scholarly journals Relação Fitoplâncton - Zooplâncton em Ambiente Oligotrófico(Fitoplankton-Zooplankton Relationship in Oligotrophic Environment)

2017 ◽  
Vol 10 (5) ◽  
pp. 1368
Author(s):  
Indira Maria Estolano Macêdo ◽  
Fábio Henrique Portella Corrêa de Oliveira ◽  
Osman Oliveira de Lira ◽  
Maria Do Rosário de Fátima Padilha ◽  
José Machado ◽  
...  
Keyword(s):  
Physicochemical Parameters ◽  
Abiotic Factors ◽  
Total Biomass ◽  
Positive Relation ◽  
Statistical Tools ◽  
Multivariate Statistical ◽  
Ecological Relationships ◽  
Abiotic Variables ◽  
Oligotrophic Ecosystem ◽  
Planktonic Community

Ecossistemas lênticos de pequeno porte respondem rapidamente às condições ambientais, influenciando a comunidade planctônica devido às flutuações bióticas e abióticas do corpo d’água. Este estudo teve como objetivo analisar os parâmetros físico-químicos e a identificação da comunidade planctônica (fitoplâncton, zooplâncton e bacterioplâncton) presentes no reservatório, correlacionando esses organismos em um ambiente oligotrófico. As análises foram realizadas mensalmente no período de julho/2014 a junho/2016. A análise de todos os parâmetros físico-químicos e biológicos foi realizados de acordo com metodologia oficial. Empregou-se ferramentas estatísticas multivariadas (ACP) e teste de Pearson para avaliar a correlação entre as variáveis abióticas e a biomassa total de cada grupo planctônico. Nesta pesquisa encontrou-se uma relação positiva entre as biomassas totais da comunidade zooplânctonica e fitoplânctonica, entretanto componentes do bacterioplancton, não foi significativo. Estes resultados indicaram que a predação e/ou competição não são relações ecológicas significativas entre as espécies zooplanctônicas e fitoplanctônicas presentes neste ecossistema oligotrófico, existindo assim uma relação favorável entre os grupos estudados. Desta forma, o desenvolvimento desses organismos foi influenciado pelas mesmas variáveis abióticas (manganês, dureza e temperatura), atuando de forma direta no estabelecimento de suas biomassas. A B S T R A C TSmall lentic ecosystems respond rapidly to environmental conditions, influencing the planktonic community due to the biotic and abiotic fluctuations of the water body. This study aimed to analyze the physicochemical parameters and identification of the planktonic community (phytoplankton, zooplankton, and bacterioplankton) present in the reservoir, correlating these organisms in an oligotrophic environment. The analyses were performed monthly from July/2014 to June/2016. The analysis of all physicochemical and biological parameters was carried out according to the conventional methodology. Multivariate statistical tools (PCA) and Pearson's test were used to evaluate the correlation between the abiotic variables and the total biomass of each planktonic group. In this research was found a positive relation between the total biomasses of the zooplanktonic community and phytoplanktonic. However, components of bacterioplankton were not significant. These results indicate that predation and competition are not significant ecological relationships between zooplanktonic and phytoplanktonic species present in this oligotrophic ecosystem, and there is a favorable relationship between the studied groups. In this way, the development of these organisms was influenced by the same abiotic variables (manganese, hardness, and temperature), acting directly in the establishment of their biomasses.Keywords: plankton, reservoir, abiotic factors. 

scholarly journals EVALUATION OF GROUNDWATER QUALITY IN AL-WAFFA AND KUBAYSA AREAS USING MULTIVARIATE STATISTICAL ANALYSIS, AL-ANBAR, WESTERN IRAQ

2020 ◽  
Vol 53 (2D) ◽  
pp. 107-127
Author(s):  
Adnan Fayydh
Keyword(s):  
Groundwater Quality ◽  
Multivariate Statistics ◽  
Physicochemical Parameters ◽  
Correlation Technique ◽  
Strong Correlations ◽  
Statistical Tools ◽  
Multivariate Statistical ◽  
Piper Diagram ◽  
Drinking Purposes ◽  
Classification Type

