Consulta: subjectFacets:"Temporal variation"
Registros recuperados: 23
Data/hora: 01/06/2024 16:38:35

Food habits of Oligoryzomys longicaudatus (Rodentia) in a steppe-forest transitional area of Argentinean Patagonia
Provedor de dados: Ecología Austral
Autores: Polop,Francisco; Sepúlveda,Lorena; Pelliza Sbriller,Alicia; Polop,Jaime; Provensal,M. Cecilia.
We described the spatial and seasonal variation of feeding habits of Oligoryzomys longicaudatus in four environments of the steppe-forest transition zone of Argentinean Patagonia. Composition of fecal pellets collected from live-trap captures was determined with microhistological techniques using an identifcation key of representative plants of our study areas. Fruits and seeds constituted 57.2% of O. longicaudatus diets, followed by foliage (26.8%) and arthropods (16.0%). Fruits and seeds, foliage parts, and arthropods were primarily found in individuáis from shrublands, forests, and peridomestic areas, whereas foliage predominated in pastures. Similarity Index revealed differences between pastures and the other environments. Diet in shrubland showed...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Diet; Spatial variation; Temporal variation; Frugivorous; Opportunism; Reservoir of Andes genotype hantavirus.
Ano: 2014
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S1667-782X2014000300005

Temporal variation of epi- and endofaunal assemblages associated with the red sponge Tedania ignis on a rocky shore (São Sebastião Channel), SE Brazil
Provedor de dados: Iheringia Série Zoologia
Autores: Leite,Fosca P. P.; Pavani,Lilian; Tanaka,Marcel O.
ABSTRACT Sponges are biogenic substrates that increase the available space on rocky shores and provide shelter for many groups of the benthic fauna, which can live both inside and on these sessile invertebrates. In order to assess the differences in temporal variation of endobiont and epibiont groups, samples of the red sponge Tedania ignis (Duchassaing &amp; Michelotti, 1864) were obtained each month for one year. The density, richness and diversity of endobiont and epibiont groups were analyzed in relation to abiotic factors. The dry mass of the sponge was negatively correlated with the density of individuals in both groups and positively with the diversity of endobionts, while organic matter was positively correlated with the diversity of epibionts....
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Biogenic substrate; Associated fauna; Diversity indicators; Temporal variation.
Ano: 2016
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0073-47212016000100207

Daily variation of zooplankton abundance and evenness in the Rosana reservoir, Brazil: biotic and abiotic inferences
Provedor de dados: Iheringia Série Zoologia
Autores: Takahashi,Érica M.; Lansac-Tôha,Fábio A.; Dias,Juliana D.; Bonecker,Claudia C.
The zooplankton community presents stochastic temporal fluctuation and heterogeneous spatial variation determined by the relationships among the organisms and environmental conditions. We predicted that the temporal and spatial zooplankton distribution is heterogeneous and discrete, respectively, and that the daily variation of most abundant species is related to environmental conditions, specifically the availability of resources. Zooplankton samples were collected daily at three sampling stations in a lateral arm of the Rosana Reservoir (SP/PR). The zooplankton did not present significant differences in abundance and evenness among sampling stations, but the temporal variation of these attributes was significant. Abiotic variables and algal resource...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Temporal variation; Rotifers; Microcrustaceans; Coexistence; Competition.
Ano: 2014
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0073-47212014000100003

Temporal variability of benthic macrofauna on Cassino beach, southernmost Brazil
Provedor de dados: Iheringia Série Zoologia
Autores: Neves,Luciano P. das; Silva,Pedro de S. R. da; Bemvenuti,Carlos E.
The temporal variability of benthic macrofauna on Cassino beach, southernmost Brazil, was studied for a period of one year (June 2004 to May 2005) based on monthly sampling. Three sites were selected distant 50m from each other. At each site, 3 transects were established, 2m equidistant from one another. Each transect extended from the base of the primary dunes to the inner surf zone at approximately 1m in depth, with 7 or 8 sampling levels. Within transects, the distance between the levels was 20m until the upper swash zone, from which distance was 10m until the 1-meter isobath. The temporal variation in the abundance of benthic macrofauna observed in the present study can be attributed to (1) the positive effects of the recruitment peaks and migration of...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Sandy beaches; Benthic macrofauna; Temporal variation; Cassino beach.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0073-47212008000100005

