scholarly journals Temporal changes of phytoplankton community at different depths of a shallow hypertrophic reservoir in relation to environmental variables

2009 ◽  
Vol 45 (2) ◽  
pp. 93-105 ◽  
Author(s):  
YongSu Kwon ◽  
SoonJin Hwang ◽  
KuSung Park ◽  
HoSeob Kim ◽  
BaikHo Kim ◽  
...  
Keyword(s):  
Environmental Variables ◽  
Phytoplankton Community ◽  
Temporal Changes ◽  
Different Depths ◽  
Hypertrophic Reservoir

scholarly journals Phytoplankton abundance, dominance and coexistence in an eutrophic reservoir in the state of Pernambuco, Northeast Brazil

2011 ◽  
Vol 83 (4) ◽  
pp. 1313-1326 ◽  
Author(s):  
Giulliari A. S. T. Lira ◽  
Elcida L. Araújo ◽  
Maria Do Carmo Bittencourt-Oliveira ◽  
Ariadne N. Moura
Keyword(s):  
Rainy Season ◽  
Phytoplankton Community ◽  
Dry Season ◽  
Cylindrospermopsis Raciborskii ◽  
Phytoplankton Abundance ◽  
Vertical Variation ◽  
Total Phytoplankton ◽  
Physical And Chemical Variables ◽  
Different Depths ◽  
Physical And Chemical

The present study reports the phytoplankton abundance, dominance and co-existence relationships in the eutrophic Carpina reservoir, Pernambuco, Brazil. Sampling was carried out at six different depths bimonthly at a single reservoir spanning two climatic periods: dry season (January, September, and November 2006) and rainy season (March, May, and July 2006). Density, abundance, dominance, specific diversity and equitability of the community were determined, along with chlorophyll a, and physical and chemical variables of the environment. Eight species were considered abundant, and their densities corresponded to more than 90% of the total phytoplankton community quantified. Cyanobacteria represented more than 80% of this density. Cylindrospermopsis raciborskii was the only dominant taxon in the dry season, and was co-dominant in the rainy season. C. raciborskii, Planktothrix agardhii and Geitlerinema amphibium had the greatest densities and lowest vertical variation coefficients. The statistical analysis indicated relationships with vertical and seasonal variations in the phytoplankton community and the following variables: total dissolved solids, water temperature, electrical conductivity and pH. The changes in the environmental variables were discrete and regulated by the establishment of precipitation however, they were able to promote vertical and seasonal instability in the structure of the phytoplankton community.

scholarly journals Influência de Variáveis Ambientais na Comunidade Fitoplanctônica nos Reservatórios Receptores do Projeto de Integração do Rio São Francisco (The Influence of Environmental Variables on Phytoplankton Community of the Receptors Reservoirs by the São...)

2013 ◽  
Vol 5 (6) ◽  
pp. 1300
Author(s):  
Gustavo Melo ◽  
Manuela Morais ◽  
Maria Do Carmo Sobral ◽  
Günter Gunkel ◽  
Renata Carvalho
Keyword(s):  
Environmental Variables ◽  
Phytoplankton Community ◽  
Multivariate Statistical ◽  
Sao Francisco River ◽  
Microbiological Characteristics ◽  
Physico Chemical ◽  
São Francisco River ◽  
Pressure Variable ◽  
Brazilian Northeast ◽  
Integration Project

O objetivo do presente trabalho é avaliar as características físico-químicas e microbiológicas dos reservatórios da região do semiárido brasileiro, receptores de água do Projeto de Integração do rio São Francisco, identificando a influência de variáveis ambientais na comunidade fitoplanctônica. Foram estudados os reservatórios de Itaparica, Poço da Cruz, Boqueirão, Armando Ribeiro Gonçalves e Castanhão. Para alcançar o objetivo proposto, foram feitas análises estatísticas multivariadas com auxílio dos programas Primer e SPSS. Verificou-se que os reservatórios se diferenciam em dois grupos (Eixo Leste e Eixo Norte), observando-se a existência de uma variação temporal. As variáveis ambientais explicaram 78% da variação do fitoplâncton. Destes 22% são explicados por variáveis tipológicas (naturais) e 56% são explicados por variáveis de pressão (efeito antropogênico). Espera-se que a transferência de água possa contribuir para melhoria da qualidade da água, sendo fundamental a implementação de medidas que promovam uma gestão integrada e sustentável das respectivas bacias hidrográficas. Palavras-chave: variáveis ambientais, fitoplâncton, reservatórios, semiárido The Influence of Environmental Variables on Phytoplankton Community of the Receptors Reservoirs by the São Francisco River Integration Project ABSTRACT This study aims to evaluate the physico-chemical and microbiological characteristics of brazilian northeast reservoirs, from the São Francisco river Integration Project, to identify the influence of environmental variables on the phytoplankton community. There were studied the reservoirs of Itaparica, Poço da Cruz, Boqueirão, Armando Ribeiro Gonçalves and Castanhão. To achieve the proposed aim, multivariate statistical analyses were performed with the Primer and SPSS programs. It was observed that the reservoirs are distinguish in two groups (East and North Axis), observing the existence of a temporal variation. It was verified that the environmental variables explained 78% of the phytoplankton variation. Of these, 22% are explained by typological variables and 56% are explained by pressure variable. It is expected that the transfer of water may improve water quality (especially in reservoirs of the East Axis). It is essential to implement actions to promote an integrated and sustainable management of their watersheds. Keywords: environmental variables, phytoplankton, reservoirs, semiarid

