大兴安岭桥弯藻科、异极藻科中国新记录植物

在对大兴安岭沼泽硅藻进行分类学研究的过程中,观察到桥弯藻科中国新记录8个分类单位,分别为平截盘状藻Placoneis explanata(Hust.)Lange-Bertalot、类冰川盘状藻Placoneis interglacialis(Hust.)Cox、近北极桥弯藻Cymbella subarctica Krammer、佛罗伦萨弯肋藻Cymbopleura florentina(Grun.)Krammer、新异肋弯肋藻Cymbopleura neoheteropleura Krammer、近尖头弯肋藻Cymbopleura subcuspidata(Krammer)Kram-mer、近喙头弯肋藻Cymbopleura subrostrata(Cl.)Krammer、埃尔金内丝藻Encyonema elginense(Krammer)Mann。异极藻科中国新记录7个分类单位,分别为英吉利异极藻Gomphonema anglicum Ehrenb.、远距异极藻Gomphonema distans(Cl.-Eul.)Lange-Bertalot&Reichardt、肯特异极藻Gomphonema khentiiense Metzeltin,Lange-Bertalot&Nergui、李氏异极藻Gomphonema liyanlingae Metzeltin&Lange-Bertalot、铲形异极藻Gomphonema pala Reichardt、假弱小异极藻Gomphonema pseudopusillum Reichardt、箭形异极藻Gompho-nema sagitta Schumann。文章对这些种类的形态特征进行了观察,对这些种类与相似种类之间的形态差异进行了比较研究,并初步探讨了这些种类的生态分布特点。对盘状藻属Placoneis Mereschkowsky、内丝藻属Encyonema Kützing和弯肋藻属Cymbopleura(Krammer)Krammer的分类特征进行了详细的描述。     

大兴安岭达尔滨湖桥弯藻科（硅藻门）中国新记录植物

报道了采自大兴安岭达尔滨湖及其周围沼泽水体的硅藻门桥弯藻科中国新记录植物9种1变种,分别为新箱形桥弯藻新月变种Cymbella neocistulavar.lunataKrammer、近箱形桥弯藻Cymbella subcistulaKrammer、疏纹内丝藻Encyonema paucistriatum(Cleve-Euler)Mann、普通内丝藻Encyonema vulgareKrammer、尖锐弯肋藻Cymbopleuraacuta(Schmidt)Krammer、英吉利弯肋藻Cymbopleura anglica(Lagerstedt)Krammer、线形弯肋藻Cymbopleura linearis(Foged)Krammer、十字形弯肋藻Cymbopleura stauroneiformis(Lagerstedt)Krammer、泰尼弯肋藻Cymbopleura tynnii(Krammer)Krammer、两尖拟内丝藻Encyonopsis amphioxys(K櫣tzing)Liu et Shi。其中两尖拟内丝藻Encyonopsis am-phioxys(K櫣tzing)Liu et Shi为新组合。对这些种类进行了光镜观察,部分种类进行了扫描电镜观察,对其分类学特征进行了详细的描述,并记录了它们的生境特征。     

中国桥弯藻科(硅藻门)的新记录植物

本文报道了采自新疆维吾尔自治区的桥弯藻科(硅藻门)中国新记录植物11种3变种,分别为Amphora mexi-cana var. major (Cleve) A. Cleve, Amphora twenteana Krammer, Encyonema cespitosum Kǖtzing, Encyonema silesiacum vat. ventriformis Krammer, Cymbopleura albanica Krammer et Miho, Cymbopleura apiculata Krammer, Cymbopleura schwe-ickerdtii Choloky, Cymbella compacta φ strup, Cymbella diversa Krammer, Cymbella excisa var. subcapitota Krammer, Cymbella hantzschiana Krammer, Cymbella scutariana Krammer, Cymbella subhelvetica Krammer, Cymbella vulgata Kram-mer.对其分类学特征进行了详细的描述,并给出了它们的生境特征.     

