂及其主要组分处理的紫椴木材试样的热解挥发性产物进行分析和鉴定;讨论FRW阻燃处理木材的热解炭化过程、阻燃剂的作用以及热解产物的结构特点。结果表明:FRW阻燃木材受热时,随着温度的升高,在FRW及其分解产物的催化下,木材逐步发生聚糖脱水、半纤维素脱乙酸、聚糖降解、木质素降解、木材热解产物聚合、脂肪族聚合物脱氧及芳构化等反应,最终炭化;FRW阻燃剂改变了木材的热解途径,并且显著降低了挥发性有机化合物的生成量。
黄土高原地区深层土壤干燥化(土壤干层)是人工林草植被过度耗水导致土壤水分负平衡的结果。概述土壤干层的研究进展,包括土壤干层的特征、类型、量化指标、成因、分布、危害及其缓减对策,指出当前研究中存在的问题,对今后研究提出建议。
植物修复是以植物忍耐和富集某种或某些有机或无机污染物为理论基础,利用植物或植物与微生物的共生体系,清除环境中污染物的一门环境生物技术,其核心是对植物能忍耐和超量积累重金属的生物学特性的利用。其具有费用低廉、节约土地资源或储藏费用、利用植物本身特性、不破坏生态环境和无二次污染等多方面的优点,有望成为一项具有广阔应用前景的治理重金属污染土壤的全新技术。基因工程技术应用于植物修复将是今后污染土壤修复研究领域的一个重要方向,这将为污染土壤植物修复的普遍推广提供了更大的可能。本文综述了近年来国内外重金属和有机物污染环境的转基因植物修复研究进展情况,重点介绍了重金属耐性基因和有机污染物耐性基因在植物清除土壤重金属和有机物污染中的应用。
从森林生物灾害与森林生态系统功能的关系、森林病虫害防治历史、社会对森林病虫害防治策略以及森林经营目标的需求出发,系统化森林有害生物控制策略—生态控制;定义森林有害生物生态控制;分析森林有害生物生态控制的特点、理论基础以及技术基石;认为自然控制论和自组织理论是森林有害生物生态控制的理论基础,森林有害生物生态控制的技术基石是森林生态系统管理;对森林有害生物生态控制遵循的原则进行讨论,包括生态系统原则、协调性原则、生态平衡原则、生态位原则、环境保护原则、协同进化原则、林副产品安全原则、生态系统稳定性原则、生态系统的高功能原则(生产力、经济效益、生态效益、社会效益)、森林生态系统生物灾害的可持续控制原则;对森林有害生物生态控制及其适用条件进行评价。森林有害生物生态控制与森林有害生物综合管理相比具有多项优点,是未来森林有害生物控制的主要方向,具有广阔的前景。
近红外光谱技术是一项新的木材无损评价方法,能够迅速、准确地对生长锥、固体木材或木粉等试样的性质进行全面无损评价,目前已广泛应用于木材性质预测、木材加工利用等方面的研究中,并为林木的定向培育、木材的遗传改良和高效利用提供技术支持。本文介绍了近红外光谱技术的基本原理及其主要应用,重点介绍了木材的近红外光谱技术及其在木材化学组成、物理力学性质、木材加工利用和木质复合材料等方面的研究成果及应用。
针对黄土高原土石山区植被群落蒸散量测定及其分量确定的问题,基于林地水分平衡原理,提出了“多树水分平衡法”的概念、具体布设和计算方法,并应用本方法较为准确地测定了2种不同密度的华北落叶松林分的蒸散量及其分量,通过与热脉冲测定方法的对比和验证,表明2种方法计算结果相差不大,说明它可以作为测水分平衡的一种方法加以应用,最后对该方法在理论和实践中存在的若干问题进行了探讨。
Western Sichuan sub-alpine is an extension of Qinghai-Tibet Plateau to southeastern China and is covered with forests in the valleys, mainly dark coniferous ones. As a result of long-term over-logging on a large scale, they have been greatly reduced and degraded. In this paper, in order to analyse the influences of forest management and topography factors on sub-alpine forest restoration in west Sichuan, Miyaluo was selected as a case study area. The cutting volume, artificial regeneration area and tending area from 1953 to 2000 were collected, forest survey and plot investigation were taken in 7 watersheds. The results showed that sub-alpine forest restoration in west Sichuan was influenced by both forest management and natural regeneration. Taking Miyaluo as an example, forest management could be divided into two stages, cutting period (1953—1978) and restoration period (1978—now), and cutting period also could be divided into period Ⅰ (1953—1965) and period Ⅱ (1966—1978). In cutting period with logging on a large scale and fast regeneration, artificial regeneration could not catch up with cutting, tending could not catch up with regeneration, the young growth tending was worse and survival rate was low, especially in period Ⅰ. That resulted in the mosaic patch of plantations, natural secondary forests and ones from both artificial and natural regeneration in cutting area. The pattern was influenced by aspect. Spruce from artificial regeneration was dominant on half-sunny and sunny slope; birch and firs from natural regeneration were on half-shady and shady slopes. In restoration period, cutting was little and stopped at last, artificial regeneration was little; survival rate was high from well tending to young growth. Spruce regenerated artificially in 1980s and at the beginning of 1990s had closed to young forests after successive tending with many years. In sub-alpine forest regions, the regeneration methods and species should be selected according to the habitat types that changed with altitude and aspect. In the sites that restoration can be go on naturally, natural regeneration should be promoted to ensure the persistence and stability of forests.
Microorganism impacts greatly on the translation and the availability of phosphorus in the soil. Inoculating the medium with Ca3(PO4)2 and lecithin as the only P source respectively with the strains of bacterial fertilizer in our laboratory, 9 strains of phosphorus-dissolving bacteria were selected. The contents of available phosphorus increased from 33.082 mg·kg-1 to 344.820 mg·kg-1 in the medium withCa3(PO4)2 and increased from 0.870 mg·kg-1 to 43.123 mg·kg-1 in the medium with lecithin. The pH of all cultures of the medium with Ca3(PO4)2 were lower than that of CK. While in cultures of the medium with lecithin, the pH values of 7 strain cultures were lower than that of CK and the other 2 strains were higher. The pH varied in 5.0~7.5.
Pinus massoniana was grown in a nurse bed consisting of a strong acidic yellow soil and inoculated with 3 strains of Laccaria bicolor, namely Lb S238A, Lb S238N and Lb 270, respectively. The growth of seedlings, particularly stems and leaves, was promoted significantly by the ectomycorrhizal(ECM) fungi in the sequence: Lb270 > Lb S238N > LbS238A. In contrast, the inhibition of aluminum translocation was observed from roots to upper parts compared to the absorption and utilization of N, P, Ca and Mg that were encouraged by ECM. Seedlings infested with Lb S238A absorbed least amount of nutrients and aluminum, while the largest amount of P, K and Mg was taken in by those with Lb 270 and the largest amount of N and Ca by those with Lb S238N。It is necessary to point out that Ca absorption and accumulation in the upper parts of pine seedling were greatly promoted by ECM inoculation. The latter in those of mycorrhizal seedlings was increased by 473%~577% over than nonmycorrhizal(NM) ones, which could benefit to the aluminum resistance of the tree seedlings. The inoculation of Laccaria bicolor could, therefore, be considered as an important and effective measurement to promote growth and nutrition and to alleviate aluminum toxicity to Pinus massoniana in south China.
This paper had developed a theoretical mathematics model of wood drying stress-strain using mathematical and physical theories and taking moisture content (MC) and microfibril angle (MFA) into consideration as explicit parameters,predicted the development of stress-strain using MATLAB software,and analyzed the effect of MC and MFA. The results showed: on the condition of making the basic parameters set,the charts plotted by MATLAB software reflected the effect of MC and MFA. Tangential and longitudinal strain changed linearly with MC. The model could be applied to analysis the development of stress_strain in drying from ultrastructural level.
Cationic rosin sizing agents can be used to neutral sizing, so the study about it is very important to papermaking industry, whose condition is converting from acidic to neutral or alkalinity, and rosin processing and utilizing industry in China. In this paper, the cationic rosin dispersion sizing agent HPCRZ was successfully prepared under high temperature and normal pressure with a cationic dispersant, which was obtained by synthesis and mixing in the laboratory. HPCRZ's properties, which included its color and state, concentration, pH value, Zeta potential and particle diameter distribution, were analyzed. The sizing degree of its paper samples was determined by Stckigt method. The permanence of its paper samples was analyzed by ageing in oven and expressed with white degree R457 and L*、a*、b* three dimensional color space. At the same time, those properties of control sample were analyzed in order to compare with it conveniently. The result showed that, HPCRZ had high cationic Zeta potential. There were two peaks in its curve of particle diameter distribution. After homogenizing, the peak of bigger particle diameter was reduced to a shoulder. Its volume average particle diameter was 0.567 μm and consistency was 0.652. The particle diameter distribution was close to that of the control. When the paper samples were making with recycled fiber, Al2(SO4)3 dosage was 1.0%, sizing agent dosage was 1.0%, temperature was 10℃, pH value was 6.0 and 5.0, and no other auxiliary agents, the sizing degree was 53 s and 67 s respectively. Its R457 decreased 2.23% and 2.64%, yellow blue axes color index b* increased 2.00 and 2.29, whole color difference ΔEab* was 2.10 and 2.33 respectively after ageing. When pH value was 6.0, temperature was 20℃, and other conditions were not changed, the sizing degree was 52 s and the R457 decreased 2.17%, b* increased 2.24, ΔEab* was 2.32. HPCRZ's sizing effective was almost same with that of the control under these experiment conditions, and the permanence was better.