Three new species of Mesabolivar (Aranea, Pholcidae) from leaf litter in urban environments in the city of São Paulo, São Paulo, Brazil
Provedor de dados: Iheringia Série Zoologia
Autores: Machado,Éwerton O.; Brescovit,Antonio D.; Candiani,David F.; Huber,Bernhard A.
In this study we describe three new litter inhabiting species of Mesabolivar González-Sponga, 1998 from nine urban forest remnants in the metropolitan region of the city of São Paulo, Brazil: M. forceps, M. mairyara and M. cavicelatus. In three of these remnants, we conduced a three year sampling using pitfall traps. Mesabolivar forceps sp. nov. was the most abundant pholcid (n=273 adults), always present in the samples, but with highest numbers in spring and summer. Mesabolivar mairyara sp. nov. was the second most abundant species (n=32), but the majority of individuals were collected in March 2001. Only three individuals of M. cavicelatus sp. nov. were collected.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Mesabolivar; Spiders; Neotropical region; Temporal variation; Taxonomy.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0073-47212007000200006

Mudanças temporais na abundância e diversidade da fauna de peixes do infralitoral raso de uma praia, sul do Brasil
Provedor de dados: Iheringia Série Zoologia
Autores: Godefroid,Rodrigo S.; Spach,Henry L.; Santos,Cesar; MacLaren,Guilherme; Schwarz Jr.,Roberto.
Abundance and diversity of the fish fauna in the shallow infralittoral region of Atami Beach, Paraná, Brazil, were studied through monthly collections between July 1998 and June 1999. A total of 7553 fishes from 70 species and 26 families, mainly juvenile forms, was captured in the area. The mean captures in number of species, number of fish and biomass were larger from the end of spring to the middle of autumn; seasonal tendency in richness, diversity (number) and equitability indices were not observed. The largest mean dissimilarity in the composition of the ichthyofauna occurred between June and May in comparison to the period between July and October. The species that contributed most to this dissimilarity were Selene setapinnis (Mitchill, 1815),...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Demersal fish; Temporal variation; Abundance; Diversity; Brazil.
Ano: 2004
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0073-47212004000100017

Diurnal temporal patterns of the diversity and the abundance of reef fishes in a branching coral patch in New Caledonia
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Mallet, Delphine; Vigliola, Laurent; Wantiez, Laurent; Pelletier, Dominique.
Small-scale spatial and temporal variability in animal abundance is an intrinsic characteristic of marine ecosystems but remains largely unknown for most animals, including coral reef fishes. In this study, we used a remote autonomous unbaited video system and recorded reef fish assemblages during daylight hours, 10 times a day for 34 consecutive days in a branching coral patch of the lagoon of New Caledonia. In total, 50 031 fish observations belonging to 114 taxa, 66 genera and 31 families were recorded in 256 recorded videos. Carnivores and herbivore-detritus feeders dominated the trophic structure. We found significant variations in the composition of fish assemblages between times of day. Taxa richness and fish abundance were greater in the early...
Tipo: Text
Palavras-chave: Coral reef fish; High-frequency sampling; Patterns; Temporal variation; Underwater video.
Ano: 2016
URL: http://archimer.ifremer.fr/doc/00326/43755/45787.pdf

Temporal variation of delta C-13 in particulate organic matter and oyster Crassostrea gigas in Marennes-Oleron Bay (France): Effect of freshwater inflow
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Riera, P; Richard, P.
The temporal variability of delta(13)C in suspended particulate organic matter (POM) and oyster Crassostrea gigas along a salinity gradient was investigated from May 1992 to September 1993 within the estuarine bay of Marennes-Oleron (France). During this period the mean daily discharge of the Charente River exhibited large seasonal variation, with a high discharge from November 1992 to January 1993. Contrary to that at the river mouth and the marine littoral, delta(13)C in POM and in oysters at mid-estuary was affected by the high flood period. The delta(13)C values of POM decreased in mid-estuary and remained at low levels during the high discharge period, indicating an increasing contribution of terrestrial inputs to the estuarine POM pool. At the same...
Tipo: Text
Palavras-chave: Temporal variation; Carbon isotope ratio; Crassostrea gigas; Particulate organic matter; Freshwater inflow.
Ano: 1997
URL: http://archimer.ifremer.fr/doc/00336/44748/44762.pdf