青海省异极藻属和桥弯藻属(硅藻门)的新变种

本文对来自青海省异极藻属和桥弯藻属(硅藻门)的三个新变种进行描述,它们是:橄榄异极藻短纹变种(Gomphonema olivaceum (Lyngbye) Kuetzing var. brevistriatum Li Y. L. et Shi, var. nov.);十字异极藻矩形变种(Gomphonema staurophorum (Pant.) Cleve-Euler var oblongum Li Y. L. et Shi, var. nov)和亚贝桥弯藻具点变种(Cymbella yabe Skvortzow var. punctata Li Y. L. et Shi, var. nov).       

中国硅藻化石新种和新记录种

在对江汉平原钻孔中的化石硅藻进行鉴定时,发现1个新种类：江汉异极藻（新种）Gomphonema jianghanensis sp.nov.,该种的主要特征为：壳面狭披针形或线性披针形,端部和基部圆形,中轴区窄。中心区宽呈横矩形,在紧靠中心区的一侧具1条很短的线纹,另一侧有时有1条很短的线纹,有时没有线纹,无孤点。壳缝呈直线,在中央区附近略弯向一侧,在极节处折向另一侧。线纹轻微放射状,中部略弯曲,在近顶端处没有线纹,在10μm内,中部具6—13条。长20—30μm,宽4—7μm。4个中国新记录属：楔异极藻属Gomphosphenia Lange-Bertalot、楔月藻属（新记录属）Cymbopleura Krammer、优美藻属Delicata Krammer、尖月藻属Encyonopsis Krammer,8个中国新记录种：微小异极藻Gomphonema minutiforme Lange-Bertalot＆Reichardt、较细楔异极藻Gomphosphenia tenerrima（Hustedt）Reichardt、舌状楔异极藻Gomphosphenia lingulatiforme（Hustedt）Lange-Bertalot、瑞克舟形藻Navicula rakowskae Lange-Bertalot、北方羽纹藻岛屿变种Pinnularia borealis var.islandica Lange-Bertalot,舟形盖斯勒藻Geissleria tectissima（Lange-Bertalot）Lange-Bertalot＆Metaeltin、岩生楔月藻小变种Cymbopleura rupicola var.minor Krammer和法国尖月藻Encyonopsis falaisensis（Grunow）Krammer,1个种的补充说明：中华优美藻Delicata sinensis Krammer ＆ Metzetin。     

西藏拉鲁湿地硅藻植物的分类研究

该文报道了2015年7月采自西藏拉鲁湿地的硅藻植物共133个分类单位,包括54属122种11变种,分别隶属于3纲12目54属,其中6种为中国新记录,分别为多罗弗里克短缝藻(Eunotia dorofeyukae Lange-BertalotM.S.Kulikovskiy)、嫌钙异极藻(Gomphonema calcifugumm Lange-BertalotE.Reichardt)、坎普登斯异极藻(Gomphonema campodunense E.Reichardt)、三角舟形藻(Navicula trilatera Bahls)、相似弯肋藻(Cymbopleura similiformis Krammer)、兰格伯泰勒特桥弯藻(Cymbella lange-bertalotii Krammer)。并对拉鲁湿地硅藻的种类组成进行了分析,指出了其中的优势属及优势种,对优势种的环境指示进行了分析。     

中国桥弯藻科(硅藻门)的新记录植物

本文报道了采自新疆维吾尔自治区的桥弯藻科(硅藻门)中国新记录植物11种3变种,分别为Amphora mexi-canavar.major(Cleve)A.Cleve,Amphora twenteanaKrammer,Encyonema cespitosumK櫣tzing,Encyonema silesiacumvar.ventriformisKrammer,Cymbopleura albanicaKrammer et Miho,Cymbopleura apiculataKrammer,Cymbopleura schwe-ickerdtiiCholoky,Cymbella compacta strup,Cymbella diversaKrammer,Cymbella excisavar.subcapitataKrammer,Cymbella hantzschianaKrammer,Cymbella scutarianaKrammer,Cymbella subhelveticaKrammer,Cymbella vulgataKram-mer。对其分类学特征进行了详细的描述,并给出了它们的生境特征。       

