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植物群落波动的类型与机理(综述) 总被引:6,自引:0,他引:6
群落波动是植物群落动态的一个重要内容,群落的波动研究对人们认识森林和草地景观动态及其开发有重要的作用。概述了群落波动的定义、原因、特性、类型和测量方法,及与群落演替的差异等,以期为群落波动的深入研究提供参考。 相似文献
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鼎湖山森林群落多样性垂直分布格局的研究 总被引:7,自引:3,他引:7
根据鼎湖山10 m×1 200 m的植物固定样带调查,沿海拔梯度对植物群落分布格局及生物多样性特性进行了分析。结果表明,本固定样带有3个森林类型,5个群落类型,构成一演替序列,但在垂直梯度上有交错现象。生物多样性指数为:乔木层,中生性阔叶林>针阔混交林>阳生性阔叶林;草本层,针阔混交林>阔叶林。阳性草本植物为主的草本群大部分生长在阳性树种为主的阔叶林和针阔混交林下,但是林下微环境变化对草本层植物优势度的影响也较大,以耐荫植物为主的草本群在阳性树种为主的阔叶林和针阔混交林也有分布,表明相同群落类型林下小环境的变化。 相似文献
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天龙山木本群落种间关系的研究 总被引:6,自引:0,他引:6
采用χ^2检验方法和相关分析等方法对山西天龙山木本植物群落进行了种间关系分析.结果表明木本植物群落的种间关系以正相关为主,但是负关联的比重也较大,而且还有一定的独立格局存在,表明物种间的关系不大稳定,群落正处于发展演替之中,同时也表明物种对环境资源的竞争并不激烈,物种资源比较丰富。 相似文献
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鄱阳湖丰水期水位波动对浮游动物群落演替的影响 总被引:1,自引:0,他引:1
为了解鄱阳湖夏季丰水期水位剧烈波动过程中浮游动物的群落演替特征,2012年夏季鄱阳湖水位剧烈波动期间,于6月24日、7月7日和8月27日当水位下降且接近17.6 m时,在江西鄱阳湖国家级自然保护区内的1个浅水碟形湖泊设置4个采样点进行采样调查。共发现浮游动物65种,其中轮虫52种,枝角类7种,桡足类6种,多为营浮游生活的广温性和嗜温性种类。单因子方差分析(one-way ANOVA)显示3个月之间浮游动物的密度和生物量均具有显著差异(P0.05),7月份浮游动物密度(1030.17±68.18个/L)显著高于6月份(325.16±41.60个/L)和8月份(203.79±24.91个/L);6月份浮游动物的生物量(0.56±0.04 mg/L)显著低于7月份(1.22±0.11 mg/L)和8月份(0.99±0.11 mg/L)。基于浮游动物多度的聚类分析和自组织映射神经网络图均揭示夏季3个月份的浮游动物可区分为明显的3个群落:6月群落、7月群落和8月群落。蒙特卡罗检验发现水温、电导率、浊度和溶氧与浮游动物群落结构变化显著相关(P0.05)。典型相关分析显示,6月份浮游动物群落与叶绿素a含量呈显著正相关关系,7月份浮游动物群落与水体温度呈显著正相关关系,8月份浮游动物群落与水深和电导率、浊度和溶氧呈显著正相关关系(P0.05)。在3个月均为优势物种的盖氏精囊轮虫与叶绿素a含量呈正相关关系(P0.05),与水温、pH、溶氧呈负相关(P0.05)。夏季水位波动过程中浮游动物的群落结构在时间上(月份之间)发生明显演替,呈现轮虫密度逐渐降低,枝角类和桡足类密度逐渐增加的变化规律。水位波动引起环境因子的改变,从而对浮游动物的群落演替产生了重要影响。 相似文献
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五针白皮松的一些群落学特征 总被引:4,自引:0,他引:4
五针白皮松的一些群落学特征邓莉兰,陆素娟,樊国盛,李乡旺(西南林学院林业系,昆明650224)关键词五针白皮松;植物群落;濒危种五针白皮松(PinussquamataX.W.Li)是近年发现的新种[1],木材结构细,纹理比云南松、比华山松更直,是有前... 相似文献
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We derive an expression for the variation between parallel trajectories in phenotypic evolution, extending the well known result that predicts the mean evolutionary path in adaptive dynamics or quantitative genetics. We show how this expression gives rise to the notion of fluctuation domains-parts of the fitness landscape where the rate of evolution is very predictable (due to fluctuation dissipation) and parts where it is highly variable (due to fluctuation enhancement). These fluctuation domains are determined by the curvature of the fitness landscape. Regions of the fitness landscape with positive curvature, such as adaptive valleys or branching points, experience enhancement. Regions with negative curvature, such as adaptive peaks, experience dissipation. We explore these dynamics in the ecological scenarios of implicit and explicit competition for a limiting resource. 相似文献
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The main purpose of this study is to examine the fluctuation characteristics of Tamarix ramosissima community from the year of 2007–2008 in desert riparian forest under human surface water-overflowing disturbance in the lower reaches of Tarim River, China. In this paper, community structure, species diversity and dominant species were chosen as the indicators which could reflect the characteristics of community fluctuation. The representative sampling method was used to investigate and measure the fluctuation process of Comm. T. ramosissima. The main results showed that species numbers of the community increased 66.7% under the surface water-overflowing