清新和阳山县圆叶乌桕群落物种多样性和优势种群动态探讨

为了解亚热带地区石灰岩山地圆叶乌桕(Triadica rotundifolia)群落的变化规律,应用样方调查法,对广东省清新县和阳山县两片石灰岩山区圆叶乌桕群落的物种多样性及其种群动态进行了研究。结果表明,在两个面积为2400 m2的样方中,共有维管植物140种,隶属于65科118属。群落均以大戟科、茜草科、芸香科、桑科和木犀科为优势科;其种子植物属的分布区类型以热带分布型为主,占总属数的79.6%,温带分布型属占18.3%。除草本层均匀度外,清新群落的各层丰富度、多样性指数和均匀度指数均比阳山群落的高。清新的圆叶乌桕种群缺乏小苗,为不稳定种群; 而阳山的圆叶乌桕种群相对年轻,为稳定种群。随着群落的演替发展,群落中圆叶乌桕的优势地位终将被其它耐荫型树种所取代。     

湖北长阳光叶珙桐群落结构研究

在野外调查基础上,分析了湖北省长阳地区光叶珙桐群落外貌与结构特征。结果表明:在2900m²的样方中,有维管植物238种,隶属于81科170属;群落植物区系丰富、古老、特有性强;群落中有金钱槭、水青树、白辛树、领春木、连香树、天师栗和大叶三七等珍稀濒危植物;其生活型以包括藤本在内的高位芽植物占绝对优势,达47.06%;叶级以中型叶为主,占68.07%,小型叶次之,占28.57%;叶型以单叶占有较大的优势,达78.99%叶质以纸质叶为主,占67.12%。群落垂直结构较复杂,成层现象明显,可分为乔木层、灌木层、草本层和层间植物;年龄结构和高度结构分析表明,光叶珙桐种群更新不良,具有衰退的趋势。     

广东南岭大东山浙江润楠群落物种多样性与区系地理成分分析

应用植被调查样地法研究了广东南岭国家级自然保护区大东山片区的浙江润楠群落的物种多样性、区系地理成分,以及优势种种群的年龄结构。结果表明：（1）在1600m2的样地内共有维管束植物73科119属169种,群落的数量优势科为樟科、蔷薇科、山茶科、壳斗科及杜鹃花科等,种类组成的科、属地理成分中热带成分分别占74·51%和70·10%,温带成分分别占23·53%和33·64%;（2）该群落浙江润楠种群以幼、中龄树为主,其优势地位明显且稳定,乔木层的亚优势树种以罗浮栲、马尾松及荷木等为主;（3）群落垂直结构分为乔木层、灌木层和草本层3层,灌木层的物种最丰富,对群落物种多样性分析发现,Simpson指数：灌木层（乔木层=草本层,Shannon指数：灌木层（乔木层（草本层,Margalef指数：灌木层（乔木层（草本层,Pielou指数：乔木层（灌木层（草本层。     

南岳篦子三尖杉群落多样性分析

采用样方法,对南岳境内的野生篦子三尖杉株群结构及物种多样性进行了调查研究。结果表明:在1 500m2样地中,共有维管束植物123种,隶属于69科99属,群落优势科不明显,种类主要集中在单种的科属内。植物生活型谱以小高位芽为主的木本植物占优势,叶的生活期以夏绿叶为主,常绿叶次之,群落外貌较整齐,冠面颜色黄绿色,结构层次明显,群落中乔木种类稀少,个体数较多,优势种为毛竹,灌木层的种类和个体数最多,优势种为篦子三尖杉等。该群落植物区系地理成分较复杂,有13个分布区类型,温带性成分占52.53%,热带性成分占38.38%,说明该群落植物属具有较强的温带性质,并表现出该区域植物从热带向温带过渡的性质。物种多样性分析显示该群落多样性指数不高,各层次的丰富度格局为灌木层草本层藤本层乔木层,多样性格局、均匀度格局和生态优势度局均为藤本层灌木层草本层乔木层。     

