scholarly journals Peer Review #1 of "The structure and diversity of freshwater diatom assemblages from Franz Josef Land Archipelago: a northern outpost for freshwater diatoms (v0.1)"

2016 ◽  
Keyword(s):  
Peer Review ◽  
Diatom Assemblages ◽  
Franz Josef Land ◽  
Freshwater Diatoms ◽  
Freshwater Diatom

scholarly journals The structure and diversity of freshwater diatom assemblages from Franz Josef Land Archipelago: a northern outpost for freshwater diatoms

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e1705 ◽  
Author(s):  
Sergi Pla-Rabés ◽  
Paul B. Hamilton ◽  
Enric Ballesteros ◽  
Maria Gavrilo ◽  
Alan M. Friedlander ◽  
...  
Keyword(s):  
Seasonal Changes ◽  
Ph Gradient ◽  
Diatom Assemblages ◽  
Diatom Flora ◽  
Human Footprint ◽  
Franz Josef Land ◽  
Freshwater Diatoms ◽  
Arctic Conditions ◽  
Cell Densities ◽  
Freshwater Diatom

We examined diatom assemblages from 18 stream and pond samples in the Franz Josef Land Archipelago (FJL), the most northern land of Eurasia. More than 216 taxa were observed, revealing a rich circumpolar diatom flora, including many undescribed taxa. Widely distributed taxa were the most abundant by cell densities, while circumpolar taxa were the most species rich. Stream and pond habitats hosted different assemblages, and varied along a pH gradient.Diatoma tenuiswas the most abundant and ubiquitous taxon. However, several circumpolar taxa such asChamaepinnularia gandrupii, Cymbella botellus, Psammothidiumsp. andHumidophila laevissimawere also found in relatively high abundances. Aerophilic taxa were an important component of FJL diatom assemblages (Humidophilaspp.,Caloneisspp. andPinnulariaspp.), reflecting the large and extreme seasonal changes in Arctic conditions. We predict a decrease in the abundance of circumpolar taxa, an increase in local (α-) freshwater diatom diversity, but a decrease in regional diversity (circumpolar homogenization) as a result of current warming trends and to a lesser extent the increasing human footprint in the region.

scholarly journals Diatom diversity and distribution in Madeira Island streams (Portugal)

2020 ◽  
Vol 8 ◽  
Author(s):  
Catarina Ritter ◽  
Pedro Raposeiro ◽  
Vítor Gonçalves
Keyword(s):  
New Records ◽  
Distribution Patterns ◽  
Diatom Species ◽  
Diatom Assemblages ◽  
Field Campaign ◽  
Madeira Island ◽  
Madeira Archipelago ◽  
Freshwater Diatoms ◽  
Freshwater Diatom

Here, we present the data obtained from the samples collected in a field campaign during the spring of 2015 which aims for a better understanding of the diversity and distribution patterns of freshwater diatoms in Madeira Island. Following European and Portuguese standards and recommendations for routine diatom sampling and analysis, we collected samples in 40 sites, distributed in 27 permanent streams and identified the diatom species present, using general diatom floras and studies in Portuguese freshwater diatoms. Little is known about the diversity and distribution of freshwater diatom assemblages from Madeira Archipelago. This study reports a survey in 40 sites in Madeira Island distributed in 27 permanent streams. A total of 965 diatom (Bacillariophyta) occurrences were recorded, belonging to 130 different taxa from 44 genera and 27 families. The families with the highest number of occurrences were Bacillariaceae (176), Achnanthidiaceae (135) and Naviculaceae (133). The two diatom endemisms, described previously in Madeira Island (Lange-Bertalot 1993), Nitzschia macaronesica Lange-Bertalot and Navicula madeirensis Lange-Bertalot, were only observed in a small number of sites, located mostly at Laurissilva forest. Sixty species are new records, not only to Madeira Island, but also to the Madeira Archipelago.

Freshwater diatom communities of the Strømness Bay area, South Georgia

1996 ◽  
Vol 8 (4) ◽  
pp. 359-368 ◽  
Author(s):  
Bart van de Vijver ◽  
Louis Beyens
Keyword(s):  
Habitat Structure ◽  
Testate Amoebae ◽  
High Conductivity ◽  
Water Bodies ◽  
Acid Water ◽  
Diatom Assemblages ◽  
South Georgia ◽  
Bay Area ◽  
Diatom Communities ◽  
Freshwater Diatom

Modern diatom samples were collected from 43 sites across the Strømness Bay area of South Georgia. From 115 taxa belonging to 22 six diatom assemblages were distinguished. A CCA-analysis indicated that the assemblages are linked to pH and conductivity ranges, and habitat structure. The Eunotia paludosa var. paludosa - Eunotia subarcuatoides assemblage occurs in small acid water bodies. Samples of the Fragilaria germainii - Pinnularia aff. anglica assemblage are found in pools with a relatively high conductivity. The Fragilaria neoproducta assemblage and the Achnanthes subatomoides - Navicula vitabunda assemblage are mainly found in larger pools and lakes. This relationship between the assemblages and pH was comparable with results found in the testate amoebae fauna of South Georgia.

Freshwater Diatom Influx in Intertropical Atlantic: Relationships with Continental Records from Africa

1989 ◽  
Vol 32 (2) ◽  
pp. 229-243 ◽  
Author(s):  
Françoise Gasse ◽  
Bjørg Stabell ◽  
Elizabeth Fourtanier ◽  
Yolanda van Iperen
Keyword(s):  
Geographical Origin ◽  
Lacustrine Sediments ◽  
West African ◽  
Diatom Assemblages ◽  
Good Tool ◽  
Fine Sediments ◽  
Chloride Water ◽  
Winter Dust ◽  
Diatom Productivity ◽  
Freshwater Diatom

AbstractDiatom assemblages from modern West African rivers and from lacustrine sediments subjected to deflation represent the present-day sources of continental diatoms to the sea. Diatom productivity in large rivers is high, especially for the genus Melosira. Windblown diatoms derive mainly from the central and northern Sahara (summer dust plume) where saline chloride-water assemblages are widespread, or from the southern edge of the Sahara (winter dust plume) where Melosira-rich assemblages of dilute water predominate. Freshwater diatom peaks in Atlantic cores may reflect (1) phases of increased river influx, correlated with humid episodes on the continent or (2) phases of enhanced deflation and wind transport during arid episodes (the single hypothesis for fine sediments from mid-ocean sites). Genus Melosira dominates the freshwater assemblages of many modern and fossil marine samples, whatever the transport agent is. Therefore, it is not an accurate paleoclimate indicator by itself, but associated taxa may provide information on the environmental and geographical origin of the displaced diatoms. This tentative approach shows that freshwater diatoms in Atlantic cores may be a good tool for reconstructing paleoclimates and for establishing continent-ocean correlations if species analyses are made and if the continental distribution of the taxa encountered is considered.

Freshwater diatoms from Pleistocene-Holocene sediments in Bunger Oasis (East Antarctica)

2019 ◽  
pp. 233-2363
Author(s):  
Mark A. Mustafin ◽  
Zinaida V. Pushina ◽  
Andrey S. Biryukov
Keyword(s):  
Shallow Lake ◽  
High Salinity ◽  
East Antarctica ◽  
Diatom Assemblage ◽  
Freshwater Lakes ◽  
Quaternary Sediments ◽  
Holocene Sediments ◽  
Freshwater Diatoms ◽  
Western Shore ◽  
Freshwater Diatom

The monodominant freshwater diatom assemblage was in first established in Quaternary sediments at an altitude of 24 m in the outcrop on the western shore of the Rybiy Khvost Bay in the Bunger Oasis (East Antarctica). The diatom assemblage is dominated by the benthic Navicula shackletoni, characteristic of hypersaline lakes.The diatom assemblage reflects the conditions for the formation of deposits in a shallow lake with high salinity. This diatom assemblage differs from the previously established diatom associations in the Holocene sediments of the freshwater lakes of the Bunger Oasis.

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