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B Kawecka - One of the best experts on this subject based on the ideXlab platform.
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benthic diatoms of an alpine stream lake network in switzerland
Aquatic Sciences, 2005Co-Authors: Christopher T. Robinson, B KaweckaAbstract:We compared the benthic diatom composition of lakes, and lake inlet and outlet streams in a high elevation catchment (∼2600 m a.s.l.) in the Swiss Alps. The catchment consisted of a southern basin mostly fed by glacial-melt water and a northern basin fed by snowmelt and groundwater. Streams in both basins flowed through a series of small lakes before converging into a lake with a primary outlet channel. The south basin had on average 4°C cooler water temperatures and 2× higher nitrate-N levels (up to 300 μg/L) than the north basin. In contrast, the north basin had higher levels (2–4×) of particulate-P, particulate-N, and particulate organic matter than the south basin. A total of 109 and 143 diatom species was identified in lakes and streams, respectively, with a similar number of species found in each basin. Aulacoseira alpigena and Achnanthidium minutissimum were common benthic algae in north basin lakes, whereas Achnanthes subatomoides, Achnanthes marginulata, Pinnularia microstauron, and Psammothidium helveticum were most common in south basin lakes. One disconnected lake in the north basin had an assemblage dominated by Tabellaria flocculosa (66%) and Eunotia tenella (14%). Principal components analysis showed a clear separation between the north and south basins in lotic diatoms. Of the 10 most common species, streams in the south basin had greater abundances of Psammothidium helveticum, Achnanthes helvetica var. minor, Achnanthes marginulata, Achnanthes subatomoides, and Diatoma mesodon than the north basin, whereas north basin streams had higher abundances of Achnanthidium minutissimum, Aulacoseira alpigena, and Luticola goeppertiana. Lake outlet assemblages were similar to respective downstream lake inlet assemblages, and assemblages changed in composition along each basins longitudinal flow path. However, Aulacoseira alpigena had higher average abundances in north basin outlets than inlets, and Achnanthidium minutissimum, Psammothidium helveticum, and Achnanthes helvetica var. minor had higher average abundances in south basin outlets than inlets. In contrast, Diatoma mesodon, Fragilaria capucina, and Gomphonema parvulum had higher average abundances in south basin inlets than outlets. The spatial patterns in species composition reflected the hierarchical interaction of landscape features (geology, hydrology) on longitudinal gradients (lake position) in the stream/lake network.
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Benthic diatoms of an Alpine stream/lake network in Switzerland
Aquatic Sciences, 2005Co-Authors: Christopher T. Robinson, B KaweckaAbstract:We compared the benthic diatom composition of lakes, and lake inlet and outlet streams in a high elevation catchment (∼2600 m a.s.l.) in the Swiss Alps. The catchment consisted of a southern basin mostly fed by glacial-melt water and a northern basin fed by snowmelt and groundwater. Streams in both basins flowed through a series of small lakes before converging into a lake with a primary outlet channel. The south basin had on average 4°C cooler water temperatures and 2× higher nitrate-N levels (up to 300 μg/L) than the north basin. In contrast, the north basin had higher levels (2–4×) of particulate-P, particulate-N, and particulate organic matter than the south basin. A total of 109 and 143 diatom species was identified in lakes and streams, respectively, with a similar number of species found in each basin. Aulacoseira alpigena and Achnanthidium minutissimum were common benthic algae in north basin lakes, whereas Achnanthes subatomoides, Achnanthes marginulata, Pinnularia microstauron, and Psammothidium helveticum were most common in south basin lakes. One disconnected lake in the north basin had an assemblage dominated by Tabellaria flocculosa (66%) and Eunotia tenella (14%). Principal components analysis showed a clear separation between the north and south basins in lotic diatoms. Of the 10 most common species, streams in the south basin had greater abundances of Psammothidium helveticum, Achnanthes helvetica var. minor, Achnanthes marginulata, Achnanthes subatomoides, and Diatoma mesodon than the north basin, whereas north basin streams had higher abundances of Achnanthidium minutissimum, Aulacoseira alpigena, and Luticola goeppertiana. Lake outlet assemblages were similar to respective downstream lake inlet assemblages, and assemblages changed in composition along each basins longitudinal flow path. However, Aulacoseira alpigena had higher average abundances in north basin outlets than inlets, and Achnanthidium minutissimum, Psammothidium helveticum, and Achnanthes helvetica var. minor had higher average abundances in south basin outlets than inlets. In contrast, Diatoma mesodon, Fragilaria capucina, and Gomphonema parvulum had higher average abundances in south basin inlets than outlets. The spatial patterns in species composition reflected the hierarchical interaction of landscape features (geology, hydrology) on longitudinal gradients (lake position) in the stream/lake network.