浙江九龙山香果树群落乔木层物种的多样性格局

为了解香果树(Emmenopterys henryi)群落的物种多样性及其驱动因素,在浙江九龙山自然保护区建立了35个以香果树为中心15 m半径的样圆,调查样圆内胸径2.5 cm以上的乔木层树木的物种和胸径。通过线性混合效应模型分析α多样性与海拔、坡向、香果树胸高断面积的关系,通过Mantel检验和方差分解分析样地间距离、海拔、坡向和香果树胸高断面积差异对β多样性的影响。结果表明,九龙山香果树群落乔木层物种丰富(50科96属145种),且以落叶或半常绿树种占优势;样地乔木层Shannon-Wiener指数为2.37～3.40,Simpson指数为0.86～0.94;群落乔木层α多样性随海拔升高呈先升高后下降的变化趋势,但与样地坡向和香果树胸高断面积无关;群落乔木层Sorenson指数为0.15～0.95,物种周转组分对群落β多样性的贡献达74.88%;样地间地理距离与乔木层β多样性及其组分呈显著正相关,样地间海拔差异与其乔木层β多样性及其物种丰富度差异组分呈显著正相关,而样地间香果树胸高断面积差异仅与物种周转组分显著正相关;样地地理距离对于乔木层β多样性及其组分具有最高的解释度(23%...     

四川米仓山自然保护区台湾水青冈群落学特征及多样性研究

以四川米仓山自然保护区内的台湾水青冈(Fagus hayatae)群落为研究对象,采用20m×30m典型样地调查的方法,对群落的物种组成、区系特征、生活型谱、重要值、物种多样性、优势种群年龄结构及群落结构的相似性等方面进行分析。结果表明:(1)米仓山自然保护区内台湾水青冈群落中共有维管束植物129种,隶属于48科83属,其中蔷薇科为优势科;植物区系以北温带、泛热带及东亚和北美洲间断分布为主,具有南北区系的特点;生活谱型主要以高位芽植物(61.16%)和地下芽植物(23.14%)为主,其它生活型较少,这与米仓山台湾水青冈群落分布区所在的地理区位相吻合。(2)乔木层中台湾水青冈种群的重要值达到42.37%,为群落的单优势种。群落中灌木层的Shannon-Wiener指数为0.97,显著高于乔木层和草本层,反映出灌木层物种丰富的特点。(3)在台湾水青冈种群年龄结构中,Ⅰ级和Ⅱ级个体所占比例为24.05%,Ⅳ级和Ⅴ级个体所占比例为54.81%,反映出种群具有不良的自然更新特点。(4)群落相似性分析表明,台湾水青冈群落可分为4个类群,类群间在物种组成方面具有显著差异。研究认为,米仓山自然保护区内的台湾水青冈的群落特征和多样性水平因地处内陆已具有明显的地域特点。     

广东省南昆山自然保护区厚叶木莲的群落特征研究

为探讨广东省南昆山濒危植物厚叶木莲(Manglietia pachyphylla)群落的结构特征,采用样方调查法对群落内的物种种类组成、区系、垂直结构和种群年龄结构等进行了研究。结果表明,在2000 m2的样地内共有维管植物236种,隶属于73科136属,以热带成分占绝对优势;优势科为樟科(Lauraceae)、山茶科(Theaceae)、壳斗科(Fagaceae)、冬青科(Aquifoliaceae)、茜草科(Rubiaceae)等。群落中以苗仔竹(Schizostachyum dumetorum)为优势种,重要值为81.09%;群落的生活型谱以中、小高位芽植物为主,占79.23%。群落属于南亚热带常绿阔叶林植被类型。群落成层现象明显,可分为乔木层、灌木层和草本层3层,层间植物丰富。对种群的年龄结构进行分析表明,厚叶木莲种群已处于衰退模式,有即将在群落中消失的可能,属于濒危物种,应加以保护。因此,对厚叶木莲及其群落在就地保护的基础上,同时要进行迁地保护及推广应用。     