The groundwater is a substantial source of fresh water and has been used for various anthropogenic uses. The aim of this work is to investigate groundwater quality and type in kubaysa and AL-Waffa areas, Anbar, Iraq using multivariate statistics approach. The groundwater was sampled from ten wells for each region during the period from October 2018 to March 2019. The levels of T, TUR, pH, EC, TDS, DO, COD, TH, Na+, K+, Ca2+, Mg2+, NH4+, Cl-, F-, SO42-,, NO3-, HCO3-, S-2 and SiO2, were measured. The majority of the physicochemical parameters exceed the permissible guidelines. Pearson’s Correlation technique, multivariate statistical tools such as cluster analysis and principle component analysis were applied to determine the groundwater type. For Al –Waffa area, the EC had a positive strong correlation with TDS, Na+, Cl-. The TDS had positive strong correlations with NO3-. TH and Ca2+ possess a very good positive correlation between each other and positive strong correlations with SO42-. Sodium has positive strong correlations with k+ and Cl-. For the kubaysa area, the EC has positive strong correlations with TDS, Na+, K+ and Cl-. The TDS have positive strong correlations with TH, Ca2+, Na+, K+, Cl-, and SO42-. The piper diagram indicates that the groundwater types in AL-Waffa and kubaysa regions are Ca2+, Mg2+, SO42- and Ca2+, Mg2+,Cl-, SO42 respectively. The results showed unsuitable water for drinking purposes and need to be treated. The main finding of the current study is a suggestion to use the multivariate statistics technique in determining the groundwater classification type as an alternative method for the piper diagram.

scholarly journals Temporal variation of the phytoplankton community at short sampling intervals in the Mundaú reservoir, Northeastern Brazil

2008 ◽  
Vol 22 (4) ◽  
pp. 970-982 ◽  
Author(s):  
Ênio Wocyli Dantas ◽  
Ariadne do Nascimento Moura ◽  
Maria do Carmo Bittencourt-Oliveira ◽  
João Dias de Toledo Arruda Neto ◽  
Airlton de Deus C. Cavalcanti
Keyword(s):  
Phytoplankton Community ◽  
Abiotic Factors ◽  
Distribution Patterns ◽  
Northeastern Brazil ◽  
Cylindrospermopsis Raciborskii ◽  
Algae Biomass ◽  
Dissolved Phosphorus ◽  
Sampling Intervals ◽  
Abiotic Variables ◽  
Dry And Rainy Seasons

The aim of this study was to determine how abiotic factors drive the phytoplankton community in a water supply reservoir within short sampling intervals. Samples were collected at the subsurface (0.1 m) and bottom of limnetic (8 m) and littoral (2 m) zones in both the dry and rainy seasons. The following abiotic variables were analyzed: water temperature, dissolved oxygen, electrical conductivity, total dissolved solids, turbidity, pH, total nitrogen, nitrite, nitrate, total phosphorus, total dissolved phosphorus and orthophosphate. Phytoplankton biomass was determined from biovolume values. The role abiotic variables play in the dynamics of phytoplankton species was determined by means of Canonical Correspondence Analysis. Algae biomass ranged from 1.17×10(4) to 9.21×10(4) µg.L-1; cyanobacteria had biomass values ranging from 1.07×10(4) to 8.21×10(4) µg.L-1. High availability of phosphorous, nitrogen limitation, alkaline pH and thermal stability all favored cyanobacteria blooms, particularly during the dry season. Temperature, pH, total phosphorous and turbidity were key factors in characterizing the phytoplankton community between sampling times and stations. Of the species studied, Cylindrospermopsis raciborskii populations were dominant in the phytoplankton in both the dry and rainy seasons. We conclude that the phytoplankton was strongly influenced by abiotic variables, particularly in relation to seasonal distribution patterns.

scholarly journals The effect of ice phenology exerted on submerged macrophytes through physicochemical parameters and the phytoplankton abundance

2015 ◽  
Author(s):  
Wojciech Ejankowski ◽  
Tomasz Lenard
Keyword(s):  
Physicochemical Parameters ◽  
Aquatic Vegetation ◽  
Myriophyllum Spicatum ◽  
Ice Cover ◽  
Water Transparency ◽  
Ceratophyllum Demersum ◽  
Total Biomass ◽  
Eutrophic Lakes ◽  
Macrophyte Species ◽  
Tn:Tp Ratio