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Diversity of epilithic diatoms in high mountain lakes under the stress of acidification (Tatra Mts, Poland)
Annales de Limnologie - International Journal of Limnology, 2003Co-Authors: B Kawecka, Joanna GalasAbstract:Using the epilithic diatoms as indicators of environmental conditions, 10 lakes in the High Tatra Mountains were characterised with regard to their stage of acidification. The diatom communities were diverse; 210 taxa were found, including 27 species of north and alpine preference. On the basis of cluster analysis, two groups of lakes were distinguished. The first group included shallow, moderately acidified lakes (Dlugi and Zmarzly Gasienicowy lakes), where acidophilous organisms prevailed, with Achnanthes marginulata being the most numerous. The structure of the diatom community in Dlugi lake was stable over 4 years of observations and did not show any progress in acidification. The second group included mostly very deep, non-acidified lakes where circumneutral organisms prevailed, and among them Achnanthes minutissima was dominant in most cases. The diatom community structures mostly confirmed the status of the lakes studied as judged from their water chemistry.
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Diatom communities in the Vanishing and Ornithologist Creek, King George Island, South Shetlands, Antarctica
Twelfth International Diatom Symposium, 1993Co-Authors: B Kawecka, M. OlechAbstract:In the diatom communities of the Vanishing and Ornithologist Creek 74 taxa were found. Most of the taxa have a cosmopolitan range and are resistant to various environmental stresses. For example, Achnanthes lanceolata var. lanceolata, is found in all types of waters and in several ecological conditions. Achnanthes delicatula ssp. delicatula,Nitzschia frustulum, N. capitellata, Navicula mutica, and N. gregaria develop both in fresh and brackish waters. Some of the organisms also settle in terrestrial environments. Navicula atomus, N. mutica,Pinnularia borealis, and Hantzschia amphioxys are common soil algae. Navicula digitulus,N. contenta, N. cohnii and Achnanthes coarctata also live in an aerial environment. Navicula atomus is well developed in eutrophic waters and Nitzschia capitellata can tolerate a high level of pollution, while Nitzschia gracilis, Fragilaria capucina, and F. alpestris appear both in oligotrophic, and enriched waters. Stenotopic ecological features are shown by Achnanthes marginulata and Navicula digitulus — known from the Alps and the North, and Navicula muticopsis characteristic for Antarctic and Subantarctic.
Myung-soo Han - One of the best experts on this subject based on the ideXlab platform.
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Ecological Studies on Togyo Reservoir in Chulwon, Korea. 7. The Colonization of Epilithic Algae on Artificial Substrata (Tiles) at Mesocosm
ALGAE, 2004Co-Authors: Kyung Ha Lee, Sook-kyung Yoon, Myung-soo HanAbstract:Patterns of epilithic algal colonization on artificial substrata (unglazed ceramic tiles) were investigated from 23rd April to 3rd July 1999 at weekly intervals over a 10 weeks period outside and inside the mesocosm in Togyo reservoir within the Civilian Passage Restriction Line near Demilitarized Zone (DMZ) in Korea. The highest standing crops of epilithic algae was 1,79810³ cells outside the mesocosm on 26th June and also inside the mesocosm those was 2,39110³ cells on 26th June, 9 weeks after the experiment began. The dominants outside the mesocosm were Achnanthes minutissima, Navicula bicephala, Oscillatoria angusta, Synedra delicastissima, S. tenuissima, S. ulna v. danica and Tabellaria flocculosa, and those inside the mesocosm were Achnanthes minitissima, Coenochloris polycocca, Fragilaria crotonenesis, Peridinium cinctum, Synedra delicatissima, Tabellaria flocculosa and Ulothrix subtilissima. Diatoms were most abundant and Achnanthes minutissima was the most important species colonizing on the tiles. Chlorophyll-a content was highest value of 5.4 mg on 19th June after 8 weeks growth outside the mesocosm and was 24.4 mg on 26th June, 9 weeks after the experiment began on tiles inside the mesocosm. It was also shown that unglazed ceramic tiles were a more suitable substratum for colonization than the glass slides. Consequently the substratum selection plays an important role in the colonization by the epilithic algal community.