湖南大围山和八面山香果树种群的年龄结构和演替动态比较

选取湖南大围山和八面山3处典型的香果树(Emmenopterys henryi)群落,通过分析香果树种群的重要值、物种多样性、年龄结构,绘制生命表和生存曲线图,并与其他不同地区3处香果树群落进行比较,探讨不同纬度、不同立地生境对香果树种群的年龄结构和演替动态的影响。结果表明:(1)大围山上游香果树群落的优势种群为多脉榆(Ulmus castaneifolia)、香果树和青钱柳(Cyclocaryapaliuru);大围山下游香果树群落的优势种群为黄檀(Dalbergia hupeana)、香果树和油茶(Camellia oleifera);八面山香果树群落的优势种群为野核桃(Juglans cathayensis)、香果树和小叶青冈(Cyclobalanopsis myrsinifolia)。(2)大围山上游香果树群落共有维管植物60科96属118种,大围山下游香果树群落共有维管植物76科120属163种,大围山上游和下游香果树群落地理成分均表现为温带成分高于热带成分;八面山香果树群落共有维管植物61科95属108种,地理成分表明热带成分高于温带成分。(3)根据年龄结构和生存分析,香果树种群在不同的群落中所处演替阶段不同,大围山上游为衰退型种群,大围山下游为稳定型种群,八面山为增长型种群,均具有代表性。(4)经分析对比,纬度位置、岩石裸露度、郁闭度、群落内优势种群的生长状况和人为破坏程度等是影响香果树种群生长趋势的因素,建议对大围山的2个香果树群落应加强后续监测,并参照八面山的香果树种群生存状况针对岩石裸露度、郁闭度等进行适当人工干扰和管理,以保障香果树种群的健康生长。     

牛洛河自然保护区东京龙脑香林群落特征研究

东京龙脑香(Dipterocarpus retusus)是国家I级重点保护野生植物,是东南亚热带雨林的标志性树种,目前有关该群落学的研究尚处于空白。该研究通过实地踏查,采用典型选样法布设4个30 m×30 m的群落样地、20个10 m×10 m的种群样方,记录样地内的物种及其株高、胸径、数量,群落特征等,并通过分布区类型划分、群落物种多样性分析及种群年龄结构划分等方法,分析了东京龙脑香林群落学与种群学特征。结果表明:(1)样地中共记录种子植物181种,隶属76科143属,其中热带性质科有58科、热带性质属有126属、热带性质种有162种,科、属、种热带成分比例分别为76.32%、88.11%、89.50%,表明该群落具有强烈的热带性质。(2)该群落物种多样性指数整体较高,多样性指数(d_(Ma)、H')在群落不同层次中均表现为灌木层乔木层草本层的特征;均匀度指数(J_(sw))在不同层次中比较接近;优势度指数(D)表现为草本层乔木层灌木层。(3)从乔木层重要值来看,东京龙脑香的最大,为26.85,显示出绝对的优势,是该群落的优势种、建群种。(4)该种群年龄结构为正金字塔型,表明该种群处于增长时期,为增长型种群。     

澳门青洲山翻白叶树群落特征及物种多样性研究

根据样方调查结果,对澳门青洲山翻白叶树(Pterospermum heterophyllum)群落的种类组成、外貌、结构特征与动态及物种多样性进行分析.结果表明:(1)在1 600 m2样地中,有维管束植物47种,隶属于29科44属;对乔木层和灌木层主要物种的重要值以及频度分析结果显示,该群落是以翻白叶树为主的单优种群落,群落种类组成多样性和水平分布不均匀,其外貌终年常绿;对优势种种群的年龄结构分析显示,该种群处于增长状态;(2)整个群落的物种丰富度Margalef指数为13.72,Shannon-Wiener指数为1.15,Simpson指数为0.875,均匀度指数为0.34,该群落的层次格局为:灌木层>藤本层>乔木层>草本层;(3) 与其他5个不同类型地区森林群的物种多样性比较结果显示,澳门翻白叶树群落的物种多样性明显低于其他5个森林群落.     

六种藓类植物茎的比较解剖学研究

通过对6种藓类植物,即褶叶青藓(Brachythecium salebrosum(Web.et Mohr.)B.S.G.)、湿地匐灯藓(Plagiomnium acutum(Lindb.)Kop.)、侧枝匐灯藓(Plagiomnium maximoviczii(Lindb.)Kop.)、大凤尾藓(Fissidensnobilis Griff.)、大羽藓(Thuidium cymbifolium(Doz.et Molk.)B.S.G.)和大灰藓(Hypnum plumaeforme Wils.)嫩茎和老茎的石蜡切片和显微观察发现,同一藓类植株的嫩茎和老茎,茎结构稳定,不同种藓类植物茎横切面具有不同特征.植物体茎横切面形状、表层细胞的层数、细胞大小和细胞壁厚薄、皮层细胞大小和形状、中轴的有无以及比例等特征可以作为藓类植物的分科分类依据之一.     

Photoregulation of seed germination of wild-type and of an aurea-mutant of tomato

Seed germination of an aurea mutant of tomato ( Lycopersicon esculentum Mill.) is promoted by continuous irradiation with red, far-red or long-wavelength far-red (758 nm) light as well as by cyclic irradiations (5 min red or 5 min far-red/25 min darkness). Far-red light applied immediately after each red does not change the germination behaviour. Seed germination of the isogenic wild-type, cv. UC-105, is promoted by continuous and cyclic red light while it is inhibited by continuous and cyclic far-red light and by continious 758 nm irradiation. Far-red irradiation reverses almost completely the promoting effect of red light. The promoting effect (in the aurea mutant) and the inhibitory effect (in the wild-type) of continuous far-red light do not show photon fluence rate dependency above 20 nmol m⁻² s⁻¹. It is concluded that phytochrome controls tomato seed germination throgh low energy responses in both the wild type and the au mutant. The promoting effect of continuous and cyclic far-red light in the au mutant can be attributed to a greater sensitivity to P_fr.     

Cause of Senescence of Nine Sorts of Flowers

The levels of endogenous phytohormones and respiratory rate in nine sorts of flowers such as Cymbidium faberi Rolfe, Nopalxochia ackermannii Kunth and others were investigated both at full bloom and senescence and meanwhile the effect of exogenous phytohormones on prolonging the blossoms and promoting ethylene production were tested. There is a high content of endogenous ethylene in all the long-lived flowere, about 3–16 folds higer than the short-lived ones. There is a high level of ABA at full blooming flowers of short-lived flowers, in which there is no or only some cytokinins in it, but the ratio of CTK (6BA+zeatin)/ABA is smaller(l.7). The endogenous ABA reached a much higher level at senescence in all nine sorts of flowers, so it is reasonable to consider that it is ABA which plays an important role of regulation in controlling flower's senescence. There is a much higher level of GA3 and zeatin in the long-lived flowers which is not demonstrated in the shortlived ones. The respiratory rate is one of the factors controtling the longevity of flowers, but it does not play a decided role. Application of 6BA and zeatin prolongs distinctly orchid’s longevity, however exogenous IAA through the promotive action on ethylene production, evidently extends the longevity of the flowers of the Nopalxochia ackermannii Kunth.     

Interconnection of parameters of regulation system of lipid peroxidation and of morphophysiological parameters of mouse liver

A complex analysis of seasonal fluctuations of the mean group parameters of the system of regulation of lipid peroxidation has been performed in liver of Balb/c mice. Association of lipid characteristics and morphophysiological parameters is studied in the Balb/c mouse liver. An inter-connection is revealed between the liver index and the amount of lysoforms of phospholipids, the scale and character of the interconnection differing essentially depending on proportion of phos-phatidylcholine in mouse liver phospholipids.     

