移山参栽培技术

人参 (ｐａｎａｘｇｉｎｓｅｎｇＣ .Ａ .Ｍｅｙ .) ,别名棒槌、棒棰、野山参、野参、山参。是五加科 ,多年生草本植物。移山参又称林下参 ,是利用野山参的小捻子或籽海在林分下培植而成的人参。移山参仅次于野山参 ,其品种在国内外是认可的 ,也是受世界各地客商欢迎的走俏品种     

林药产业发展前景及主要栽培技术

当前林药产业发展已经成为西部开发、农业产业结构和退耕还林工程后续产业开发的热点。湘西自治州对发展林药产业十分重视，针对目前在栽培和开发中出现的问题，结合国内外药材市场开发现状，对湘西州木本药材开发优势及林药栽培技术与管理措施进行了论述。     

黑龙江道地药材玉竹栽培技术

文章介绍了玉竹的生物学特性、生态学特性,药用及食用价值,并结合黑龙江省实际论述了道地药材玉竹的栽培技术。     

近天然天麻栽培技术

天麻 (ＧａｓｔｒｏｄｉａｅｌａｔａＢｌ.)为兰科多年生草本植物 ,别名赤箭、鬼督邮、定风草等 ,具有祛风、镇痛功能 ,主治头痛、眩晕、中风惊厥、手脚麻木、脑神经紊乱等症。由于具有良好的药用价值及保健功能 ,以天麻为主要原料的新产品不断增加 ,价格居高不下 ,产品供不应     

西藏野生藏药材驯化技术研究

对西藏42种野生藏药材进行了45d的野外调查,掌握了大量的第一手资料和采集了一定数量的种质资源。通过3年多来的田间试验,对其11种采用移地栽培技术和32种采用直播育苗方法,分别做了移栽后的综合性状表现观察和播种后的出苗情况以及苗期生长发育特性、物候期现象、大田栽培及田间管理等方面作较全面的试验研究。初步总结西藏不同地区的藏药材种质资源差异性较大,其成活率也有明显的差别,对于部分药用及经济价值较好的藏药材进行了重点观察,并已掌握了18种藏药材的育苗和大田栽培技术要点。为西藏今后开展人工栽培藏药材工作奠定了良好的基础。     

适期采收药材 提高药材质量

药材的采收期直接影响药材的产量、品质和收获效率 ,适期采收对药材的产量、品质和收获效率都有良好作用。1.根、根茎类药材采收根、根茎类药材应以秋冬或初春季节 ,植物地上部分枯萎后比较适宜。此时植物处于休眠状态 ,营养物质消耗少 ,有效成分积累较高。丹参在第四季收获 ,其丹参酮及次甲丹参醌含量较其他季节收获高 2～ 3倍。石菖蒲挥发油含量在冬季高于夏季。牛膝根中甾酮含量在 11月15日最高 ,同期 ,地上部分甾酮含量降到最低。姜黄、郁金生产上常在 1月采收 ,实际上两者的姜黄素含量在 10月份即达最高 ,此时姜黄、郁金药材外观饱满 ,…     

药材林的栽植及生药的采集

药材林的栽植及生药的采集李仲喜充分利用荒山秃岭和空闲地，大量栽植药材林，若精耕细作，在林下还可种植草本药材，或果药、菜药间作，利用树木枝杈培养木耳、香菇等菌类，均能创造较高的经济价值。人工栽植药材林属营造经济林范畴，它以成活为标准，并要求达到速生、丰...     

北药开发大有可为

北药开发大有可为刘世英，朱东辉所谓“北药”即北方药材资源，其开发主要包括药材种植、采集，以北药为主要原料的成药、系列保健药、药酒、药用调味品、化妆品等的研制生产。这种开发，不仅有经济效益，而且有社会效益；不仅有现实意义，而且有长远意义。第一，它是调整...     

外来植物对我国城市生态系统的影响

外来植物在我国城市园林绿化中起到了重要作用,但在生态与环境保护方面也带来了一些严重问题。本文在简要分析城市植被系统单一性与脆弱性特征的基础上,探讨了外来植物对城市生态系统中土壤理化性状与含水量的影响;分析了在外来植物作用下,城市植物群落结构变化与逆向演替的原因,城市生态系统中物种多样性与生态系统多样性下降原因和遗传多样性改变机理。最后从外来植物生物学特性与适应性以及环境和人为因素这几个方面分析了外来植物种群形成乃至成灾的机制。     

