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Search Results: 1 - 10 of 56043 matches for " 集团结构 "
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吉林省西部草原蝗虫群落的集团结构
李宏实?
生态学报 , 1991,
Abstract: 本文应用生态学中正在发展的集团理论,分析了吉林省西部草原蝗虫群落的结构及种间关系。该蝗虫群落由13种蝗虫组成。根据蝗虫的取食行为和栖息地选择两项生态指标,运用模糊聚类分析和主成分量分析方法,将蝗虫群落划分为4个集团,并研究了各集团内部和集团之间蝗虫的生态关系,以及环境因素对蝗虫行为的作用。文中还讨论了有关资源的确定,竞争理论和集团理论等问题。
GUILD STRUCTURE OF GRASSHOPPER COMMUNITY IN THE GRASSLAND OF WEST JILIN PROVINCE
吉林省西部草原蝗虫群落的集团结构

Li Hong-Shi,
李宏实

生态学报 , 1991,
Abstract: In this article, the developing theory of guild in ecology is applied to study on the guild structure of grasshopper community in the grassland of west Jilin prvince. This grasshopper community consisted of 13 species of grasshopper. The cluster analysis and principal components analysis were made on the basis of foraging behavior and habitat choice as indicators to divide this grasshopper community into four guilds.They were Euchorthippus unicolor, Oxya chinensis, "the guild of perching on the surface of earch and foraging in lower level", and "the guild of perching on the plant and foraging in upper level", The ecological relationships within the guilds and between the different guilds and the effects of environmental factors on the behaviors of grasshopper were studied and reasonaly explained from point-view of ecology. Some issues concerning the theories of guild and competition were also discussed.
大别山山地次生林鸟类群落集团结构的季节变化
动物学研究 , 2009, DOI: 10.3724/SP.J.1141.2009.03277
