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1.
山东近海鱼类群落分类多样性   总被引:6,自引:0,他引:6  
李凡  周兴  张岚  任中华  吕振波 《生态学报》2015,35(7):2322-2330
根据相关文献整理了山东近海鱼类名录,并根据1998—2009年山东近海鱼类调查名录,应用平均分类差异指数(Δ+)和分类差异变异指数(Λ+)研究了鱼类分类学多样性特征。结果表明,山东近海鱼类名录包括2纲28目91科169属225种,1998年调查仅2纲11目41科58属62种,2006年调查为1纲13目41科71属78种,2009年调查为1纲9目32科55属62种。1998年—2009年调查鱼类种类远远低于鱼类名录记录的种数,分类阶元包含指数较低,平均每属包含1.1种。根据山东近海鱼类名录计算鱼类平均分类差异指数为66.1,分类差异变异指数为141.7;1998—2009年历次调查鱼类平均分类差异指数在60.9—62.7之间,分类差异变异指数在65.4—92.3之间。将1998—2009年历次调查鱼类群落分类多样性指数计算值叠加到山东近海鱼类总名录的95%置信漏斗曲线图,结果表明大部分调查值在置信漏斗曲线之外,目前山东近海鱼类分类多样性已大幅下降。  相似文献   

2.
Savannas are characterized by a sharp seasonality, in which the water shortage defines the community functioning. Hyperseasonal savannas, however, experience additionally waterlogging in the rainy season. Since waterlogging may cause local extinctions of intolerant species, we asked whether waterlogging constricts the phylogenetic structure of a hyperseasonal savanna. We studied a hyperseasonal cerrado, comparing it with a nearby seasonal cerrado, never waterlogged, in Emas National Park, central Brazil. In each vegetation form, we sampled all vascular plants by placing fifty 1-m2 quadrats in five surveys. We compared the phylogenetic structure of both vegetation forms, calculating their taxonomic distinctness, taxonomic diversity, expected taxonomic distinctness, and species, genus, and family similarities. The taxonomic distinctness of both cerrados was similar and the values of similarities were high, but taxonomic diversity and expected taxonomic distinctness were lower in the hyperseasonal cerrado than in the seasonal one. Assuming that phenotypic attraction is the major process organizing local communities, the waterlogging in hyperseasonal cerrado assembles phylogenetically unrelated species that have converged on similar habitat use. As a consequence, the habitat use of hyperseasonal cerrado species is a trait widespread in the phylogeny of seasonal cerrado. Waterlogging constrains the phylogenetic structure of the hyperseasonal cerrado, especially by reducing species diversity. In more ecological terms, we can only fully assess the phylogenetic structure of a community if we consider the species abundance.  相似文献   

3.
Most ecological diversity indices summarize the information about the relative abundances of species without reflecting taxonomic differences between species. Nevertheless, in environmental conservation practice, data on species abundances are mostly irrelevant and generally unknown. In such cases, to summarize the conservation value of a given site, so‐called ‘taxonomic diversity’ measures can be used. Such measures are based on taxonomic relations among species and ignore species relative abundances. In this paper, bridging the gap between traditional biodiversity measures and taxonomic diversity measures, I introduce a parametric diversity index that combines species relative abundances with their taxonomic distinctiveness. Due to the parametric nature of the proposed index, the contribution of rare and abundant species to each diversity measure is explicit.  相似文献   

4.
Patterns of spatial autocorrelation of biota may reveal much about underlying ecological and biological forces responsible for generating the patterns. Operationally, ecological work and many applied problems (e.g., impact detection, ecosystem health assessment using reference sites) require statistical knowledge of autocorrelation patterns. Here, we report on assemblage-level autocorrelation in the benthic-invertebrate assemblages of riffles in two adjacent, relatively pristine rivers in south-eastern Victoria, Australia (40 km reaches of the Wellington and Wonnangatta rivers). The assemblages of the Wellington River were strongly autocorrelated, but those of the Wonnangatta River showed a distance-independent pattern. There was no effect of taxonomic resolution, rarity protocols or whole-assemblage surrogates on the inferred levels of autocorrelation. We conclude that there is little evidence that one can assume the pattern of spatial relationships among invertebrate faunas within a river, and this probably holds true for the usual set of taxonomic resolutions and subsets used to discern changes wrought by human impacts.  相似文献   