The technic of rose otto production from Qinwei rose(Rosa damascena Mill cv. “Kazanluk”) was studied. The reflux distillation technic with two different distillation velocities in was a superior method to produce otto. The quality of the otto was high in conformity with ISO 9842 and БДС 653. The optimum process was as follows: fresh flower, salting, distillation, segregation and product finally. The principal technic parameters were as follows∶salting (flower∶salt=4∶1,w/w) 1~25 d; 1∶4 of flower to water during distillation; distillation at 100 L·h-1 for 3 h first, and 125 L·h-1 for 1 h subsequently.
根据2001年出版的《中国植被图集》,应用地理信息系统(GIS)ARC/INFO(NT版)和数字化仪,提取梭梭荒漠植被信息,绘制梭梭荒漠植被地理分布专题图,并以此为基础,对梭梭荒漠植被的群落类型、分布格局及其斑块特征进行分析;同时,结合近年来对梭梭荒漠植被结构的调查结果,对我国梭梭荒漠植被状况进行评价。结果表明:我国现存梭梭荒漠植被总面积约11.4万km2,其中,以新疆分布的面积最大,约占全国梭梭荒漠植被总面积的73.1%,其次是内蒙古,约占全国的14.1%,青海省和甘肃省的分布面积较小,分别占全国的7.9%和4.9%;不同梭梭荒漠群落类型的面积不尽相同,其中,梭梭柴砾漠的面积约占全国梭梭荒漠植被总面积的37.3%,梭梭柴沙漠约占全国的21.3%,白梭梭荒漠约占全国的23%,其他梭梭荒漠群落类型的总面积约占全国的19.4%。我国梭梭荒漠植被分布在107.6—77.3°E,47.4—36.1°N;垂直分布87~3174m;在梭梭荒漠植被分布区的东界和南界,主要分布的梭梭荒漠群落类型是梭梭柴砾漠,在西界和北界,主要分布的是梭梭柴沙漠。组成我国梭梭荒漠植被的斑块共180个,主要特征是:小斑块多,大斑块少,斑块之间的面积相差悬殊,多数斑块之间距离较远。虽然我国梭梭荒漠植被分布面积大,但群落盖度小,盖度小于30%的面积约占现存梭梭荒漠植被总面积的70%。
以苏北地区1991—2001年的数据,采用随机前沿生产函数的效率模型和超越对数生产函数对农田林网和小片林对农业总产值、种植业产值和畜牧业产值的贡献程度进行计量并分析,结果表明:农田林网对上述3个产值的生态贡献率为负值,小片林对上述3个产值的生态贡献率为正值,林业、种植业和畜牧业之间存在明显的联合生产效果。需要扩大小片林面积和对现有农田林网进行适当改造,以期取得更好的效果。
观测了王朗自然保护区紫果云杉林、岷江冷杉林和白桦林3种森林群落一个观测年的大气降雨量、穿透雨量和茎流量,并对其中的养分元素进行了同步取样分析。结果表明:1)3个森林群落穿透雨的硫(S)及铵态氮(NH4+-N)浓度都低于大气降雨中的浓度,说明S和NH4+-N在经过林冠表面时被吸附,而穿透雨中的硝态氮(NO3-N)、钾(K)、钙(Ca)、镁(Mg)、全碳(C)和全磷(P)等元素浓度都高于大气降雨中的浓度;2)所有样地茎流中的养分元素浓度都明显高于大气降雨和穿透雨中营养元素的浓度;3)C、N(NH4+-N、NO3--N)、P、K、Ca、Mg、S等随大气降雨输入林地的量分别为40.57、6.44、0.40、38.69、39.92、8.27和44.25kg·hm-2a-1;4)测定期间,S(岷江冷杉林和紫果云杉林内)、P(紫果云杉林内)及3种森林群落中的NH4+-N、NO3--N和Ca的林地净输入量都为负值,而K、C、Mg、和P(白桦林和岷江冷杉林内)为正值;5)3种森林群落内穿透雨和茎流中的S和C可能主要来自于林冠淋溶,而NH4+-N、NO3--N、K(白桦林和紫果云杉林内)、Ca、Mg和P等主要来自于林冠截获的大气干沉降,岷江冷杉林内K与林冠淋溶和林冠截获的干沉降都密切相关。降雨持续时间长、降雨量小及较高的林冠截留量可能是造成林地净输入量为负值的原因。
树木叶片的养分再吸收效率能够反映树木对养分保存、利用以及对养分贫瘠环境的适应能力。以科尔沁沙地东南缘章古台地区樟子松人工林为研究对象,分析了11、20、29、45年生树木叶片的基本特征、养分含量及其再吸收效率。结果表明:叶片衰老后其质量和面积明显减少;叶片凋落前的平均养分含量没有表现出随樟子松年龄增加而出现有规律的变化;凋落叶片中的N、P、K、Mg含量表现出随年龄增加而增加的趋势,而Ca的趋势与之相反;11年生和20年生的樟子松叶片N、P、K的再吸收效率相似,都显著高于29年生和45年生樟子松(P<0.05),而樟子松叶片对Mg的再吸收效率表现出随年龄增大而显著降低,Ca随叶片的衰老而不断累积,再吸收效率表现为负值,20年生的樟子松叶片Ca再吸收效率最大,11年生和45年生最低。樟子松叶片的N、P、K、Mg养分再吸收效率随年龄增加而降低的趋势表明,随年龄增加樟子松对贫瘠养分生境的适应能力逐渐降低,反映了樟子松养分保存方面的衰退特征。
对白梭梭同化枝自然水分胁迫下的季节抗旱特征进行研究。结果表明:自然干旱胁迫条件下,不同生长发育时期同化枝的主导抗旱生理因子不同。5月31日至6月29日盛花期间,同化枝内源ABA含量甚微,气孔导度值与光合强度处于生长发育过程的最高水平,可溶性糖含量呈现下降趋势,而脯氨酸含量略有增加,植物通过渗透调节作用适应此阶段轻度干旱胁迫;6月29日至7月26日盛夏期间,ABA迅速积累,气孔导度值降为生长发育过程的最低值,叶绿素分解,可溶性糖与脯氨酸均呈现快速积累趋势,且可溶性糖积累强度大于脯氨酸;8月9日至8月22日同化枝生长发育后期,ABA急剧积累为生长发育过程的最高浓度,气孔导度值有所增大,脯氨酸和可溶性糖保持在高水平平稳变化。此阶段高浓度ABA调节植物生理过程适应干旱的效应受CTK、IAA两种内源激素的抑制,进而抑制脯氨酸和可溶性糖的继续积累。
针对红松果林从幼龄到开花阶段植株体内激素水平的变化、激素水平的季节动态以及施入赤毒素(GA3)后对植株开花的作用,从果林中选取7~8年生、11~12年生和17~18年生3个年龄阶段的植株为对象进行研究。结果表明:红松幼龄时生长素(IAA)和玉米素核苷(ZR)的含量偏低,随着树龄增大而升高,至18年左右其含量又逐渐降低;激素的季节动态变化为5月末IAA和ZR的含量达到了最高水平,7月中旬后明显降低;从不同性型植株的激素水平来看,雌型植株体内IAA、ZR和脱落酸(ABA)的含量在春、夏、秋3个季节均高于同龄的雄型植株,3种激素的平均高出值分别为36.11%,43.58%和31.68%;施入外源激素20mg的GA3或玉米素(ZT)时,对增加雌球花数量有较好效果。
对不同含水量肉桂离体胚进行超低温(LN2)保存,采用不同冷冻方式、解冻方式及防冻剂预处理,并测定超低温保存前后的脱氢酶、电导率、α-淀粉酶生理生化指标。结果表明:超低温保存的技术关键是减少保存材料在脱水过程中所受的伤害,以及采用适宜的冷冻和解冻方式和添加适宜的防冻剂。防冻剂预处理可以适当提高保存含水量,增加含水量范围。肉桂离体胚没有添加防冻剂时最适宜保存含水量为30%~40%(w∶w),采用快冻快解处理。防冻剂预处理后的保存效果比没有防冻剂预处理的更佳,采用缓冻快解或快冻缓解处理较为适宜。
以玉露桃和湖景蜜露桃幼胚及幼胚子叶为试材,研究基本培养基类型、激素、损伤方式等因素对再生的影响。结果表明:培养基是影响幼胚诱导愈伤组织的最重要因素,MS适合供试材料诱导愈伤组织;激素诱导愈伤组织因品种而异,NAA1.0mg·L-1对45d、0.5mg·L-1对55d玉露,BA0.5mg·L-1对55d湖景蜜露效果较好,在试验浓度范围内2,4-D对供试幼胚均无明显效果;幼胚的发育状态是影响诱导愈伤组织的另一因素,玉露桃45d愈伤组织诱导率最高,达96.6%,而55d诱导率为81.6%。愈伤组织可在MS+0.05mg·L-1 NAA+1.0mg·L-1BA培养基上分化成芽,再生芽在1/2MS+1.0mg·L-1IBA培养基上生根。幼胚子叶不定芽再生培养基的激素配比为NAA0.50mg·L-1+BA10.0mg·L-1、NAA0.05mg·L-1+TDZ3.0mg·L-1;带胚芽子叶纵向刻伤再生率高;不定梢(芽)在1/2MS+2%蔗糖+7.5g·L-1琼脂+IBA1.0mg·L-1+Ad20mg·L-1的培养基上能生根。
对菲白竹、平安竹、金镶玉竹、锦竹、菲黄竹、花秆佛肚竹、秋竹、爬竹、香竹、刺黑竹和水竹等11种观赏竹种,分别采用成年竹当年新萌发嫩芽或当年生带侧芽枝条为初始外植体,以MS为基本培养基,附加不同种类和浓度的植物生长调节物质诱导丛生芽及再生植株。结果表明:外植体经诱导产生丛生芽后,亲缘关系较近的竹种,丛生芽增殖培养基有一定相似性;适宜的生根培养基是试管快繁成功的关键,不同竹种丛生芽生根难易差别较大,丛生竹生根率可达95%以上,而散生竹则较难生根,加入一定浓度的细胞分裂素BA,生根率可达65%~90%不等。再生植株在自动间歇式喷雾下的纯蛭石基质中移栽成活率可达90%左右。通过对再生植株表型相关性状观察,多数种类未发生明显的变异。采用已开花植株新萌发的嫩芽进行组织培养,再生植株易出现开花现象。
1976年6月在江西省奉新县下林场开展间伐强度对杉木林生长效应的定位研究,供试林分10年生,1996年11月,历时20年。结果表明:强度、中度、弱度间伐林分平均树高及其定期生长量均比对照有所提高,增加约3%~8%,但定期生长量无显著差异,间伐不能有效促进树高生长。间伐林分平均胸径及其定期生长量比对照分别增加约7%~19%和6%~28%,均显著或极显著大于对照,间伐可有效促进胸径生长。间伐林分总断面积及其定期生长量比对照分别增加约4%~6%和1%~7%,但间伐强度之间无显著差异;间伐林分保留木断面积小于对照,间伐不能有效增加林分总断面积、保留木断面积及其生长量。间伐林分单株材积及其定期生长量于伐后5年和8年即有显著或极显著差异,间伐可以有效促进林分个体生长量。间伐林分单位面积材积总生长量比对照增加约2%~4%,保留木材积、活立木主伐材积及其定期生长量与对照比较增减值均在允许误差范围之内,差异不显著,间伐不能有效增加材积生长量及其总产量。按生长效果而言,杉木林实行占株数40%左右强度间伐为宜。
