长白山地区曲尾藓属植物生态分化的排序研究

曲尾藓属(ＤｉｃｒａｎｕｍＨｅｄｗ.)属于顶蒴藓类植物,在长白山地区主要分布于苔原、森林林下和沼泽地中[1,2]。分析曲尾藓属植物对不同生态环境的适应特点和种间生态关系,对揭示该属植物物种分化的生态学机制,有一定学术价值。排序是分析植物群落分布与环境关系的常用方法,以往人们主要是应用ＤＣＡ、ＰＣＡ等方法,因而不同种类与环境关系的解释带有较大的主观性。典范对应分析能够在同一排序图上展示植物种类与环境因子的关系,是当前最有效的排序方法,其结果的生态学解释比较客观。Ｓｌａｃｋ指出应用排序也能够研究植物种间的生态位分…     

东灵山植物群落生活型谱的比较研究

应用由丹麦学者Ｒａｕｎｋｉａｅｒ提出的生活型分类系统,研究了北京东灵山植物群落的生活型,并编制了主要植物群落类型的生活型谱。同时,用主成分分析（ＰＣＡ）作为排序的方法和系统聚类中的离差平方和法与类平均法,对东灵山植物群落的生活型谱进行了排序和分类。并用双重筛选逐步回归的方法分析了环境（气候和土壤）因子与植物群落生活型谱梯度的关系,建立了相应的数学模型。研究结果表明：东灵山地区植物群落生活型谱的特征符合暖温带植物生活型谱的基本特点,地面芽植物占的比例最大。但不同植物群落因所存在的生境有差异,也表现出各自的谱特征。排序的结果与用植物种类成分进行的ＤＣＡ 排序结果吻合度较好,排序的环境梯度特征也十分明显。研究结果还表明：地下芽和中高位芽对于温度梯度的反应比较灵敏;其次是小高位芽和一年生植物;对于水分梯度的变化,则以地上芽和矮高位芽植物的反应比较强烈和敏感。温带植被生活型谱主要特征的地面芽植物在本地区表现稳定,不随各植物群落和水热梯度发生大的波动,显示出地带性的强大约束力。所建立的海拔梯度和群落类型与生活谱的统计数学模型,对于中高位芽、矮高位芽和地下芽植物的相关较好,估测的精度高,而对其它几种生活型的估测较差     

甘南玛曲植物群落的多元分析与环境解释

应用无偏对应分析（ＤＣＡ）及二岐指示种分析（ＴＷＩＮＳＰＡＮ）对玛曲１７８个植物群落样方资料进行了多斐邓和数量分类,并应用植物群落的排序值与环境参数的多元回归分析出各群类型的定量环境解释,探讨了该区植物群的基本类型生态梯度及其与环境因子的定量关系。结果表明,玛曲的植物群落类型及基分布主要取惟地热量和湿度,并可通过环境参数地数字表达式定量地确定。     

DCCA排序轴分类及其在关帝山八水沟植物群落生态梯度分析中的应用

首次在ＤＣＣＡ排序的基础上使用排序轴分类法（ＯＡＣ）,将其发展为一个新的典范分类方法,并应用这种方法对山西关帝山八水沟的植物群落进行了数量分类,共划分出５类,效果较好。方差分析与多重比较表明,环境与群落结构因子在不同群落之间存在较为显著的差异,表明ＤＣＣＡ排序轴分类法能较好地反映群落与环境的变异。因为ＤＣＣＡ排序轴分类同时结合了植被因子与环境因子,所以它能较好地表达植物群落的环境梯度和结构梯度,反     

梯度分析技术用于植物抗旱性的研究

将梯度分析技术引入植物抗旱性的研究,对植物的解剖结构指标进行分析。在ＰＣＡ分析结果的基础,通过引进ＰＣ间的因子ａｊ,梯度分析技术用于植物抗旱性的研究比用于植物群落的研究,其结果更具有观性,明确性,是研究植物抗旱性的一个可行、有效的技术手段。     

冰下水生维管束植物生产力的研究

冰下水生维管束植物生产力的研究刘国才,金天明,崔雅杰（内蒙古哲里木畜牧学院,通辽０２８０００）关键词冰下水生维管束植物,生产力ＳＴＵＤＩＥＳＯＮＰＲＯＤＵＣＴＩＶＩＴＩＥＳＯＦＵＮＤＥＲ－ＩＣＥＶＡＳＣＵＬＡＲＨＹＤＲＯＰＨＹＴＥＳ￥ＬｉｕＧｕｏｃａ...     

