scholarly journals Influence of environmental factors on the interannual variability of macrozoobenthos of the floodplain lakes

2021 ◽  
Vol 4 (2) ◽  
Author(s):  
Alexandr A. Prokin ◽  
Dmitry G. Seleznev ◽  
Alexander I. Tsvetkov
Keyword(s):  
Environmental Factors ◽  
Floodplain Lakes ◽  
Species Number ◽  
Water Conductivity ◽  
Structure Of Communities ◽  
Composition And Structure ◽  
Total List ◽  
Associated Species ◽  
First Time ◽  
Temperature Water

The changes in depth, temperature, water conductivity, and dissolved oxygen concentration in six floodplain lakes are described in regard to the dynamics of spring flooding and overgrowth by macrophytes. The influence of these factors on the composition and structure of macrozoobenthos communities is analyzed. The observed number of species refers to 60% of the theoretically predicted, which allows us to assume that the fauna has been identified sufficiently enough to analyze the interannual changes. Six families of invertebrates, which form together 55% of the fauna, are the richest in species number. The distribution of species by families also confirms enough data on the fauna representing in the obtained and analyzed samples. Abundance of only two species depend significantly on environmental characteristics; the taxonomic and trophic groups exhibit more links to the environment. Totally, 45 mutually associated species (43.7% of the total list) have been identified; they form 8 groups that are characterized by connectivity of the species composition ranging as 0.28–1.0 link/species, the average connectivity strength of 0.67–0.80, and the strength of species connectivity of 0.38–0.84 (the last index is proposed for the first time). Groups of mutually associated species may be defined as “faunistic cores of communities” confined to certain lakes and/or years of study. According to the redundancy analysis with multidimensional scaling ordination, the environmental factors affect the quantitative characteristics and overall taxonomic richness of communities. The indices, describing the structure of communities, do not depend on the analyzed factors, which is also confirmed by correlation analysis.

Effect of Artificial Grassland Establishing on the Vegetation Restoration in the Degraded Ecosystem

2014 ◽  
Vol 955-959 ◽  
pp. 3474-3478
Author(s):  
Tie Jun Sun
Keyword(s):  
Species Diversity ◽  
Community Composition ◽  
Early Period ◽  
Vegetation Restoration ◽  
Bromus Inermis ◽  
Perennial Grasses ◽  
Species Number ◽  
Composition And Structure ◽  
Degraded Ecosystem ◽  
Annual Grasses

Experiment was executed to plant Bromus inermis artificially in the degraded ecosystem, and study effect of grass planting on vegetation restoration. The results indicated that natural vegetation restored rapidly in the degraded ecosystem in two years after grass planted. But species diversity changed little in the early period of vegetation restoration, while vegetation biomass, coverage and anti-interference improved quickly. In addition, species number and important value of perennial grasses increased while those of annual grasses decreased. Then community composition with annual plants mainly changed gradually into that with perennial plants mainly after Bromus inermis planted. However, overground biomass and coverage of restored vegetation and dominance of Bromus inermis planted decreased after vegetation cut once a year. And species diversity and important value of annual grasses increased. Thus it could be good for uniformity of species distribution and stability of community composition and structure to develop.

scholarly journals Development of passive sampler POCIS for the analysis of polar pesticides in surface water

2015 ◽  
Vol 18 (2) ◽  
pp. 132-144
Author(s):  
Trang Thi Nhu Tran ◽  
Ty Thi Pham ◽  
Hai Lam Son Truong
Keyword(s):  
Surface Water ◽  
Environmental Factors ◽  
Pesticide Residues ◽  
Passive Sampling ◽  
Sampling Method ◽  
Passive Sampler ◽  
Polar Pesticides ◽  
Sampling Process ◽  
European Standards ◽  
First Time

The first time in Vietnam a passive sampling method has been developed to analyse the polar pesticides in surface water. The initial investigations of POCIS were performed for 7 polar pesticides as simazine,thiodicarb, carbofuran, chlortoluron, atrazine, isoproturon, and diuron. We determined the sampling rates RS for these substances ranged from 0.369 to 0.962 L day- 1. The obtained values of ku and RS showed the important influence of environmental factors such as flow on the ability to integrate polar pesticides in passive sampling process. This method can be applied to determine these 7 polar pesticides in surface water at trace levels according to European standards for pesticide residues in water (< 0.1 μg L-1).