Abstract: 2007年12月—2008年12月,在大别山鹞落坪,对落叶阔叶次生林鸟类的集团结构的季节变化特征进行了研究。采用连续取样法采集鸟类取食行为数据,用聚类分析法对繁殖和非繁殖季节鸟类群落进行集团划分,通过无倾向对应分析(DCA)对32种森林鸟类的两个季节资源利用特点进行了研究。结果表明,鸟类群落在非繁殖季节可以分为地面、灌丛、树干(枝)、冠层等4个取食集团,而在繁殖季节还出现空中取食集团;候鸟影响鹞落坪次生林鸟类群落取食集团的结构,产生新的取食集团。DCA的第一轴主要代表鸟类取食高度信息,第二轴主要代表鸟类取食位置信息,第三轴代表鸟类取食方式和取食基质信息;用DCA前两轴对32种鸟类排序表明,有6种鸟主要在第一轴发生变化,有4种鸟主要在第二轴发生变化。
潜在洞巢资源差异对次级洞巢鸟及繁殖鸟类群落的影响
周大庆,周春发,邓文洪*
生物多样性 , 2009,
Abstract: ?为了解次生林中潜在洞巢资源(包括各种啄木鸟的啄洞和人工巢箱)的多寡对次级洞巢鸟集团及繁殖鸟类群落结构的影响,2007年11月至2008年7月,我们在吉林省吉林市大岗林场选择洞巢密度不同的样地,对其次级洞巢鸟及鸟类群落结构进行了比较研究。根据洞巢资源密度我们将9块样地分为3组,即巢箱区(啄洞密度最低,悬挂人工巢箱使其潜在洞巢资源总密度大幅提高)、低密度区(啄洞密度较低,无巢箱)和高密度区(啄洞密度较高,无巢箱),调查了3组样地内鸟类的组成和密度、潜在洞巢资源的利用情况等。3组样地中均调查到4种初级洞巢鸟,其种类组成略有不同;4种次级洞巢鸟在3组样地广泛分布,分别为白眉姬鹟(ficedulazanthopygia)、大山雀(parusmajor)、沼泽山雀(p.palustris)和普通鳾(sittaeuropaea)。巢箱区和高密度区的次级洞巢鸟总密度显著高于低密度区。巢箱区同高密度区一样,大山雀和白眉姬鹟的密度显著高于低密度区,这是由于大山雀和白眉姬鹟是人工巢箱的主要利用鸟种,而沼泽山雀和普通鳾的密度在三组样地间差异不显著。初级洞巢鸟总密度与啄洞密度、次级洞巢鸟总密度与潜在洞巢资源总密度都呈显著正相关关系。潜在洞巢资源丰富的样地中鸟类群落多样性指数显著高于潜在洞巢资源贫乏样地中的鸟类群落多样性指数,人为增加洞巢资源可以改变鸟类群落组成并显著提高群落的多样性指数。三组样地中鸟类群落的均匀性、丰富度指数和种间相遇率没有显著差异,群落相似性指数也相近。高密度区和低密度区鸟类群落集团结构相似。次级洞巢鸟密度的增加短时期内未对群落内其他主要鸟种的密度产生显著影响。研究结果显示,初级洞巢鸟的密度决定了啄洞的丰富程度,而洞巢资源的差异会对次级洞巢鸟集团的分布模式产生影响,进而影响整个繁殖鸟类群落的结构。
科尔沁平原丘陵草甸草原蝗虫群落集团结构
孙嵬,类成平,张柱亭,董辉,钱海涛,丛斌**
生态学杂志 , 2013,
Abstract: ?近年来,科尔沁平原丘陵草甸草原大面积、高密度发生蝗虫灾害,威胁着牧业生产的正常发展。本文应用生态学中的集团理论,设置蝗虫的取食行为和栖息地选择两项生态指标的多个梯度,对该区草原蝗虫的群落结构及种间关系进行了分析。结果表明:通过聚类分析蝗虫群落可以划分成6个集团,各集团之间在栖息环境及适应性上存在明显差异,说明多样的生境为蝗虫提供了多样的生存空间,在光照、地形等环境因子及蝗虫自身生物学特性的影响下,蝗虫为使生存适合度达到最大,在对适宜生境的选择中,形成了不同的资源利用集团;蝗虫的生态指标梯度按主成分分析可简化为3个主成分因子,累积贡献率达82.91%,代表的生物学信息为蝗虫对地面基层、取食高度、地形以及阴影的选择;不同的蝗虫种类因对生境资源的利用程度不同,表现出不同的生态位宽度,对生境资源利用的相似程度决定了蝗虫种间生态位重叠值的高低。
Influence of potential cavity resources on secondary cavity-nesters and breeding bird community composition
潜在洞巢资源差异对次级洞巢鸟及繁殖鸟类群落的影响

