北京东灵山地区植物群落多样性研究

友样带法研究了北京东灵山地区落叶阔叶林物种组成随海拔梯度表现出的变化格局。通过变换分割样带的尺度,考察了环境的中变化对群落主要组成物种的分布及优势程度的影响。东灵山落叶阔叶林优势各辽东五角枫几乎遍布整个样带,其它伴生乔木对种表现出明显的分布替代格局,以占据率和单种率考察了尺度地群落特征分析的影响。本区落叶阔叶林１ｍ样带了佳分割尺度为：乔木层４０ｍ,更新层８０ｍ、灌木层２０ｍ。样带法在研究植物群落随     

北京东灵山地区植物群落为多样性的研究

选用描述种种－我度关系的 共８个模型（对数级数分布ＬＳ、对数正态分布ＬＮ、负二项分布ＮＢ和几何分布ＧＯＭ以及“分割线段”模型ＢＳＭ、天府闰优先占邻模型ＮＰＭ、Ｚｉｐｆ模型ＺＭ和和Ｚｉｐｆ－Ｍａｎｄｅｌｂｒｏｔ模型ＺＭＭ）对东灵山地区９个类型的森林群落进行了研究。结果表明,ＬＳ和ＮＢ对大多数群落可以很好地拟合,ＬＮ和ＧＯＭ对第五个群落都不能很好地拟合;ＺＭＭ可以很好地、ＮＰＭ也可以较好地拟合第一个群     

呼伦贝尔草原植物群落空间格局及其环境解释

草地不同植物群落的空间分布结构及群落内部的物种组成结构的研究,一直是草原植物群落生态学最核心的问题之一。在2006年野外实地采样的基础上,运用DCCA除趋势典范对应分析(detrended canonical correspondence analysis)对影响呼伦贝尔草原植物群落结构的地形和土壤环境因素进行了定量的分解。结果表明:纯土壤环境因子可以解释的物种多度变化为12.48%,纯地形因子可以解释的物种多度变化为8.34%,两者耦合的部分为4.76%,不可解释的部分为74.42%。地形因子通过影响水热组合的再分配,对群落结构起起较大作用。在诸多因子中,土壤总氮、有效钾、有效氮、有效磷、有机质以及坡形决定了群落小生境的变化,导致群落类型分布的梯度变化。     

北京东灵山地区植物群落多样性的研究

利用盖度和重要值两个多度指标对北京东灵山地区小龙门林场的５个植物群落进行了研究,以考察样本大小对多样性测度的影响,并设计了３处方法来确定临界样方数量（即多样必否则测度趋于稳定时的样方数量）。结果表明,用盖度和重要值作为多度指标进行植物群落多样性的研究是合适的,并且得出的结果也是一致的;当取比例因子ｋ１＝０．２时,计算临界样方数量的第二种方法与直观判断比较吻合;丰富度指数不太稳定,临界样方数量在２０     

不同复垦方式煤矿排土场植物群落与土壤因子的关系

选取6个样地,采用协同样方法采样,对内蒙古黑岱沟露天煤矿排土场与原始植被地的植物及土壤因子进行对比研究。结果表明:(1)通过TWINSPAN划分法得到8个植物群落,经DCA法分析核实,与TWINSPAN划分结果一致。(2)油松+蒙古冰草复垦模式比新疆杨+紫花苜蓿复垦模式生态适应性差,紫花苜蓿丧失优势种的地位而被拂子茅取代。(3)剔除频度小于5%,获得228×74的样方-物种原始数据矩阵,对11个环境因子测定,采取\"前向选择\"和\"Monte Carlo检验\"确定了7个代理变量,形成228×7的样方-环境因子数据矩阵,经DCCA分析群落分布、格局及组成主要受土壤有机质(第1轴)、土壤密度(第2轴)两因子影响;第1轴特征值0.895,贡献率58.7%,沿着第1轴群落依次从类型Ⅷ、Ⅶ、Ⅴ、Ⅲ、Ⅳ、Ⅱ、Ⅰ土壤有机质逐渐变大;第2轴特征值0.356,贡献率17.4%,沿着第2轴,群落Ⅰ、Ⅱ、Ⅴ、Ⅶ土壤密度依次变小。(4)排土场群落物种组成较原始群落简单,现有群落既未向复垦设计的方向发展,也未向原始植被方向演化。     

深圳湾浮游植物群落结构特征及其与环境因子的关系

为研究深圳湾海域浮游植物的群落结构及其与水环境的关系,分别于春夏秋冬(2013年8月至2014年4月)四个季度对深圳湾进行采样分析,并对调查区域内的浮游植物及其主要环境因子进行了相关性分析.结果表明,深圳湾海域共鉴定出浮游植物111种(包括变种和变型):硅藻35属86种,甲藻4属15种,绿藻6属6种,蓝藻3属4种,其中...     