不同磷水平下刺梨实生苗生长及根系形态特征与内源激素含量的关系

【目的】探究不同磷水平对‘贵农5号’刺梨实生苗生长、根系形态变化的影响及其与内源激素的相互作用,了解刺梨应对低磷胁迫的适应策略,为喀斯特地区低磷土壤刺梨的磷养分管理和生长调控提供科学依据。【方法】采用基质培养方法,设5、25、45、65和85 mg·L^-1有效磷含量的5个供磷水平处理,对不同处理的生长和根系形态指标及叶、根中内源激素含量进行测定,解析不同磷水平下根系形态与内源激素含量变化的关系。【结果】1) 45 mg·L^-1磷水平下实生苗生长的最好,整株生物量、主根长度、总根尖数和根的总长度、总体积、总表面积、平均直径、侧根长度和数量、一级侧根密度均最大,根和叶中的GA₁₊₃含量最高,ABA含量最低。2)供磷水平低于或高于45 mg·L^-1后,植株生长受到抑制,生物量明显减小,GA₁₊₃含量降低,ABA含量增大,上述根系形态指标变小。在5 mg·L^-1的低磷胁迫下,植株根冠比、2级、3级侧根密度和根毛的密度及长度达到最大。3)根和叶中的IAA及ZR含量随磷水平的降低而增大。4)不同磷水平下植株的生长指标和生物量大小与根和叶中的IAA和ZR含量间均表现出极显著(P<0. 01)的一元二次非线性回归关系,与GA₁₊₃和ABA的含量分别呈极显著(P<0. 01)正相关和极显著(P<0. 01)负相关。供磷水平过低、过高对植株生长的抑制是IAA、ZR、GA₁₊₃、ABA含量改变后协同作用的结果。低磷水平下根的生长抑制与叶和根中的IAA、ZR和ABA含量增大和GA₁₊₃含量降低有关,高浓度的GA₁₊₃和低浓度的ABA能促进主根的伸长和侧根的形成,而高浓度的IAA和ZR对根毛的形成及伸长和增加根毛的密度有促进作用。【结论】45 mg·L^-1磷水平下刺梨实生苗生长和根系发育最好,主根长度、总根尖数和根的总长度、总体积、总表面积、平均直径、侧根长度和数量、一级侧根密度最大。降低或提高磷水平后植株生长受到抑制,上述根系形态指标随之变小。低磷胁迫下刺梨实生苗根冠比和2、3级侧根密度、根毛密度及长度明显增大。供磷水平变化导致刺梨实生苗叶和根中IAA、ZR、GA₁₊₃、ABA的含量发生改变,并共同对植株生长和根系形态变化产生协同调控作用。根冠比的增大,2、3级侧根密度和根毛密度及长度的增加是刺梨实生苗应对低磷胁迫采取的适应策略,根和叶中高水平的ZR和IAA发挥重要的促进和调控作用。     

我国林木扦插基质研究现状与展望

文中从常用基质类型、基质的理化性质、基质的配比以及基质对插穗生根和生长的影响等4个方面综述了我国林木扦插基质的研究现状。用作林木扦插的基质可分为有机和无机2大类型,常用的有蛭石、珍珠岩、泥炭、河沙、椰糠、黄心土等。目前对常用基质的理化性质的研究缺乏系统性,还不能满足标准化、规模化、工厂化生产基质的要求;对基质和其他影响插穗生根因素的交互作用以及基质影响插穗生根的机制研究不够深入,缺乏主要林木扦插基质的标准性状参数,还未能找到很好的泥炭替代品。今后应加强基质理化性质、基质同其他影响扦插生根因子交互效应、珍稀树种和品种适宜基质以及泥炭替代品等4个方面的研究,以期为最终形成一套基质标准化生产和选择配制的理论体系并应用于生产提供参考。     

Three-dimensional modelling of wood fracture in mode I, perpendicular to the grain direction at fibre level

A coupled experimental and numerical modelling approach was used to investigate the mechanism of softwood fracture at the fibre level. First, a three-dimensional mixed lattice-continuum fracture model was developed to investigate the mechanism of wood fracture, taking into account the porosity of its structure and its heterogeneities at the fibre level. The critical volumes in the specimen where crack propagation was more probable were modelled by a lattice that could show the alternation of earlywood and latewood fibres, and the other regions were considered as the continuum medium. The proposed model was used to investigate the mode I fracture of a small softwood sample in RL orientation. Secondly, a method was developed for microscopic observation of the crack trajectory and investigating the mechanism of initiation and propagation of cracks. This approach was used for microscopic investigation of the fracture behaviour of spruce specimens in mode I and RL orientation. The results of the numerical study were compared with the experimental results. The prepeak and postpeak behaviour of the obtained stress-displacement curve and also the crack opening trajectory in cross-section and longitudinal section in the model and experiments were in good agreement. Both the model and the microscopic observation showed that in mode I fracture and RL orientation, the main trajectory of the crack propagates in the earlywood ring.     