disturbance within two years comparing with it under non-disturbance. The Sorensen similarity coefficient of plant species is 0.75 in community under the disturbance and non-disturbance, indicating that species composition is very similar and main structure of the community has not changed on these two different treatments. Species diversity index of Comm. T. ramosissima changed a lot under the disturbance. Compared with it under non-disturbance, species richness and species diversity have been increasing while species evenness declined slightly under the disturbance. The numbers and kinds of dominant species also changed in community under the disturbance, of which the dominance of T. ramosissima is significantly increased. Compared with the river channel water disturbance, surface water-overflowing disturbance could enhance seed germination and plant growth through the effect of shallow soil moisture and its physic-chemical properties. And it improved the germination of plant seed in the soil and promoted the clone growth of plant reproductive body. As a result, species diversity was increased and species composition happened significantly changed in Comm. T. ramosissima influenced by the water-overflowing disturbance. In addition, community hierarchical structure was getting more complex. And then, it was concluded that water-overflowing disturbance is an effective way to positively affect the fluctuation of Comm. T. ramosissima in the lower reaches of Tarim River. Thus, it can make up for the insufficient effectiveness of river channel water disturbance to restore damaged vegetation. 相似文献
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The influences of surface water-overflowing disturbance on the fluctuations of Tamarix ramosissima community in Western China 下载免费PDF全文
The main purpose of this study is to examine the fluctuation characteristics of Tamarix ramosissima community from the year of 2007–2008 in desert riparian forest under human surface water-overflowing disturbance in the lower reaches of Tarim River, China. In this paper, community structure, species diversity and dominant species were chosen as the indicators which could reflect the characteristics of community fluctuation. The representative sampling method was used to investigate and measure the fluctuation process of Comm. T. ramosissima. The main results showed that species numbers of the community increased 66.7% under the surface water-overflowing disturbance within two years comparing with it under non-disturbance. The Sorensen similarity coefficient of plant species is 0.75 in community under the disturbance and non-disturbance, indicating that species composition is very similar and main structure of the community has not changed on these two different treatments. Species diversity index of Comm. T. ramosissima changed a lot under the disturbance. Compared with it under non-disturbance, species richness and species diversity have been increasing while species evenness declined slightly under the disturbance. The numbers and kinds of dominant species also changed in community under the disturbance, of which the dominance of T. ramosissima is significantly increased. Compared with the river channel water disturbance, surface water-overflowing disturbance could enhance seed germination and plant growth through the effect of shallow soil moisture and its physic-chemical properties. And it improved the germination of plant seed in the soil and