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| Registros recuperados: 154 | |
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| Guimaraens,Mariana Alves de; Macedo,Silvio José de; Oliveira-Carvalho,Maria de Fátima de; Burgos,Douglas Correia; Pereira,Sonia Maria Barreto. |
| The diversity of algal banks composed of species out the genera Gracilaria Greville and Hypnea J.V. Lamouroux have been impacted by commercial exploitation and coastal eutrophication. The present study sought to construct dynamic models based on algal physiology to simulate seasonal variations in the biomasses of Gracilaria and Hypnea an intertidal reef at Piedade Beach in Jaboatão dos Guararapes, Pernambuco State, Brazil. Five 20 × 20 cm plots in a reef pool on a midlittoral reef platform were randomly sampled during April, June, August, October, and December/2009 and in January and March/2010. Water temperature, pH, irradiance, oxygen and salinity levels as well as the concentrations of ammonia, nitrate and phosphate were measured at the sampling site.... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Algal biomass; Eutrophication; Sandstone reefs; Trophic models. |
| Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-84042012000400010 |
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| Gatiboni,Luciano Colpo; Smyth,Thomas Jot; Schmitt,Djalma Eugenio; Cassol,Paulo Cezar; Oliveira,Clovisson Menotti Boeira de. |
| The State of Santa Catarina, Brazil, has agricultural and livestock activities, such as pig farming, that are responsible for adding large amounts of phosphorus (P) to soils. However, a method is required to evaluate the environmental risk of these high soil P levels. One possible method for evaluating the environmental risk of P fertilization, whether organic or mineral, is to establish threshold levels of soil available P, measured by Mehlich-1 extractions, below which there is not a high risk of P transfer from the soil to surface waters. However, the Mehlich-1 extractant is sensitive to soil clay content, and that factor should be considered when establishing such P-thresholds. The objective of this study was to determine P-thresholds using the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Eutrophication; Swine manure; Environmental pollution. |
| Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832015000401225 |
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| Schmitt,Djalma Eugênio; Comin,Jucinei José; Gatiboni,Luciano Colpo; Tiecher,Tales; Lorensini,Felipe; Melo,George Wellington Bastos de; Girotto,Eduardo; Guardini,Renato; Heinzen,Janaína; Brunetto,Gustavo. |
| Phosphorus (P) applications to vineyards can cause P accumulation in the soil and maximize pollution risks. This study was carried out to quantify the accumulation of P fractions in sandy soils of vineyards in southern Brazil. Soil samples (layers 0-5, 6-10 and 11-20 cm) were collected from a native grassland area and two vineyards, after 14 years (vineyard 1) and 30 years (vineyard 2) of cultivation, in Santana do Livramento, southern Brazil, and subjected to chemical fractionation of P. Phosphorus application, especially to the 30-year-old vineyard 2, increased the inorganic P content down to a depth of 20 cm, mainly in the labile fractions extracted by anion-exchange resin and NaHCO3, in the moderately labile fraction extracted by 0.1 and 0.5 mol L-1... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Phosphate fertilization; Eutrophication; Vineyards. |
| Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832013000200018 |
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| Benício,Luíz Paulo Figueredo; Silva,Rejane Alvarenga; Lopes,Júnia Aparecida; Eulálio,Denise; Santos,Rodrigo Morais Menezes dos; Aquino,Leonardo Angelo de; Vergütz,Leonardus; Novais,Roberto Ferreira; Costa,Liovando Marciano da; Pinto,Frederico Garcia; Tronto,Jairo. |
| The current research aims to introduce Layered Double Hydroxides (LDH) as nanomaterials to be used in agriculture, with particular reference to its use as storage and slow release matrix of nutrients and agrochemicals for plant growing. Structural characteristics, main properties, synthesis methods and characterization of LDH were covered in this study. Moreover, some literature data have been reported to demonstrate their potential for storage and slow release of nitrate, phosphate, agrochemicals, besides as being used as adsorbent for the wastewater treatment. This research aims to expand, in near future, the investigation field on these materials, with application in agriculture, increasing the interface between chemistry and agronomy. |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Layered compounds; Nutrient slow release; Eutrophication; Nutrient reuse. |
| Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832015000100001 |
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| Gebrim,Fabrício de Oliveira; Novais,Roberto Ferreira; Silva,Ivo Ribeiro da; Schulthais,Fernanda; Vergütz,Leonardus; Procópio,Lorena Costa; Moreira,Frederico Fonseca; Jesus,Guilherme Luiz de. |
| The eutrophication of aquifers is strongly linked to the mobility of P in soils. Although P mobility was considered irrelevant in a more distant past, more recent studies have shown that P, both in organic (Po) and inorganic forms (Pi), can be lost by leaching and eluviation through the soil profile, particularly in less weathered and/or sandier soils with low P adsorption capacity. The purpose of this study was to determine losses of P forms by leaching and eluviation from soil columns. Each column consisted of five PVC rings (diameter 5 cm, height 10 cm), filled with two soil types: a clayey Red-Yellow Latosol and a sandy loam Red-Yellow Latosol, which were exposed to water percolation. The soils were previously treated with four P rates (as KH2PO4 ) to... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Eutrophication; Environmental critical level; Mehlich-1; Olsen. |
| Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832010000400019 |
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| Domingos,Vanessa D.; Martins,Dagoberto; Costa,Neumarcio V.; Costa,Andreia C. P. R. da; Marchi,Sidnei R. de. |
| ABSTRACT The objective of this study was to evaluate the initial growth of emergent plants of Brachiaria subquadripara under different conditions of availability levels of the nutrients nitrogen (N), phosphorus (P), and potassium (K) provided to the plants via nutrient solution in a greenhouse. The treatments consisted of five concentrations of N (0, 42.0, 84.0, 126.0, and 168.0 mg L-1), five concentrations of P (0, 6.2, 12.4, 18.6, and 24.8 mg L-1) and five concentrations of K (0, 46.8, 93.6, 140.4, and 187.2 mg L-1) which were adapted from a base solution. The results showed that the initial growth of plants was slow up to 21 days after transplantation (DAT) and it increased in accordance with increments in N, P, and K concentrations in the nutrient... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Urochloa subquadripara; Urochloa arrecta; Aquatic plant; Weed; Eutrophication; Water reservoir. |
| Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662015000600560 |
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| WOELFL,STEFAN; VILLALOBOS,LORENA; PARRA,ÓSCAR. |
| Lake Riñihue is the last in a chain of glacially derived oligotrophic lakes in southern Chile and was the subject of limnological research by Dr. Hugo Campos and co-workers at the Universidad Austral de Chile, Valdivia, Chile, since the 1970's. Prof. Campos died in the field in 1998, and this paper now presents a review of these data with comments on methodology relevant to trophic parameters of this lake. Data are presented on inorganic nutrients, chlorophyll a, phytoplankton biomass, primary production and Secchi depth obtained over a period of 21 years between 1978 and 1997 in order to evaluate potential changes in these parameters over time. Non-parametric Wilcoxon rank sum tests were applied to determine temporal trends and revealed: (1) total... |
| Tipo: Journal article |
Palavras-chave: Eutrophication; North Patagonian lake; Nutrients; Trophy; Analytical methods. |
| Ano: 2003 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2003000300010 |
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| Almanza,Viviana; Parra,Oscar; Bicudo,Carlos E. De M.; Baeza,Carolina; Beltran,Johana; Figueroa,Ricardo; Urrutia,Roberto. |
| BACKGROUND: During the last decades the frequency and global distribution of toxic cyanobacteria blooms has increased globally, which has been attributed to the eutrophication and climate change. In Chile there have been reports on blooms in aquatic ecosystem in localities with high density population and on the presence of five congeners of microcystins but only two documented toxics blooms with hundreds fish kills. We investigated the presence of toxic cyanobacteria blooms in the Lo Galindo urban lake, Concepción city, and the environmental factors that influence the abundance of cyanobacteria and microcystins concentration. Lo Galindo Lake, is used for various recreational and eventually as a drinking water source RESULTS: Toxic blooms of Microcystis... |
| Tipo: Journal article |
Palavras-chave: Microcystin; Microcystis aeruginosa; Scums blooms; Dispersive blooms; Eutrophication; Urban lake; Chile. |
| Ano: 2016 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2016000100008 |
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| Sharpley,Andrew. |
| ABSTRACT Eutrophication of surface waters remains a major use-impairment in many countries, which, in fresh waters, is accelerated by phosphorus (P) inputs from both point (e.g., municipal waste water treatment plants) and nonpoint sources (e.g., urban and agricultural runoff). As point sources tend to be easier to identify and control, greater attention has recently focused on reducing nonpoint sources of P. In Brazil, agricultural productivity has increased tremendously over the last decade as a consequence, to a large extent, of increases in the use of fertilizer and improved land management. For instance, adoption of the “4R” approach (i.e., right rate, right time, right source, and right placement of P) to fertilizer management can decrease P runoff.... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Fertilizer management; Conservation practices; Runoff; Erosion; Eutrophication. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162016000100001 |
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| Shigaki,Francirose; Sharpley,Andrew; Prochnow,Luís Ignácio. |
| Eutrophication has become a major threat to water quality in the U.S., Europe, and Australasia. In most cases, freshwater eutrophication is accelerated by increased inputs of phosphorus (P), of which agricultural runoff is now a major contributor, due to intensification of crop and animal production systems since the early 1990s'. Once little information is available on the impacts of Brazilian agriculture in water quality, recent changes in crop and animal production systems in Brazil were evaluated in the context of probable implications of the fate of P in agriculture. Between 1993 and 2003, there was 33% increase in the number of housed animals (i.e., beef, dairy cows, swine, and poultry), most in the South Region (i.e., Paraná, Rio Grande do Sul, and... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Diffuse pollution; Eutrophication; Poultry production; Swine production; Surface runoff. |