<p>The physicochemical parameters of water, the concentration of chlorophyll-<em>a</em> and the submerged aquatic vegetation (SAV) were studied to evaluate the effects of different winter seasons on the biomass of macrophytes in shallow eutrophic lakes. We hypothesised that a lack of ice cover or early ice-out can influence the physicochemical parameters of water and thus change the conditions for the development of phytoplankton and SAV. The studies were conducted in four lakes of the Western Polesie region in mid-eastern Poland after mild winters with early ice-out (MW, 2011 and 2014) and after cold winters with late ice-out (CW, 2010, 2012 and 2013). The concentrations of soluble and total nitrogen, chlorophyll-<em>a</em> and the TN:TP ratio in the lakes were considerably higher, whereas the concentration of soluble and total phosphorus and water transparency were significantly lower after the MW compared with after the CW. No differences were found in water temperature, reaction and electrolytic conductivity. Low water turbidity linked with low concentration of chlorophyll-<em>a</em> after the CW resulted in increased water transparency and the total biomass of the SAV. The negative effect of the MW on the macrophyte species was stronger on more sensitive species (<em>Myriophyllum spicatum</em>,<em> Stratiotes aloides</em>) compared with shade tolerant <em>Ceratophyllum demersum</em>. Our findings show that the ice cover phenology affected by climate warming can change the balance between phytoplankton and benthic vegetation in shallow eutrophic lakes, acting as a shift between clear and turbid water states. We speculate that various responses of macrophyte species to changes in the water quality after two winter seasons (CW and MW) could cause alterations in the vegetation biomass, particularly the expansion of shade tolerance and the decline of light-demanding species after a series of mild winters.</p>

scholarly journals Relative importance of the bacteria Brucella, Salmonella, Staphylococcus and other indicator bacteria in some mountain farm waters in West-Cameroon (Central Africa) and the potential role of some environmental factors

2020 ◽  
Vol 8 (2) ◽  
pp. 081-084
Author(s):  
Pierrette Ngo Bahebeck ◽  
Mireille Ebiane Nougang ◽  
Paul Alain Nana ◽  
Claire Stéphane Metsopkeng ◽  
Antoine Tamsa Arfao ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Surface Waters ◽  
Brucella Abortus ◽  
Physicochemical Parameters ◽  
Potential Role ◽  
Abiotic Factors ◽  
Central Africa ◽  
Mountainous Regions ◽  
Brucella Suis

A bacteriological and physicochemical study was conducted in the waters of farms in mountainous regions of Cameroon. The different water samples were collected during two campaigns in December 2018 and February 2019. Ten stations representing the drinking water supply points in our study area were identified. The results showed that these waters contained both pathogenic and commensal fecal bacteria. The highest abundances reached 10x103 CFU/100mL for Salmonella sp., 72x103 CFU/100mL for Staphylococcus aureus, 102x103 CFU/100mL for Brucella suis and 40x103 CFU/100mL for Brucella abortus. These abundances were subject to space-time fluctuations. Water contamination by tweezers was not general and was present only in surface waters (rivers and ponds). The water in the ponds, rivers and wells analyzed were all basic, with low mineralization on average. The dissolved oxygen ranged from 37.5 to 70.6%, nitrate from 3.7 to 19.8 mg/L and iron from 0.01 to 3.5 mg/L. Most of the physicochemical parameters were relatively stable during the two campaigns. The degree of correlation between the physicochemical parameters and the abundance dynamics of the isolated bacteria was heterogeneous. This was clearly more pronounced with Salmonella sp. and Brucella suis. This would be due to the fraction of metabolically active cells present when the bacteria are exposed to unfavorable conditions. Correlations with the abiotic factors were less marked with Staphylococcus aureus and Brucella abortus; this would be due to their tolerance to environmental stresses.

scholarly journals Evaluation of the Swat River, Northern Pakistan, water quality using multivariate statistical techniques and water quality index (WQI) model