四川邛海湖湿地水生维管植物的现状调查

本研究对邛海湖湿地水生维管植物种类及分布状况进行了调查.结果表明,邛海湖湿地现有水生维管束植物77种,隶属于25科50属.其中,蕨类植物5种,隶属2科3属;被子植物72种,隶属23科47属.从植物生态类型和生活型方面来划分,邛海水生维管束植物可分为湖区水生维管植物、河口滩涂植物和湿生植物三种类型.它们主要分布在湖泊的北面、西面和南面.区系分析结果表明,邛海水生维管束植物共有7种分布类型,其中以世界性分布型植物种最多.邛海湿地自然着生的水生植物群落破坏严重,挺水植物以上群落基本消失,浮水植物和沉水植物分布区锐减,分布深度退缩,分布密度减小.针对邛海湿地水生维管束植物存在问题,笔者提出了相应的解决方法和建议.该研究为邛海湿地的恢复和重建提供了理论依据.     

黑龙江流域的水生维管束植物

水体中水生维管束植物的种类粗成及数量的多寡,对于渔业是有着密切关系的。有些主要的经济鱼类(如草鱼、鳊、鲤、鲫等)是以水生维管束植物作主要的食料,也有很多产粘着性卵的鱼类(如鲤、鲫、鲶等)要把卵产在水生植物上;一些高等水生植物的多寡也直接或间接地影响底棲生物和浮游生物的生长繁殖。另一方面,有些高等水生植物的大量繁殖,     

东湖大型围隔及围栏内植物群落和水质的变化

为恢复湖泊水生植被,初步研究了建在武汉东湖的大型围隔、围栏中的植物群落和水质的季节动态以及两者间的关系,结果表明：围隔、围栏中,植物生物量明显增加,漂浮植物易定植,水绵和刚毛藻易发生,植物群落结构难以自然地得到优化;养鱼对水生维管束植物的生长和恢复不利;水中总氮与总磷的变化具一致性,它们与水生植物的生物量间关系密切,围隔中水生植物的良好生长使水的总氮、总磷浓度明显降低     

林区火灾后植物群落与冻土环境的多元分析

本文运用国际较为先进的双向指示种分析(TWINSPAN)多元等级分划分类方法和无趋势对应分析(DCA)排序方法对大兴安岭阿木尔林区1987年特大森林火灾后的植物群落进行了研究。通过排序结果和冻土环境的多元分析,得出：DCA排序轴1代表了土壤岩性与地形的梯度而决定植物群落的分布;DCA排序轴2则反映了森林火烧的程度梯度,并通过冻土融化深度和浅层地温值的变化而影响植物群落的分布,运用相关回归分析方法,定量地找出了它们之间相互关系的回归方程。 据此,进而探讨了该地区森林火灾后冻土环境的变化对植物次生演替方向和进程的影响。     

Primary Study on Interrelation Between Plant Communities and Environmental Factors in the North Shore of Qinghai Lake

Eighteen plant communities were surveyed by quaduats in the north shore of Qinghai Lake. The communities were analyzed using PCA (principal component analysis) ordination and regression procedure to determine the distribution patterns of the plant communities and relationship between the communities and environmental factors. The results showed that the distribution of the plant communities were closely related to the moisture and salt content of soil. The correlation between species diversity or ecological dominance of the communities and gradient of environmental factors was not significant, but the two indexes of community showed multivarient line relationship with the first principal component, or the gradient of soil water, and the regression model as below: Y =- 4.85 4–1.47X1 4- 10.71X2 (P<0. 01).     