5.
二月兰形态性状的变异分析   总被引:10,自引:0,他引:10  
二月兰(Orychophragmus violaceus)是集食用、保健、饲用和观赏于一身的优良地被植物。其遗传背景单一、生长周期短,是发展模式植物的优良材料。为了开发其育种价值,我们对二月兰的形态变异式样进行了初步分析。共选取了北京和南京地区的7个居群的34个表型性状进行观测。通过计算分析发现:株高、茎和花序分枝等性状受环境影响较大,因而其分类价值不大;叶形、毛被、叶缘锯齿等性状的变异在居群内是连续的,所以也不是可靠的分类性状;而花部性状的一些变异,包括花瓣的颜色、大小、形态,基本不受环境影响,且这些变异在居群内是不连续的,所以其分类价值相对较高。对17个数值性状的方差分析和多重比较结果表明,在同一年度内,大部分性状在不同地区间差异不显著,在居群间差异极显著;而在不同年度内,居群间差异不显著。最后,对7个居群和30个表型性状进行了数量分类:Q分析表明北京颐和园、南京紫金山山顶公园和南京中山植物园居群比较相似,而北京圆明园、北京海淀区后八家苗圃、南京情侣园和北京天坛公园居群较相似。R分析揭示了二月兰花部、叶部、反映植株毛被和颜色以及表现植株生长量的性状间均具有一定的相关性。这些研究可为种下等级的划分和进一步的遗传研究以及品种培育提供一定的参数资料。  相似文献   

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以厦门湾为研究区域,收集2014—2015年大型底栖动物的调查数据,计算了大型底栖动物的分类学多样性指数,分析了分类学多样性指数与传统生物多样性指数的相关性和依从性,并从多个角度探讨大型底栖动物的分类充分性。结果表明,厦门湾大型底栖动物分类多样性指数(Δ)介于6.04—83.71之间,平均值为68.26,站位分布不均匀;分类差异性指数(Δ~*)介于74.27—99.54之间,平均值为84.23;平均分类差异指数(Δ~+)、分类差异变异指数(Λ~+)的理论平均值分别为86.82、345.0,个别站位落在95%置信区间外,表明局部区域环境受到了一定程度扰动。Δ、Δ~*与Margalef指数、Pielou均匀度指数、Shannon-Wiener指数、Simpson指数呈显著相关,而Δ~+、Λ~+与传统多样性指数间无显著相关;分类学多样性指数可作为传统生物多样性指数的补充。种级、属级和科级的同一多样性指数间呈显著线性相关,拟合度较高(多数R2﹥0.9);根据三个分类水平站位的nMDS二维排序图、2-STAGE的相似性和聚类图,种级、属级和科级的群落结构一致性强,属级较种级丢失的信息约8%、科级为20%,因此在条件有限的情况下,大型底栖动物的监测与评价可根据实际的条件和需求适当将生物鉴定放宽至属水平。  相似文献   

8.
9.
Two dates of publication have been associated with the hidden angelshark Squatina occulta. Additionally, the name of the second author of this species has been cited with different spellings in different publications. Both inconsistencies are addressed in this study. It is suggested that the hidden angelshark be consistently cited as Squatina occulta Vooren & da Silva 1991.  相似文献   

10.
Biological knowledge can be inferred from three major levels of information: molecules, organisms and ecologies. Bioinformatics is an established field that has made significant advances in the development of systems and techniques to organize contemporary molecular data; biodiversity informatics is an emerging discipline that strives to develop methods to organize knowledge at the organismal level extending back to the earliest dates of recorded natural history. Furthermore, while bioinformatics studies generally focus on detailed examinations of key 'model' organisms, biodiversity informatics aims to develop over-arching hypotheses that span the entire tree of life. Biodiversity informatics is presented here as a discipline that unifies biological information from a range of contemporary and historical sources across the spectrum of life using organisms as the linking thread. The present review primarily focuses on the use of organism names as a universal metadata element to link and integrate biodiversity data across a range of data sources.  相似文献   

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13.
SEALY, J. R, 1983. A revision of the genus Nomocharis Franchet. A taxonomic revision of the genus Nomocharis Franchet is presented, recognizing seven species. Notes are given on the species and hybrids in cultivation. A key for identification of the species and an index to specific epithets, including synonyms, are given, together with species excluded from the genus. Herbarium specimens are cited.  相似文献   

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15.
蜱类分类系统的变更   总被引:1,自引:0,他引:1  
陈泽  杨晓军  刘敬泽 《昆虫知识》2009,46(2):323-326
随着分子生物学技术在蜱类研究中的应用,及对蜱类系统发生的深入研究,蜱的分类及命名发生了很大变更。而中国在这一领域的研究还停留在20世纪90年代,分类系统过时。文章对中国曾经采用的蜱类分类系统与现今世界上普遍认可的分类系统进行了详细比较,以期引起注意,从而促进蜱类系统学及其他研究领域的发展。  相似文献   

