Annual survey of planktonic dinoflagellates and related cysts in the Gulf of Trieste (Northern Adriatic Sea)

Abstract

A survey of planktonic dinoflagellates and related cysts was carried out in the Gulf of Trieste throughout one year from April 1992 to March 1993. 113 taxa were recovered by the analysis of phytoplankton net samples. The most represented genera were Protoperidinium (34 species), Ceratium (24 species), Dinophysis (15 species), Gonyaulax (11 species) and Prorocentrum (8 species). A particular attention was given to potentially toxic species belonging to the genera Dinophysis, Alexandrium and Prorocentrum. The highest number of species (67 species) was recorded in July, and the lowest one (18 species) in February.

33 cyst morphotypes were recorded by the analysis of sediment samples. The most represented genera were Protoperidinium (8 morphotypes), Scrippsiella (3 morphotypes), Gonyaulax (3 morphotypes) and Alexandrium (2 morphotypes); the cysts most frequently found were those of Conyaulax polyedra and Alexandrium pseudogonyaulax.     

基于可培养方法分析云南腾冲小空山火山谷芽胞杆菌分布特征

【目的】为了解云南腾冲小空山火山谷土壤中可培养芽胞杆菌种类分布特征。【方法】采用可培养手段对小空山火山谷阳坡、谷底和阴坡土壤中的芽胞杆菌进行分离培养,根据16S rRNA基因序列同源性对分离菌株进行鉴定,并分析系统发育地位。利用Canoco5软件分析采样点芽胞杆菌种类分布特征与土壤样品理化性质的相关性。【结果】从火山谷土壤样品中共分离获得180株芽胞杆菌,16S rRNA基因测序鉴定结果表明分离菌株隶属于芽胞杆菌纲2个科(芽胞杆菌科和类芽胞杆菌科)、6个属、34个种,其中芽胞杆菌属(Bacillus) 11个种,类芽胞杆菌属(Paenibacillus) 14个种,短芽胞杆菌属(Brevibacillus)3个种,赖氨酸芽胞杆菌属(Lysinibacillus)4个种,嗜冷芽胞杆菌属(Psychrobacillus)1个种和绿芽胞杆菌属(Viridibacillus)2个种,其中7个菌株与其最近模式菌株16SrRNA相似性低于种的界定阈值(98.65%),为芽胞杆菌潜在新物种。优势属为芽胞杆菌属和类芽胞杆菌属,优势种为蕈状芽胞杆菌(Bacillusmycoides),图瓦永芽胞杆菌(Bacillustoyonensis),蜡状芽胞杆菌(Bacilluscereus),解木糖赖氨酸芽胞杆菌(Lysinibacillusxylanilyticus),蜂房类芽胞杆菌(Paenibacillusalvei)和沙地绿芽胞杆菌(Viridibacillus arenosi)。其中16个种分离自阳坡,29个种分离自阴坡,9个种分离自谷底,三者共同种类为6种。阳坡、谷底和阴坡的芽胞杆菌种群分布Bray-Curtis相似性为62.4%,多样性分析结果表明,Shannon指数(H′)大小次序为阴坡阳坡谷底。环境因子分析发现,芽胞杆菌种群分布多样性特征与其土壤的海拔高度、碳氮比和硫含量呈负相关,而和碳源和氮源含量呈正相关。【结论】从以上结果得出,云南腾冲火山谷有着较为丰富的芽胞杆菌资源,且还存在可分离培养的芽胞杆菌的潜在新物种,为利用火山微生物资源提供了保障。     

Phloemophagous and xylophagous insects, their parasitoids, predators and inquilines in the branches of the most important oak species in Serbia

Altogether 26 species of phloemophagous and xylophagous insects, 47 species of parasitoids, 14 species of predators and 7 species of inquilines were identified on the branches of Quercus cerris, Q. frainetto, Q. petraea and Q. robur, diameter 3–15 cm, at 24 sites in Serbia over the period 1992–1996. The greatest number of the identified species were taken from Q. petraea branches (66), followed by Q. cerris (49), Q. frainetto (48) and Q. robur (43). Among the identified phloemophagous and xylophagous insects, the most frequent and the most abundant species were Scolytus intricatus, Agrilus angustulus and Xylotrechus antilope. The most frequent and the most abundant parasitoid was Ecphylus silesiacus. In some samples, the species Entedon ergias, Cheiropachus quadrum and Dendrosoter protuberans were also among the more abundant parasitoids. The most significant predator was the species Tilloidea unifasciata, and the most significant inquilines were the species Poecilothrips albopictus and Asynapta pectoralis.     