清潩河(许昌段)流域生物群落特征及其与环境因子的关系

以清潩河(许昌段)流域为研究对象,通过野外调查和室内测定,对水生植物、河岸带植物和大型底栖动物的群落特征、水体和表层沉积物的环境因子特征进行研究,分析清潩河流域内的生物多样性.结果表明: 流域内共有水生植物12种,河岸带植物66种,大型底栖动物10种.群落间环境因子变异较大,其中,水体的铵氮、总氮、总磷、表层沉积物的氧化还原电位、重金属镉、汞、锌的变异显著.典范对应分析表明: 水体理化性质如化学需氧量、温度、pH、溶解氧、总磷是影响水生植物的关键环境因子;水体氧化还原电位、pH和表层沉积物的镍、汞、有机质、铅、镉是影响河岸带植物分布的关键因子;表层沉积物的pH、温度、氧化还原电位、砷、铅、镍和水体温度是影响大型底栖动物的关键环境因子.清潩河(许昌段)流域水质污染严重,生物群落多样性低,沿河的污水处理及保护与恢复生物类群的工作迫在眉睫.     

广西英罗港红树植物群落的非线性排序

采用主分量分析 (PCA)、无偏主分量 (DPC)和非度量多维调节 (NMDS)等方法对广西英罗港 2 2个红树植物群落样地进行了排序。PCA和 DPC分析结果表明 ,取样数据具有明显的非线性结构。通过 NMDS分析 ,得到二维 NMDS排序格局 ,它能较好地反映了红树植物群落与环境因子之间的相互关系。     

缙云山常绿阔叶林的排序

排序概念由苏联学者拉孟斯基(1930)第一次提出并首先用环境梯度为坐标去排列植物群落。然而,这一方法在60年代电子计算技术的普遍应用和连续性学派(个体学派)兴旺发达起来以后,才迅速发展起来。排序是植物群落样本的一种空间排列,是揭示其空间连续变化的有效技术。至今方法很多,但一般分为两类,一类是用环境因子进行排列,称为直接排序,或称直接梯度分析,或者就叫梯度分析。另一类是用植物群落本身的特征(属性)来排序,称为间接排序,或间接     

塔里木河中下游湿地及周边植物群落与环境因子的关系初探

选取塔里木河中下游湿地及周边16个典型植物群落样地调查和环境因子数据,采用主分量分析(PCA)排序技术和回归分析,定量分析湿地及周边植物群落在空间上的分布格局,以及群落结构特征和环境梯度之间的关系.结果表明,影响塔里木河中下游湿地及周边植物群落分布的第1主分量中,土壤水分和盐分影响最大,贡献率为35.70％;在第2主分量中,土壤养分的影响最大,贡献率为25.97％.植物群落分布的生境可分为沼生轻盐中营养生境、湿生中盐中营养生境、中生中盐低营养生境和中旱生重盐低营养生境4种类型.沿不同生境依次分布着沼泽植被、草甸植被、河岸疏林和盐生荒漠 盐化灌丛植被.塔里木河中下游湿地及周边植物群落的生态优势度与土壤水分和盐分复合梯度呈显著的一元线性相关.二元回归分析结果显示,塔里木河中下游湿地及周边土壤水分和盐分复合梯度与多样性指数和生态优势度二元指标呈极显著相关.     

河西走廊盐化草甸主要植物群落分布特点及其土壤环境特征

 采用系统网格法调查河西走廊盐化草甸典型地段的植被和土壤环境因素,用DCA排序技术进行定量分析,来划分该区植物群落的分布格局,并以土壤环境指标(有机质、全盐含量、pH值、潜水位埋深)解释其所形成的5个样方组,反映出内陆干旱次生盐渍化区土壤水盐分布的差别同潜水位的关系。     

Macrophyte community structure and species occurrence in relation to environmental determinants in the ephemeral aquatic habitats of Gavdos,Greece