为丰富种质资源,在黄土高原丘陵沟壑区引进乔木树种105个,分属于15科25属,进行筛选、驯化,鉴选出了适宜该区坡地生长的樟子松、油松、侧柏、刺槐,适宜沟底生长的山杨、胡杨、乌柳,经济树种梅杏、红枣、桃等8科12属90余个优良树种。并研究了其立地条件及水、肥需求规律,提出了不同树种立地范围。结果表明:刺槐耗水量较大但能提高土壤有机质含量;油松、侧柏耗水量较少适于旱坡地种植;杏宜种植于水肥条件较好的阳坡或半阴坡;梨阴坡、阳坡均可;枣应植于阳坡等。
利用白蛾周氏啮小蜂防治美国白蛾,在老熟幼虫期和化蛹初期分别放蜂1次,放蜂量为美国白蛾幼虫数量的5倍,连续放蜂防治两代美国白蛾,就可将其种群数量有效控制,使有虫株率降到1.25%,天敌的总寄生率达到92.67%。放蜂防治后连续5年,共追踪调查10代美国白蛾的发生情况,发现这种小蜂具有良好的持续控制效果。美国白蛾在防治后第2年至第5年有虫株率均保持在0.1%以下的低水平,天敌的寄生率仍高达92%,表明持续控制作用十分显著。研究中,还对我们计算出的回归模型y=-51.60795+77.47512lgx进行了实际检验。结果显示,利用该模型计算出的多种天敌的总寄生率与实际调查所得的总寄生率之间没有显著差异,因此,该模型可以用于调查天敌的寄生率,能够大大节约工作量,利于生产单位实际应用。
多基因转化是基因工程研究热点之一。本研究应用DNA重组技术,将两个抗病机制不同,抗菌谱较广的抗病基因(天麻抗真菌蛋白GAFP和兔防御素NP1基因)构建在一个植物表达载体pBin35SGAFP-NP1上,两者具有各自的CaMV35S启动子和Nos终止子。通过根癌农杆菌介导,采用叶盘法转化烟草,PCR和PCR-Southern分析证明已将NP1和GAFP基因整合到烟草基因组中。离体抑菌实验表明转基因植株对真菌和细菌表现出一定的抗性。以上结果表明通过该表达载体进行遗传转化可获得含双价抗病基因植物,并能有效表达,提高转基因植物抗病能力。
根据2000—2001年甘肃省第3次大熊猫调查资料,利用SPSS和SAS软件,对甘肃省大熊猫栖息地生境进行了统计分析。结果表明:甘肃省大熊猫主要栖息在以缺苞箭竹为优势的下木种群森林群落中,其垂直活动范围主要集中在海拔1600~2800m处,水平分布在文县和迭部一带;竹类种群的特性、地理环境和森林群落的完整性是大熊猫栖息生存的3个主要综合要素;甘肃省大熊猫的生境特征基本稳定,但该区竹类种群的正态性分布和人为干扰强度是构成其生境不稳定的重要潜在因素。
通过观察黑翅土白蚁的觅食行为,对黑翅土白蚁的食物选择性作了研究。室内结果表明:在6种纯饵料中,小米粉的被食率、泥被面积及泥被覆盖率均最高,其泥被出现时间仅长于松木粉,但两者间无显著差异。在5种添加物中,除15%黑木耳外,15%香菇、10%松花粉、10%白砂糖、15%蜂蜜都能显著提高小米粉对黑翅土白蚁的诱食效果,其中又以10%白砂糖的增效作用最为明显。野外试验结果表明,小米粉+10%白砂糖诱饵对黑翅土白蚁的诱食效果优于小米粉诱饵。可见,小米粉+10%白砂糖是最优化的饵料组合,可作为黑翅土白蚁毒饵中的饵料组分。
对大兴安岭林区兴安落叶松林、樟子松林和白桦林3个可燃物类型的68块样地的郁闭度、胸径、树高、林龄等林分因子和地表可燃物(1h、10h、100h时滞可燃物和灌木)的载量进行了野外调查和室内实验分析与计算,应用Spss统计软件,对不同种类可燃物载量与林分因子进行回归分析,并建立了数学模型,利用林分因子来推算不同种类可燃物的载量,并取得较为满意的结果。
对植物空间格局提出独占圆的新概念,证明与独占圆有关的3个引理,从而提出均匀度指标,进一步推导均匀度的理论分布及格局类型检验方法。用高精度仪器测量林木空间位置分布,应用新的均匀度指标进行格局类型检验。新的均匀度指标计算方便,有更好的理论依据和直观性,特别适用于森林择伐对空间格局的控制。
分别应用水、甲酰胺和二碘甲烷3种不同性质的液体,研究木材吸收液体的动力学过程及在毛细管和非毛细管2个方向的不同吸收特征。结果表明:木材吸收液体过程无论在毛细还是非毛细管方向都为三段式进行,其特征是初始和最后阶段为线性吸收,即具有零级动力学吸收的特征;而中间阶段则具有复杂的一级和二级吸收反应动力学的特征。根据吸收现象分析,液体的粘度、极性及Lewis酸碱反应性都将影响木材的吸收过程。根据所记录的动态吸收曲线,文中给出了木材吸收液体的动力学模型及参数。
从钢丝绳、支架、线形参数、滑车4个方面详细地阐述帽儿山溜索的设计过程,同时介绍帽儿山溜索的安装和使用过程。帽儿山溜索是利用抛物线理论和重力下滑原理进行设计的,设计比较系统;帽儿山溜索安装简单,充分利用了场地自然条件,降低建设成本。该溜索的研制和成功使用,为其他溜索设计提供了实际参考价值。
研究利用棉秆为原料,采用磷酸活化法制备活性炭的工艺,探讨制备过程中诸因素对活性炭性能的影响,得出适宜的工艺条件。结果表明:利用棉秆以磷酸为活化剂,可制得性能优良的活性炭产品;所得活性炭产品得率为34%,活性炭对亚甲基兰脱色力为292.7mg·g-1,碘吸附值898.2mg·g-1,所制备的活性炭对Cr(Ⅵ)有较好的吸附性能。
通过对桦木单板表面化学镀镍,可以得到连续、均匀的镀层,从而制得具有良好导电性和电磁屏蔽功能的木材-金属复合材料。扫描电子显微镜(SEM)观察表明:看似光滑的桦木单板表面是很粗糙的,经化学镀后桦木表面金属感极强,但基本构造没有明显改变。利用能谱(EDS)和X射线光电子能谱(XPS)分析表明:镀层中主要成分为镍,磷含量很低。X射线衍射仪分析表明镀层为多晶结构。此木材-金属复合材料的电磁屏蔽效能在9kHz~1.5GHz的频率范围内可达到60dB,导电性和导热性能较素材有显著提高。
在综合分析热分析法、锥形量热仪法和FTIR法获得的FRW阻燃机理研究结果并吸收木材阻燃机理研究现有成果的基础上,推导进而提出了木材阻燃剂FRW的阻燃机理。其主要内容是:1)FRW阻燃木材受热时,阻燃剂FRW分解产生不燃性气体和不挥发的酸性熔融物质,具有降低体系温度和氧气浓度及屏蔽热辐射的作用,降低了木材的热解速度;2)FRW的组分硼酸和GUP的酸性分解产物催化木材脱水、降解,以及木材热解产物的缩合、聚合、芳构化等反应,能改变木材的热解途径并使其向着有利于炭化的方向变化,FRW显著的催化成炭作用,使阻燃木材的燃烧放热量大大降低,这是FRW阻燃机理的主要方面;3)硼酸与GUP起阻燃作用的温度和方式不同,并且有相互补充的作用,因而表现出阻燃协同效应。
通过对杉木和I-72杨人工林木材南北向、不同高度位置、不同径向位置横向干缩(弦、径向)的测量,研究上述3个因素对2种木材横向干缩(弦、径向)的影响规律。结果表明:南北向的不同对杉木和I-72杨人工林木材的干缩均无显著影响;高度位置的不同对杉木和I-72杨木的弦向干缩均有显著影响,而对径向干缩则无显著影响;径向位置的不同对杉木和I-72杨人工林木材的径、弦向干缩均有极显著影响:从树皮到髓心,木材径、弦向干缩逐渐减小,与其基本密度的变化趋势一致。
对原木中微小单元进行动力学分析,确定应力波沿原木轴向传播的波动方程,应用分离变量法,得出应力波沿原木轴向传播的位移、速度、应力和应变方程。根据波动学理论中的反射和透射原理,从传播方向与界面垂直和不垂直2个方面得出界面两侧位移、速度、应力、应变的关系式。在此基础上,建立传播方向与界面垂直情况下的应力波沿原木径向或弦向传播的位移、速度、应力和应变方程。从这些方程可以得出:微小单元的位移、速度、应力和应变不仅与原木试件的弹性模量、密度有关,而且与小锤的敲击力、小锤与原木试件作用时间、敲击方向有关。
分析我国实施清洁发展机制(CDM)林业项目的利弊因素,阐述在我国开展CDM造林项目的可行性;通过对影响CDM碳汇市场主要因素的分析,估计了我国CDM造林项目的潜力。结果表明,在我国实施CDM造林项目是可行的,我国在第1承诺期CDM碳汇市场的份额估计最高可达20%。我国应尽快启动CDM造林试验项目,并开展相关的能力建设以及政策和方法学的研究。
夏、商与西周三代,是中国古代文明由兴起到繁盛的重要历史时期。先民们为了发展农业而大面积毁林开荒,砍伐林木以满足生产生活需要,致使破坏森林资源的程度越来越严重,并时常引发生态危害。为了节制森林利用和减缓生态破坏,更有效地保护利用森林资源,产生了某些较原始的关于森林利用和生态保护的思想意识,包括对森林动植物的图腾崇拜,五行学说对“木”的认识,阴阳学说与生态安全,森林与生态资源持续利用等思想。在这些朴素的生态思想意识的支配和指导下,相对加强了对森林生态资源的保护和管理。
以黄土高原森林植被为重点,利用一定的论据讨论黄土无林论、草原次生论、厚层黄土观、400mm降水论、气候变迁论等立论的缺陷以及植被分区所存在的歧义。以排它法表明以延安一线、长城沿线等为标志的植被地带性原则的合理性,认为黄土高原具有森林发育的地带性环境。
林火蔓延是林火行为的主要表现形式。本文对各种林火蔓延的计算机模拟和可视化技术的最新研究状况和发展趋势进行综述。首先,分析林火蔓延相关数学模型的类别和特点、模型发展方向与体系形成。其次,讨论基于元胞自动机的和惠更斯原理的二维林火模拟与显示技术,以及三维虚拟林火环境构建技术。最后,就林火蔓延模拟与管理信息系统的最新发展进行概括。认为林火蔓延模拟与可视化的研究与开发除向高精度与实用化等方向发展外,今后将更注重真实感环境下的多维虚拟森林景观构建、多用户参与的快速决策能力(如协同灭火)以及网络信息服务等方面。
东北、内蒙古国有林区是国务院确定的国家所有的最大的重点林区。长期以来,政企不分、政资不分、企资不分已成为制约林区加快发展的主要障碍。研究森工林区管理体制问题对于重点国有林区定位和发展具有重要的意义。本文通过林区管理体制的现状与问题分析,指出现行管理体制的弊端主要表现为森森资源管理、企业经营管理、社会行政事务管理“三种职能”履行不到位。通过改革环境分析,提出了林区管理体制改革的设想。认为改革的方向是在重点国有林区建立“三权分治”和“专业化经营”的管理体制,打破林区目前森林资源管理、企业经营、社会行政事务“三权合一”的管理体制,构建森林资源、企业经营、社会行政事务管理“三个主体”,强化森林资源、企业经营、社会行政事务管理“三种职能”,促进林区生态经济社会全面、协调、可持续发展。