采煤塌陷区不同地貌类型植物群落多样性变化及其与土壤理化性质的关系

通过对神府-东胜矿区2种不同地貌类型下沉陷样地及对照样地地表植被进行调查,研究不同地貌类型、不同沉陷位置的群落多样性变化及其与土壤理化性质的关系。研究结果表明:(1)哈拉沟矿区(黄土丘陵地貌)植物种类较丰富,大柳塔矿区(风沙地貌)植被种类较单一;达乌里胡枝子作为风沙地貌沉陷区指示物种,其演替机制符合忍耐作用理论,紫翅猪毛菜作为黄土丘陵沟壑地貌沉陷区指示物种,其演替机制是促进理论和竞争共同作用的结果。(2)沉陷干扰12a后,2个研究区Shannon-Wiener指数分别增加了54.60%,73.85%,风沙地貌研究区土壤含水量和脲酶活性分别增加了8.64%和57.14%,黄土丘陵沟壑地貌研究区土壤有机质增加了47.73%。(3)采煤塌陷后,风沙地貌矿区坡中位置过氧化氢酶活性下降63.50%,土壤体积含水量降低58.70%,植物群落多样性显著降低;坡底位置土壤含水量、土壤养分、植物群落多样性均显著提高,土壤理化性质和植物群落多样性变化协同一致。(4)风沙地貌区植物群落多样性与土壤含水量存在显著正相关关系,黄土丘陵沟壑地貌区植物群落多样性与土壤有机质含量存在显著负相关关系。     

浙江天童常绿阔叶林土壤的空间异质性及其与地形的关系

运用地统计学方法,分析了浙江天童常绿阔叶林土壤pH值、全碳、全氮和全磷的空间异质性及分布格局,并基于RDA排序和偏回归方法定量评价了海拔、凹凸度和坡度等地形因子对土壤性质的影响程度.结果表明:常绿阔叶林土壤的pH值、全碳、全氮和全磷的变异系数分别为5.18％、42.98％、36.55％和46.27％;土壤性质的空间自相关范围为81.6～54.5 m,pH值、全碳和全氮呈中等程度的空间自相关,而全磷存在强烈的空间自相关;pH值、全碳和全氮均呈零星斑块状空间分布,全磷则呈条带状分布;地形因子中,pH值和全磷受凹凸度的影响最大,为负相关,凹凸度能单独解释pH值和全磷空间变异的21.24％和14.62％;全碳和全氮受海拔影响最大,呈正相关,海拔能单独解释金碳和全氮空间变异的10.54％和10.60％.不同地形因子对土壤性质各指标空间变异的影响程度存在差异,与本地区酸性降雨分配及局地土壤水分含量和气温受地形的影响有关.     

渭河平原地区夏季鸟类群落结构

在渭河平原咸阳地区选取有代表性的7种生境,采用样带法取样,选用Shannon-Wiener、Pielou指数和多元变量分析法进行鸟类群落结构分析。共发现63种鸟类,隶属于13目29属47科。7个样区的鸟类组成表明水域面积是影响特定鸟类（水鸟）分布的重要因子。α多样性指数和干扰程度呈线性关系（Y=2.945-0.352X)。而中等偏上的均匀度表明不同样区种群的分布较为均匀。进一步对鸟类群落结构进行聚类分析、多维尺度分析以及主分量分析后表明：按照人为干扰程度的大小将7个样区划分为3－4个群落组合;多维尺度分析的结果比聚类分析的结果更接近实际情况;在人为干扰的前提下,类似生境（相同高程或相近水域面积）鸟类群落的相似性程度并不高。     

秋、冬季北部湾浮游介形类群落多元分析

根据对北部湾生态环境综合调查所采集的浮游动物样品,对北部湾秋、冬季浮游介形类组成及群落结构进行了多元分析.结果表明,测区内浮游介形类种类为11种,分属于低盐暖水类群、广温广盐类群和高温高盐类群3个生态类群;海区内的平均丰度较低,其中针刺真浮萤数量最多,为海区的绝对优势种,左右着整个北部湾浮游介形类的数量.聚类分析和MDS分析表明,北部湾浮游介形类为一个结构相对稳定的群落,秋、冬季可看成是一个群落的2个亚群;对各聚类组的丰度与水温、盐度相关分析表明,水温、盐度对浮游介形类群落结构变化所产生的作用较小,但存在一定的规律性;在冬季,底层温盐对群落Ⅱ产生显著影响.     

Bacterioplankton community structure in a eutrophic lake in relation to water chemistry

Bacteria are thought to be closely involved in the biogeochemical cycling of the nutrient elements in freshwater ecosystems. In contrast, little is known about the relationship between the bacterial community structure and the environmental factors. In order to investigate the spatial variety of bacteriplankton community structure in Lake Xuanwu (Nanjing, China) and the effects of water quality on the microbial community composition, denaturing gradient gel electrophoresis (DGGE) and multivariate statistical analysis were carried out. Eight major factors of water quality such as total organic carbon, ammonium, nitrate, nitrite, total nitrogen, total phosphorus, dissolved oxygen and pH were measured in eight different samples. The significant differences of water characteristics among different sites were revealed by principal component analysis. Results of multidimensional scaling analysis demonstrated that lake water quality played a crucial role in bacterioplankton community composition. Canonical correspondence analysis was carried out to infer the relationship between environmental variables and bacterial community structure. An influence of total nitrogen, ammonium and pH on the bacterial community was observed. The sequencing analysis results of excised DGGE bands revealed that Bacteroidetes and Proteobacteria were the dominant bacterial groups in Lake Xuanwu.     