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Ecological Studies on Togyo Reservoir in Chulwon, Korea. 8. The Epilithic Algal Community after the Experimental Acidification on the Artificial Substrata (Tiles) at Mesocosm
ALGAE, 2004Co-Authors: Kyung Ha Lee, Sook-kyung Yoon, Myung-soo HanAbstract:The epilithic algal communities on the artificial substrata (unglazed ceramic tiles) were investigated from 5th July to 24th July 1999 with two or three days intervals for elucidating the effects of the experimental acidification. They were harvested inside the mesocosm with and without the acid treatment on Togyo reservoir within the Civilian Passage Restriction Line near Demilitarized Zone (DMZ) in Korea. After the colonization of epilithic algal community, their standing crops revealed different patterns outside and inside the mesocosm. However the time lapse of 5 days was observed on the inside with acid treatment. The dominant species were different: Achnanthes minutissima was outside but Coenochloris polycocca was inside and inside with acid treatment. The differences in floral composition were also found. Achnanthes minutissima which has been the most important species in the colonization by the epilithic algal community of the mesocosm was less important at the lower pH. Coenochloris polycocca is a species well adapted to low pH.
Christopher T. Robinson - One of the best experts on this subject based on the ideXlab platform.
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benthic diatoms of an alpine stream lake network in switzerland
Aquatic Sciences, 2005Co-Authors: Christopher T. Robinson, B KaweckaAbstract:We compared the benthic diatom composition of lakes, and lake inlet and outlet streams in a high elevation catchment (∼2600 m a.s.l.) in the Swiss Alps. The catchment consisted of a southern basin mostly fed by glacial-melt water and a northern basin fed by snowmelt and groundwater. Streams in both basins flowed through a series of small lakes before converging into a lake with a primary outlet channel. The south basin had on average 4°C cooler water temperatures and 2× higher nitrate-N levels (up to 300 μg/L) than the north basin. In contrast, the north basin had higher levels (2–4×) of particulate-P, particulate-N, and particulate organic matter than the south basin. A total of 109 and 143 diatom species was identified in lakes and streams, respectively, with a similar number of species found in each basin. Aulacoseira alpigena and Achnanthidium minutissimum were common benthic algae in north basin lakes, whereas Achnanthes subatomoides, Achnanthes marginulata, Pinnularia microstauron, and Psammothidium helveticum were most common in south basin lakes. One disconnected lake in the north basin had an assemblage dominated by Tabellaria flocculosa (66%) and Eunotia tenella (14%). Principal components analysis showed a clear separation between the north and south basins in lotic diatoms. Of the 10 most common species, streams in the south basin had greater abundances of Psammothidium helveticum, Achnanthes helvetica var. minor, Achnanthes marginulata, Achnanthes subatomoides, and Diatoma mesodon than the north basin, whereas north basin streams had higher abundances of Achnanthidium minutissimum, Aulacoseira alpigena, and Luticola goeppertiana. Lake outlet assemblages were similar to respective downstream lake inlet assemblages, and assemblages changed in composition along each basins longitudinal flow path. However, Aulacoseira alpigena had higher average abundances in north basin outlets than inlets, and Achnanthidium minutissimum, Psammothidium helveticum, and Achnanthes helvetica var. minor had higher average abundances in south basin outlets than inlets. In contrast, Diatoma mesodon, Fragilaria capucina, and Gomphonema parvulum had higher average abundances in south basin inlets than outlets. The spatial patterns in species composition reflected the hierarchical interaction of landscape features (geology, hydrology) on longitudinal gradients (lake position) in the stream/lake network.
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Benthic diatoms of an Alpine stream/lake network in Switzerland
Aquatic Sciences, 2005Co-Authors: Christopher T. Robinson, B KaweckaAbstract:We compared the benthic diatom composition of lakes, and lake inlet and outlet streams in a high elevation catchment (∼2600 m a.s.l.) in the Swiss Alps. The catchment consisted of a southern basin mostly fed by glacial-melt water and a northern basin fed by snowmelt and groundwater. Streams in both basins flowed through a series of small lakes before converging into a lake with a primary outlet channel. The south basin had on average 4°C cooler water temperatures and 2× higher nitrate-N levels (up to 300 μg/L) than the north basin. In contrast, the north basin had higher levels (2–4×) of particulate-P, particulate-N, and particulate organic matter than the south basin. A total of 109 and 143 diatom species was identified in lakes and streams, respectively, with a similar number of species found in each basin. Aulacoseira alpigena and Achnanthidium minutissimum were common benthic algae in north basin lakes, whereas Achnanthes subatomoides, Achnanthes marginulata, Pinnularia microstauron, and Psammothidium helveticum were most common in south basin lakes. One disconnected lake in the north basin had an assemblage dominated by Tabellaria flocculosa (66%) and Eunotia tenella (14%). Principal components analysis showed a clear separation between the north and south basins in lotic diatoms. Of the 10 most common species, streams in the south basin had greater abundances of Psammothidium helveticum, Achnanthes helvetica var. minor, Achnanthes marginulata, Achnanthes subatomoides, and Diatoma mesodon than the north basin, whereas north basin streams had higher abundances of Achnanthidium minutissimum, Aulacoseira alpigena, and Luticola goeppertiana. Lake outlet assemblages were similar to respective downstream lake inlet assemblages, and assemblages changed in composition along each basins longitudinal flow path. However, Aulacoseira alpigena had higher average abundances in north basin outlets than inlets, and Achnanthidium minutissimum, Psammothidium helveticum, and Achnanthes helvetica var. minor had higher average abundances in south basin outlets than inlets. In contrast, Diatoma mesodon, Fragilaria capucina, and Gomphonema parvulum had higher average abundances in south basin inlets than outlets. The spatial patterns in species composition reflected the hierarchical interaction of landscape features (geology, hydrology) on longitudinal gradients (lake position) in the stream/lake network.