16.
一个植物分类数据库   总被引:4,自引:0,他引:4  
汪庆  凌萍萍   《广西植物》1998,18(4):357-362
本文介绍了一个苔藓植物分类数据库的设计及其结构,是使用VisualBasic40,以中国苔藓植物的标本,学名,分布,文献,分类性状等为基本资料,以打印标签、名录、文献索引,构成分类性状的原始数据矩阵,并与数量分类程序,以及DELTA,PAUP和CLUSTAN等应用程序的连结为目标进行开发的。其基本构想是在这样一个框架之下,逐渐积累中国苔藓植物的基本资料,能够完成大部分的标本室和分类学工作,并在使用过程中进一步扩展和完善其结构和功能,从而为中国苔藓植物的研究提供极大的便利。  相似文献   

17.
Livestock grazing has been considered to be one of the major causes for biodiversity degradation worldwide. In this study, we examined this effect on Afromontane grassland birds by comparing their diversity between ungrazed and grazed grassland sites in the northern Bale Mountains, Ethiopia. We counted birds and recorded vegetation height and cover along 28 (14 in each land‐use type) 1 km transects. We used six different diversity measures (richness, evenness, Shannon diversity, taxonomic diversity and taxonomic distinctness) to express bird diversity and explored which of these measures better reveal the diversity pattern. Vegetation structure differed significantly between the two sites; the first two principal components accounted for 78% of the variation. Discriminant function analysis (DFA) showed bird diversity to differ significantly between the two sites; taxonomic diversity (Delta) contributed the most to the difference between the two sites, while species richness contributed the least. The results of ANOVA indicated that all diversity measures, except species richness, were significantly higher in the protected site compared to the unprotected site. In general, this study showed that grazing had negatively affected bird diversity in the study area and the use of taxonomic diversity measures had enabled us to reveal the impact better.  相似文献   

18.
Aim To compare patterns and drivers of freshwater fish introductions across five climatically similar regions and evaluate similarities and differences in the non‐native species introduced. Location Five mediterranean‐climate regions: California (USA), central Chile, south‐western Australia, the Iberian peninsula (Spain and Portugal) and the south‐western Cape (South Africa). Methods Species presence–absence for native and non‐native fishes were collated across the regions, and patterns of faunal change were examined using univariate and multivariate statistical approaches. Taxonomic patterns in freshwater fish introductions were evaluated by comparing the number of species introduced by order to the numbers expected from binomial probabilities. Factors influencing multiple introductions of freshwater fish species in mediterranean regions were determined using generalized linear modelling. Results High levels of endemism (70–90%) were revealed for south‐western Cape, south‐western Australia and Chile. Despite their high rates of endemism, all regions currently have more non‐native species than endemic species. Taxonomic selection was found for five orders, although this was only significant for Salmoniformes across regions. The average increase in regional compositional similarity of fish faunas resulting from non‐native fish introductions was 8.0%. Important factors predicting multiple introductions of a species include previous introduction success and mean latitude of its distribution Main conclusions The mediterranean‐climate regions of the world, separated by vast distances, originally had a few fish species in common but are now more similar, owing to species introductions, illustrating the extent and importance of taxonomic homogenization. Introductions are largely driven by taxonomically biased human interests in recreational fisheries, aquaculture and ornamental pet species.  相似文献   

19.
徐剑 《四川动物》2005,24(3):337-339
根据外部形态、核型以技精子形态等特征,角蟾科分布于中国的角蟾属(Megophrys)较之拟髭蟾属(Leptobrachium)是更为原始的类群,角蟾科动物中拟角蟾属(Ophryophryne)与角蟾属亲缘关系较近,短腿蟾属(Brachytarsophrys)是较为原始的类群,且应为一无效属,无耳蟾属(Atympanophrys)应为一有效属。角蟾属可以分为两个种组,其是峨嵋角蟾种组比较进化,白颌大角蟾种组比较原始。  相似文献   

20.
蒙古口蘑分类地位研究   总被引:1,自引:0,他引:1  
董冬  图力古尔 《菌物研究》2013,11(3):172-175
利用LSU序列分析技术研究蒙古口蘑分类地位,用最大简约法和最大似然法构建系统发育树。结果表明:蒙古口蘑形成一独立分支,与白蘑属Trciholoma亲缘关系较远,蒙古口蘑应从Trciholoma属中划分出来,放入新属———白丽蘑属(新拟)Leucocalocybe,并命名为蒙古白丽蘑(新拟)Leucocalocybe mongolicum(Imai)X.D.Yu&Y.J.Yao。  相似文献   

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