我国荒漠化的形成原因和分布特征

世界上的沙漠主要分布在副热带，唯独我国的沙漠分布在温带。根据有关文献和1994年我国沙漠化普查资料，介绍了国内外现代干旱和沙漠化现状，分析了青藏高原隆升、末次大冰期、水土资源分布、气候变化、社会经济干旱和人类不合理经济活动对我国北方沙漠化形成和分布的影响，以及未来的发展趋势，并建议要尽快实施跨流域调水、节水林牧业和依法治沙，进而彻底改变“三北”地区的干旱荒漠面貌。     

油茶病虫害发生的现状及其环境因子研究

对国内油茶病虫害发生相关研究进行了总结,分析了我国油茶病虫害的发生现状;结合油茶的地理分布、生态学特性和油茶病虫害的发生种类,提出与油条病虫害发生相关的环境因子.通过掌握环境因子的变化提高预测、防治油茶病虫害发生的频率,从而提高油茶的产量.     

Changes in soil properties and vegetation characteristics along a forest-savanna gradient in southern Venezuela

Vegetation cover in the Gran Sabana highlands (southern Venezuela) appears as a complex mosaic of tall to low forests, bush vegetation and savannas. In this study we described the changes in structure and floristic composition along a forest-savanna gradient consisted of tall forest (TF), medium forest (MF), low forest (LF) and open savanna (S), and analyse the possible reasons for the observed changes. The results showed no obvious differences in the soils properties along the vegetation gradient. All sites presented shallow soils (<50 cm depth) with high percentage of sand and with dominance of quartz, kaolinite and oxides of iron and aluminum. The soil chemical characteristics were unfavorable and similar along the vegetation gradient. The major soil difference was related with the presence of an organic layer on the soil surface of TF and MF and their absence on the soils of LF and S. Abundant residues of large trees were found on the forest floor of TF, MF and LF. These residues presented no signs of burning in TF, while in MF and particularly in LF were charred. This observation joined to the presence of charcoal within the mineral soil of S and the absence of the organic surface layer in LF and S indicated that fire has affected with different intensity or frequency the studied vegetation gradient. Large differences in the structure and floristic composition were found between TF, MF, LF and S. These differences could not be explained by changes in the mineralogical and chemical characteristics of the soil but only by fire which triggers the conversion. We concluded that the studied vegetation gradient represents stages in a temporal change from forest to savanna caused by fire, and this change has implied an impoverishment of tree species, a drastic reduction of biomass in terms of basal area, a drastic change of the floristic composition and the loss of the organic surface layer, which play an important role to maintain the fertility of these soils.     

丙烯酸/丙烯酰胺共聚吸水树脂竞聚率及吸液性能

采用溶液聚合方法,以丙烯酸(AA)与丙烯酰胺(AM)为单体,N,N'-亚甲基双丙烯酰胺(NMBA)为交联剂,过硫酸钾(KPS)为引发剂合成了高吸水性二元树脂——聚丙烯酸-丙烯酰胺(PAAAM),并进行了吸液性能研究.结果表明,该树脂吸水倍率达2 451 g/g,吸生理盐水倍率达119 g/g.考察了n(AM)∶n(AA)摩尔配比对PAAAM的吸蒸馏水、0.9%NaCl溶液中的吸液性能,得到不能仅靠改变单体的摩尔比来改善PAAAM的吸液性能,合成PAAAM的相对较佳反应条件有赖于更具体细致的试验设计才能得以确定.反复吸水次数越多,PAAAM的吸液倍率不断下降.通过元素分析法测定了AM/AA共聚吸水树脂的竞聚率,AM和AA两单体的竞聚率分别为0.943、0.791.     

一个世纪来黑龙江省森林景观动态研究

With the help of GIS tool of ARC/INFO,ARCVIEW and FRAGSTATS,the map of forest resource distribution of Heilongjiang Province was analyzed in 1896,1949 and 1981.Using total area,mean patch size,patch density,coefficient of patch size variation,mean patch fractal dimension and mean shape index,we studied the change of forest landscape pattem and the change of each patch types in this region.As a result,the total area of forest landscape and mean patch size decreased sharply,the quantity and density of patches increased,the juxtaposition of patches weakened,the shape of patch tended to become regular,and the border of patch simplified.All these showed that the forest landscape of this area tended to fragment gradually,and the fragment of Korean pine forest is the severest.the diversity of whole forest landscape and the eveness of landscape types distribution reduced gradually.Human impact,instead of climate change and forest community succession,is the most important reason for such dramatic chages.     

现代生态位理论的发展及其主要代表流派

全面而深入地评析生态位理论的形成、演变过程和最新发展动态及其代表性流派的主要学术观点.指出在这些流派当中,最具影响力的流派,并分析各流派之间的区别与联系、优点与不足,同时,对迄今为止生态位理论的发展历史进行阶段划分,最后,对现代生态位理论的发展方向和前景进行深入讨论.