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1.
武汉东湖的浮游绿藻、甲藻和隐藻   总被引:4,自引:1,他引:3  
1981年9月至1982年8月间,每月定期从东湖的2个采集点,共采得24号东湖标本。经鉴定有绿藻门、甲藻门、隐藻门藻类共91种(包括变种、变型),其中有1个新种,1个新变型,以及11个种,1个变种和3个变型为我国的新记录。在鉴定的这些种类中,有12种是有机质丰富的、水体中常见的种类,占整个绿藻种数的14%。一年内各个月中多次出现的种类,在有机质丰富的水体中,常见的种类就占将近半数。鼓藻种类和数量很少。优势种类主要以蓝藻为主,这些特点都说明与东湖的富营养化有密切的关系。  相似文献   

2.
鄂西地区裸藻的初步研究   总被引:3,自引:1,他引:2  
在鄂西的五峰、宜都、宜昌、当阳及神农架林区一带,采集到裸藻门植物16属140种(包括变种和变型)。属于绿色裸藻类的有116种,无色裸藻类的有24种,其中有5个新种,7个新变种,3个新变型,有20种是我国新记录。在采集区域内的地形大体上可以分成三种不同的类型,即:山岳地区(采得裸藻5种),河谷盆地地区(采得裸藻40种)和沿长江丘陵地区(采得裸藻128种)。静止水体由于地形的差异,体积的大小和水质的肥沃程度不同,都对裸藻门植物的生长有重要的影响。    相似文献   

3.
新足螨属是一个不大的属,主要分布于热带和亚热带地区。个别种类可在温带地区找到。至今全世界共报道22个种和变种。其中分布在亚洲的最多,约占总数的一半,计12个种;非洲次之,有6个种和1个变种;欧洲最少,仅有3个种。在我国记载过的有两个种,即N.emodioides Krantz(西藏)和N.vanderhammeni Krantz(福建)。本文根据1974年在云南采得的材料记述一个新种和一个新纪录。至此,新足螨属已知的种类共有23个种和变种,而在我国已记录的共4种。  相似文献   

4.
广西蕨类植物区系的基本特征   总被引:8,自引:0,他引:8  
周厚高  黎桦  周琼  谢义林 《广西植物》2004,24(4):311-316
对广西蕨类植物区系的组成、特征、区系地理成分作了详细阐述。该蕨类区系十分丰富 ,现已发现 5 6科、1 5 8属、85 4种 (变种、变型 )。区系地理成分复杂 ,属划分为 1 4种类型 (变型 ) ,种划分为 1 8种类型 (变型 )。文中对该区系的性质进行了探讨 ,认为该区系是热带向亚热带过渡的植物区系 ,南部具有热带性质 ,北部具有亚热带性质 ,中部是过渡区  相似文献   

5.
新足螨属Neopodocinum系Oudemans于1902年建立的,迄今属中共有25个种和亚种。虽然模式种标本采自荷兰,但本属种类大多分布于热带和亚热带,以亚洲的种类为最多,计14种。它们常附着于粪食性金龟类甲虫体上,也可采自小型哺乳类体上及其巢穴中。1983年冬在云南的蜣螂体上又采得一种新足螨,经鉴定系未曾描述过的种类,订  相似文献   

6.
乌江河岸带维管植物区系的初步研究   总被引:1,自引:0,他引:1  
对乌江河岸带维管植物区系的研究结果表明,河岸带共有维管植物69科187属302种,其中蕨类植物9科10属16种,裸子植物1科1属1种,被子植物59科176属285种。生活型以草本为主,其次是灌木。科、属、种的分布区类型多样,在科级水平上有7个类型和4个变型,在属级水平上有13个类型和10个变型,在种级水平上有15个类型和13个变型。地理联系较为广泛,与北温带植物区系联系最为紧密,其次是泛热带植物区系和东亚植物区系。科、属的优势现象较为明显。该河岸带植物区系呈亚热带性质,与热带植物区系有较高的亲缘关系。  相似文献   