scholarly journals Benthos Algae Communities of Saline Rivers in the Lake Elton Basin: Taxonomic and Quantitative Structure

2021 ◽  
pp. 383-397
Author(s):  
O. G. Gorokhova ◽  
Т. D. Zinchenko
Keyword(s):  
Dominant Species ◽  
Structural Transformations ◽  
Hypersaline Lake ◽  
Quantitative Structure ◽  
Volgograd Region ◽  
Structure Of Communities ◽  
Saline Rivers ◽  
Critical Salinity ◽  
Lake Elton ◽  
First Time

For the first time, an assessment was given of the taxonomic and quantitative structure of the phytobenthos of seven saline rivers in the basin of the hypersaline lake Elton (Volgograd Region). Main types of algacenoses developing on substrates were revealed, namely: diatom phytobenthos, communities of diatoms with cyanoprokaryotes, cyanobacterial films and mats, and epiphyton. The phytobenthos consists of local, mosaic-distributed communities with a small similarity of their species composition. The algacenosis structure is determined by Bacillariophyta (with the predominance of species of the genus Navicula) and Cyanoprokaryota (of the genera Phormidium, Leptolyngbya, and Geitlerinema). The abundance and biomass values vary widely, reaching their highest values (109,834–417,472 mln cells/m2 and 523.6–567.6 g/m2 ) in cyanobacterial communities of mesohaline rivers with their salinity up to 16–19 g/L. Mineralization as a factor influencing the structure of communities, most rigidly acts in the estuarine sections of rivers, by controlling the composition of the dominant species. For critical salinity values (> 70 g/L), characteristic structural transformations of communities by the type of replacement of planktonic and benthic Bacillariophyta and Cyanoprokaryota by planktonic Chlorophyta (of the Dunaliella genus) and picoplankton were established.

scholarly journals Doppler temperatures from O(<sup>1</sup>D) airglow in the daytime thermosphere as observed by the Wind Imaging Interferometer (WINDII) on the UARS satellite

2002 ◽  
Vol 20 (2) ◽  
pp. 203-212 ◽  
Author(s):  
C. Lathuillère ◽  
W. A. Gault ◽  
B. Lamballais ◽  
Y. J. Rochon ◽  
B. H. Solheim
Keyword(s):  
Atmospheric Composition ◽  
Large Set ◽  
Temperature Variations ◽  
Data Processing Software ◽  
Imaging Interferometer ◽  
Composition And Structure ◽  
Instruments And Techniques ◽  
The Mean ◽  
First Time ◽  
Good Agreement

Abstract. From 1992 to 1997, the WINDII interferometer on board the UARS satellite acquired a large set of thermospheric data from the O(1D) and O(1S) airglows. We report here for the first time on daytime O(1D) Doppler temperatures obtained with version 5.11 of the WINDII data processing software. Using a statistical analysis of the temperatures independently measured by the two WINDII fields of view, we estimate that the temperature variations larger than 40 K can be considered as geophysical. Comparisons of WINDII temperatures measured during magnetically quiet days with temperatures obtained by the MSIS-90 and DTM-94 thermospheric models show a 100 K bias. We demonstrate, however, that the modeled temperature variations represent very well the mean temperature variation observed by WINDII over 4 years. We also show that the observed latitudinal/local time variation is in very good agreement with the two empirical models. Finally, the temperature variations during a magnetically disturbed day are found to be qualitatively well represented in form by the models, but largely underestimated. The presence of non-thermal atoms and instrument related issues are discussed as possible explanations for the 100 K bias between the WINDII Doppler temperatures and the empirical models.Key words. Atmospheric composition and structure (air-glow and aurora; pressure, density and temperature; instruments and techniques)

scholarly journals Impact of environmental factors on growth and satratoxin G production by strains of Stachybotrys chartarum

2012 ◽  
Vol 5 (1) ◽  
pp. 37-43 ◽  
Author(s):  
S. Frazer ◽  
J. Pestka ◽  
J. Kim ◽  
A. Medina ◽  
D. Aldred ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Water Availability ◽  
Indoor Environment ◽  
Potato Dextrose Agar ◽  
Enzyme Linked Immunosorbent Assay ◽  
Stachybotrys Chartarum ◽  
Data Sets ◽  
Elisa Method ◽  
Contour Maps ◽  
First Time