promoted the clone growth of plant reproductive body. As a result, species diversity was increased and species composition happened significantly changed in Comm. T. ramosissima influenced by the water-overflowing disturbance. In addition, community hierarchical structure was getting more complex. And then, it was concluded that water-overflowing disturbance is an effective way to positively affect the fluctuation of Comm. T. ramosissima in the lower reaches of Tarim River. Thus, it can make up for the insufficient effectiveness of river channel water disturbance to restore damaged vegetation. 相似文献
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选择长白山阔叶红松林、白桦林和落叶松林3种林型,对各林型蛾类的群落结构和多样性进行了比较。结果表明:蛾类各科(亚科)在3种林型中的比例分配明显不同。阔叶红松林中尺蛾科数量占优绝对优势,占47.0%,其次是舟蛾科,为9.3%。优势种为台褥尺蛾,占17.2%;从蛾类总种数和蛾类个体总数上看,白桦林中蛾类物种丰富度、多度和多样性指数明显高于阔叶红松林和落叶松林,优势度指数则最低;白桦林的优势种有尘尺蛾、枞灰尺蛾和双星白枝尺蛾;在落叶松林中,灯蛾科、波纹蛾科和枯叶蛾科的多度都比阔叶红松林和白桦林高,其优势种为阿泊波纹蛾。 相似文献
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大青沟森林植物群落物种多样性研究 总被引:45,自引:1,他引:45
大青沟森林植物种类非常丰富,约占内蒙古自治区植物种数的三分之一,生物资源十分丰富。本文分别用Simpson指数、Shannon-Wienner指数和均匀度指数计测生态优势度、不同植物群落的物种多样性、群落物种多度的均匀度。结果表明:由于大青沟森林植物群落属于隐域性植被,从沟底到沟沿,小气候的差异较为明显,存在着生境梯度,但由于乔、灌、草综合作用的影响,各群落类型及生境梯度上的物种多样性的差异不十分明显。这可能是特殊森林群落类型长期适应隐域性生境条件的结果,它为我们改造周边环境提供了有益的启示。 相似文献
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The plant rhizosphere is a dynamic environment in which many parameters may influence the population structure, diversity
and activity of the microbial community. Two important factors determining the structure of microbial community present in
the vicinity of plant roots are plant species and soil type. In the present study we assessed the structure of microbial communities
in response to four plant species (i.e. maize (Zea mays L.), oat (Avena sativa L.), barley (Hordeum vulgare L.) and commercial grass mix) planted in soil with different land use history (i.e. arable land under crop rotation, maize
monoculture and permanent grassland). Both factors, plant species and land use history, showed clear effects on microbial
community and diversity as determined by PCR-DGGE fingerprinting with universal and group-specific bacterial primers. Moreover,
we explored the rhizosphere effect of these plant species on the abundance of bacterial antagonists of the potato pathogen
Rhizoctonia solani AG3. The data showed that the abundance and taxonomic composition of antagonists differed clearly between the different plants.
The highest percentages of antagonists were found in maize and grass rhizosphere. When antagonistic Pseudomonas populations were compared, the highest, abundance and diversity of antagonists were detected in barley and oat rhizospheres,
as compared to maize and grass rhizosphere. The results obtained in our study demonstrate clearly that plant species and soil
type are two important factors affecting the structure of total bacterial, Pseudomonas and Bacillus community. 相似文献
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外生菌根(ECM)真菌可促进宿主植物对土壤中水分和营养的吸收,提高宿主植物的抗逆性及对环境的适应,在森林生态系统的物质循环中发挥了重要作用。为探明寒温带地区ECM真菌多样性和群落组成以及土壤理化因子对真菌群落组成的可能影响机制,采用高通量测序(Illumina Miseq)平台对大兴安岭4种典型森林类型白桦、樟子松、兴安落叶松和偃松的根围土壤ECM真菌群落组成进行了分析。结果表明,4种典型森林类型根围土壤中共获得167个ECM真菌可操作分类单元(OTUs),隶属于2个门、4个纲、10个目、24个科、36个属。在门水平上,担子菌门(Basidiomycota)真菌的相对丰度占96.4%,子囊菌门(Ascomycota)真菌占3.6%。在属水平上,红菇属(Russula,30.2%)、丝膜菌属(Cortinarius,17.1%)、Piloderma(9.6%)、棉革菌属(Tomentella,7.2%)、丝盖伞属(Inocybe,7.2%)和蜡壳耳属(Sebacina,6.2%)的相对丰度均>5.0%,是该地区的优势ECM真菌类群。不同森林类型的优势ECM真菌在属水平上的组成存在显... 相似文献