7.
四川裸子植物区系研究   总被引:10,自引:0,他引:10  
李仁伟  张宏达 《广西植物》2001,21(3):215-222
四川裸子植物 9科 2 8属 1 0 1种 (含变种 ) ,区系成分为亚热带类型。东部地区古地理环境温和稳定 ,至今保存着许多珍稀孑遗的类群 ;西部地区古地理环境变化频繁 ,科、属少而种类丰富。东、西部差异明显。松柏类在这一地区十分突出 ,集中了从原始到进化的几乎各个类群的代表。四川裸子植物区系既不是泛北极区系迁移的产物 ,也不是热带区系的后裔 ,而是在二叠纪以来的地质历史发展过程中本地起源和发展起来的。  相似文献   

8.
武汉东湖浮游藻类物种多样性的研究   总被引:35,自引:7,他引:28  
从 1994年 1月至 1996年 12月 ,每月定期从东湖四个常规采样站采集浮游藻类标本进行研究。经鉴定共发现 2 6 0个分类单位 ,隶属于 7个门的 99个属 ,其中有 2种为中国新记录。以 1995年浮游藻类的群落结构进行分析的结果是 :浮游藻类的种类数以绿藻门最多 ,硅藻门次之 ;各站基本上均以夏季种类最多 ,其次为秋季和春季 ,冬季最低 ;四个站中分布的种类差异不明显 ,各站都出现的种类数占全部种类数的 39.6 % ;不同的站或同一个站在不同的季节其优势类群亦不同。计算了与水体营养类型有关的浮游藻类群落的两种指标—多样性指数和硅藻商。对东湖浮游藻类群落结构的特征及变化与水质的关系进行了探讨 ,从浮游藻类群落的演替指出东湖的富营养化程度自2 0世纪 5 0年代以来一直在加剧。  相似文献   

9.
云南哀牢山国家级自然保护区蕨类植物生态地理研究   总被引:2,自引:0,他引:2  
报道了哀牢山国家级自然保护区蕨类区系有蕨类植物48科、118属、446种(包括变种和变型)。从蕨类植物的垂直分布、东西分布和生态类型的划分等几个方面对哀牢山国家级自然保护区蕨类植物生态进行探讨并得出以下结论:(1)在海拔分布上,蕨类植物有着与不同植被相关的生态适应性,2000~2800 m的中山湿性常绿阔叶林和山顶苔藓矮林地带蕨类植物种类最为丰富,附生蕨类植物占到了该海拔地带蕨类植物总种数的28.5%;(2)东坡有蕨类植物387种,西坡则只有355种,东西坡共有种达295种;(3)哀牢山国家级自然保护区蕨类植物可划分为16个生态类型,本区明显地以阴生植物、亚高温植物和中生植物居多,附生植物种类所占比例大,旱生植物和石生植物种类少等为主要生态特征。哀牢山国家级自然保护区蕨类植物的温度生态类型以亚热带植物种类为主,温带植物和寒温带植物少。  相似文献   

10.
初步探讨了广东阳春鹅凰嶂自然保护区蕨类植物区系的地理特点,结果表明:本区有蕨类植物134种(包括变种与变型),隶属于38科72属,优势成分以水龙骨科、金星蕨科、鳞毛蕨科等系统演化上较高级的类群为主。区系单种属较多,起源古老,地理成分复杂,但热带、亚热带成分占主导地位。这些区系特征与本区古老的地质和优越的水热条件密切相关。  相似文献   