scholarly journals Structural changes of the phytoplankton and epiphyton in an urban hypereutrophic reservoir

2016 ◽  
Vol 28 (0) ◽  
Author(s):  
Lucineide Maria Santana ◽  
Carla Ferragut
Keyword(s):  
Species Richness ◽  
Water Flow ◽  
Structural Changes ◽  
Light Availability ◽  
Temporal Changes ◽  
Nutrient Concentrations ◽  
Nitrogen And Phosphorus ◽  
Nutrients Availability ◽  
High Species Richness ◽  
Different Depths

Abstract: Aim This study evaluated the temporal changes of phytoplankton and epiphyton structure and their relationships with limnological factors in an urban hypereutrophic reservoir (Rasgão Reservoir, Brazil). Methods We collected water sample and phytoplankton in different depths at two sites (dam and near tributary input) in summer and winter 2010. Epiphyton on Salvinia spp. was sampled only at site near the tributary input. We determined limnological variables and structural attributes (species composition, density, biovolume, descriptors species, diversity) for both communities. Results Phytoplankton density and epiphyton density and biovolume were higher in the winter (dry season), which occurred the higher nutrient concentrations and lower water flow. Chlorophyceae was dominant in the phytoplankton in both period and Cyanobacteria was the second most abundant class in the winter. In the epiphyton, Bacillariophyceae was dominant in the summer and Cyanobacteria in the winter. The increase in light availability and water flow can have provided high species richness and diversity in the summer. Conclusion Temporal changes in the structure of phytoplankton and epiphyton on Salvinia were more related to increased nutrients availability (nitrogen and phosphorus) and flow variations in a hypereutrophic reservoir.

scholarly journals Investigating Spatial and Vertical Patterns of Wetland Soil Organic Carbon Concentrations in China’s Western Songnen Plain by Comparing Different Algorithms

2020 ◽  
Vol 12 (3) ◽  
pp. 932 ◽  
Author(s):  
Yongxing Ren ◽  
Xiaoyan Li ◽  
Dehua Mao ◽  
Zongming Wang ◽  
Mingming Jia ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Land Surface ◽  
Environmental Variables ◽  
Support Vector ◽  
Wetland Soil ◽  
Songnen Plain ◽  
Attribute Importance ◽  
Organic Carbon Concentration ◽  
Different Depths

Investigating the spatial and vertical patterns of wetland soil organic carbon concentration (SOCc) is important for understanding the regional carbon cycle and managing the wetland ecosystem. By integrating 160 wetland soil profile samples and environmental variables from climatic, topographical, and remote sensing data, we spatially predicted the SOCc of wetlands in China’s Western Songnen Plain by comparing four algorithms: random forest (RF), support vector machine (SVM) for regression, inverse distance weighted (IDW), and ordinary kriging (OK). The predicted results of the SOCc from the different algorithms were validated against independent testing samples according to the mean error, root mean squared error, and correlation coefficient. The results show that the measured SOCc values at depths of 0–30, 30–60, and 60–100 cm were 15.28, 7.57, and 5.22 g·kg−1, respectively. An assessment revealed that the RF algorithm was most accurate for predicting SOCc; its correlation coefficients at the different depths were 0.82, 0.59, and 0.51, respectively. The attribute importance from the RF indicates that environmental variables have various effects on the SOCc at different depths. The land surface temperature and land surface water index had a stronger influence on the spatial distribution of SOCc at the depths of 0–30 and 30–60 cm, whereas topographic factors, such as altitude, had a stronger influence within 60–100 cm. The predicted SOCc of each vertical depth increased gradually from south to north in the study area. This research provides an important case study for predicting SOCc, including selecting factors and algorithms, and helps with understanding the carbon cycles of regional wetlands.

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