珍稀濒危植物江南油杉群落乔木层主要树种种间关联性分析

基于2×2列联表,采用方差比率法(R_v)、x²检验、Pearson相关系数检验和Spearman秩相关系数检验等方法,对福建君子峰国家级自然保护区江南油杉(Keteleeria fortunei var. cyclolepis)群落乔木层主要树种进行种间关联性分析,并通过主成分分析(PCA)划分生态种组。结果表明,21种主要树种总体表现为不显著负关联,且江南油杉与其他物种多呈不显著相关。210个种对中,正相关的有110对,负相关的有81对,不相关的有19对,正负比1.36。绝大多数种对间呈不显著相关,显著率仅为0.48%,物种间相互独立。Pearson相关系数和Spearman秩相关系数检验结果具有一致性,负相关种对数大于正相关种对数,绝大多数种对不显著,显著率分别为6.19%和7.14%。与x²检验相比,Pearson相关系数和Spearman秩相关系数检验方式更加灵敏。运用PCA二维排序可将主要树种划分为4个生态种组,同一生态种组内物种的生态习性和资源需求相似,多呈正相关,种对间相互依赖共存;不同生态种组间物种多呈负...     

祁连山东段高寒植被群落特征及其与地形气候因子关系研究

地形气候因子与物种分布的关系影响着高寒植被群落的演替,同时对山地水源涵养林功能和结构的维持具有重要的意义。以祁连山东段水源涵养林为研究对象,基于野外植物群落物种组成及地形气候因子调查数据,运用数量分类与排序等方法,探究了高寒植物群落特征及其与地形气候因子的关系。结果表明:65个调查样方中出现181个植物种,隶属40科,124属。科的物种组成及占总物种数比例分别为菊科30个种,占16.57%;蔷薇科17个,占9.44%;禾本科13个种,占7.22%;豆科11个种,占6.11%。毛茛科10个种,占5.56%。单属种82个,占总属数的66.13%。群落层片由乔木层、灌木层和草本层组成,乔木8种,灌木25种,草本148种。乔木层优势种有青海云杉、祁连圆柏、红桦。灌木层优势种有金露梅、山生柳、匙叶小檗、高山绣线菊。草本层优势种有甘肃薹草、珠芽蓼、早熟禾、唐松草、甘青蒿。TWINSPAN将高寒植被群落划分为7个群丛类型:群丛I红桦-红花蔷薇-甘肃薹草B.albosinensis-Rosa moyesii-C.kansuensis,群丛II青海云杉-匙叶小檗-甘肃薹草P.crassifolia-B.vernae-C.kansuensis,群丛III祁连圆柏-高山绣线菊-珠芽蓼Sabina chinensis-Spiraea alpine-P.viviparum,群丛IV高山绣线菊+鬼箭锦鸡儿-珠芽蓼S.alpine+Caragana jubata-P.viviparum,群丛V沙棘+甘青蒿+鼠掌老鹳草Hippophae rhamnoides+A.tangutica+Geranium sibiricum,群丛VI沙棘+苦荬菜+苦荞麦H.rhamnoides+Ixeris polycephala+Fagopyrum tataricum,群丛VII沙棘-冰草+西北沼委陵菜H.rhamnoides-Agropyron cristatum+Comarum salesovianum。7个群丛在DCA排序图上聚集分布,反映了较好的环境梯度。CCA排序结果表明,海拔是祁连山高寒植被群落植物种分布的最重要环境因子,其次是降水、温度、坡向、坡度。     