中国舟形藻科（硅藻门）新记录植物

报道了2006～2007年9月间采自中国吉林、辽宁两省的舟形藻科中国新记录植物5种5变种,分别为Navicula arkona Lange-Bertalot ＆ Witkowski, Hippodonta linearis（0strup） Lange-Bertalot, Metzehin ＆ Witkowski, Geissleria decussis （Hustedt） Lange-Bertalot ＆ Metzehin, Geissleria kriegeri （ Krasske ） Lange-Bertalot ＆ Metzehin, Pinnularia divergens var. media Krammer, Pinnularia dubitabilis var. minor Krammer, Pinnularia lundii var. lirvearis Krammer, Pinnularia rhombarea var. variarea Krammer, Pinnularia stomatophora var. irregularis Krammer, Alveovallum beyensii Lange-Bertalot ＆ Krammer。对部分种类进行了光镜观察,部分种类进行了扫描电镜观察;对它们的分类学特征进行了详细的描述,并记录了它们的生境特征。     

异极藻属(硅藻门)5种中国新记录

对采自海南省三亚亚龙湾国家森林公园,湖北省神农架大九湖湿地和黑龙江省兴凯湖湿地的硅藻标本进行分类学研究,发现异极藻属植物中国新记录5种,分别是狭状披针异极藻(Gomphonema acidoclinatum LangeBertalotReichardt)、矛形异极藻(Gomphonema hasta D.Metzeltin)、林氏异极藻(Gomphonema kobayashiae MetzeltinLange-Bertalot)、宽缘异极藻(Gomphonema latipes E.Reichardt)和隐形异极藻(Gomphonema occultum ReichardtLange-Bertalot)。对相似种类之间的形态差异进行比较,为中国异极藻属植物的分类学研究提供基本资料。     

异极藻科八个分类单位的分类学问题初探

利用光学显微镜和扫描电镜对东北异极藻科植物３属８个分类单位即：异极藻属２种２变种１变型：细异极藻箭头变处Ｇ．ｓａｂｔｉｌｅ ｖａｒ．ｓａｇｇｉｔａ（Ｓｃｈｕｍ．．）Ｃｌ．Ｋ．,缢缩异极藻头状变种意大利变型Ｇ．ｃｏｎｓｔｒｉｃｔｕｍ ｖａｒ．ｃａｐｉｔａｔｕｍ ｆ．ｉｔａｌｌｉｃａ Ｍａｙｅｒ．,柔弱异极藻Ｇ．ｔｅｎｅｌｌｕｍ Ｋｕｔｚ．,半孔异极藻Ｇ．ｓｅｍｉａｐｅｒｔｕｍ Ｇｒｕｎ．长异极藻延长     

江汉平原晚更新世化石硅藻新种和新记录属种

在对江汉平原钻孔中属晚更新世地层的化石硅藻进行鉴定时,发现1个新种:Geissleria jianghanensis sp.nov.Li,2个中国新记录属:Geissleria和Aneumast us,6个中国新记录:Cymbella neuquina var.fastigata(Krasske)Krammer,Maidana et Villanueva,Cymbella perfossilis Krammer,Cymbella neocistula Krammer,Cym-bella neocistula var.islandica Krammer,Cymbella subcistula Krammer,Gomphonema lippertii Reichardt etLange-Bertalot。     

Benthic algal response to hyporheic-surface water exchange in an alluvial river

We studied the response of benthic algae to points of hyporheic-surface water exchange in the main channel of the Middle Fork Flathead River within the Nyack Flood Plain, Montana. We examined hyporheic exchange at 120 sites using piezometers and measuring vertical hydraulic gradient (VHG), hydraulic conductivity, and vertical discharge. We removed benthic algae from a single cobble at each site, and we used VHG to group sampling sites for statistical analysis. Algal cell density and chlorophyll a concentration were significantly higher at sites with hyporheic discharge (+VHG, upwelling) compared to both sites with hyporheic recharge (−VHG, downwelling) and sites with no hyporheic-surface water exchange (=VHG, neutral) (ANOVA, P < 0.05). The assemblages of algae at upwelling sites were also significantly different from downwelling and neutral exchange sites (ANOSIM, P < 0.05). Filamentous green algae Stigeoclonium sp. and Zygnema sp. and a chrysophyte, Hydrurus foetidus (Villars) Trevisan were abundant at upwelling sites, whereas an assemblage of diatoms Achnanthidium minutissimum (Kützing) Czarnecki, Cymbella excisa Kützing, Diatoma moniliformis Kützing, and Gomphonema olivaceoides Hustedt, were the most abundant taxa at downwelling and neutral exchange sites, occurring attached to, or in close association with the stalks of Didymosphenia geminata (Lyngbye) Schmidt. These data show that benthic algal communities are structured differently depending on the direction of hyporheic flux in the main channel of a large alluvial river, suggesting that hyporheic-surface exchange may influence the spatial distribution of main-channel benthic algae in rivers with hyporheic-surface water connectivity. Handling editor: J. Padisak     