Luc Ector - One of the best experts on this subject based on the ideXlab platform.
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Achnanthes Bory Sensu Stricto (Bacillariophyta) from Terrestrial Habitats of Rio de Janeiro (Brazil), with Description of Achnanthes pseudoinflata sp. nov.
Diversity, 2020Co-Authors: Mateusz Rybak, Luc Ector, Łukasz Peszek, Łukasz Skoczylas, Teresa Noga, Carlos E. WetzelAbstract:The aim of the present work was to present the ecological and morphological characteristics of species from the genus Achnanthes Bory sensu stricto, which develops in terrestrial mosses near the Rio de Janeiro Botanic Garden, Brazil. A literature comparison was made with other similar species, including the LM and SEM analysis of original material bearing Achnanthes inflata (Kutzing) Grunow housed at the Grunow Collection in Vienna, and data from the available literature. Samples were collected from clumps of moss growing on tree trunks, and from a concrete wall within the botanic garden. Four taxa from the genus Achnanthes were recorded: A. coarctata, A. inflata var. gibba, A. mauiensis and Achnanthes pseudoinflata sp. nov. The main morphological differences between these taxa were cell dimensions (length and width), striae and areolae density. The most common diatom species found in these samples were Humidophila sp. (90%), Humidophila contenta (74.8%), Luticola moreirae (17.9%), and Achnanthes pseudoinflata sp. nov. (7.4%).
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analysis of the type material of Achnanthes hauckiana grunow achnanthaceae bacillariophyceae
Botany Letters, 2020Co-Authors: Antonija Kulas, Luc Ector, Bart Van De Vijver, Marija Gligora UdovicAbstract:The type material of Achnanthes hauckiana Grunow has been investigated using light and scanning electron microscopy. The species, transferred to the genus Planothidium, was frequently reported from...
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Investigations of the type materials of Achnanthes parallela J.R.Carter and Achnanthes petersenii Hustedt (Bacillariophyceae) with comments on the genus Rossithidium Round & Bukhtiyarova
Botany Letters, 2019Co-Authors: Ingrid Jüttner, Carlos E. Wetzel, David M. Williams, Luc EctorAbstract:Achnanthes parallela J.R.Carter was described from Lindean, Scotland, a freshwater species widely distributed in lochs of the southern Scottish uplands. It is currently regarded as a synonym of Ach...
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Achnanthes citronella, A. trachyderma comb. nov. (Bacillariophyta) and allied taxa pertaining to the same morphological group
Phytotaxa, 2015Co-Authors: Catherine Riaux-gobin, Pierre Compère, Friedel Hinz, Luc EctorAbstract:Several diatoms in the family Achnanthaceae (Bacillariophyta), mainly from marine environments, have species with strongly apiculate, lemon-shaped valves. Some of them originally described under the genus Cocconeis ( i . e ., C . trachyderma or C . citronella ), while others were first described as Stauroneis species [ i . e . Stauroneis apiculata or S .(?) obesa ]. Afterwards, Cocconeis citronella has been recombined within Achnanthes by Hustedt. The type material of C . citronella from Albert Mann’s collection, housed in the Smithsonian Institution (US), has been examined with light microscope; some ambiguities are pointed out and new details added to the original description. The intricate history of the latter taxon is redrawn and comparison with allied taxa are tentatively addressed. Cocconeis trachyderma is lectotypified and recombined as Achnanthes trachyderma comb . nov . Stauroneis apiculata and S .(?) obesa are recombined as Achnanthes apiculata comb . nov . and Achnanthes obesa comb . nov . respectively. The examination with light and scanning electron microscope of several marine samples from the Society Archipelago details the unique morphology of Achnanthes trachyderma which, until recently, has been often misidentified as Achnanthes citronella due to certain similarities between both taxa.