A study of fungal spore poupulations in the atmosphere of Kuwait

The fungal air-spora of Kuwait was investigated using the Petri-dish trapping technique. During the period from 1st April, 1974 to 30th June, 1975, a total of 3685 colonies were recorded from 2 % malt agar plates. Fifty-five genera and 116 species were identified. Alternaria occupied the first place in the order of percentage incidence, being represented by 18.3% of the entire catch, followed by Aspergillus (17.1%), Penicillium (14%), Cladosporium (13.6%), Drechslera (13.3%), and Ulocladium (7.1%). The widest spectrum of species was displayed by Aspergillus (possessed 19 species) followed by Penicillium (17 species), Alternaria (6 species), Drechslera (5 species), and Ulocladium (4 species). The monthly total number of fungi showed marked seasonal periodicity with the greatest number of colonies occurring in March–April and November. The lowest counts were recorded in mid-summer (July) and mid-winter (January). Only 220 colonies and 17 species of thermophilous fungi were reported from plates incubated at 45 °C. The most common species were Aspergillus fumigatus and A. terreus.     

RELATIONSHIP BETWEEN PRESENCE OF A MOTHER CELL WALL AND SPECIATION IN THE UNICELLULAR MICROALGA NANNOCHLORIS (CHLOROPHYTA)1

The cell division mechanisms of seven strains from six species of Nannochloris Naumann were analyzed and compared with those of three species of Chlorella Beijerinck and Trebouxia erici Ahmadjian using differential interference microscopy and fluorescence microscopy. Nannochloris bacillaris Naumann divides by binary fission and N. coccoides Naumann divides by budding. Distinct triangular spaces or mother cell walls were found in the dividing autosporangia of the other five strains from four species of Nannochloris, three species of Chlorella, and T. erici. In an attempt to infer an evolutionary relationship between nonautosporic and autosporic species of Nannochloris, we constructed a phylogenetic tree of the actin genes using seven strains from six species of Nannochloris, three species of Chlorella, and T. erici. Nannochloris species were polyphyletic in the Trebouxiophyceae group. Two nonautosporic species of N. bacillaris and N. coccoides were monophyletic and positioned distally. Moreover, to determine their phylogenetic position within the Trebouxiophyceae, we constructed phylogenetic tree of 18S rRNA genes adding other species of Trebouxiophyceae. Nannochloris species were polyphyletic in the Trebouxiophyceae and appeared in two different lineages, a Chlorella–Nannochloris group and a Trebouxia–Choricystis group. The nonautosporic species, N. bacillaris and N. coccoides, and three autosporic species of Nannochloris belonged to the Chlorella–Nannochloris group. Nannochloris bacillaris and N. coccoides were also monophyletic and positioned distally in the phylogenetic tree of 18S rRNA genes. These results suggest that autosporulation is the ancestral mode of cell division in Nannochloris and that nonautosporulative mechanisms, such as binary fission and budding, evolved secondarily.     

茂兰喀斯特常绿落叶阔叶混交林群落组成和优势种更新类型

为探讨茂兰喀斯特森林群落结构和优势种更新机制,对茂兰自然保护区常绿落叶阔叶混交林群落进行了调查。结果表明,群落中有木本植物37科58属70种,以樟科、蔷薇科、无患子科和漆树科为主。常绿树种41种,占总种数的58.6%;落叶树种29种,占总种数的41.4%,这体现了喀斯特常绿落叶阔叶混交林的群落学性质。群落的优势乔木树种有轮叶木姜子(Litseaverticillata)、青冈栎(Cyclobalanopsisglauca)、狭叶润楠(Machilusrehderi)和翅荚香槐(Cladrastisplatycarpa)等。灌木优势种有皱叶海桐(Pittosporumcrispulum)、裂果卫矛(Euonymusdielsianus)、革叶铁榄(Sinosideroxylonwightianum)和南天竹(Nandina domestica)等。优势种种群结构有5种类型:单峰型,如樱桃(Cerasus pseudocerasus)、南酸枣(Choerospondias axillaris)等阳性乔木,为林窗更新种,随林窗的郁闭将衰退消失;逆J字型,如轮叶木姜子、香港四照花(Dendrobenthamia hongkongensis)、皱叶海桐等耐荫性强的常绿阔叶树种,更新能力较强,为顶极群落优势种;间歇型,如青冈栎、狭叶润楠、齿叶黄皮(Clausena dunniana)等树种,群落中的个体多集中在小径级阶段,能长期存在于群落中;L字型,如桂皮(Cinnamomumtamala)、梓叶槭(Acer catalpifolium)、革叶铁榄等;单柱型,如石岩枫(Mallotus repandus)、南天竹等常绿灌木树种,个体集中于幼苗、幼树阶段,为顶极群落亚乔木层和灌木层的主要组成种。因此,这表明调查区域的植物群落处于相对稳定的顶极阶段。     