The aims of this study were to explore the environmental factors that determine the distribution of plant communities in temporary rock pools and provide a quantitative analysis of vegetation–environment relationships for five study sites on the island of Gavdos, southwest of Crete, Greece. Data from 99 rock pools were collected and analysed using Two-Way Indicator Species Analysis (TWINSPAN), Detrended Correspondence Analysis (DCA) and Canonical Correspondence Analysis (CCA) to identify the principal communities and environmental gradients that are linked to community distribution. A total of 46 species belonging to 21 families were recorded within the study area. The dominant families were Labiatae, Gramineae and Compositae while therophytes and chamaephytes were the most frequent life forms. The samples were classified into six community types using TWINSPAN, which were also corroborated by CCA analysis. The principal gradients for vegetation distribution, identified by CCA, were associated with water storage and water retention ability, as expressed by pool perimeter and water depth. Generalised Additive Models (GAMs) were employed to identify responses of four dominant rock pool species to water depth. The resulting species response curves showed niche differentiation in the cases of Callitriche pulchra and Tillaea vaillantii and revealed competition between Zannichellia pedunculata and Chara vulgaris. The use of classification in combination with ordination techniques resulted in a good discrimination between plant communities. Generalised Additive Models are a powerful tool in investigating species response curves to environmental gradients. The methodology adopted can be employed for improving baseline information on plant community ecology and distribution in Mediterranean ephemeral pools. Handling editor: S. M. Thomaz     

Macrofungal diversity and community ecology in mature and regrowth wet eucalypt forest in Tasmania: A multivariate study

Abstract The biodiversity of macrofungi in mature and young regrowth Tasmanian wet forests is described at the species level and at the community level. The macrofungal communities studied were much more species‐rich than their vascular plant counterparts, with the total number of macrofungal taxa outnumbering vascular plants by four to one. This ratio applied in both mature and young regrowth forest sites. Some 242 taxa of macrofungi were recorded, of which 132 were identified to species level, the remainder to species groups or higher taxa. Distinct communities could be discerned from multivariate analysis (ordination and classification) of vascular plant and macrofungal data from the mature and regrowth sites. The two vascular plant communities had different fire histories, and this difference is also assumed to account for the separation of the macrofungal communities of the two forest types. There was generally a high level of congruence between the vascular plant and the macrofungal communities. However, one young regrowth site, which was relatively close to the mature sites in the ordination space for the analysis of vascular plants, was distant from the mature forest sites for the analysis of macrofungi. Another regrowth site, which had experienced wildfire rather than silvicultural regeneration, clustered with mature sites for some analyses of the macrofungal assemblage. Variation in the macrofungal communities was correlated with a different set of the measured environmental variables than was variation in the vascular plant communities. Mature and young regrowth forests were found to have distinctly different macrofungal floras, with approximately 40% of the taxa in each forest type being restricted to that type of site. Suitable indicator taxa (restricted or preferential to particular forest types) for use in further studies are suggested.     

Can dispersions be used for discriminating water quality status in coastal ecosystems? A case study on biofilm-dwelling microbial eukaryotes

Multivariate dispersions are an effective ecological indicator to evaluate the environmental heterogeneity and human disturbance in global ecological research. To explore the feasibility of the dispersions for assessing water quality status, a dataset of the biofilm-dwelling microbial eukaryote communities was studied in coastal waters of the Yellow Sea, northern China at two numerical resolutions. The community dispersion patterns represented a significant variability in both community structure and species composition in response to environmental heterogeneity. Multivariate approaches revealed that the species composition was the primary contributor to the community dispersion. Mantel analysis showed that the spatial variations in both community structure and species composition were significantly correlated with the changes of the nutrients, pH, dissolved oxygen (DO) and chemical oxygen demand (COD). The dispersion measures at both numerical resolutions were found to be remarkably related to the nutrient ammonium nitrogen and DO. Thus, we suggest that multivariate dispersions of the microbial eukaryote communities may be used as a potential bioindicator of water quality status in marine ecosystems.     

The Ability of Aquatic Macrophytes to Assess Fish Farm Pollution in Two Salmon Rivers

The wastewater from freshwater fish farming is responsible for important water quality modifications in receiving ecosystems. These point source pollution cause local problems for the management of the freshwater environment, especially in salmon rivers. The aim of this paper is to study the relationship between plant communities and environmental factors in two rivers basins on which seven fish farms are located and to assess the relative part of water pollution compared to other environmental factors involved in water plant distribution. The disturbance due to fish farming wastewater increased both richness and diversity of aquatic plant communities and modified the distribution of 11 aquatic macrophytes. Nevertheless, the main factors involved in the aquatic plant distribution in the whole data set were not the location upstream or downstream from one point source pollution but the belonging to one river system and the habitat physical features. Relevant prediction of macrophytic communities is a useful tool for bioindication purposes but several groups of variables that manifest themselves at different spatial levels must be considered.