11.
A total of 48 algae samples were collected from southern bays of the Donghu Lake from September in 1963 to December in 1964.The desmids were very plentiful,164 species,75 varieties and 13 forms belonging to 20 genera were identified.Among these,two species,seven varieties and two forms are new to science**,and 12 species,25 varieties and five forms are recorded for the first time in China.The dominant species with frequent occurrence were 11 species and one variety in four seasons. The result of counting and analysing the samples collected in different seasons (six times for each) shows that the number of the taxa of Desmids in summer (June and August)was the highest,that in autumn and winter (September,October and December) the next,and that in spring (April) is the lowest.Fourty five of 252 desmids taxa are tropical and subtropical,among which 19 are either endemic to or common in S and SE Asia. The desmid flora of Wuhan district is therefore subtropical in nature and closely related to the S and  相似文献   

12.
About one hundred genera with more than 300 species have been identified in water samples, net haul material, periphyton samples from artificial substrate, and benthos and sediment samples collected during 1969–1972. More than 40 taxa of lower rank (subspecies, varieties, forms) were recorded. The most prominent algal groups were diatoms with 138 taxa, and green algae with 122 taxa of which the majority was desmids. The material from the epipelic and epilithic communities in the lake is very scarce, while the list of plankton species is relatively complete, with the exception that a large number of small flagellates could not be identified to species level. The taxa which were identified, are presented in a list with additional notes on occurrence.  相似文献   

13.
79 taxa of desmids belongig to 17 genera were observed in 17 samples collected from several parts in Basrah district, South Iraq. 3 genera viz. Actinotaenium, Docidium and Spondylosum, and 41 taxa are new records for Iraqi waters. Distribution of taxa in the area studied as well as in the whole country (when available) are given. Some slight morphological variations in desmids were observed due to the alkaline nature of water.  相似文献   

14.
Studies on coccolithophorids in Mexico are rather scarce, probably due to the use of traditional methods for studying marine phytoplankton (e.g. collection, preservation and analysis). This is the first study of the coccolithophorid flora from west coast of Baja California, Mexico. Bottle samples (4 l) were taken at various depths (5, 25 and 50 m), at fixed stations located on perpendicular transects along the west coast of Baja California, considering three different zones: North, Central and South. A total of 32 samples were studied by optical and scanning electron microscopy, yielding 24 taxa identified (17 species and 5 nominal varieties, plus 2 different varieties). The coccolithophorid assemblages are considered subtropical and coastal (with many cosmopolitan taxa). Emiliania huxleyi and Gephyrocapsa oceanica were the most abundant (relative abundance) and widespread species in the study area. We report 15 new records for the Mexican Pacific. The zonal and vertical distribution of some taxa are briefly discussed, as well as the taxonomy of Rhabdosphaera claviger, Helicosphaera carteri, H. hyalina and related taxa.  相似文献   

15.
朱华   《广西植物》1995,(4):307-318
本文研究了中国产粗叶本属植物30种4亚种和7变种的地理分布,划分出三个分布区类型,十二个变型和四个亚变型。根据种多度和分布特征,中国粗叶本属植物在分布上表现出与中国的热带雨林、季雨林区,南亚热带常绿阔叶林带和中亚热带常绿阔叶林带相匹配的分布规律,并受几条植物地理界线的作用。通过对地理替代类群和一些特殊分布式样的分析,显示了所谓的“田中线”和一条北起四川峨眉向南经贵州西南部至广西西部的界线对粗叶木种的分布,特别是对中国-喜马拉雅和中国-日本替代分布具有明显的作用。这导致笔者认为“田中线”作为中国-日本分布的西界而另一第线作为中国-喜马拉雅分布的东界。进一步的分析还揭示由云南南部沿缅甸、泰国向南延伸的横断山余脉既充做一条植物南-北迁移的通道又是一条中南半岛西部(印-缅)与东部(印度支那-华南)的植物地理界线。  相似文献   