Assessment of Water Pollution using Diatom Community Structure and Species Distribution — A Case Study in a Tropical River Basin

A study on biological assessment of water pollution using diatom community structure and species distribution was carried out in the Linggi River Basin, Malaysia which was polluted by various urban, industrial and agricultural wastes. A total of 86 diatom taxa belonging to 21 genera were recorded from all eight sampling stations located in the basin, of which 70 species were found on artificial substrates; the remaining 16 species were recorded exclusively on natural substrates. The number of diatom species observed between the stations varied from 22-47 species. The dominant diatom species in decreasing order of abundance were Eunotia vanheurckii, Nitzschia palea, Achnanthes saxonica, Gomphonema parvulum and Achnanthes minutissima. The most common clean water species were Achnanthes minutissima, A. linearis and Synedra rumpens. The most tolerant species were Nitzschia palea followed by Gomphonema parvulum and Pinnularia braunii. Eunotia vanheurckii and Navicula cryptocephala occurred in high densities at both unpolluted and polluted stations and can be considered as the common facultative or indifferent species. Although a large number of species were recorded at the unpolluted stations, equivalent number of species were also found at the moderately polluted stations. However, the number of species was reduced at grossly polluted stations. Nevertheless, a marked variation in species association exists between the unpolluted and polluted stations, but not among the polluted stations to distinguish the type and degree of pollution.     

Phylogenetic relationships between Leymus (Poaceae,Triticeae) and related diploid Triticeae species based on isozyme and genome-specific random amplified polymorphic DNA (RAPD) markers

Abstract

To investigate the phylogenetic relationships between Leymus and related diploid species of the Triticeae tribe, the esterase isozyme (EST), superoxide dismutase (SOD) isozymes, and genome-specific random amplified polymorphic DNA (RAPD) markers were used to analyze for 14 Leymus species, together with two Psathyrostachys species (Ns), three Pseudoroegneria species (St), two Hordeum species (H), Lophopyrum elongatum (E^e), Australopyrum retrofractum (W), and Agropyron cristatum (P). The data were used to construct dendrograms by means of UPGMA in the NTSYS-pc computer program. The results suggested that (1) isozyme analysis can be used in the systematic studies of these perennial Triticeae; (2) there is a close relationship between Leymus, Psathyrostachys juncea, three Pseudoroegneria species, and Lophopyrum elongatum; (3) the Ns genome-specific RAPD marker was present in all 14 polyploid species of Leymus, while the E^e and P genome-specific RAPD markers were absent in 14 polyploid species of Leymus; the St, W and H genome-specific RAPD markers were present in some species of Leymus; (4) Leymus species have multiple origins, and different Leymus species derived their genomes from different donors.     

Cellulose-decomposing fungi of desert soils in Saudi Arabia

Seventy-five species in addition to 5 varieties of cellulose-decomposing which belong to 27 genera were collected during this investigation. Aspergillus (12 species + 4 varieties), Alternaria (4 species), Stachybotrys (3 species + 1 variety), and Penicillium (12 species) were of high frequency of occurrence, of which A. fumigatus, A. niger, A. terreus, A. alternata, A. tenuissima, S. atra, P. citrinum and P. corylophilum were the most common. Six genera were of moderate frequency and these were Botryotrichum (2 species), Macrophomina (1 species), Drechslera (5 species), Ulocladium (4 species), Chaetomium (7 species) and Curvularia (4 species) of which B. atrogriseum, D. spicifera, D. sativus, Ubotrytis, C. spirale and C. lunata were the most prevalent. Five and twelve genera were recovered on cellulose-Czapek's agar plates in low and rare frequency of occurrence, respectively.     