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morphological variability within the achnanthidium minutissimum species complex bacillariophyta comparison between the type material of Achnanthes minutissima and related taxa and new freshwater achnanthidium species from portugal
Phytotaxa, 2015Co-Authors: Maria Helena Novais, Ingrid Jüttner, Bart Van De Vijver, Maria Manuela Morais, Lucien Hoffmann, Luc EctorAbstract:Two new taxa similar to Achnanthidium minutissimum were common and abundant in samples collected during a survey of benthic diatoms in watercourses from mainland Portugal. They are described here as A . duriense , sp . nov . and A . lusitanicum , sp . nov . In addition, the recently described A . pseudolineare is reported from various localities and its ecology is described in detail. The new Achnanthidium species from Portugal were compared with the type material of morphologically similar taxa: Achnanthidium microcephalum , Achnanthes minutissima , A . minutissima var. cryptocephala , A . minutissima var. inconspicua and A . nana . The analysis of this type material confirmed that Achnanthes minutissima var. cryptocephala should be regarded as a different taxon, and a new combination is proposed, Achnanthidium neocryptocephalum , stat., comb. et nom . nov . Achnanthes minutissima var. inconspicua is now considered as a younger synonym of Achnanthidium lineare . Based on a detailed morphological study of specimens of Achnanthes nana from Scotland, Nepal and Portugal, this taxon is transferred to the genus Achnanthidium as Achnanthidium nanum , comb . nov .
Kyung Ha Lee - One of the best experts on this subject based on the ideXlab platform.
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Ecological Studies on Togyo Reservoir in Chulwon, Korea. 7. The Colonization of Epilithic Algae on Artificial Substrata (Tiles) at Mesocosm
ALGAE, 2004Co-Authors: Kyung Ha Lee, Sook-kyung Yoon, Myung-soo HanAbstract:Patterns of epilithic algal colonization on artificial substrata (unglazed ceramic tiles) were investigated from 23rd April to 3rd July 1999 at weekly intervals over a 10 weeks period outside and inside the mesocosm in Togyo reservoir within the Civilian Passage Restriction Line near Demilitarized Zone (DMZ) in Korea. The highest standing crops of epilithic algae was 1,79810³ cells outside the mesocosm on 26th June and also inside the mesocosm those was 2,39110³ cells on 26th June, 9 weeks after the experiment began. The dominants outside the mesocosm were Achnanthes minutissima, Navicula bicephala, Oscillatoria angusta, Synedra delicastissima, S. tenuissima, S. ulna v. danica and Tabellaria flocculosa, and those inside the mesocosm were Achnanthes minitissima, Coenochloris polycocca, Fragilaria crotonenesis, Peridinium cinctum, Synedra delicatissima, Tabellaria flocculosa and Ulothrix subtilissima. Diatoms were most abundant and Achnanthes minutissima was the most important species colonizing on the tiles. Chlorophyll-a content was highest value of 5.4 mg on 19th June after 8 weeks growth outside the mesocosm and was 24.4 mg on 26th June, 9 weeks after the experiment began on tiles inside the mesocosm. It was also shown that unglazed ceramic tiles were a more suitable substratum for colonization than the glass slides. Consequently the substratum selection plays an important role in the colonization by the epilithic algal community.
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Ecological Studies on Togyo Reservoir in Chulwon, Korea. 8. The Epilithic Algal Community after the Experimental Acidification on the Artificial Substrata (Tiles) at Mesocosm
ALGAE, 2004Co-Authors: Kyung Ha Lee, Sook-kyung Yoon, Myung-soo HanAbstract:The epilithic algal communities on the artificial substrata (unglazed ceramic tiles) were investigated from 5th July to 24th July 1999 with two or three days intervals for elucidating the effects of the experimental acidification. They were harvested inside the mesocosm with and without the acid treatment on Togyo reservoir within the Civilian Passage Restriction Line near Demilitarized Zone (DMZ) in Korea. After the colonization of epilithic algal community, their standing crops revealed different patterns outside and inside the mesocosm. However the time lapse of 5 days was observed on the inside with acid treatment. The dominant species were different: Achnanthes minutissima was outside but Coenochloris polycocca was inside and inside with acid treatment. The differences in floral composition were also found. Achnanthes minutissima which has been the most important species in the colonization by the epilithic algal community of the mesocosm was less important at the lower pH. Coenochloris polycocca is a species well adapted to low pH.