我国实施退耕还林政策的地区大多为贫困农村地区,低收成的退耕地上养活着大量低水平的农村劳动力,因此退耕还林工程欲想实现国家的退耕还林目标,就必须关注并妥善处理地方政府财政收入、农户生活水平和退耕还林目标三者之间的关系。在贫困山区必须将退耕还林工程与脱贫工作紧密结合。贵州省古胜村实施的自然保护与社区发展项目以退耕还林的实施为背景,以优化地区发展条件和提高地区自我发展能力为切入点开展工作,充分体现生产发展、生活提高、生态改善的“三生共赢”的原则,在短短的2年内使全村初步实现了发展模式的转变。本文通过对该项目运作过程的分析说明:1)在退耕还林背景下的脱贫工作必须要有外部力量的介入;2)外部力量的介入应以转变当地干群的发展观为根本,以提升贫困农村地区的自我发展能力为主线;3)外部力量投入后,其运作方式决定退耕还林工程和脱贫工作的实施效果,而“本土化+制度化”这一策略值得借鉴。
The condition of soil structure is an important factor to affect soil fertility.The soil heterogeneity,which embodies the landscape heterogeneity,has an important role in revealing the form mechanism,function and variation of landscape.In this paper,the soil physical property heterogeneities of six types of forest landscape in Wuyishan scenery district include Pinus massoniana forest, Cunninghamia lanceolata forest,economic forest,bamboo forest,broad leaved forest and Camellia sinensis plantation were analyzed,and the fractal model was used to study the soil aggregate structure.The results showed that the soil physical property heterogeneities of different forest landscapes were distinct.The stand structure of three natural forests( Pinus massoniana forest, Cunninghamia lanceolata forest and broad leaved forest)were more complex than that of three artificial forests(economic forest,bamboo forest and Camellia sinensis plantation),thus,their fractal dimensions of soil aggregate were lower,the contents of the particle > 0.25 mm aggregate and > 5 mm aggregate were higher,the capacity of stable aggregate composition under water and permeability of soil were more splendid,the performance of self-regulation and resistance were better,and the non-capillary pore of soil were more flourishing than artificial forests. The regression models for fractal dimension (D)of aggregated structure and water stable aggregate(>0.25 mm and >5 mm)content,and for D and destroyed structure percentage were further established,and the results indicated the their regression relationships of all the models were remarkable,therefore,the fractal dimension of soil structure could be used as an index in characterizing the soil fertility.
Soil samples archived over four decades were used in an incubation experiment to measure the effects of reforestation on nitrogen dynamics in old agricultural fields. Samples collected from 0 to 7.5 cm and 35 to 60 cm depths in Calhoun,South Carolina USA at intervals ranging between five and nine years since 1962 were incubated aerobically at 30 ℃ for 30 days using a system specially designed to maintain constant soil moisture. Mineral N was measured in 2 mol·L-1 KCl extracts. The ratio of mineralized N to total N rapidly decreased in the first two decades of forest development. Within 20 years after planting, plenty of available N had been accumulated in the biomass, which had a significant negative correlation with soil total N (rtop-0.828~-0.898; rdeep-0.848~-0.989). It indicated that agricultural inputs of N were important to early tree development. Significantly, by age 40, soil mineral N had increased to 50%of that in the beginning of tree planting. The accretion of mineralizable N suggests that forest floor is serving as an increasingly important source for this nutrient. Further, it indicates that forest managers have the opportunity to manipulate a large pool of forest organic matter to sustain soil N supply.
In order to discuss the relationship among the wild herbaceous peonies native in China according to microscopic characteristics, the pollen grains of four wild herbaceous peonies were examined under scanning electron microscope (SEM), and the data acquired were used in clustering analysis. The result with SEM showed distinctly distinguishing extine surface pattern of taxonomic importance among the four species: reticulate pattern for Paeonia lactiflora; micro-foveolate, regulate and regulate-foveolate pattern for P. veitchii; regulate and subcerebro-reticulate pattern for P. obovata; regulate pattern for P. anomala var. intermedia . The result with clustering analysis suggested the close relationship between P. veitchii and P. anomala var. intermedia for their Euclidean distance was only 2.51, and the alienation between P. lactiflora and the other three species for their Euclidean distances were all more than 5.00. In addition, we deduced P. obovata may be the linkage between subsect Foliolatae and subsect Dissectifoliae for its pollen morphology was appreciably inclined to P. veitchii and P. anomala var. intermedia.