Analyse et modélisation des évolutions à long terme de la biodiversité phytoplanctonique dans les zones côtières sous l’effet des pressions environnementales et anthropiques
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Hernandez Farinas, Tania.
Coastal areas are highly-dynamic systems exposed to the effect of climate variations and human impacts, influencing the community diversity. In these ecosystems, the phytoplankton constitutes the base of food webs and integrates the effects of global changes and quality variations of coastal waters. In this context, the general objective of this study was to assess the long-term changes in the diversity of phytoplankton communities in coastal waters at different dcales and levels of organisation. Firstly, the data collected by the Phytoplankton and Phycotoxin Monitoring Network from the IFREMER was examined to study the temporal variations of the assemblages within the last two decades along the French coast and to assess the relationship with the...
Tipo: Text
Palavras-chave: Variation temporelle; Niche ecologique; Forme de vie; Modele dynamique lineaire; Methode multi-tableaux; Temporal variation; Ecological niche; Life-forms; Dynamic linear model; Multi-table analysis.
Ano: 2015
URL: http://archimer.ifremer.fr/doc/00315/42648/42032.pdf

Distribution and temporal variation of mega-fauna at the Regab pockmark (Northern Congo Fan), based on a comparison of videomosaics and geographic information systems analyses
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Marcon, Yann; Sahling, Heiko; Allais, Anne-gaelle; Bohrmann, Gerhard; Olu, Karine.
The Regab pockmark is a large cold seep area located 10 km north of the Congo deep sea channel at about 3160 m water depth. The associated ecosystem hosts abundant fauna, dominated by chemosynthetic species such as the mussel Bathymodiolus aff. boomerang, vestimentiferan tubeworm Escarpia southwardae, and vesicomyid clams Laubiericoncha chuni and Christineconcha regab. The pockmark was visited during the West African Cold Seeps (WACS) cruise with RV Pourquoi Pas? in February 2011, and a 14,000-m2 high-resolution videomosaic was constructed to map the most populated area and to describe the distribution of the dominant megafauna (mussels, tubeworms and clams). The results are compared with previous published works, which also included a videomosaic in the...
Tipo: Text
Palavras-chave: Cold seep; Fauna; Mosaic; Pockmark; Regab; Temporal variation.
Ano: 2014
URL: http://archimer.ifremer.fr/doc/00144/25528/23765.pdf

Optimizing cost-efficiency of long term monitoring programs by using spatially balanced sampling designs: The case of manila clams in Arcachon bay
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Kermorvant, Claire; Caill-milly, Nathalie; Bru, Nooelle; D'Amico, Franck.
Funding lake is one major issue in ecology, in particular at local scale. It is known that sustainable management of a natural population requires a good understanding of its functioning, itself dependent on a good long term monitoring program. Such programs are usually very difficult to implement, especially for resources characterized by high spatio-temporal variation in their distribution, resulting in a trade off between efficiency and costs. Today, thanks to rapidly evolving statistical theory, new survey designs are developed, some with the characteristic of well balancing samples in the study area. This paper aims at demonstrating that theses advanced sampling designs perform better than the usual ones for long term monitoring program of local...
Tipo: Text
Palavras-chave: Arcachon bay; Balanced acceptance sampling; Spatial sampling; Spatial variation; Temporal variation; Virtual ecology.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00469/58064/60460.pdf

Modélisation de l'influence de la température sur la mortalité des œufs d'anchois de l'écosystème du Benguela sud.
Provedor de dados: Ocean Docs: e-repository of  publications
Autores: Koné, Vamara.
L'influence de la température sur la mortalité des oeufs d'anchois dans l'écosystème du Benguela sud apparaît très variée. Les simulations ont montré une sensibilité à la valeur seuil de température létale, une variabilité de l'indice de mortalité en fonction de la zone, de la période et de la profondeur de ponte. L'approche IBM utilisée dans le cadre de cette étude est un bon outil d'investigation des processus essentiels, aussi bien physiques que biologiques, qui contrôlent le transport des oeufs et des larves de la zone de ponte à la zone de nourricerie sur la côte ouest. Cette étude est applicable aux ressources des petits pélagiques associés à l'upwelling Ivoiro-Ghannéen au nord du golf de Guinnée.
Tipo: Journal Contribution
Palavras-chave: Temporal variation; Fishing mortality.
Ano: 2011
URL: http://hdl.handle.net/1834/5807