16.
广西特有植物的研究(续完)   总被引:2,自引:1,他引:1  
陆益新  黄广宾  梁畴芬   《广西植物》1989,(3):201-210
<正> 二、广西特有植物区系的特征和地理分布 (一)广西特有植物的科、属、种构成 就迄今我们收集到的资料,广西有维管束植物7217种(包括种下等级),隶属于288科,1778属。其中特有属10个,它们是:辛木属(Sinia,含1种,金莲木科),异裂菊属(Heteroplexis,含3种,菊科),和属于苦苣苔科的单卒苣苔属(Metebriggsia,含2种),圆果苣苔属(Gyrogyne,含1种),瑶山苣苔属(Dayaoshania,含1种),密叶苣苔属(Buxiphyllum,1种),异片苣苔属(Allostigma,含1种),裂檐苣苔属  相似文献   

17.
As peri-implantitis is an emerging problem, the development of validated animal models is mandatory. The aim of this pilot study was to provide a first step in describing the normal oral flora of minipigs. In five minipigs, samples of the oral flora were collected with sterile cotton swabs from the buccal gingiva of the lower jaw. Two swabs per animal were collected, followed by bacterial isolation under both aerobe and anaerobe conditions. Microbiological analyses included biochemical tests, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and 16S rDNA gene sequence analysis. A total of 61 taxa were detected, 14-21 different bacterial taxa from each minipig. Among the Gram-positive cocci, mainly staphylococcal and streptococcal species were identified. Different Actinomyces species were the most abundant taxa in the group of Gram-positive rods. Among the anaerobic bacteria, the Gram-negative genera Fusobacterium, Bacteroides and Prevotella were the most often observed taxa. This is the first study which begins to describe the normal oral flora in minipigs in cultures to allow for the detection of a broad spectrum. Several bacterial species identified are different from human ones. No specific species for peri-implantitis could be detected in that healthy sample.  相似文献   

18.
Suspended and benthic algal communities from a mildly acidic, third-order Rhode Island stream were examined to determine the seasonal distribution, abundance and diversity of the lotic desmids. Within a one-year sampling period, 148 species and 202 subspecific taxa of desmids were identified, representing 23 genera. Species of Cosmarium and Closterium accounted for approximately 70% of the desmids present, and were the most diverse and abundant taxa during all seasons except spring, when Hyalotheca dissiliens was the dominant desmid species. Average abundance and species richness generally were greatest during summer for both suspended and benthic desmids. Most desmids occurred in benthic habitats, and were randomly distributed among substrata. Average seasonal abundance was 7.4 × 104 cells·g?1 dry wt substratum, among 13 types of substrata. Highest desmid abundance was measured among substrata with intricate morphologies, such as Fontinalis spp., which was associated with 1.2 × 106 desmid cells·g?1 dry wt substratum, or 1.7 × 103 cells·cm?2 substratum. Cell division was observed for 70 desmid taxa, and average seasonal reproduction (based on cell numbers) among all substrata ranged from 4% in winter to 20% during summer. In addition, sexually produced zygospores were found occasionally for H. dissiliens. Desmids were distributed among most substrata examined in this stream, with abundance comparable to reported estimates from softwater lakes and acid bogs. In contrast to established dogma, lotic desmids are not incidental drift organisms, but rather comprise a viable and persistent component of the stream periphyton.  相似文献   

19.
Summary

A detailed study of the desmid flora of the area covered by the parish of Assynt, West Sutherland, has been made. Some 79 samples have been examined necessitating more than 1200 separate determinations of 291 taxa present. Amongst the desmids identified there are some extremely rare species and others newly recorded for the British Isles. The survey has shown that this sector of Sutherland is a prime area of the United Kingdom for the study of these fascinating and beautiful micro-algae.  相似文献   

20.
Desmids from the Auvergne (France)   总被引:3,自引:2,他引:1  
An investigation has been made into the present occurrence and distribution of desmids in the French Auvergne. 27 samples from different habitats revealed the presence of 280 taxa belonging to 251 species, of which 120 had not previously been recorded from this region.The number of taxa per sample varied from 2 to 118; especially the samples from mesotrophic lakes were very rich in desmid species. An annotated list with corresponding figures of the recognized taxa is presented, and previous reports relating to desmids from the study-area are discussed.  相似文献   

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