Uncertainty of using habitat fidelity in biomonitoring based on benthic diatoms - the Raška River case study

Epilithic diatoms are frequently recommended for river biomonitoring, while much less emphasis is placed on epiphytic communities. This study considers use of epiphytic and epilithic diatom communities from the Ra?ka River in biomonitoring. A total of 212 diatom taxa were recorded in both communities. Dominant diatoms were Achnanthidium minutissimum (Kützing) Czarnecki, A. affine (Grunow) Czarnecki, A. subatomus (Hustedt) Lange-Bertalot, Amphora pediculus (Kützing) Grunow, Diatoma vulgaris Bory, Gomphonema tergestinum (Grunow) Fricke, Cocconeis placentula var. lineata (Ehrenberg) Van Heurck, Melosira varians Agardh and Navicula tripunctata (Müller) Bory. Redundancy analysis (RDA) was used to detect the relationships between diatoms, some environmental factors and sampling sites. Diatoms of the epiphytic community showed a clearly grouping in relation to the sampling sites as compared with diatoms of the epilithic community. Species common to both communities showed a similar correlation with some environmental variables (BOD, pH, NH₄⁺, TP, NO₃^? and conductivity), with three exceptions (Diatoma vulgaris, Cymbella compacta, and Encyonema silesiacum). Pearson’s correlation coefficient showed correlation between selected environmental variables and diatom indices calculated using OMNIDIA 6.2 software (TDI, IPS, CEE, GENRE, TID, SID, SHE and IDSE/5). Diatoms of the epiphytic community are more clearly clustered in relation to the sampling sites as compared with diatoms of the epilithic community. According to our results there is still “place” in biomonitoring for epiphytic community. The present study highlights the necessity of sampling both epiphytic and epilithic communities because substrate specificity could play important role in biomonitoring.     

ITS1 sequences of type specimens of Gigartina and Sarcothalia and their significance for the classification of South African Gigartinaceae (Gigartinales,Rhodophyta)

Uncertainties about the identity of type specimens of red algae have frequently led to taxonomic and nomenclatural confusion. A procedure for extracting PCR-amplifiable DNA from formalin-fixed material and herbarium specimens was used to investigate the taxonomic status of several South African Gigartinaceae. We compared nucleotide sequences in the internal transcribed spacer 1 (ITS1) region in type specimens and other historically important collections presently referred to Gigartina bracteata, G. radula and G. stiriata. The following opinions are supported: (1) Fucus bracteatus S.G. Gmelin, Chondrodictyon capense Kützing and Iridaea clathrata Decaisne represent a single species of South African Gigartina (G. bracteata (S.G. Gmelin) Setchell & Gardner) in which the disintegration of tetrasporangial sori results in a reticulate thallus. (2) Mastocarpus polycarpus Kützing, M. incrassatus Kützing and Iridaea lapathifolia Kützing represent a single species of South African Gigartina (G. polycarpa (Kützing) Setchell & Gardner) that has often, but erroneously, been called G. radula (Esper) J. Agardh. (3) Mastocarpus verrucosus Kützing is a later heterotypic synonym of Iridaea papillosa Bory (Sarcothalia papillosa (Bory) Leister) and was based on material that probably came from southern South America rather than from South Africa, the provenance given by Kützing. (4) Fucus stiriatus Turner and Sphaerococcus burmannii C. Agardh represent a single species of South African Sarcothalia (S. stiriata (Turner) Leister).     