Recommendations for monitoring avian populations with point counts: a case study in southeastern Brazil
Provedor de dados: Papéis Avulsos de Zoologia
Autores: Cavarzere,Vagner; Moraes,Gabriel Parmezani; Roper,James Joseph; Silveira,Luís Fábio; Donatelli,Reginaldo José.
In the northern hemisphere, bird counts have been fundamental in gathering data to understand population trends. Due to the seasonality of the northern hemisphere, counts take place during two clearly defined moments in time: the breeding season (resident birds) and winter (after migration). Depending on location, Neotropical birds may breed at any time of year, may or may not migrate, and those patterns are not necessarily synchronous among species. Also in contrast to the northern hemisphere, population trends and the impact of rapid urbanization and deforestation are unknown and unmonitored. Throughout one year, we used point counts to better understand temporal patterns of bird species richness and relative abundance in the state of São Paulo,...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Bird surveying method; Breeding Bird Survey; Christmas Bird Count; Methodological protocols; Pan-European Common Bird Monitoring Scheme; Temporal variation; Seasonal variation.
Ano: 2013
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0031-10492013003200001

Quantitative variables applied to phenological studies of Sargassum vulgare C. Agardh (Phaeophyceae - Fucales) from Ilha Grande Bay, State of Rio de Janeiro
Provedor de dados: Revista Brasileira de Botânica
Autores: Széchy,Maria Teresa M. de; Galliez,Maron; Marconi,Márcia I.
The suitability of quantitative variables for phenological studies was evaluated in a population of the brown seaweed Sargassum vulgare from "Praia das Gordas", Angra dos Reis, Ilha Grande Bay, state of Rio de Janeiro. From June 1998 to May 1999, twenty adult individuals were randomly sampled at bimonthly intervals. Fifteen variables related to the vegetative and reproductive development of perennial and non-perennial parts of the individuals were quantified. Variables related to the non-perennial parts were more useful than those related to the perennial parts, because they showed a clear variation over the year. Vegetative development declined from June to October, and increased from October to February, when maximum median values of thallus height,...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Methodology; Reproduction; Sargassum; Temporal variation; Vegetative development.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-84042006000100004

Temporal variation on the diet of the South American Tern (Sterna hirundinacea, Charadriiformes: Laridae) on its wintering grounds
Provedor de dados: Revista Chilena de Historia Natural
Autores: ALFARO,MATILDE; MAUCO,LAURA; NORBIS,WALTER; LIMA,MAURICIO.
The diet of the South American Tern (Sterna hirundinacea) and its seasonal variation during the 2005 and 2006 non-reproductive seasons in the Uruguayan Atlantic coast was analyzed. Diet was assessed by the analysis of pellets collected in the Rocha lagoon sandbar, a major tern roosting area in Uruguay, aiming to analyze the hypothesis that terns feed mainly on the Argentine Anchovy (Engraulis anchoita) during the wintering period. A total of 844 pellets were collected, 442 in 2005 and 402 in 2006. Diet was composed of fish (88 %), insects (9 %) and crustaceans (3 %). The main fish species consumed was the Argentine Anchovy (77.7 %), followed by Marini's Anchovy (Anchoa marinii) (7.9 %) and the Striped Weakfish (Cynoscion guatucupa) (3.6 %). Insects and...
Tipo: Journal article
Palavras-chave: Feeding ecology; Migration; Temporal variation; Terns; Uruguay.
Ano: 2011
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2011000300011

Soil CO2 emission of sugarcane fields as affected by topography
Provedor de dados: Scientia Agricola
Autores: Brito,Liziane de Figueiredo; Marques Júnior,José; Pereira,Gener Tadeu; Souza,Zigomar Menezes; La Scala Júnior,Newton.
The spatial and temporal variation of soil CO2 emission is influenced by several soil attributes related to CO2 production and its diffusion in the soil. However, few studies aiming to understand the effect of topography on the variability of CO2 emissions exist, especially for cropping areas of tropical regions. The objective of this study was to evaluate the spatial and temporal changes of soil CO2 emission and its relation to soil attributes in an area currently cropped with sugarcane under different relief forms and slope positions. Mean CO2 emissions in the studied period (seven months) varied between 0.23 and 0.71, 0.27 and 0.90, and 0.31 and 0.80 g m-2 h-1 of CO2 for concave (Conc), backslope (BackS) and footslope (FootS) positions, respectively....
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Soil respiration; Temporal variation; Spatial variation; Soil attributes; Soil porosity.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162009000100011