The black mould Stachybotrys chartarum and its mycotoxins have been linked to damp building-associated illnesses. The objective of this study was to determine the effects of water availability (water activity, aw) and temperature on growth and production of satratoxin G (SG) by a macrocyclic trichothecene-producing strain (IBT 7711) and non-producing strain (IBT 1495) of S. chartarum. Growth studies were carried out on potato dextrose agar modified with glycerol to 0.995-0.92 aw at 10-37 °C. Growth extension was measured and the cultures were extracted after 10 days and a competitive enzyme-linked immunosorbent assay (ELISA) method used to quantify the SG content. Growth was optimal at 25 to 30 °C at 0.995 aw, but this was modified to 0.98 aw at 30 °C for both strains (1.4-1.6 mm/day, respectively). The ELISA method revealed that, in contrast to growth, SG production was maximal at 20 °C with highest production at 0.98 aw (approximately 250 μg/g mycelia). When water was freely available (0.995 aw), SG was maximally produced at 15 °C and decreased as temperature was increased. Interestingly, the strain classified as a non-toxigenic produced very low amounts of SG (<1.6 μg/g mycelia) that were maximal at 25 °C and 0.98 aw. Contour maps for growth and SG production were developed from these data sets. These data have shown, for the first time, that growth and SG production profiles are very different in relation to key environmental conditions in the indoor environment. This will be very useful in practically determining the risk from exposure to S. chartarum and its toxins in the built environment.

scholarly journals Pleistocene climate change and the formation of regional species pools

2019 ◽  
Vol 286 (1905) ◽  
pp. 20190291 ◽  
Author(s):  
Joaquín Calatayud ◽  
Miguel Ángel Rodríguez ◽  
Rafael Molina-Venegas ◽  
María Leo ◽  
Jose Luis Horreo ◽  
...  
Keyword(s):  
Historical Events ◽  
Deep Time ◽  
The North ◽  
Relative Contribution ◽  
Pleistocene Climate ◽  
Composition And Structure ◽  
Species Pools ◽  
Dispersal Barriers ◽  
Climate Cooling ◽  
Associated Species

Although the description of bioregions dates back to the origin of biogeography, the processes originating their associated species pools have been seldom studied. Ancient historical events are thought to play a fundamental role in configuring bioregions, but the effects of more recent events on these regional biotas are largely unknown. We used a network approach to identify regional and sub-regional faunas of European Carabus beetles and developed a method to explore the relative contribution of dispersal barriers, niche similarities and phylogenetic history on their configuration. We identify a transition zone matching the limit of the ice sheets at the Last Glacial Maximum. While southern species pools are mostly separated by dispersal barriers, in the north species are mainly sorted by their environmental niches. Strikingly, most phylogenetic structuration of Carabus faunas occurred during the Pleistocene. Our results show how extreme recent historical events—such as Pleistocene climate cooling, rather than just deep-time evolutionary processes—can profoundly modify the composition and structure of geographical species pools.

Occurrence of Hybrids Between Longnose Sucker (Catostomus catostomus) and White Sucker (C. commersoni) in Upper Kananaskis Reservoir, Alberta

1973 ◽  
Vol 30 (4) ◽  
pp. 557-560 ◽  
Author(s):  
Joseph S. Nelson
Keyword(s):  
Environmental Factors ◽  
Habitat Disturbance ◽  
White Sucker ◽  
Morphometric Data ◽  
Species Introduction ◽  
Isolating Mechanisms ◽  
Catostomus Catostomus ◽  
Longnose Sucker ◽  
First Time

Hybrids between longnose sucker (Catostomus catostomus) and white sucker (C. commersoni), identified on the basis of intermediacy in several scale counts and in morphometric data, are recorded for the first time from Canada. The weakening of isolating mechanisms permitting hybridization was attributed to environmental factors, particularly species introduction and habitat disturbance. There was no evidence of swamping.

scholarly journals Parasite Community of Cichla kelberi (Perciformes, Cichlidae) in the Três Marias Reservoir, Minas Gerais, Brazil

2014 ◽  
Vol 23 (3) ◽  
pp. 367-374 ◽  
Author(s):  
Michelle Daniele Santos-Clapp ◽  
Marilia Carvalho Brasil-Sato
Keyword(s):  
Parasite Community ◽  
Minas Gerais ◽  
Ecological Requirements ◽  
Biogeographical Distribution ◽  
Positive Correlations ◽  
Associated Species ◽  
First Time ◽  
Peacock Bass ◽  
Três Marias Reservoir

