ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1992.tb01827.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

A review of H. Skuja's phycological research carried out in Latvia during the period 1924–1944. It is due to his research that the number of algal species identified in Latvia increased from 200 to 2300. 50 species and varieties, and 9 genera were described by him as ne

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1992.tb01828.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

In June 1991 a peculiarUroglenaspecies was found in two small ponds, the Ugglehult Ponds, situated close to Aneboda, central Småland, Sweden. The colonies contained well‐developed spiny stomatocysts. An EM investigation verified that thisUroglenawas a new species which has here been given the nameUroglena dendracanthabecause of the conspicous tree‐like sp

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1992.tb01829.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

This paper describes several populations of gomphosphaerioid cyanophytes collected in nordic lakes in central Finland, southern Sweden, central Canada (Manitoba, Ontario) and northern Japan (Hokkaido). Variation ofCoelosphaerium minutissimumis discussed and compared with the related species,C. subarcticumandC. punctiferumsp. nov. Two related species,Snowella septentrionalisandS. fennicasp. nov. are compared and characterized. In the genusWoronichinia, three new species are described and the phenotypic variability of the common plankticW. naegelianais recorded. Survey data and an identification key of the genusWoronichiniaare included. The morphology of two plankticGomphosphaeriaspecies (G. natansandG. virieuxii) from central Canadian lakes is described.

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1992.tb01830.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

The flora of silica‐scaled chrysophytes (Chrysophyceae and Synurophyceae) is known from two previous investigations in southern Greenland, from Narssaq (61°N) and Nuuk (64°N).In connection with a course in Arctic Biology 25.7.‐20.8 1990 chrysophyte samples were obtained from altogether 53 localities, 41 from the Godhavn region in Disko Island (69°N) and 12 from S0ndre Str0mfjord (67°N). The localities were lakes, ponds and puddles, on basalt or an acid bedrock. Fixed samples were examined by EM, and altogether twenty species were identified by their silica scales. Eight of these were new to Greenland, viz.Spiniferomonas silverensis, Mallomonas acaroides, M. alpina, M. crassisquama(previous records proved to belong toM. duerrschmidliae), M. oviformis, M. paludosa, M. tonsurata, andSynura mammillosa.The composition of the flora is discussed from ecological and biogeographic vie

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1992.tb01831.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Finds of the rare epiphytic rhodophyteBalbiania investiens(Acrochaetiales) from River Österdalälven in Dalecarlia, Sweden, are described. Its distribution, history and taxonomy are presented and discussed. Information on its host, represented by certain species of the genusBatrachospermum(Nemalionales), is given with particular reference to ecology and distribution in Sweden. The algal composition and water chemistry of one new Swedish location are presented and categorized according to Israelson's classification of Scandinavian running water

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1992.tb01832.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

External morphological features and growth characteristics of the dinoflagellatesCeratium hirundinellaandC. furcoideswere investigated in relation to the environmental conditions in Lake Erken. Three distinct population maxima were distinguished, one in June, one in July, and one in September.C. hirundinelladominated the spring and summer populations.C. furcoideswas rare in June, but it continuously increased and composed ca. 18% of theCeratium‐cettsin the autumn. The size of aC. hirundinelladecreased during the investigation period and a form with a long horn disappeared in June.Ceratiumwas most numerous during the warmer periods in summer when a distinct thermocline appeared and before the turnover period in September. The alga preferred depths down to 3 m where the blue light dominated and the following parametric magnitudes could be measured: oxygen contents>5 mg 1‐1, pH>7, HCO3,>1.7 meq. · 1‐1, and a specific conductivity of ca. 250 mS · cm‐1. The algal growth periods displayed doubling times of 2.63 and 4.04 days at surface temperatures of 19°C and 15°C, respectively. The water transparency decreased 3.8 m whenCeratiumreached cell densities of 13 individuals · ml‐1(0–10 m depth). Its vertical migration demonstrated a dial rhythm with accumulation of cells in the surface waters during the day. Complicated patterns of surface avoidance occurred in clear weather and u

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1992.tb01833.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

The distribution ofPeridinium willeiandP. volziiwas studied in Danish lakes. Both species were confined to lakes with concentrations of Total P<0.15 mg 1‐1, with the majority of occurrences at Total P concentration between 0.020–0.040 mg 1‐1and concentrations of PO4P between detection limit and 0.040 mg 1‐1. The occurrence of the species in relation to inorganic N compounds (NH4N and NO2+ NO3N) was significantly broader forP. willeithan forP. volzii: P. willeihad an almost even distribution within a wide range of NH4N, whereasP. volziimainly occurred between 0.001 and 0.10 NH4N 1‐1.P. willeihad an almost even distribution at values beween 0.005 and 0.42 mg NO2+ NO3N 1‐1, whereasP. volziimainly occurred below 0.050 mg NO2+ NO3N 11.P. willeiwas found at pH values between 4.2 and 8.5, whereasP. volziiwas confined to lakes with a slightly basic pH. The study confirmed the broad limits ofP. willeiand the much more narrow limits ofP. volziiin relation to seasonal occurrence and pH, as well as an affinity of the former to ponds and lakes with a rich bottom vegetation. The study also showed, however, that the species were not as widespread and common in recent Danish lake phytoplankton as generally stated by previous authors. The use of different ecological factors to give weight to species separation is discussed. The inclusion ofP. volziiinP. willeiproposed by Popovsky&Phiester is not supported by the present study, as the two taxa appear to have different ecological

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1992.tb01834.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

A geographical survey was made of the distribution of diaphanoidCeramiain the Baltic Sea and adjacent waters west of the Baltic. It was found thatCeramiumplants with so‐called ‘Gobi's’ parasporangia (monosporangia) have a wide distribution in the Baltic Sea at salinities of ca (3) 5–8%. This brackish‐waterCeramiumis here described as a new species,Ceramium gobii.At higher salinities in the south of the Baltic Sea and on the Swedish west coast, round parasporangia (polysporangia) indicate the occurrence of otherCeramiumspecies. The new species is very similar to the brackish‐water speciesCeramium radiculosum, which was described from river‐mouths to the Gulf of Trieste (Italy). A comparison was made of several diaphanoidCeramiumspecies,C. diaphanum, C. tenuicorne, C. gobii, andC. radiculosum, including (1) size of male plants, (2) type of paraspores, (3) vegetati

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1992.tb01835.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

In Sweden the recovery process of the four largest lakes (<500 km2) has been followed since the mid‐1970's when the phosphorus loading was reduced by approximately 50%. A ten‐year investigation period before that acts as a basis of comparison. The response of the dominating species in the phytoplankton communities in the eutrophic Lake Mälaren and the oligotrophic Lake Vättern is discussed also in relation to a pristine state of the lakes. The long‐term investigations with monthly sampling make a natural phytoplankton biomass variation range possible to establish ‐ a range that is mainly due to effects of weather fluctuations. In order to get a tool for water management where disturbing and highly disturbing total phytoplankton volumes can be anticipated from a certain phosphorus concentration, a model is suggested based on experiences from more than 50 Swedish lakes investigated during a series

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1992.tb01836.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY