Diatom species composition along a thermal gradient in the Portneuf River, Idaho, USA

Hydrobiologia ◽  
1989 ◽  
Vol 185 (1) ◽  
pp. 41-54 ◽  
Author(s):  
Deanna K. Vinson ◽  
Samuel R. Rushforth
Keyword(s):  
Species Composition ◽  
Thermal Gradient ◽  
Diatom Species ◽  
Portneuf River

Distribution of moss-inhabiting diatoms along an altitudinal gradient at sub-Antarctic Îles Kerguelen

2007 ◽  
Vol 19 (1) ◽  
pp. 17-24 ◽  
Author(s):  
Niek J.M. Gremmen ◽  
Bart van de Vijver ◽  
Yves Frenot ◽  
Marc Lebouvier
Keyword(s):  
Species Richness ◽  
Species Composition ◽  
Altitudinal Gradient ◽  
Cross Validation ◽  
Strong Relationship ◽  
Distribution Patterns ◽  
Common Species ◽  
Important Variable ◽  
Diatom Species ◽  
Expected Species Richness

Altitudinal gradients provide excellent opportunities to study relationships between species distribution and climatic variables. We studied the species composition of 39 samples of moss-inhabiting diatoms, collected at 50 m intervals from 100–650 m above sea level. The samples contained a total of 130 diatom species, of which 51 occurred in 10 or more samples. Altitude appeared to be the most important variable explaining variation in species composition. Of the 51 common species, 33 showed a significant relationship with altitude. Although the majority of the latter declined with increasing altitude, for nine species the probability of occurrence first increased with increasing elevation, but decreased again at higher altitudes, and four species increased systematically with elevation. As a result, expected species richness per sample decreased from an estimated 43 at 100 m to 25 species per sample at 650 m. Diatom distribution patterns proved to be suitable predictors of the altitudinal position of sample sites. Cross-validation yielded a strong relationship between predicted and observed altitudes.

scholarly journals Ecological assessment using diatom community in Avarga Toson Lake (Mongolia)

2021 ◽  
Vol 20 (1) ◽  
pp. 526-530
Author(s):  
Ts. Bukhchuluun
Keyword(s):  
Species Composition ◽  
Human Activities ◽  
Dominant Species ◽  
Sediment Accumulation ◽  
Ecological Assessment ◽  
Livestock Grazing ◽  
Diatom Species ◽  
Diatom Community ◽  
Diatom Communities ◽  
High Sediment

A total of 32 diatom species were recorded in Avarga Toson Lake. Motile diatom species are dominatingin diatom communities. The species composition of two coexisted lakes is markedly different. Diatom richness, speciescomposition, and dominant species indicate that Burd lake is polluted by livestock grazing or domestic pollution, andToson Lake is polluted by human activities with high sediment accumulation at the bottom.

New records of centric diatoms from Yakutia (Bolshoe Toko Lake): SEM morphology, ecology and distribution

2018 ◽  
Vol 52 (2) ◽  
pp. 245-252 ◽  
Author(s):  
S. I. Genkal ◽  
V. A. Gabyshev
Keyword(s):  
Species Composition ◽  
River Basin ◽  
New Records ◽  
Water Bodies ◽  
Centric Diatom ◽  
Diatom Species ◽  
Centric Diatoms ◽  
Sem Study ◽  
First Time ◽  
Sem Morphology

As a result of a SEM study of phytoplankton, the first data on centric diatom species composition in Bolshoye Toko Lake, Yakutia, were obtained. Ten species (Aulacoseira — 5, Cyclotella — 1, Discostella — 1, Handmannia — 1, Pliocaenicus — 1) were found, and one taxon from the genus Pliocaenicus was identified to the genus level. Of these, nine taxa are reported for the first time in the water bodies of the Aldan River basin and Discostella guslyakovyi in Yakutia.

scholarly journals Temporal variation in the phytoplankton community of Acapulco Bay, Mexico

2012 ◽  
Vol 3 (1) ◽  
pp. 4 ◽  
Author(s):  
Agustín A. Rojas-Herrera ◽  
Juan Violante Gonzalez ◽  
Sergio García-Ibáñez ◽  
Víctor M.G. Sevilla-Torres ◽  
Jaime S. Gil-Guerrero ◽  
...  
Keyword(s):  
Species Composition ◽  
Temporal Variation ◽  
Rainy Season ◽  
Phytoplankton Community ◽  
Species Abundance ◽  
Sampling Period ◽  
Dry Season ◽  
Nutrient Concentrations ◽  
Diatom Species ◽  
Oceanic Environments

<p>Species composition and abundance of the phytoplankton community in Acapulco Bay, Mexico, were studied from May to December 2009. Samples were collected at 5 stations (4 coastal and 1 oceanic) at 3 depths (1, 5 and 10 m). Eighty-seven species were identified: 54 dinoflagellates, 32 diatoms and 1 silicoflagellate. The community was structured mainly by adiaphoric species, that is, species adapted to both neritic and oceanic environments. Species abundance and composition varied significantly during the sampling period due to increased nutrient concentrations in the rainy season. Dinoflagellate species were more abundant during the dry season, and diatom species dominated numerically during the rainy season.</p>

Thalassiosira duostra (Bacillariophyta), a new for the flora of Russia freshwater diatom species

2019 ◽  
Vol 53 (1) ◽  
pp. 7-14
Author(s):  
S. I. Genkal
Keyword(s):  
Species Composition ◽  
Original Description ◽  
Published Data ◽  
Diatom Species ◽  
Centric Diatoms ◽  
Internal Part ◽  
Quantitative Characteristics ◽  
Internal Arrangement ◽  
Freshwater Diatom

The study of archive materials has made it possible to specify species composition of the genus Thalassiosira and discover a new for the flora of Russia representative of centric diatoms, T. duostra, in Cheboksary and Tsimlyansk reservoirs and the Oka River. The valve diameter and number of central futoportulae in the examined material differ insignificantly from the original description and published data. By the general valve outline, structure and arrangement of central and marginal fultoportulae and quantitative characteristics, T. duostra is very similar to Сonticribra weissflogii and Thalassiosira faurii, which may result in inaccurate identification of these species. In the Сonticribra weissflogii the rimoportula is located not in a ring of marginal fultoportulae but closer to the valve center and its internal part is significantly larger than in Thalassiosira duostra. The external arrangement of marginal fultoportulae (tubes of the processes are outwardly directed at different angles) and their internal arrangement (the processes are arranged in two rings, they are more dense in the ring which is closer to the valve face) is a good specific feature that differentiates T. duostra and T. faurii.

A regional paleolimnological assessment of the impact of clear-cutting on lakes from the west coast of Vancouver Island, British Columbia

2001 ◽  
Vol 58 (3) ◽  
pp. 479-491 ◽  
Author(s):  
Kathleen Laird ◽  
Brian Cumming ◽  
Rick Nordin
Keyword(s):  
Organic Matter ◽  
Species Composition ◽  
West Coast ◽  
Forest Harvesting ◽  
Diatom Species ◽  
The West ◽  
Clear Cutting ◽  
Before And After ◽  
The Impact ◽  
Reference Lakes

The impact of forest harvesting on lakes within the temperate rainforest on the west coast of Vancouver Island was examined in a paleolimnological study of four lakes that had 35–92% of their watersheds progressively clear-cut over a period of 15–30 years (impact lakes) and four lakes that had experienced little or no known anthropogenic disturbance in their watersheds (reference lakes). Changes in diatom species composition and percent organic matter in the 210Pb-dated sediment cores were compared over the last 100 years in each of the impact lakes before and after the onset of forest harvesting, which began in 1950, and before and after 1950 in the four reference lakes. Only one impact lake showed significant changes in percent organic matter. Significant changes (p < 0.05) in species composition following forest harvesting were detected in all four impact lakes and in one of the four reference lakes. However, the changes in diatom species composition following clear-cutting in the impact lakes were small, with changes in the relative abundance of the most common species being maximally 20%, but more typically 3–10%.

scholarly journals Diatom (Bacillariophyceae) flora of early Holocene freshwater sediments from Skalafjord, Faeroe Islands

2003 ◽  
Vol 22 (2) ◽  
pp. 183-208 ◽  
Author(s):  
Ewa Witon ◽  
Andrzej Witkowski
Keyword(s):  
Species Composition ◽  
Northern Europe ◽  
Diatom Species ◽  
Marine Waters ◽  
Core Section ◽  
Lower Water Level ◽  
Storegga Slide ◽  
Marine Flora ◽  
Rising Sea Level ◽  
Freshwater Diatom

Abstract. Relative abundance data of diatom (Bacillariophyceae) species were generated for sediment core SKPC-01B from the Skalafjord, Faeroe Islands. The record shows distinct temporal changes in species composition. In the lowermost 65 cm of the 230 cm long core a species-rich freshwater diatom assemblage was found. Most of the taxa observed in this section are typical of oligotrophic to dystrophic lakes in northern Europe (Scandinavia, Iceland and Spitsbergen). Above this interval the diatom flora is dominated by marine taxa. The change from a freshwater to a marine flora is inferred to be caused by rising sea-level that took place about 7700–6400 years BP. Drastic changes in the diatom species composition within the transitional core section show that environmental change in the Skalafjord took place in several pulses. The first stage included strong inflow (possibly catastrophic) of marine waters. As a possible trigger of this phenomenon the tsunami released by the Storegga Slide is proposed. Before the final flooding by marine waters, freshwater conditions were re-established within the Skalafjord. These results have important implications for the interpretation of the palaeogeographical development of the Eysturoy area. Hence, it is suggested that the Storegga Slide led to inflow of marine waters at a distinctly lower water level in the area of the Skalafjord than proposed in recent publications and that the inundation of the threshold in the fjord happened after the tsunami.

A regional paleolimnological assessment of the impact of clear-cutting on lakes from the central interior of British Columbia

2001 ◽  
Vol 58 (3) ◽  
pp. 492-505 ◽  
Author(s):  
Kathleen Laird ◽  
Brian Cumming
Keyword(s):  
British Columbia ◽  
Organic Matter ◽  
Species Composition ◽  
Sediment Cores ◽  
Forest Harvesting ◽  
Diatom Species ◽  
Clear Cutting ◽  
Before And After ◽  
The Impact ◽  
Reference Lakes

The impact of forest harvesting on lakes within the central interior of British Columbia was examined in a paleolimnological study of six lakes that had 28–82% of their watersheds clear-cut (impact lakes) and four lakes that had experienced no logging in their watersheds (reference lakes). Changes in diatom species composition and percent organic matter in 210Pb-dated sediment cores were compared over the last 80 years in each of the impact lakes before and after the onset of forest harvesting and, in the reference lakes, before and after 1960 (the average onset of logging in five of the six impact lakes) and before and after 1975 (the onset of logging in one impact lake). Significant changes in species composition of diatoms following forest-harvesting activities were detected in four of the impact lakes and three of the reference lakes; however, the changes in diatom species composition were small, with changes in the relative abundance of the most common species being at most 11%. Significant increases in the percent organic matter after 1960 were found in one impact lake and three reference lakes; again these changes were small, with increases of 2–5%.

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