凉水国家级自然保护区森林群落结构及物种多样性分析

利用在凉水国家级自然保护区设置的9个样方的调查资料,用丰富度指数、多样性指数和均匀度指数对该区主要森林群落结构及物种多样性进行了分析研究.结果表明,不同群落间的物种多样性存在差异,主要表现为生于坡地的森林群落类型的物种多样性指数总体上高于生于谷地的云冷杉林和红皮云杉林.同一群落不同层次的物种多样性也存在差异,丰富度指数除在云冷杉林和红皮云林中表现为草本层>乔木层>灌木层外,其它群落中均表现为草本层>灌木层>乔木层;均匀度指数在谷地云冷杉林和红皮云林及坡地毛缘苔草毛榛子红松林中表现为草本层>灌木层>乔木层,在其它群落中均表现为灌木层>草本层>乔木层;Simpson指数和Shannon-Wiener指数在各群落间变化比较复杂,但其变化趋势相同.群落的物种多样性还与群落所处的演替阶段有关,就凉水国家级自然保护区内的红松林而言,随着群落的演替,丰富度和Shannon-Wiener多样性指数呈现增加的趋势,当到达顶级群落时又略有降低;而Simpson指数和Pielou均匀度指数变化不明显.     

大石门沟森林公园群落结构与物种多样性特征

采用典型样地法,利用物种多样性指数、均匀度指数、生态优势度指数分析大石门沟森林公园群落结构和物种多样性.结果表明:1)乔木和草本种类丰富,但灌木种类较少.调查区域内乔木共28种,灌木26种,草本91种,分属58科107属,各种类主要以阔叶落叶种为主;2)群落水平结构分布规律不明显,但在垂直结构上呈现出一定的规律性,可分为乔木层、草本层、灌木层.乔木层和草本层结构相对复杂稳定,灌木层结构单一;3)各群落乔木层优势种明显,群落Ⅰ、群落Ⅱ、群落Ⅲ都由3~4个优势种组成,群落Ⅳ乔木层只有1种优势种,如果不进行人工干预,短时间不会改变这种状况;4)群落间的物种多样性指数差异不显著,但各群落的灌木层多样性指数远小于乔木层和草本层,即草本层乔木层灌木层,物种多样性与物种丰富度和分布均匀度呈正相关.整体来看,大石门沟森林公园物种多样性指数整体趋势为群落Ⅱ群落Ⅲ群落Ⅰ群落Ⅳ.     

云南鸡足山元江栲群落和高山栲群落的群落多样性研究

本文报告云南鸡足山元江栲群落和高山栲群落多样性的研究结果．群落多样性包括物种多样性和结构多样性．研究表明：①群落的物种多样性,元江栲群落低于高山栲群落;发育盛期群落低于过渡地段的或发育晚期的群落;高山栲群落随层次的升高指数降低,元江栲群落则以灌木层为最高、草本层较低．②结构多样性用考虑群落层次结构时物种多样性指数的增量来度量,元江栲群落高于高山栲群落;发育盛期群落高于过渡地段的或发育晚期的群落．③比较稳定的植物群落,其物种多样性指数较低,而结构多样性指数较高．     

缙云山森林次生演替序列群落结构,物种多样性与稳定性关系

基于物种多样性导致稳定性理论,从层次结构和物种多种性指数方面着手,测度和分析了缙云山森林次生演替序列群落的物种多样性与稳定性关系．结果表明,随着群落稳定程度的增加,灌木层、乔木层个体数比例增大,而草本层比例则呈下降趋势;相对稳定的顶极群落,各层次的物种多样性指数（Ｈ）和均匀度指数（Ｊ）波动水平较小;不稳定的发展中群落,各层次的Ｈ和Ｊ波动水平较大,灌木层和草本层建立初期Ｈ和Ｊ较高,以后下降;而乔木层建立初期Ｈ和Ｊ较低,以后上升,最后各层次的Ｈ与Ｊ均趋向一致．测定方法上,认为物种多样性指数和均匀度指数比层次结构图更为有效．     