Armeniaca vulgaris × A. sibirica is a new almond-apricot species of Armeniaca genus in Baiyushan mountainous area of northern Shaanxi that introduced from Zhuolu County, Hebei Province 12 years ago. After 11 years investigated and observed, the florescence of A. vulgaris × A. sibirica is the earliest and the shortest compared with A. vulgaris , A. vulgaris var . Ansu and A.sibirica ; the number of non-harvest year caused by frost is the most; number of root is the least, and root distribution is lowest and narrowest; trunk diameter, height, and crown diameter are the least; almond is changed smaller and smaller with the tree age increased; production of stone is lower than A. vulgaris var . Ansu and A.sibirica ; in small hilly region and medium mountain regionⅠ, production value is lower than A. vulgaris and higher than A. vulgaris var . Ansu and A.sibirica ; in medium mountain regionⅡ, production value is lower than A. vulgaris var . Ansu and A.sibirica ,very lower than A. vulgaris . A. vulgaris × A. sibirica shouldn't be a dominating species in Baiyushan mountainous area.
Soil culture experiment at two phosphorus levels was conducted to study the relationship between phosphorus environment and growth as well as dry mater accumulation of six classical Chinese tulip tree provenances from various areas.The result showed that phosphorus supply would accelerate the growth and dry matter accumulation of Liriodendron chinese ,which would adapt to phosphorus starvation by increasing root-shoot-ratio and the relative value of root parameters.The western provenances were observed to grow better at two phosphorus levels than the eastern ones. The response model of phosphorus was varied with the provenances tested.It was found that Tongdao of Hunan and Wuyishan of Fujian were less sensitivity to phosphorus with high phosphorus efficiency and productivity,while Shaoyang of Hunan and Suichang of Zhejiang were more sensitivity to phosphorus with low phosphorus efficiency. Well-developed lateral root system and more fibrous roots under low phosphorus was perhaps one of the important reasons for the provenances with high phosphorus efficiency.It was preliminarily determined that Liping of Guizhou was an excellent provenance with moderate sensitivity to phosphorus, while Tongdao of Hunan was superior provenance with high tolerability to low phosphorus stress or high phosphorus efficiency.
The spatial distributions of the effective nitrogen and phosphorus possess great heterogeneity in forest soil, which results in unbalance supply of introgen and phosphorus for the rhizosphere of forest trees. In this resent paper,unbalance supply of nitrogen and phosphorus was applied to Fraxinus mandshurica seedlings, and we studied the uptake of nitrogen and phosphorus,growth response,and the ability to integrate nitrogen and phosphorus resources of these seedlings.Our results showed that total amount of nitrogen and phosphorus in an individual seedling supplied with balanced nitrogen and phosphorus was significantly higher than that in an individual seedling supplied with unbalanced nitrogen and phosphorus.Nitrogen concentration in leaves of nitrogen-deficient seedlings was significantly lower than that in leaves of nitrogen-enough seedlings.Nitrogen deficiency increased specific leaf area.Unbalance supply of nitrogen and phosphorus reduced biomass partitioning to leaves and increased biomass partitioning to roots.Total biomass of seedlings supplied with balanced nitrogen and phosphorus was significantly higher than that of seedlings supplied with unbalanced nitrogen and phosphorus,suggesting that F. mandshurica seedlings don’t have ability to integrate nitrogen and phosphorus resources.
Fixed sample plots were set up for researching competition relationships between Manglietia yuyuanensis and Cunninghamia lanceolata in 17-year-old M.yuyuanensis stands mixed with C.lanceolata. The interspecific competition intensity in different mixed stands was determined by using the competition indexes constructed with diameter of breast height, the volume of tree crown and distance between trees, through Hegyi's Competition Index Model. The results showed that the spatial distribution of M. yuyuanensis in mixed stands was stochastic, the numbers of M. yuyuanensis and C. lanceolata around each M. yuyuanensis increased with the increase of the distance. Under the steady density, the ratios of C.lanceolata to M. yuyuanensis directly affect the interspecific competition and the growth. When the ratios of C.lanceolata to M. yuyuanensis were in the scope of 9-1 to 7-3, M. yuyuanensis had the obvious increase production trend compared with its pure stand. When the ratio was 9-1, the tree height and the diameter of breast height of M. yuyuanensis increase by 22.3% and 69.3% respectively; likewise, when the ratio was 8-2, they increase by 23.2% and 56.9% respectively, because at this ratio, the number of M. yuyuanensis in mixed stand was so low that its competition was mainly the interspecific competition from C.lanceolata. The competition index of M. yuyuanensis was 1.67 times lower than that in pure stand, especially the competition index constructed by the tree-crown volume was 21 times lower. However, when the ratios were in the scope of 6-4 to 5-5, M. yuyuanensis obviouly decreased production compared with pure stand, the intraspecific competition of M. yuyuanensis becomes stronger when its number increased. Based on the mechanism of stemwood cultivation, initial planting density of M. yuyuanensis trees should be reduced properly and higher ratio of C.lanceolata to M. yuyuanensis should be 8-2 or small higher in order to realize the cultivation goal of large timber of M. yuyuanensis .
By radiating the worms eclosioned 3~5 days using 20~160 Gy60Coγ, the sterility of Monochamus alternatus was studied. The results showed that the irradiation makes Monochamus alternatus worms to sterilize; the males are more sensitive to irradiation than females; 40 Gy is a full sterility for the worms dosage, 20 Gy is a minimum sterility dosage.
This paper deals with the discolorations of the canes of three rattan species, I.e., Calamus simplicifolius , Calamus tetradactylus , Daemonorups margaritae and its cause. The apparatus, X25F Xenon Fade Meter and CR-300 Chromatic Aberration Meter and the extractions, hot water and alcohol-benzene were applied for the test. The preliminary results indicated that the discoloration of D. margaritae was severer than the other. This is related with extract of the rattan cane because quantity of photoinduced discoloration (Δ E*ab) was significantly decreased after extracting and the quantity of the extract of D. margaritae was largest than the other. There was similar effect between the hot water and alcohol-benzene extracting on the discoloration.
This paper had developed a theoretical mathematics model of wood drying stress-strain using mathematical and physical theories and taking moisture content (MC) and ratio of every layer into consideration as explicit parameters,predicted the development of stress-strain using MATLAB software,and analyzed the effect of MC and ratio of every layer. The results showed that on the condition of making the basic parameters set,the charts plotted by MATLAB software reflected the effect of MC and ratio of every layer. Total strain changed linearly with MC. The model could be applied to analyze the drying characters of a specimen with symmetric properties through the thickness.
通过外加氮源或将杉木针叶与林下植物叶混合来改变杉木林凋落物中针叶的养分状况,与杉木林针叶凋落物分解进行比较,分析针叶养分状况及其对杉木林凋落物分解速率和养分释放的影响。结果表明:将杉木针叶与林下植物叶混合和外加氮源均对凋落物分解有不同程度的促进作用。经过153d的分解后,未经处理的杉木针叶干质量损失率为20.49%,与林下植物叶混合的凋落物干质量损失率为43.67%,其促进作用最大;外加4gNaNO3的促进作用次之,凋落物干质量损失率为42.07%;外加2g NaNO3的凋落物干质量损失率为29.13%。对分解过程中各试验方案的凋落物干质量保留率进行方差分析,在开始的62d内,与林下植被叶混合的杉木针叶凋落物分解速率和其他3种处理之间的差异显著,62d后未经处理的杉木针叶与加2g NaNO3的凋落物的分解速率没有显著差异,它们与加4g NaNO3或林下植物叶的凋落物的分解速率差异显著。凋落物分解速率与凋落物初始C∶N比值存在显著的线性关系。外加N源和与林下植物叶混合后,凋落物N的含量增加0.6~1.6倍,C∶N比值下降0.4~0.6倍,凋落物底物质量提高,分解速率增大。分解过程中,C质量不断下降,损失24.7%~47.4%,杉木针叶中N出现富集作用,外加N源和与林下植物叶混合的凋落物N释放一定数量后保持稳定的状态。可见,外加适量N源和与林下植物叶混合能提高凋落物底物质量,促进凋落物分解和养分的释放,对维持杉木林的土壤肥力有着重要作用。
在25年生的马尾松林下分别补植拉氏栲、青栲、闽粤栲、格氏栲和苦槠,形成针阔混交异龄林。补植16年后,对上述5种混交林类型及马尾松纯林的森林凋落物量、养分含量及周转时间进行研究。上述5个混交群落和马尾松纯林的年凋落物量分别为6149.1、7533.2、6741.1、7151.5、8041.7和3442.8kg·hm-2。各混交群落总凋落物量的季节动态呈双峰型,第1次峰值出现在2—4月份,第2次峰值出现在8、9月份。在凋落物组成中,枯叶占绝对优势,占凋落物总量的50%~71%,其余依次为枯枝6%~26%、树皮9%~19%、果实和其他组分5%~17%。各混交群落中来自马尾松的凋落物占50%~58%,来自阔叶树的凋落物占42%~50%,且两者的组成有明显差异。凋落物各组分的养分含量存在较大差异,N、P、K、Ca、Mg的含量范围分别为3.25~12.98、0.24~0.97、0.37~6.55、12.77~35.40、2.35~6.10g·kg-1。各林分类型凋落物中养分元素的年归还总量为Ca>N>Mg>K>P。5个混交林群落及马尾松纯林凋落物中的养分年归还总量分别为238.05、213.77、223.93、289.90、304.12和142.01kg·hm-2。6个群落的森林地被物现存量分别为8448.0、15565.8、11993.7、12718.6、6974.2和5020.0kg·hm-2,其中L层在各群落中所占比例分别为47.2%、59.6%、51.3%、61.0%、85.4%及86·3%,平均为61.7%。森林地被物中各养分元素的含量在群落和组分之间存在明显差异,但总的趋势表现为Ca>N>Mg>K>P。最后,通过对年凋落量和林地凋落物积累量的比较分析,上述6个群落的凋落物周转时间预测值依次为0.76、1.42、0.97、1.17、0.84及1.52年,其中枯枝的周转时间明显大于枯叶,且马尾松的枯叶和枯枝的周转时间普遍大于阔叶树。
从栓皮栎萌生苗的径级大小、数量、种群性状分化和内部基因层次上阐明其变异和适应对策,从机理上探讨栓皮栎对不同生境的适应对策。从萌生苗分布情况看,每个地区萌生苗的径级大小和数量均不同:在秦岭分布中心,萌生苗的数量相对较少,而在巴山北坡和黄龙山区,几乎每个径级中都有一定数量的萌生苗;萌生幼苗的数量弥补了实生苗数量的不足,帮助栓皮栎种群度过幼苗匮乏期,使种群能够自我更新。在不同生境中栓皮栎种群的枝长、分枝角度、分枝率、等位基因频率和分化系数等性状参数也发生了变异,从分布中心到分布边缘,当年生枝条的长度逐渐减小,而分枝角度和叶倾角呈现出增大趋势,逐步分枝率R1∶2、R2∶3和总体分枝率Rb也存在明显的差异。EST、SOD2种酶的基因变异频率呈现出逐渐减小的趋势,而EST、SOD、PGI、ACP和ADH的分化系数则呈现出增大趋势。这些变化是栓皮栎种群应对外界环境的一种适应性反应。
对马尾松和马尾松彩色豆马勃菌根植株内碳水化合物及其代谢酶进行测定,研究酸沉降(pH6.0、4.0、3.0、2.0)和铝胁迫(铝理论浓度为75、150μmol·L-1)对其体内糖积累和转运的影响。结果表明:酸沉降和铝胁迫抑制了叶绿素和干质量的积累,两者呈较好的正相关(r=0.949)。叶内可溶性糖含量明显减少;轻度酸沉降促进根、茎内可溶性糖积累,强酸则抑制其积累;酸和铝胁迫抑制了糖向根系转运。低铝胁迫下酸沉降抑制菌根内海藻糖积累,而高铝胁迫促进其积累,并与海藻糖酶活性呈负相关(r=-0.857);轻度酸沉降促进根、茎、叶内葡萄糖积累,强酸沉降抑制其积累;葡萄糖-6-磷酸脱氢酶和海藻糖酶活性受低铝胁迫诱导和高铝胁迫的抑制。菌根的形成能增加叶绿素和干质量的积累,并减少糖向葡萄糖形式转化。
模拟三峡库区消落带土壤水分变化特征设置常规生长水分条件(CK组,土壤含水量为田间持水量的60%~63%)、轻度干旱水分胁迫(T1组,土壤含水量为田间持水量的47%~50%)、土壤水饱和(T2组,土壤表面一直处于潮湿状态)以及水淹(T3组,苗木根部淹水超过土壤表面1cm)4个不同处理组,对落羽杉和池杉当年实生幼苗的光合特性以及生理生态适应机制进行对比研究。研究发现在T2和T3组,落羽杉幼苗的光合色素含量显著低于池杉幼苗。在CK组,2树种幼苗净光合速率Pn、蒸腾速率Tr、气孔导度Gs、水分利用效率WUE、表观光能利用效率LUEapp和表观CO2利用效率CUEapp的平均值均无显著差异。但是在T2组,落羽杉幼苗的Pn、LUEapp和CUEapp平均值显著低于池杉幼苗的平均值,与之在T3组的Gs平均值显著大于池杉幼苗形成鲜明对比。在T1组,2种植物的Pn、LUEapp和CUEapp平均值显著低于其他3种水分条件下的值。池杉幼苗在T1组仍然保持着与CK组一致的Tr和Gs平均值,与落羽杉幼苗在T1组的Tr和Gs平均值显著低于CK组形成对比。研究结果表明,落羽杉和池杉均具有耐水湿性特点,均可考虑列为三峡库区消落带防护林体系建设树种。但池杉树种的耐旱与耐水湿特性优于落羽杉,最适宜于在土壤饱和水环境中生长。
根据毛果杨AP3同源基因(PTD)设计一对PCR引物,以毛白杨基因组DNA为模板,通过PCR技术分离克隆了毛白杨AP3同源基因PtAP3。分析表明该基因全长1813bp(包括引入的酶切位点),包括7个外显子和6个内含子,编码238个氨基酸。在GenBank中进行blast检索,发现其氨基酸序列与大丁草、矮牵牛、百合、玫瑰、苹果、毛果杨AP3同源基因的氨基酸序列具有52%~82%的同源性。PtAP3蛋白具有非常保守的MADS-box序列,推测其为转录因子。Southern杂交分析发现,该基因在毛白杨雄株中为双拷贝,而在雌株中则为单拷贝。为进行功能分析,构建了正反义表达载体,通过农杆菌介导转化获得了一些转基因烟草植株。
以福建省漳平五一林场马尾松无性系种子园自由授粉子代半同胞家系为研究对象,分析其树高、胸径、材积、冠幅、通直度、高径比、冠径比、木材基本密度、管胞长度和宽度、管胞长宽比等性状,发现家系间除管胞长宽比性状差异显著,其余性状均达差异极显著,暗示着马尾松种子园半同胞家系间存在较为丰富的变异,具选育潜力。8年生林分内各性状的家系遗传力以树高性状为最高(0.691),其次是木材基本密度(0.640)。各性状间的相关性分析结果表明,生长量性状的改良可间接改善通直度,且生长量性状与木材基本密度存在显著正相关关系,木材基本密度与管胞长度和宽度不相关。采用10%入选率,发现5年生林分和8年生林分入选家系一致,材积遗传增益分别达19.74%和19.23%,且5年生林分和8年生林分生长量性状的遗传相关极显著,认为马尾松制浆造纸材短轮伐期的初选年龄可确定为5年生;根据性状遗传力的相对大小和典型相关分析的结果,认为马尾松家系选择可适当注重树高生长量指标。以树高和材积为选择指标,按照10%入选率,兼顾材性和种子园内无性系的开花结实情况,筛选出制浆造纸材短轮伐期优良家系12个。
对湖南株洲22~25年生的樟树、枫香、杜仲、桂花4个树种树干茎流及林外大气降水中N、P、SiO2、K、Ca、Mg、Cu、Zn和Mn 9种养分元素含量进行为期1年测定。结果表明:不同月份大气降水养分元素含量不同,各元素各月平均含量按大小排序为Ca>SiO2>Zn>NH4+-N>K>NO3--N>Fe>Mg>Mn>P>Cu;大气降水经过林冠层后,树干茎流中各养分元素含量变化基本一致,均表现季节动态变化,相对于大气降水,大多数元素含量增加;树种之间的茎流养分特征表现不同,按总含量值排序依次为枫香、杜仲、樟树、桂花;不同养分元素之间的相对含量也表现出较大的差别,养分含量中K、Ca、NH4+-N、SiO2含量最高,NO3--N、Mg、Mn、Zn居中,Fe、P、Cu最低;4个树种共同表现出对Fe、Zn的负淋溶,尤以Zn最显著。
经过3年的调查研究,报道了长白山国家级自然保护区共有野生药用植物106科333属613种,分别占吉林省野生药用植物科、属、种数的88.21%、69.66%、58.21%。其中珍稀濒危药用植物39种,占长白山区珍稀濒危药用植物总数的63.93%;东北道地药材有19种。多年生草本类413种,占药用植物总数的67.37%;全草类、根类和根茎类最多,分别占药用植物总数的50.08%、16.48%和12.89%。46.10%的种类属于北温带分布区类型。94.29%的种类分布在海拔720~1000m的红松针阔混交林中。优势科主要有菊科、毛茛科、蔷薇科等。优势属主要有蓼属和乌头属等。提出保护和开发利用的具体建议。
以1、2和3年生火炬树克隆分株为研究材料,分别于2003年生长季取样,研究激素的种类和含量、光合产物分配特征以及前后端水平侧根的形态解剖差异。结果证实:9株1年生火炬树克隆分株测定器官14C同位素活度均呈现饲喂叶>茎>前端(RDF)>后端(RDB)的递降序列;火炬树1~4年生克隆分株前端侧根次生木质部宽度超过后端侧根次生木质部宽度,在于前端侧根形成层分裂活动活跃,次生木质部导管直径和密度大;1年和3年生火炬树克隆分株前端的IAA/GA3比值高于后端的IAA/GA3比值。分析认为:火炬树克隆分株水平侧根直径不对称与光合产物趋前积累、激素水平以及形成层活动等因素密切相关。火炬树克隆分株的茎和前端侧根分别属于优先和次优先生长与光合产物的贮藏中心。
对固定样地调查,采用伐桩的径、高度、萌芽的数量、萌芽的生长情况等指标,分析东北东部林区主要阔叶树种的伐桩萌芽更新规律。结果表明:在一定的伐桩径范围内,伐桩萌生枝数随着伐桩径的增大而增多;增长到一定程度后随着伐桩径的增大而减少;得出不同树种萌芽能力较强的年龄范围的伐桩径级。对于不同阔叶树种,伐桩高与当年生萌生枝数量的关系存在着不同的变化规律,研究地点具有产生萌芽能力的阔叶树种可划为3种类型:对数型、直线型、指数型,阔叶树的萌生枝高生长与伐桩径和伐桩高无明显关系。第2年伐桩萌生枝的数量与伐桩径的关系在总体趋势上与第1年基本相同,同时次年仍有新的萌生枝产生,但数量很少。与第1年不同之处在于萌生枝开始死亡,一方面,伐桩产生的萌生枝越多,死亡的数量也增大;另一方面,第2年的伐桩存活率在不同种类树种间差别较大:水曲柳高达96.2%,槭树为23.3%,榆树类为21.8%。所探讨的树种在研究区域内都有“萌代主”的能力,并且不同树种以及同一树种不同年龄,“萌代主”的能力和单个伐桩保存的萌生大树的数量不同。