2020 ◽  
Vol 27 (31) ◽  
pp. 38545-38558 ◽  
Author(s):  
Shah Jehan ◽  
Ihsan Ullah ◽  
Sardar Khan ◽  
Said Muhammad ◽  
Seema Anjum Khattak ◽  
...  
Keyword(s):  
Water Quality ◽  
Health Risk ◽  
Physicochemical Parameters ◽  
Quality Index ◽  
Statistical Techniques ◽  
Northern Pakistan ◽  
Multivariate Statistical Techniques ◽  
Multivariate Statistical ◽  
Poor Water Quality ◽  
Swat River

Abstract This study evaluates the characteristics of water along the Swat River, Northern Pakistan. For this purpose, water samples (n = 30) were collected and analyzed for physicochemical parameters including heavy metals (HM). The mean concentrations of physicochemical parameters and HM were within the drinking water guideline values set by the World Health Organization (WHO 2011) except 34%, 60%, and 56% of copper (Cu), nickel (Ni), and lead (Pb), respectively. Pollution sources were identified by various multivariate statistical techniques including correlation analysis (CA) and principal component analysis (PCA) indicating different origins both naturally and anthropogenically. Results of the water quality index (WQI) ranged from 13.58 to 209 with an average value of 77 suggesting poor water quality for drinking and domestic purposes. The poor water quality was mainly related to high sodium (alkalinity) and salinity hazards showing > 27% and 20% water samples have poor alkalinity and salinity hazards, respectively. Hazard quotient (HQ) and hazard index (HI) were used to determine the health risk of HM in the study area. For water-related health risk, HQingestion, HQdermal, and HI values were > 1, indicating noncarcinogenic health risk (NCR) posed by these HM to the exposed population.

Comparative evaluation of spectroscopic models using different multivariate statistical tools in a multicancer scenario

2011 ◽  
Vol 16 (2) ◽  
pp. 025003 ◽  
Author(s):  
A. D. Ghanate ◽  
S. Kothiwale ◽  
S. P. Singh ◽  
Dominique Bertrand ◽  
C. Murali Krishna
Keyword(s):  
Comparative Evaluation ◽  
Statistical Tools ◽  
Multivariate Statistical

Les députés et les partis politiques sortants profitent-ils d'un avantage électoral ? Une analyse des résultats électoraux au Québec

2017 ◽  
Vol 50 (3) ◽  
pp. 723-746 ◽  
Author(s):  
Ariane Blais-Lacombe ◽  
Marc André Bodet
Keyword(s):  
Political Parties ◽  
Small Difference ◽  
Statistical Tools ◽  
Multivariate Statistical ◽  
National Assembly ◽  
Incumbent Party ◽  
Electoral Performance ◽  
The Impact ◽  
Opposition Parties

AbstractUsing official electoral results from provincial elections since 1973, we evaluate the incumbency effect in Quebec by measuring the impact of a combination of characteristics related to candidates and political parties. We verify whether the presence of an incumbent candidate is necessary to ensure that the incumbent party benefits from an electoral advantage. We also compare the magnitude of the incumbency effect between governing and opposition parties. Making use of parametric multivariate statistical tools, we conclude that political parties benefit from an electoral advantage in Quebec. Except for ministers who make a small difference, simple Members of the National Assembly (MNAs) do not improve their electoral performance, while in some cases new candidates with incumbent parties perform better.

scholarly journals Statistical Elucidations of The Seasonal Ambience of Physicochemical Characteristics of Coastal Waters Around South Andaman, India

2021 ◽  
Author(s):  
Venkatesan Shiva Shankar ◽  
Neelam Purti ◽  
Dharanirajan Kesavan ◽  
Pm Mohan ◽  
Narayani Subramanian ◽  
...  
Keyword(s):  
Water Pollution ◽  
Seasonal Variations ◽  
Coastal Waters ◽  
Physicochemical Parameters ◽  
Physicochemical Characteristics ◽  
Coastal Regions ◽  
Multivariate Statistical ◽  
South Andaman ◽  
Nitrite Nitrate ◽  
Statistical Results