浙江天台山七子花群落与其他森林群落物种多样性比较

应用物种丰富度、物种多样性指数及群落均匀度等对分布在浙江天台山的七子花群落与马尾松群落、甜槠群落、苦枥木群落的物种多样性进行了比较．结果表明，对木本植物而言，七子花群落的物种丰富度比马尾松群落、甜槠群落大，比苦枥木群落小；七子花群落的物种多样性指数、群落均匀度均比马尾松群落、甜槠群落、苦枥木群落大；各群落的木本植物物种多样性均大于草本植物。一般地，七子花群落的乔木层、灌木层、草本层的物种多样性指数、群落均匀度比相应的马尾松群落、甜楮群落大。在七子花群落、马尾松群落、甜槠群落的垂直结构中，物种多样性指数由大到小的顺序为灌木层-乔木层-草本层。     

旅游步道对保护区群落结构的影响

系统研究了河南龙池曼自然保护区旅游步道对群落物种组成、物种种数、物种个体数、物种盖度及重要值的影响。结果表明：旅游对步道两侧草本层、灌木层盖度的影响最大,对群落重要值的影响次之,对物种种数的影响较小,但对物种的组成成分有较大影响。在步道两侧的２ｍ处物种个体数最大;３ｍ以外,个体数逐渐减少。     

贵州施秉榧树群落结构与物种多样性研究

为了解贵州榧树群落结构与物种多样性状况,以期为榧树种质资源的保护与利用提供部分依据,我们采用样方法对6个榧树群落面积为5 m×5 m样地内的物种组成、群落结构进行调查分析,结果表明:榧树在群落中可实现正常更新,表现为增长型.榧树群落中有维管植物47科68属78种,就其生活型而言,群落中木本植物41种,其中常绿树种30种.群落垂直结构可分为灌木层、乔木层和草本层,层间层则种类较少;而物种多样性指数较高的为灌木层,其次为草本层,物种均匀度指数以草本层最高,乔木层次之,也即草本层的优势度更为明显,这说明群落次生性较强.尽管榧树可以自我更新,但我们仍建议适度进行抚育以促进其幼树生长.     

关帝山林区森林植被生物多样性研究

根据物种多样性测度公式,把19块标地按乔木层、灌木层、草本层3个层次,分别计算各标地的物种多样性指数。根据计算结果,指出：各森林群落物种丰富度均表现为草本层〉灌木层〉乔木层的特点。多样性指数总体趋势因森林群落不同而有所差异：落叶松森林群落表现为草本层〉灌木层〉乔木层;油松、桦树、杨树森林群落表现为灌木层〉草本层〉乔木层;各森林群落中草本层与灌木层多样性指数均比较接近。并根据研究结果对关帝林区今后的森林经营方向提出了几点可行性建议。     

山西五鹿山森林群落分类及物种多样性研究

采用样方法对山西五鹿山自然保护区森林群落进行调查,设置60个样地256个森林样方,运用TWINSPAN双向指示种分析法对该区森林群落进行分类,并采用patrick指数、Shannon-Wiener指数和Pielou指数对五鹿山森林群落的物种多样性进行分析.结果表明：TWINSPAN将保护区的森林群落划分为华北落叶松林、油松林、白皮松林、辽东栎林等15个群落类型.不同群落类型的物种多样性指数值D、H＇和J在描述群落性质时不具有严格的一致性,但都较好地反映了不同植物群落类型在物种组成方面的差异.同时,分析群落多样性与植物生长型的关系得出,森林群落的丰富度指数和多样性指数均表现为草本层〉灌木层〉乔木层.     

浙江丽水太山芒萁灌草丛群落研究

通过样方调查,对芒萁灌草丛不同恢复阶段的群落特征进行了分析,结果表明,芒萁群落乔木种类较为单一,物种的丰富度,多样性和均匀性都随年龄增加而逐渐增加,群落不同恢复阶段各层物种的相关系数较高,群落年龄结构属于增长型,灌木层-草本层-乔木层的物种多样性依此递减.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that