对福建南靖国有林场山地麻竹笋用林采用五因素二次回归正交试验设计进行配方施肥研究。结果表明:氮、磷、钾、有机肥对竹笋产量影响的回归方程显著,氮、磷对麻竹出笋数量回归方程的影响显著,氮、磷(P2O5)、钾、花生饼的最佳施肥量分别为0.2195、0.8258、0.1906、2.3055t·hm-2;竹笋最高产量的氮、磷(P2O5)、钾、花生饼施肥量分别为0.2186、0.8262、0.1899、2.3064t·hm-2。
证伪了森林生态效益补偿研究的2个理论假设:具有正外部性的经济活动需获得补偿,森林生态效益(使用价值)即森林生态价值。说明森林生态效益补偿研究尚缺乏必要的理论支撑。林业补助是政府为鼓励营林生产而对营林活动进行补助的制度设计,其理论基础是利益导向学,即生产要素向投资回报率高的行业流动。林木补偿是政府为了生态安全限制林木所有权行使对林木所有者造成经济损失的一种弥补措施,其理论依据是法理上的既得权说、特别牺牲说及公平负担说。构建林业补助与林木补偿制度替代现行的森林生态效益补偿制度是适应林业生产发展的制度改革。
河西走廊地区非常干旱,并且年蒸发量是降水量的20多倍,土壤含沙量高,灌水后渗漏严重,保水性差,致使草坪种植用水量增大,成本高,且种植的草坪质量不佳。在该区的干旱荒漠区沙地使用沙地底层衬膜、喷灌等节水技术,进行草坪种植试验,并与传统的大水漫灌进行田间试验比较。结果表明:沙地底层衬膜节水种植草坪的技术,可以明显节约用水(只需传统漫灌的1/3),在此基础上加上喷灌系统,需水量只需传统漫灌的1/4。对3种方法种植的草坪质量进行了观测,观察项目包括成坪性、叶绿素含量、分蘖数、均一性、抗病性、质地等。最后采用灰色关联度评定法进行评定,结果表明:在沙地底层衬膜技术的基础上加上喷灌系统,种植的草坪质量最佳。沙地底层衬膜节水种植草坪技术虽然在第1年需要较大的人力投资,但如果地膜使用寿命按15年计算,由于种植效果明显优于常规种植方法,所以经济效益极其显著。从长远看,沙地底层衬膜节水种植草坪技术不仅经济效益好,而且每年可节约灌水约5000m3·hm-2,为沙地实行节水栽培奠定了良好的基础。
在对标准BP神经网络试验分析的基础上,通过输入矢量归一化处理、主成分分析、增加验证集、改进训练学习算法、扩大隐层和输出层规模等措施,对BP神经网络自动分类系统进行改进;利用改进后的BP系统对吉林省汪清林业局的典型针阔混交林TM遥感图像进行辩识、分类试验研究。结果表明:改进后的BP网络分类系统自动分类精度提高了19.14%,比传统无监督自动分类精度提高8.55%,达到了区分森林类型的分类要求。研究还显示了该改进系统应用于针阔混交林TM遥感图像自动分类识别的精度随网络规模增大而提高。
利用抗松材线虫血清建立在疫木切面上直接进行免疫组化染色检测松材线虫抗原的方法。ELISA和免疫斑点印迹的结果表明:该方法对松材线虫具有较好的特异性,可以检测出木材表面0.1μg的线虫抗原,显示了较好灵敏度。自然感染松材线虫的黑松疫木免疫组化的染色结果表明:该方法可以清晰地检出管胞处松材线虫蛋白抗原的存在。
肥须亚麻蝇(PC)和巨尾阿丽蝇(AG)幼虫的干物质中蛋白质含量高于60%,成虫干物质中蛋白质含量高于70%。幼虫、成虫必需氨基酸总的含量[g·(100g)-1蛋白质]在46~59之间,均高于FAO/WHO的标准模式35;幼虫、成虫必需氨基酸与氨基酸总量的比值均大于40%的标准模式。在必需氨基酸中,除缬氨酸、蛋氨酸+胱氨酸含量低于优质蛋白模式外,其余均高于标准模式。幼虫的脂肪含量为20%左右,成虫的脂肪含量不到10%,成虫、幼虫不饱和脂肪酸含量均达脂肪酸总量的70%以上。必需脂肪酸均为亚油酸,幼虫亚油酸含量高于40%,成虫亚油酸含量仅为17%左右。PC和AG幼虫中Fe、Zn的含量分别是Fe684、664μg·g-1,Zn170.5、158.0μg·g-1。幼虫Ca含量相当于优质大豆,分别为0.46%、0.48%;P含量高于一般奶粉,分别为0.57%、0.54%。PC、AG幼虫的Ca、P比值分别为0.81、0.89,均高于0.5的理想值。
根据黑龙江省1980—1999年的森林火灾统计数据和对黑龙江省各森林类型地上生物量的估算,计算出黑龙江省森林年平均森林火灾损失地上生物量391758.65~522344.95t,占全国的6.4%~8.4%。年均释放碳176291.39~235055.23t,约占全国年均森林火灾排放碳的8%。用排放比法得出黑龙江省年平均森林火灾释放的CO2、CO、CH4、NMHC量分别为581761.6~775682·25t、34892.275~46523.04t、14091.11~18788.15t和6500~9000t。
采用风洞模拟方法,对通风结构、疏透结构和紧密结构3种防火林带迎风面的风速进行测定,绘制了3种结构防火林带迎风面的相对风速等值线图;根据风速的分布特征,采用多模型选优的方法,确定了山脊防火林带迎风面的相对风速预测模型。结果表明:紧密结构与疏透结构的防火林带迎风面的阻风性能比较好,最小相对风速达到70%以下,而通风结构的阻风性能最小,迎风面的最小相对风速在80%左右。如考虑其综合防火效能则以疏透结构的防火林带阻火性能最佳。
采用双因子交叉分组(2×2)试验设计方案,考察精料的蛋白质水平与能量浓度对成体大熊猫日粮消化率影响的显著性。结果表明:精料的蛋白质水平对粗蛋白和粗脂肪的消化率均产生了极显著影响(P<0.01,正相关),精料的能量浓度对粗蛋白的消化率产生了显著影响(P<0·05,负相关);二因素对其他各项消化率的影响均不显著(P>0·05);此外,对粗蛋白消化率而言,二因素互作效应显著(P<0·05);各试验期之间消化率多重比较结果显示,精料配方4(CP20·61%×GE18·08MJ·kg-1)为优选配方。本研究说明:精料的蛋白质水平及能量浓度对成体大熊猫日粮消化率产生了一定的影响,成体大熊猫倾向于高蛋白、低能量的精料。
以市场上购买的气干核桃楸、水曲柳和红松板材为试材,采用基于打击音的快速傅里叶变换(FFT)频谱分析方法,检测试材的动态抗弯弹性模量,并与力学实验机测定的试材静态抗弯弹性模量作比较。结果表明:用声共振FFT快速自动检测实木板材的弹性模量具有普遍性意义,且比简单根据木材密度估计的方法提高了木材静弹性模量推测的准确度和精度。
以国产B229型四四砂架人造板双面宽带砂光机为研究对象,从易产生横纹缺陷入手,对其砂架部件、整机等分别采用试验模态分析(EMA)及功率谱密度法(PSD)来开展振动动态特性研究。在模态试验中,采取测量点固定、改变激振点的跑点测量方法,得到固定测量点对各激振点频响函数,并应用SISO频响函数识别法,通过频响函数曲线拟合来完成模态参数识别,获到典型的整机、砂架部件的频响函数图和接触辊的二阶振型图。通过PSD分析,获得砂光机的PSD图谱和激励频率等。
采用特定设计的双螺杆和单螺杆串联挤出机组,以挤出的方式制备木粉/聚丙烯复合材料。主要采用静态力学试验、动态力学热分析(DMTA)和扫描电子显微镜(SEM)观察等方法,研究了马来酸酐改性的三元乙丙橡胶(EPDM-MA)对木粉/聚丙烯复合材料的静态力学性能、动态力学性能和吸水性能的影响。静态力学性能试验结果表明:添加适量的EPDM_MA有利于提高木粉/聚丙烯复合材料的拉伸和弯曲强度,冲击强度的提高最为显著,但EPDM_MA的添加对复合材料的模量有不利影响。动态力学性能分析结果表明:复合材料的储能模量(E′)和损耗因子(tanδ)的峰值均随EPDM-MA加入量的增加而降低,后者说明EPDM-MA改善了木粉与聚丙烯的界面结合;EPDM-MA的加入,使得复合材料的主转变温度略向高温方向移动,并且在-50℃左右的低温区出现了次级转变峰,表明EPDM-MA对复合材料的热性能产生影响,尤其有利于改善其耐低温冲击性能。SEM研究结果表明:EPDM-MA的添加不仅提高了木粉和聚丙烯的界面结合,并且以直径约为0.1~1μm的球状粒子形态分散于聚丙烯中,能够通过自身的塑性变形而提高复合材料的抗冲击性能。EPDM-MA的添加,有效降低了复合材料的吸水性。
为弄清不同变异类型杜仲果实含胶特性的变异规律,为杜仲胶优良资源的选择和有效利用提供理论依据,采用典型样株和随机取样的方法;含胶率的测定利用杜仲胶综合提取法。结果表明:4个变异类型的果实形态大小存在极显著差异。不同变异类型在果实形态大小上的不同,表明不同类型生长发育特性的差异;不同变异类型果实含胶率和果皮含胶率均存在极显著差异。果实含胶率和果皮含胶率以浅纵裂型最高,深纵裂型最低。
应用高温干燥与常温干燥有机结合的工艺技术(简称蒸汽综合干燥法),对意杨25mm厚板材进行处理,在预热阶段进行充分的汽蒸处理,而后进入常压过热蒸汽干燥工艺阶段,当含水率降到25%时,转入常温干燥工艺阶段,直到干燥阶段结束。这样既缩短了干燥周期又提高了干燥质量,同时也提高了干燥窑的生产效率。
大气中CO2等温室气体浓度上升引起的全球变暖,威胁着人类生存和社会经济的可持续发展。在减少温室气体排放、稳定大气CO2浓度的措施中,森林和林业活动扮演着重要的角色。森林可吸收并固定大气CO2,是大气CO2的吸收汇和贮存库;而毁林是大气CO2的重要排放源。通过适当的林业活动可增强碳吸收汇、保护现有的碳贮存,通过替代措施可减少化石燃料引起的温室气体排放。因此,林业活动在未来减缓大气温室气体上升方面将发挥重要作用。阐明了全球和中国森林生态系统在减缓大气CO2浓度上升中的作用以及与土地利用变化和林业有关的减排增汇措施和潜力,以期对我国制定CO2减排增汇政策提供参考依据。
植物多酚作为一类天然大分子化合物广泛存在于植物体内,并在制革、化工、医药、农业、食品、材料等领域得到了很好的应用。在崇尚环保、提倡绿色科学的今天,植物多酚的研究取得了许多进展。本文从植物多酚的传统工业和精细加工工业2个方面讨论了植物多酚化学研究的发展趋势和广阔的应用前景。
It was researched that the numbers and biomass of soil microorganisms in different development stage of Chinese Fir plantation in Shanxia Farm of Sub-tropical Forestry Center, CAF in Fenyi Country, Jiangxi Province. The trend of the numbers and biomass of soil microorganism, the numbers of bacteria and the content of available N, P was decreased from juvenile to medium plantation, and increased from medium to mature plantation. But it was not found the trend from the numbers of fungi and actinomycetes, the content of available K,total N, P, K, in different development stage of Chinese Fir plantation.
Based on the whole stand model of Daqingshan, using simulation method, the impact of measurement error of number of trees per hectare, average diameter, dominant height, average height and form height on the whole stand model were studied. The result indicated that, beting estimated by least square method, basal area model, average diameter model, number of trees per hectare model had obvious biases, but dominant height model, average height model and form height model had no clear biases.
The physiological and anatomical changes in leaves of Poinsettia (Euphorbia pulcherrima) tube-plantlets occurred in the process of transplantation and acclimation were investigated in this paper. Before transplantation and acclimation, leaves of the tube_plantlets were apparently thin and the vascular system was not well developed, and the net photosynthetic rate of the plantlet was low, but the stomatal conductance and transpiration rate of the leaves were relatively high. At the early stage of transplantation, the tube-plantlet was vulnerable to relative low humidity and intense light that could resulted in wilting of leaves due to excess water loss. During the acclimatization, the net photosynthetic rate of the plantlets increased progressively and the stomatal conductance and transpiration rate decreased gradually, accompanied by an increase in the thickness of the leaves and the size of leaf epidermal cells, together with the fully development of vascular system, palisade and spongy tissues in leaves. The results indicated that the acclimatization could greatly improve the photoautotrophic ability of the tube-plantlets, bring anatomical changes to the plantlets in order to avoid excessive leaf dehydration for the gradual adaptation of the plantlets to natural environment.