RAPD analysis of the intraspecific and interspecific variation and phylogenetic relationships of <Emphasis Type="Italic">Aegilops</Emphasis> L. species with the U genome

RAPD analysis was used to study the genetic variation and phylogenetic relationships of polyploid Aegilops species with the U genome. In total, 115 DNA samples of eight polyploid species containing the U genome and the diploid species Ae. umbellulata (U) were examined. Substantial interspecific polymorphism was observed for the majority of the polyploid species with the U genome (interspecific differences, 0.01–0,2; proportion of polymorphic loci, 56.6–88.2%). Aegilops triuncialis was identified as the only alloploid species with low interspecific polymorphism (interspecific differences, 0–0.01, P = 50%) in the U-genome group. The U-genome Aegilops species proved to be separated from other species of the genus. The phylogenetic relationships were established for the U-genome species. The greatest separation within the U-genome group was observed for the US-genome species Ae. kotschyi and Ae. variabilis. The tetraploid species Ae. triaristata and Ae. columnaris, which had the UX genome, and the hexaploid species Ae. recta (UXN) were found to be related to each other and separate from the UM-genome species. A similarity was observed between the UM-genome species Ae. ovata and Ae. biuncialis, which had the UM genome, and the ancestral diploid U-genome species Ae. umbellulata. The UC-genome species Ae. triuncialis was rather separate and slightly similar to the UX-genome species.     

气候变化下中国主要生物燃油树种分布与变迁

生物燃油树种是发展生物质能源,实现化石能源替代战略的重要物质基础,明确当前和未来气候变化下我国生物燃油树种适生区分布,对保护和利用生物燃油树种,促进林业生物能源产业发展,保障能源安全和实现“双碳”目标具有重要意义。基于我国10个主要生物燃油树种的1037条树种分布数据和20个环境变量,利用最大熵模型(MaxEnt)预测了各树种当前和未来气候情景下(2050年和2070年的RCP4.5情景)的潜在适生区,得到了影响各树种分布贡献率最大的环境因子,并对我国各区域主要种植树种进行了区划。结果表明：(1)MaxEent模型预测效果较好,各树种模拟结果AUC值均在0.9以上。(2)影响各种分布的贡献率较高的环境因子因树种而异,最暖季度降水量和温度季节性变化标准差的相对贡献率较高。(3)10个生物燃油树种极高适生区面积范围在43.38万km²—117.74万km²之间,可根据模拟结果将树种分布划分为北部、中东部、东南部和西南部4个亚区,北部亚区主要树种为文冠果(Xanthoceras sorbifolium)和欧李(Cerasus humilis),中东...     

广西景天科景天属植物小志

该文基于文献考证、馆藏标本鉴定及野外调查，对广西景天属(Sedum L.)植物进行了系统的梳理，对景天属植物物种多样性进行概述，确定目前分布有17种，其中有6个新记录种。该文概述了广西景天属植物物种多样性，订正了藓状景天(S.polytrichoides Hemsl.),简述了6个新记录种，即钝萼景天(S.leblancae Hamet.)、黎平景天(S.lipingense R. B. Zhang, D. Tan&R. X. Wei)、龙泉景天(S.lungtsuanense S. H. Fu)、圆叶景天(S.makinoi Maxim.)、细小景天(S.subtile Miq.)、土佐景天(S.tosaense Makino),并提供其形态特征集要与彩色照片。该文还对广西景天属植物的多样性以及资源潜在利用价值等进行了讨论，并附有分种检索表和各个分类群在广西的分布情况，为该属后续的研究与利用提供了本底资料。     

Species diversity of lepidopteran stem borer parasitoids in cultivated and natural habitats in Kenya