Daqing Zhou,Chunfa Zhou,Wenhong Deng,
周大庆
,周春发,邓文洪

生物多样性 , 2009,
Abstract: To explore how density of potential cavity resources (including cavities and artificial nest boxes) affects the composition and distribution of secondary cavity-nesting guilds, as well as the community structure of breeding birds, we studied plots with different densities of nest cavities in Dagang Forestry Farm, Jilin Province, China from November 2007 to July 2008. Based on the density of cavity resources, the nine sample sites were divided into three treatments, i.e., NBP (nest-box plots with less cavities and high-density nest boxes), LDP (low-density cavities plots without nest boxes) and HDP (high-density cavities plots without nest boxes). We then surveyed avian communities and noted the use of cavities and artificial nest boxes. All the treatments contained four primary cavity excavators, and three species were the same. Four secondary cavity nesters were widespread in the three treatments, including the great tit {Parus major), marsh tit (P. palustris), yellow-rumped flycatcher (Ficedula zanthopygia) and eurasian nuthatch (Sitta europaea). Total densities of secondary cavity nesters in NBP and HDP were higher than that of LDP. Densities of great tits and yellow-rumped flycatchers were higher in NBP and HDP than in LDP, because they were major users of nest boxes. There were no significant differences in the densities of marsh tits and eurasian nuthatches among treatments. A significant positive correlation was detected between the density of primary cavity excavators and cavity density, and also between the density of secondary cavity nesters and potential cavity resources. Bird species diversity indices were lower in LDP than in NBP and HDP. Nest-box addition could potentially regulate the composition of avian communities by increasing bird species diversity indices. We observed no differences in evenness, species richness indices or probability of interspecific encounter (PIE) among treatments, and Serensen similarity indices differed little among treatments. There were no obvious differences in structure of breeding bird guilds between HDP and LDP. Nine species were found in all the three treatments, and their densities were not affected by the temporary increase in secondary cavity nesters. We hypothesize that density of primary cavity excavators determines the density of cavities in forests, which may change distributional patterns of secondary cavity-nester guilds, and therefore affect the structure of breeding avian communities.
Seasonal Dynamics of the Avian Guild Structure of Mountain Secondary Forest in Dabieshan Mountain
大别山山地次生林鸟类群落集团结构的季节变化

刘 彬,周立志 汪文革,沈三宝,韩德民
动物学研究 , 2009,
Abstract: Between December 2007 and December 2008, we studied the avian guilds structure of the secondary broad-leaved forests in Yaoluoping, Dabieshan Mountain, Anhui Province. We used focal sampling method to observe feeding behaviors of the bird community, and collected food resource utilization data. PC-ORD was used in Cluster Analysis for the guild structures in the two seasons, and Detrended Correspondence Analysis (DCA) for the feeding patterns of the 32 birds in both the breeding/non-breeding seasons. Results indicated that during the non-breeding season, the bird community could be divided into four guilds: ground forager, shrub forager, tree trunk (branches) forager, and canopy forager. In addition to the four listed guilds, there was an air foraging guild during the breeding season. The first axis of DCA represented the information of the foraging height, the second axis represented the information of the foraging position, and the third axis represented the information of the foraging pattern and the foraging matrix. The ordination for the 32 birds by the first two DCA axes indicated the behavior of 6 birds mainly changed along the first DCA axis, which represented the change information of the foraging height. Additionally, behavior of 4 birds mainly changed along the second DCA axis, which represented the change information of the foraging position.
基于虚拟力牵引的社团划分算法
顾亦然,戴晓罡
南京邮电大学学报(自然科学版) , 2013,
Abstract: 文中基于虚拟引力的思想,提出了一种新的社团划分算法。其基本思想是将相连节点之间看作是引力,不相连节点看作是斥力,让节点之间进行相互作用,直到节点以社团的形式聚集起来,从而达到划分社团的目的。通过在计算机生成网络和已知社团结构的现实网络中对本算法进行仿真,发现算法具有较高可靠性和接近线性的时间复杂度。
企业集团重组问题研究
系统工程理论与实践 , 2003,
Abstract: ?运用企业理论的分析框架对企业集团的重组问题进行了模型描述.区别不存在企业间交互影响和考虑企业间交互影响两种情况,考察了不同控制结构和资源配置方式下,集团内企业在提高投入的激励方面的变化,及其对集团整体福利的影响.给出了描述集团重组策略的命题,证明了命题结论,并据此对企业集团重组安排提出建议.
联合国安理会改革的进程及前景分析
徐刚,梁嘉真?
天府新论 , 2011,
Abstract: 在联合国60多年的发展历程中,尤其是冷战结束后,关于安理会改革的呼声日渐高涨。安理会改革从1993年成立工作组至今已经走过了17个年头,经历了三大阶段,出现了不少方案。但是,由于国际社会与联合国机制之间存在需求与供给不平衡的矛盾,以及改革程序的复杂,导致了改革的进程比较缓慢。基于以往的经验和教训,联合国的改革可走一条"先标准后地位、先扩大后否定"的渐进式道路。
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