The radiation energy environment, energy balance and water environment have been studied by means of the 3 treatments of covering plastic film, straw and planting Trifolium repens on the ground of Zanthoxylum bungeanum plantation in Feng County, Shaanxi. The results showed that the ground reflectivity and the canopy net radiation increased in the conditions of covering plastic film, straw and planting T. repens on the ground, so that the reflections in the middle part increased 53.3%,26.3% and 0.8% than that of the contrast. In the heat balance, the hidden heat flux in the conditions of covering plastic film, straw and planting T. repens accounts for 60.2%,62.4% and 65.8% of the net radiation energy, the reaction heat flux accounts for 30.4%,29.7% and 27.1%, and the soil heat flux accounts for 9.4%,7.9% and 7.1%. The soil water content in 0~50 cm were higher 5.6%,8.7% and 13.9% in covering plastic film, straw and planting T. repens on the ground than in the contrast. The transpiration rate of the leaves of Z. bungeanum were 1.6,1.4,1.1 times in planting T. repens,covering plastic film and straw on the ground as that of the contrast in May.
The aseptic seedlings of Albizia julibrissin were divided into two groups. One group was inoculated by rhizobia and the other was designed as control without inoculation. These two groups were all cultivated in sterilized cultured liquid for about two weeks. In the first group,the root hairs did not form on the main roots,but formed a lot on the base part of the lateral roots. In the second group, the root hairs did not form not only on the main roots but also on the lateral roots. The root segments which have distinctive deformation of root hairs from first group were cut off and fixed, in the meanwhile the corresponding root segments were cut off from the contrastive group and fixed. These two groups of roots segments were treated as semi-thin section and ultrathin sections, then were observed by optical microscope and transmission electron microscope. The result showed that the transfer cells with wall ingrowths on the tangential exowall of the root's epiderm and exodermis cells, are easy to be found in the root segments which has distinctive deformation of root hair. The wall ingrowth lies not only in root epidermal cells but also in the root exodermis cells, while there is no wall ingrowth in root epiderm and exodermis cells of A. julibrissin which is not inoculated by rhizobia. This suggested that the forming of root hairs and transfer cells in epiderm and exodermis of A. julibrissin is resulted from the inducement of rhizobia of A. julibrissin.
Rust of Sambucus williamsii and hyperparasite of the rust were found in Fengtong Zhai national nature sanctuary area. The pathogen was identified as Aecidium sambuci. The hyperparasite occurred on lower leaf surface rust spot. The characteristics of hyperparasitism was henna powdery. The hyperparasite live on aecium of A. sambucii and hinder the releasing of aeciospore. The hyperparasite was identified as Tuberculina sp.. This paper reported the symptom of the rust and the morphological characteristics of the rust pathogen. The hyperparasitism of A. sambuci and the morphological characteristics of the Tuberculina sp. Were also reported.
Wikstroemia chamedaphne was investigated for its acarocidal activity against Tetranychus viennensis, a serious pest of many crops including apple trees in China. Its active constitutes were extracted,separated and purified. The results indicated that the extraction of petroleum ether from WCME (Wikstroemia chamaedaphne methanol extract) appeared a strong acarocidal activity. The adjusted mortalities of egg,larva and female mite were 74.48%,100.00% and 100.00% respectively, while the LC_(50) values were 2.106 2、0.304 1 and 0.771 6 mg·mL-1 respectively.
This paper investigates the possibility of measuring the surface roughness of wood by the laser displacement sensor. Ten points_based mean roughness of the planed surface of Douglas, Hinoki, Beech and Padauk was measured by using the laser displacement meter and the stylus instrument to clarify the characteristics of both instrument. The measured roughness from the laser displacement sensor at the processing speed of 6 m·min-1 for forth wood specimens coincided with the value obtained from the stylus instrument by using a proportion coefficient between them.
The two methods of making rectangle_section curve woods were bending shape process or milling, which was analyzed in this paper. The difference of fibrin distributing and the variety of strength that caused were explained. The material mechanical theory was used to the numerical analysis of curve wood strength. The bending wood was stronger than milled curve wood,which was improved by the theory in this paper.With the curvature's increasing,the strength difference between them was greater.According to this theory,the strength difference of bending wood and milled wood was worked out by several parameters.In the application of curve wood,the theory of strength analysis was provided.
Growth quality of urban trees should include exterior growth quality, interior growth quality and anti-natural-calamity ability. To determine the whole growth quality of a tree, it is necessary to observe exterior characters of every part of the tree carefully. The hollows of the roots caused by decay or rot can be detected by Resistograph, and the hollows of the trunks can be detected by Resistograph and a stress wave meter.
对近年来国家自然科学基金资助林学项目进行归纳和分析,阐述我国林学基础研究的人力设施资源、研究布局以及当前的研究现状和特点。根据国家自然科学基金委员会“支持基础研究,坚持自由探索,发挥导向作用”的新时期战略定位,结合国际研究前沿和我国林业发展的重大科技需求,明确今后基金资助和管理的重点,提出未来我国林学基础研究需要加强的几个方面。
(月刊 1955年创刊) 主管:中国科学技术协会 主办:中国林学会 出版:《林业科学》编辑部 主编:尹伟伦 国内统一刊号:CN 11-1908/S 国际标准刊号:ISSN 1001-7488 国内邮发代号:82-6