Field surveys were conducted during 2005 to 2007 to assess the species diversity of stem borer parasitoids in cultivated and natural habitats in four agroecological zones in Kenya. In total, 33 parasitoid species were recovered, of which 18 parasitized six stem borer species feeding on cereal crops, while 27 parasitized 21 stem borer species feeding on 19 wild host plant species. The most common parasitoids in cultivated habitats were Cotesia flavipes Cameron, Cotesia sesamiae (Cameron), Pediobius furvus Gahan and the tachinid Siphona sp., whereas in natural habitats, Siphona sp. was the most common. The majority of parasitoids were stenophagous species; only five species –Cotesia sp., Enicospilus ruscus Gauld and Mitchell, Pristomerus nr. bullis, Sturmiopsis parasitica (Curran) and Syzeuctus ruberrimus Benoit – were monophagous. In both cultivated and natural habitats, parasitoid species diversity was highest on the most dominant stem borers Busseola spp. and Chilo spp. On cereal crops, parasitoid diversity was highest on maize and among wild host plants, it was highest on Setaria spp. The ingress‐and‐sting attack method was the most common strategy used by parasitoids in both habitats. In all agroecological zones, parasitoid species diversity was significantly higher in natural than in cultivated habitats. Furthermore, the majority of parasitoid species were common to both cultivated and natural habitats. It was concluded that natural habitats surrounding cereal crops serve as refugia for sustaining the diversity of stem borer parasitoids from adjacent cereal fields.     

Mixed Herbs Drugs: Inhibitory Effect on Growth of the Endogenous Mycoflora and Aflatoxin Production

Twenty commercial mixed herbal drugs were examined for mycological profile. Aspergillus species were the predominant fungi found in the drugs. Other fungi harboured in the drugs with less frequency were Paecilomyces species, Eurotium species, Monascus species, Acremonium species, Penicillium species, Cladosporium species, Scopulariopsis species, Phialophora species and Fonseceae species. Fungal count was between 1.0 log₁₀ CFU and 2.4 log₁₀ CFU per gram of sample. When the drugs were incubated in 85% humidity at 25°C, fungal colonies grew on only two of the drugs. The mixed herbal drugs were extracted with water and the extracts were used to grow Aspergillus parasiticus. All extracts reduced aflatoxin B₁ and aflatoxin G₁ production by 62–97%. All but two of the extracts reduced aflatoxin B₂ and aflatoxin G₂ production by 39–95%. It can be concluded that the commercial powdered mixed herbal drugs contained low number of endogenous fungi, and these drugs are inhibitory to the growth of its endogenous fungi and aflatoxins production by aflatoxigenic fungi.     

Macaranga and Mallotus species (Euphorbiaceae) as indicators for disturbance in the mixed lowland dipterocarp forest of East Kalimantan (Indonesia)

The indicator value (IV) of Macaranga and Mallotus species (Euphorbiaceae) for different types of disturbance in lowland dipterocarp forest was assessed by counting and identifying all individuals of species of these genera taller than 30 cm in 45 (10 m×300 m) plots at nine locations. Twelve Macaranga and nine Mallotus species were found. The main forest disturbance types (primary forest, secondary forest, selectively logged forest, forest burned once, and repeatedly burned forest used for shifting-cultivation) each had their own set of indicator species. The level of disturbance in the forest types was assessed by measuring nine forest structural parameters. The occurrence of Macaranga and Mallotus species was closely related to the level of disturbance in a forest. Most Macaranga species were characteristic of high disturbance levels, while most Mallotus species preferred intermediate to low levels of disturbance. However, both genera had species at both disturbance extremes. Using multiple regression analysis, combinations of Macaranga and Mallotus species were formed and used to predict the separate forest structural parameters and the general level of disturbance of a forest. The Macaranga and Mallotus species could be grouped into (1) primary forest ‘remnant’ species; (2) generalist pioneer species; and (3) high disturbance pioneer species.     