Spatial and temporal dynamics of the steady-state phytoplankton assemblages in a temperate shallow hypertrophic lake (Lake Manyas,Turkey)

Spatial and temporal dynamics of phytoplankton biomass and species composition in the shallow hypertrophic Lake Manyas, Turkey, were studied biweekly from January 2003 to December 2004 to determine steady-state phases in phytoplankton assemblages. Steady-state phases were defined when one, two or three coexisting species contributed to at least 80% of the standing biomass for at least 2 weeks and during that time the total biomass did not change significantly. Ten steady-state phases were identified throughout the study peiod. During those periods, Achnanthes microcephala (Kützing) Cleve twice dominated the phytoplankton biomass alone and contributed to more than 50% of the total biomass in seven phases. Microcystis aeruginosa (Kützing) Kützing, Anabaena spiroides Klebahn, Cyclotella stylorum Brightwell, Pediastrum boryanum (Turpin) Meneghini and Phacus pusillus Lemmermann were also represented once in steady-state phytoplankton assemblages. A. microcephala was dominant usually during cold periods of the year, while M. aeruginosa and A. spiroides were usually dominant in warm seasons. The total number of species showed a clear decrease during steady-state phases at all stations. All stations were significantly different in terms of the measured physical and chemical parameters (P < 0.05) and phytoplankton biomass (F = 117, P < 0.05).     

Hydrological controls on the diatom assemblage of a seasonal arctic river: Boothia Peninsula,Nunavut, Canada

This study characterizes the melt season diatom assemblage of a middle arctic river with respect to hydrological conditions. In addition, the potential to identify species that show a strong affinity for the lotic environment provides an opportunity to interpret stratigraphic changes in these species in the lake sedimentary record in terms of past hydrological change. Understanding long-term hydrological variability is critical for assessing both current and future environmental change. Significantly higher relative abundances of Achnanthes minutissimaKützing, Fragilaria capucina var. vaucheriae (Kützing) Lange-Bertalot, Diatoma tenuisAgardh, Cymbella arctica(Lagerstedt) Schmidt, C. minutaHilse ex. Rabenhorst, C. silesiaca Bleisch and Encyonema fogedii Krammer in the lotic environment throughout the 2001 growing season compared to the lacustrine sedimentary record suggest that these species characterize the Lord Lindsay River diatom assemblage. Comparison of seasonal abundances of these taxa to hydrological parameters including discharge, electrical conductivity, and water temperature reveal key information about the character of this community. The fact that the river diatom assemblage changes very little throughout the sampling period, despite major changes in hydrological conditions, suggests a degree of resilience and inherent structure in the community. However, a decrease in diatom biomass in response to rapid and dramatic changes in hydrological conditions following a major rainfall event suggests that a threshold tolerance may exist, with potentially important implications for interpreting stratigraphic changes in the paleoenvironmental record.     

SCANNING ELECTRON MICROSCOPY OBSERVATIONS OF DEFORMITIES IN SMALL PENNATE DIATOMS EXPOSED TO HIGH CADMIUM CONCENTRATIONS1

Different types of malformations are likely to affect the morphology of diatoms when exposed to particularly unstable environmental conditions, the most easily identifiable being distortion of the whole frustule. In the present study, we investigated, by means of SEM, valve abnormalities induced by high cadmium contamination (100 μg · L^?1) in small pennate diatoms. Changes in the shape of Amphora pediculus (Kütz.) Grunow and anomalous sculpturing of the cell wall of many species, such as Encyonema minutum (Hilse) D. G. Mann, Mayamaea agrestris (Hust.) Lange‐Bert., Gomphonema parvulum (Kütz.) Kütz., or Eolimna minima (Grunow) Lange‐Bert., were observed, which were not, or almost not, noticeable in the LM. With consideration to current knowledge of diatom morphogenesis, metal uptake by the cell would induce, directly or indirectly, damage to many cytoplasmic components (e.g., microtubules, cytoskeleton, Golgi‐derived vesicles) involved in the precisely organized silica deposition. This study confirms that many species, whatever their size, are likely to exhibit morphological abnormalities under cadmium stress, and that this indicator may be valuable for the biomonitoring of metal contamination, even if SEM observations are not necessary for routine studies.