生态位理论研究中的数学方法

各种不同的生态位参数测定公式,从不同的侧面揭示物种之间及物种的个体之间的结构关系;多元统计方法的引用,为H-生态位的分析提供了合适的数学模型;运用集合论方法研究群落生态位,为深入探讨群落中物种间的竞争、共存及互作机制提供更多的信息。     

张家口土壤蜘蛛群落结构及多样性研究

1996年8月中旬,在张家口地区4种生境中共捕获土壤蜘蛛461头,隶属于12科54种(属)。研究表明:4种生境中的土壤蜘蛛群落相似性很小,群落结构组成不同,丰富度、多样性指数、均匀度、优势度也不同。植被类型、疏密程度是影响群落结构的主要生态因子,农事活动是另一个重要影响因素。     

Community–habitat relationships in coastal streams in Big Sur, California, USA: travertine influences macroinvertebrate abundance and community structure

Travertine deposition occurs in streams worldwide but its effects on stream communities are poorly understood. I sampled benthic macroinvertebrates, periphyton, and reach-scale environmental variables in coastal streams in Big Sur, central California, USA, to determine the specific effects of travertine that occurred at some sites as well as to provide a broader assessment of community–habitat relationships. Total density and biomass of macroinvertebrates varied 6- and 9-fold across sites, respectively, and chlorophyll a concentrations varied 10-fold, but invertebrate and periphyton abundances were not correlated. Baetis tricaudatus (Ephemeroptera), Simuliidae (Diptera), and Chironomidae (Diptera) dominated macroinvertebrate communities across all sites, although differences in the relative abundances of these and other taxa produced moderate variation in community structure among sites (Bray-Curtis similarity coefficients of 47–84). Variation in community structure was related to a number of habitat features, notably travertine but also including variables reflecting channel morphology, flow, substrate size, and riparian tree type. Median density and biomass of macroinvertebrates were more than twice as high at sites without travertine than sites with travertine. Taxa richness also was higher at sites without travertine, and community structure differed moderately between sites with and without travertine, although there were no particular assemblages associated with either group. Non-metric multidimensional scaling (MDS) and cluster analysis of similarities in community structure appeared to separate sites with either travertine or high fines from sites without those conditions. These results demonstrate that travertine can have strong effects on stream communities, and additional studies are needed to identify the full range of effects on ecosystems and to evaluate the potential consequences of travertine for conservation efforts such as biomonitoring programs and threatened species management. Handling editor: R. Bailey     

First Results of Definition and Reduction of Characteristics and Discrimination in Multivariable Psychophysiological Investigations

In this paper, the statistical analysis of the comprehensive data obtained from multivariable dynamic (psychophysiological) tests by means of a hybrid computing system and the results obtained are represented. Focal point is the establishment of a set of characteristics according to pertinent and statistical aspects as well as the application of the multivariate variance and discrimination analysis to this set of characteristics for the classification of given “reaction types” (RT). The discriminations carried out for the classes made visible the differences between them clearly. The physiological and possible pathophysiological significance of the results cannot be dealt with in this paper.     

Vertical distribution of bacterial community structure in the sediments of two eutrophic lakes revealed by denaturing gradient gel electrophoresis (DGGE) and multivariate analysis techniques

Vertical distribution of bacterial community structure was investigated in the sediments of two eutrophic lakes of China, Lake Taihu and Lake Xuanwu. Profiles of bacterial communities were generated using a molecular fingerprinting technique, denaturing gradient gel electrophoresis (DGGE) followed by DNA sequence analysis, and the results were interpreted with multivariate statistical analysis. To assess changes in the genetic diversity of bacterial communities with changing depth, DGGE banding patterns were analysed by cluster analysis. Distinct clusters were recognized in different sampling stations of Lake Taihu. Canonical correspondence analysis (CCA) was carried out to infer the relationship between environmental variables and bacterial community structure. DGGE samples collected at the same sampling site clustered together in both lakes. Total phosphorus, organic matter and pH were considered to be the key factors driving the changes in bacterial community composition.     

北京西郊农田土壤螨类的群落结构及施用农药的影响

北京西郊韩家川的试验农田主要分为非施药农田和溴氢菊酯喷洒农田两类,经过两年的调查研究,共获得土壤螨标本9948只,分属于4亚目39属。通过对土壤螨类在不同环境下的密度、频率、多样性指标的测定及F测验,得出溴氢菊酯对土壤螨类群落结构影响甚微,在土壤中易于分解,不致出现污染问题。