| Ano: 2006 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162006000200013 |
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| Bertol,Oromar João; Rizzi,Nivaldo Eduardo; Favaretto,Nerilde; Lana,Maria do Carmo. |
| The no-till system has been intensively used in the state of Paraná, Brazil, and it has increased the nutrients level at the soil surface. This has contributed for nutrient losses via runoff and consequently, off-site water pollution. The objective of this study was to evaluate phosphorus loss in surface runoff by simulated rainfall on an Oxisol, under no-till system following application of mineral fertilizer and liquid swine manure. Nitrogen, soil and water losses from the same study are reported in a separated paper. The application of liquid swine manure, compared with mineral fertilization, increased runoff concentration of total P, particulate P and dissolved reactive P by 193%, 111% and 506%, respectively, averaged for all rainfall intensities.... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Liquid swine manure; Water quality; Eutrophication; Soil erosion; Conservation tillage. |
| Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162010000100010 |
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| POOT-DELGADO,Carlos Antonio; OKOLODKOV,Yuri B.; AKÉ-CASTILLO,José Antolin; RENDÓN von OSTEN.,Jaime. |
| ABSTRACT Cyanobacteria inhabit hypersaline, marine and freshwater environments. Some toxic and non-toxic species can form harmful blooms. The aim of this study was to identify potentially harmful cyanobacterial species in the oyster banks of Términos Lagoon, the southeastern Gulf of Mexico. Six sample sites (up to 2-m depth) were monitored monthly from August 2012 to September 2013. Water temperature, salinity, pH, dissolved oxygen saturation (% DO), inorganic nutrients and abundance of cyanobacteria were determined. Temperature and salinity were characterized by marked seasonal differences (26.8 to 30.6 °C and 6.1 to 19.5, respectively). The pH values (ranging from 7.1 to 8.4) and the % DO (88.4 to 118.2 %) suggest a predominance of photosynthetic... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Annual cycle; Cyanobacteria; Eutrophication; Gulf of Mexico; Harmful algal blooms. |
| Ano: 2018 |
URL: http://www.scielo.org.co/scielo.php?script=sci_arttext&pid=S0120-548X2018000100051 |
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| Dantas,Ênio Wocyli; Moura,Ariadne do Nascimento; Bittencourt-Oliveira,Maria do Carmo; Arruda Neto,João Dias de Toledo; Cavalcanti,Airlton de Deus C.. |
| 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... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Cylindrospermopsis raciborskii; Eutrophication; Nutrients; Water supply reservoir. |
| Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-33062008000400008 |
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| Borburema,Henrique Douglas dos Santos; Lima,Ruth Pessoa de; Miranda,George Emmanuel Cavalcanti de. |
| ABSTRACT Global change and coastal eutrophication are affecting macroalgae worldwide. We analyzed the effects of increased water temperature (25, 28 and 32 °C) and eutrophication on the growth of Bostrychia binderi and Bostrychia montagnei in a range of salinities (18, 24, 30, 36 and 42 PSU) through three independent multifactorial experiments. Both species had higher growth at 25 °C than at 28 and 32 °C (warming scenario projected by IPCC), suggesting a negative effect of ocean warming. The species showed a broad tolerance to the range of salinities tested, with higher growth at 36 and 42 PSU, as a local adaptation strategy. Oligotrophic seawater significantly affected the growth of both species because the lowest growth was found in this condition,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Bostrychia; Bostrychietum; Climate change; Ecophysiology; Estuarine macroalgae; Eutrophication; Global change; Growth; Salinity variation; Sea level rise. |
| Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-33062020000400662 |
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| Lima, Paulo de Freitas; Sousa, Mart Som Reis; Porfírio, André Ferreira; Almeida, Beatriz Soares; Freire, Rogério Herlon Furtado; Santaella, Sandra Tédde. |
| The Carlson’s (1977) Trophic State Index (TSI) is a widely employed tool to estimate the degree of eutrophication in a reservoir. In Brazil, the need of a classification system that would take into account regional characteristics employed adjusted indexes generated by data from reservoirs in the southeastern region of the country. Current research compares responses for Carlson’s TSI (1977) and its derivations for Brazilian reservoirs from data collected in the Pereira de Miranda Reservoir (State of Ceará, Brazil), and analyzes the influence of local conditions on results and their applicability to reservoirs in the semiarid region. TSIs were calculated by data on total phosphorus, chlorophyll a and water transparency. The reservoir was estimated as... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Ciências biológicas; Ecologia (2.05.00.00-9) hydro-climatic conditions; Eutrophication; Limiting nutrient; Phosphorus; Nitrogen; Chlorophyll a Ecologia de ecossistemas (2.05.02.00-1). |
| Ano: 2015 |
URL: http://periodicos.uem.br/ojs/index.php/ActaSciBiolSci/article/view/27160 |
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| Registros recuperados: 154 | |
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