Abstract The coastal areas of Port Blair in Andaman are threatened by severe water pollution due to the human settlements in these regions. The objective of this study was to determine the level of pollution in ten different anthropogenically dynamic coastal regions by assessing the seasonal variations of various physicochemical characteristics. The regions selected for this study were Burmanallah (BA), Carbyn's Cove (CC), Chattam (CH), Flat Bay (FB), HADDO Harbour (HH), Junglighat Bay (JB), Minne Bay (MB), Phoenix Bay (PB), Sisostris Bay (SB) and Wandur (WA) in South Andaman. The study was carried out from January 2018 to December 2018 to investigate seasonal variations in the physicochemical parameters such as pH, temperature, salinity, dissolved oxygen, nitrite, nitrate, ammonia, silicate, phosphate, and chlorophyll-α using multivariate statistical analysis. Statistical analyses suggest that the regions of JB and MB were highly polluted while, BA, CC, FB, and WA were the least polluted. Landuse and land cover analysis of the study area further facilitated and supported the multivariate statistical results.

scholarly journals Effects of clear-cutting and selective felling in Swedish Boreal coniferous forest: response of invertebrate taxa eaten by birds

1995 ◽  
Vol 6 (2-3) ◽  
pp. 79-90 ◽  
Author(s):  
Ola Atlegrim ◽  
Kjell Sjöberg
Keyword(s):  
Indirect Effects ◽  
Abiotic Factors ◽  
Coniferous Forest ◽  
Bird Species ◽  
Sun Exposure ◽  
Total Biomass ◽  
Insectivorous Birds ◽  
Short Term ◽  
Field Layer ◽  
Clear Cutting

Our aim was to analyse the short-term effects (0-4 years) of selective felling and clear-cutting on the food resources of insectivorous birds. Literature data on bird diets showed that herbivorous larvae (Lepidoptera and Hymenoptera: Symphyta) and spiders (Araneae) were used by 81 and 50%, respectively, of 16 bird species breeding in the Swedish boreal coniferous forest. A field study comparing selective fellings, clear-cuttings and uncut controls showed considerable effects of clear-cutting on both terricolous and field layer invertebrates. Clear-cuttings had significantly lower abundance and biomass, and a different composition of herbivorous larvae and spiders, as well as a lower total biomass of invertebrates in the field layer than controls. Drastic changes of abiotic factors (like increased temperature range) following clear-cutting may directly affect the occurrence of invertebrates. However, indirect effects (like increased sun exposure, affecting food plant quality for herbivorous larvae) are probably also responsible. Selective fellings did not differ from controls in the occurrence of herbivorous larvae and spiders. Therefore, over the four-year term of our study, selective felling seems to provide birds with conditions similar to uncut forest for invertebrates used by birds.

scholarly journals Spatial and temporal distribution of Pseudis minuta (Anura, Hylidae, Hylinae) and environmental variables related to its reproductive activity in Reserva Biológica do Lami, southern Brazil

2010 ◽  
Vol 100 (2) ◽  
pp. 145-150 ◽  
Author(s):  
Caroline Zank ◽  
Marcos Di-Bernardo ◽  
Raúl Maneyro ◽  
Patrick Colombo ◽  
Luciana A. Fusinatto ◽  
...  
Keyword(s):  
Environmental Variables ◽  
Abiotic Factors ◽  
Temporal Distribution ◽  
Reproductive Activity ◽  
Spatial And Temporal Distribution ◽  
Southern Brazil ◽  
Porto Alegre ◽  
Abiotic Variables ◽  
Temperature Water ◽  
Pseudis Minuta

We studied the reproductive biology of a population of Pseudis minuta Günther, 1858 from Reserva Biológica do Lami (30º 15' S; 51º 05' W), Porto Alegre, southern Brazil. We assessed the spatial and temporal distribution of individuals (males, females, juveniles) and explored potential relationships with environmental variables. Field activities encompassed bimonthly surveys in three semi-permanent ponds, each one during approximately two days and two nights, from August 2004 to July 2005. We recorded differences in the sites used by males, females and juveniles, with males occupying deeper and more distant places from the border. The temporal distributions of individuals, calling sites and amplectant pairs indicated that the reproductive activity of P. minuta is related to some of the studied abiotic factors. Calling males presented statistical differences in relation to non-calling males for all daily abiotic variables analyzed (air temperature, water temperature, relative humidity and rainfall), as well as to monthly temperature and rainfall. The number of active males, females and juveniles was influenced by at least one of the daily or monthly environmental variables analyzed. We conclude that the reproduction in this species is seasonal and may be partially determined by abiotic factors.

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