A total of 112 specimens of yellow peacock bass, Cichla kelberi, were collected in the Três Marias Reservoir, upper São Francisco River, State of Minas Gerais, between 2004 and 2005. Twelve species of parasites were collected: two species of ectoparasites (the monogenetic Gussevia sp. and the copepod Ergasilus sp.); and ten species of endoparasites, including four species of adult endoparasites: the cestodes Proteocephalus macrophallus and P. microscopicus, and the nematodes: Capillostrongyloides sentinosa and Rhabdochona acuminata, and six species of larval endoparasites: the metacercariae of Austrodiplostomum compactum and the nematodes: Hysterothylacium sp., Contracaecum sp. Type 1, Procamallanus (Spirocamallanus) inopinatus, Spiroxys sp., and Goezia sp.. A significant positive correlation in the abundance of the two adult endoparasites species, P. macrophallus and P. microscopicus, may indicate that such associated species had the same ecological requirements. The positive correlations between the prevalence of the larval endoparasites, Hysterothylacium sp. and A. compactum, may indicate that there was opportunism for the two generalists species. Ergasilus sp., C. sentinosa, R. acuminata and Hysterothylacium sp. were recorded for the first time in C. kelberi, and this increased their list of known hosts. In addition, both proteocephalid species and C. sentinosa can extend their known biogeographical distribution to the Três Marias Reservoir.

scholarly journals Modelling the relationship between environmental factors, transcriptional genes and deoxynivalenol mycotoxin production by strains of two Fusarium species

2010 ◽  
Vol 8 (54) ◽  
pp. 117-126 ◽  
Author(s):  
M. Schmidt-Heydt ◽  
R. Parra ◽  
R. Geisen ◽  
N. Magan
Keyword(s):  
Environmental Factors ◽  
Control Strategies ◽  
Fusarium Species ◽  
Fusarium Culmorum ◽  
Mycotoxin Production ◽  
Contour Maps ◽  
Complex Interactions ◽  
Time Changes ◽  
First Time ◽  
The Relationship

The effect of changes in temperature/water activity ( a w ) on growth, deoxynivalenol (DON) production and trichothecene gene cluster expression (18 genes) for strains of Fusarium culmorum and Fusarium graminearum was studied. The expression data for six key transcription genes ( TRI4, TRI5 , TRI6, TRI10, TRI12 and TRI13 ) were analysed using multiple regression analyses to model the relationship between these various factors for the first time. Changes in a w and temperature significantly ( p = 0.05) affected growth and DON. Microarray data on expression of these genes were significantly related to DON production for both strains. Multi-regression analysis was done and polynomial models found to best fit the relationship between actual/predicted DON production relative to the expression of these TRI genes and environmental factors. This allowed prediction of the amounts of DON produced in two-dimensional contour maps to relate expression of these genes to either a w or temperature. These results suggest complex interactions between gene expression ( TRI genes), environmental factors and mycotoxin production. This is a powerful tool for understanding the role of these genes in relation to environmental factors and enables more effective targeted control strategies to be developed.

scholarly journals ‘Out of tune’: consequences of inbreeding on bird song

2016 ◽  
Vol 283 (1835) ◽  
pp. 20161142 ◽  
Author(s):  
Raïssa A. de Boer ◽  
Marcel Eens ◽  
Wendt Müller
Keyword(s):  
Environmental Factors ◽  
Bird Song ◽  
Song Learning ◽  
Male Quality ◽  
Limited Evidence ◽  
Serinus Canaria ◽  
Genetic And Environmental Factors ◽  
First Time

The expression of bird song is expected to signal male quality to females. ‘Quality’ is determined by genetic and environmental factors, but, surprisingly, there is very limited evidence if and how genetic aspects of male quality are reflected in song. Here, we manipulated the genetic make-up of canaries ( Serinus canaria ) via inbreeding, and studied its effects upon song output, complexity, phonetics and, for the first time, song learning. To this end, we created weight-matched inbred and outbred pairs of male fledglings, which were subsequently exposed to the same tutor male during song learning. Inbreeding strongly affected syllable phonetics, but there were little or no effects on other song features. Nonetheless, females discriminated among inbred and outbred males, as they produced heavier clutches when mated with an outbred male. Our study highlights the importance of song phonetics, which has hitherto often been overlooked.

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