新疆地图衣属地衣分类学研究

该研究以新疆的地图衣科(Rhizocarpaceae)地图衣属(Rhizocarpon)100余份地衣标本为材料,通过形态解剖学观察、化学成分分析及分子学鉴定的方法了解新疆地图衣属地衣的物种多样性。结果表明:(1)鉴定出7种地图衣属地衣,包括1个中国新记录种,命名为淡黄色地图衣(R.atroflavescens),6个常见种分别是黑红地图衣(R.badioatrum)、灰地图衣(R.disporum)、双孢地图衣(R.geminatum)、地图衣(R.geographicum)、巨地图衣(R.grande)和岩表地图衣(R.superficiale)。(2)编制了新疆22种地图衣属地衣的分种检索表。(3)系统发育分析结果表明,新疆地图衣属地衣的分子鉴定与形态解剖特征结果一致,更准确地证明淡黄色地图衣为中国新记录种。(4)对已报道的新疆22种地图衣属地衣的地区分布及海拔分布统计显示,新疆22种地图衣属地衣在世界各地均有分布,其中亚洲分布最丰富;该22种地图衣属地衣从低海拔到高海拔都有分布,且各海拔高度物种分布不均匀,总体在高海拔地区分布的物种较多。     

Molecular phylogeny of black flies (Diptera: Simuliidae) from Thailand, using ITS2 rDNA

The sequences of the second internal transcribed spacer (ITS2) of ribosomal DNA (rDNA) were determined for 40 black fly species from Thailand, belonging to 4 subgenera of the genus Simulium, namely Gomphostilbia (12 species), Nevermannia (5 species), Montisimulium (1 species), Simulium sensu stricto (21 species), and an unknown subgenus with one species (Simulium baimaii). The length of the ITS2 ranged from 247 to 308 bp. All black fly species had high AT content, ranging from 71 to 83.8%. Intraindividual variation (clonal variation) occurred in 13 species, ranging from 0.3 to 1.1%. Large intrapopulation and interpopulation heterogeneities exist in S. feuerboni from the same and different locations in Doi Inthanon National Park, northern Thailand. Phylogenetic relationships among 40 black fly species were examined using PAUP (version 4.0b10) and MrBAYS (version 3.0B4). The topology of the trees revealed two major monophyletic clades. The subgenus Simulium and Simulium baimaii were placed in the first monophyletic clade, whereas the subgenera Nevermannia + Montisimulium were placed as the sister group to the subgenus Gomphostilbia in the second monophyletic clade. Our results suggest that S. baimaii belongs to the malyschevi-group or variegatum-group in the subgenus Simulium. The molecular phylogeny generally agrees with existing morphology-based phylogenies.     

Microscale distribution patterns in high Arctic soil microarthropod communities: the influence of plant species within the vegetation mosaic

We tested the hypothesis that within a relatively homogeneous vegetation type the spatial configuration of different plant species may be a determining factor in the composition of the soil animal communities. Six vascular plant species (Luzula confusa, Dryas octopetala, Cassiope tetragona, Salix polaris, Silene acaulis and Saxifraga opposigifolia), growing within high Arctic Saxifraga‐lichen heath vegetation, showed different distributional patterns. Luzula confusa and S. polaris were ubiquitous throughout while D. octopetala and C. tetragona had the most scattered distributions. Soil microarthropod density varied significantly among plant species from 18 000 (S. polaris) to 42 000 m^?2 (S. acaulis). Few significant numerical interrelationships were found between the population densities of the different Collembola or cryptostigmatic mite species or between microarthropod densities and variation in the physical properties of the soil associated with each plant species. However, despite the high similarity of species present, Discriminant Analysis idengified distinct microarthropod assemblages associated with each plant species. Over 70% of microarthropod samples taken from soil beneath S. polaris or L. confusa were correctly classified. Rank order of animal species abundance, however, varied among plant species. The collembolan Folsomia quadrioculata ranked first in five of the six plant species but the mite Camisia anomia was numerically dominant under S. polaris. The second most abundant species was much more variable. Despite these variations, the shape of the species rank abundance curve for microarthropods was remarkably similar for all plant species, with rank one and two species comprising ca 55 and 27% of the fauna respectively. These conclusions were reinforced by χ² analysis which idengified significantly distinct faunal communities between each plant species. Those microarthropod species contributing most to these between‐plant differences, as measured by higher or lower than expected populations, were idengified and were shown to be not always the most abundant species. Thus, on a local scale plants of different species were shown to act as useful proxy indicators of soil conditions that affect the soil microarthropod community. This should be taken into account when designing sampling programmes for soil invertebrates.