龙胆科药用植物化学成分的研究现状

龙胆科植物在我国的分布范围很广,且多数为药用植物,其多数种属的药用植物,至今其化学成分尚未被系统研究。综述了目前龙胆科药用植物的化学成分的研究现状及一般提取方法,对近年来发现的环烯醚萜及裂环烯醚萜类化合物进行了总结,为本科药用植物的更深入研究提供了参考。     

Physiological characteristics of various species of strains of carboxydobacteria

Seven strains of aerobic carbon monoxide-oxidizing bacteria (carboxydebacteria) when growing on CO as sole source of carbon and energy had doubling times which ranged from 12–42 h. The activity profiles obtained after discontinuous sucrose density gradient centrifugation indicated that the CO-oxidizing enzymes are soluble and the hydrogenases are membrane-bound in all strains examined. The CO-oxidizing enzymes of Pseudomonas carboxydohydrogena, Pseudomonas carboxydoflava, Comamonas compransoris, and the so far unidentified strains OM2, OM3, and OM4 had a molecular weight of 230,000; that of Achromobacter carboxydus amounted to 170,000. The molecular weights of the CO-oxidizing and H₂-oxidizing enzymes turned out to be identical. The cell sonicates were shown to catalyze the oxidation of both CO and H₂ with methylene blue, thionine, phenazine methosulfate, toluylene blue, dichlorophenolindophenol, cytochrome c or ferricyanide as electron acceptors. Methyl viologen, benzyl viologen, FAD⁺, FMN⁺, and NAD(P)⁺ were not reduced. The spectrum of electron acceptors was identical for all strains tested. Neither free formate, hydrogen nor oxygen gas were involved in the CO-oxidation reaction. Methylene blue was reduced by CO at a 1:1 molar ratio. The results indicate that CO-oxidation by carboxydobacteria is catalyzed by identical or similar enzymes and that the reaction obeys the equation CO+H₂OCO₂+2H⁺+2e^- as previously shown for Pseudomonas carboxydovorans.Dedicated to Otto Kandler remembering almost three decades of enjoyable cooperation     

Modulation of allostery of pyruvate kinase by shifting of an ensemble of microstates

Since the introduction of the concepts of allostery about four decades ago, much advancement has been made in elucidating the structure-function correlation in allostery. However, there are still a number of issues that remain unresolved. In this review we used mammalian pyruvate kinase (PK) as a model system to understand the role of protein dynamics in modulating cooperativity. PK has a triosephosphate isomerase (TIM)(α/β)₈ barrel structural motif. PK is an ideal system to address basic questions regarding regulatory mechanisms about this common (α/β)₈ structural motif. The simplest model accounting for all of the solution thermodynamic and kinetic data on ligand-enzyme interactions involves two conformational states, inactive E^T and active E^R. These conformational states are represented by domain movements. Further studies provide the first evidence for a differential effect of ligand binding on the dynamics of the structural elements, not major secondary structural changes. These data are consistent with our model that allosteric regulation of PK is the consequence of perturbation of the distribution of an ensemble of states in which the inactive E^T and active E^R represent the two extreme end states. Sequence differences and ligands can modulate the distribution of states leading to alterations of functions. The future work includes: defining the network of functionally connected residues; elucidating the chemical principles governing the sequence differences which affect functions; and probing the nature of mutations on the stability of the secondary structural elements, which in turn modulate allostery.     

（鱼句）亚科花（鱼骨）型鱼类骨骼系统的比较

对我国花型Hemibarbuspattern鱼类作了骨骼系统比较,结果表明,此类型鱼类脑颅较长,副蝶骨平直或稍弯曲,眶蝶骨腹纵嵴发达(铜鱼Coreius septentrionalis例外),下颞窝和咽突中等大,基枕骨后突发达;脑颅中的上筛骨的后突、侧筛骨的外筛突,蝶耳骨的外突、上耳骨的后突、围眶骨和后颞窝等均有明显的差异;咽颅中的舌颌骨、尾舌骨、鳃盖骨和下咽齿的列数等又有显著的区别;附肢骨骼中的腰带骨、脊椎骨中的复合神经骨和第4椎骨腹侧的悬器等也有不同之处。据此,这些差异和区别可作为属间或种间的分类依据。