Potencial atrator de peixes ósseos em recife artificial no litoral norte do estado do Rio de Janeiro, Brasil
Provedor de dados: Zoologia
Autores: Gomes,Marcelo Paes; Novelli,Ronaldo; Faria,Vicente Vieira; Zalmon,Ilana Rosental.
Artificial reefs have become an important and popular resource enhancement technique by concentrating fishes and by increasing natural production of biological resources. In order to increase the necto-benthic colonization potencial, an artificial reef was installed on the northern coast of Rio de Janeiro (21º27'S, 41ºOO'W), an area with typically low relief bottom. Measuring nearly 1500 m², the reef consisted of four sets of different materials randomly disposed: concrete pipes (N = 12); tires structures (N = 20); and cement tanks (N = 7) and pre-made blocks (N = 4). ln order to determine the artificial reef effects on the teleost community, trammel nets were used for monthly sampling the reef site (RA) and on a control area (AC) with sandy bottom. During...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Artificial reef; Osteichthyes; Community structure; Temporal variation; Northern coast of Rio de Janeiro.
Ano: 2001
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-81752001000300014

Algas perifíticas em dois ambientes do baixo rio Doce (lagoa Juparanã e rio Pequeno – Linhares, Estado do Espírito Santo, Brasil): variação espacial e temporal - DOI: 10.4025/actascibiolsci.v30i4.535
Provedor de dados: Acta Scientiarum: Biological Sciences
Autores: Cavati, Bruna; UFES/Vitória; Fernandes, Valéria de Oliveira; UFES/Vitória.
A pesquisa objetivou avaliar a variação espacial e temporal da comunidade de algas perifíticas em dois ambientes do baixo rio Doce: lagoa Juparanã e rio Pequeno. Foram realizadas coletas trimestrais (agosto/04 a maio/05) em duas estações amostrais, uma na lagoa e outra no rio. Foram coletados pecíolos de Eichhornia azurea (Sw.) Kunth. Os atributos da comunidade analisados foram: riqueza de táxons, freqüência de ocorrência, densidade, abundância e dominância. Na lagoa Juparanã, foram registrados 86 táxons e a densidade variou de 20.592 ind cm-2 (mai/05) a 88.712 ind cm-2 (nov/04). No rio Pequeno, foram registrados 83 táxons e a densidade variou de 16.049 ind cm-2 (fev/05) a 71.663 ind cm-2 (ago/04). Em ambos os ambientes, as classes predominantes...
Palavras-chave: Algas perifíticas; Variação espacial; Variação temporal periphytic algae; Spatial variation; Temporal variation.
Ano: 2008
URL: http://periodicos.uem.br/ojs/index.php/ActaSciBiolSci/article/view/535

Ground level photosynthetically active radiation dynamics in stands of Acacia mearnsii De Wild
Provedor de dados: Anais da Academia Brasileira de Ciências
Autores: PÉLLICO NETTO,SYLVIO; SANQUETTA,CARLOS R.; CARON,BRAULIO O.; BEHLING,ALEXANDRE; SIMON,AUGUSTO A.; CORTE,ANA PAULA D.; BAMBERG,ROGÉRIO.
ABSTRACTThe objective is to study the dynamics of photosynthetic radiation reaching the soil surface in stands of Acacia mearnsii De Wild and its influence on height growth in stands. This fact gives rise to the formulation of the following hypothesis for this study: "The reduction of the incidence of light inside the stand of black wattle will cause the inflection point in its height growth when this reaches 4 to 5 m in height, i.e. when the stand is between 2 and 3 years of age". The study was conducted in stands in the state of Rio Grande do Sul, Brazil, where diameters at breast height, total height and photosynthetically active radiation available at ground level were measured. The frequency tended to be more intense when the age of the stands...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Burr function; Light intensity; Probabilistic models; Temporal variation.
Ano: 2015
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652015000401833

Monitoring studies should consider temporal variability to reveal relations between cyanobacterial abundance and environmental variables
Provedor de dados: Anais da Academia Brasileira de Ciências
Autores: WOJCIECHOWSKI,JULIANA; PADIAL,ANDRÉ A.
One of the main goals of monitoring cyanobacteria blooms in aquatic environments is to reveal the relationship between cyanobacterial abundance and environmental variables. Studies typically correlate data that were simultaneously sampled. However, samplings occur sparsely over time and may not reveal the short-term responses of cyanobacterial abundance to environmental changes. In this study, we tested the hypothesis that stronger cyanobacteria x environment relationships in monitoring are found when the temporal variability of sampling points is incorporated in the statistical analyses. To this end, we investigated relationships between cyanobacteria and seven environmental variables that were sampled twice yearly for three years across 11 reservoirs,...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Harmful algae; Reservoir; Management; Limnological variables; Temporal variation; Neotropics.
Ano: 2015
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652015000401717

Seasonal effects of wastewater to the water quality of the Caeté river estuary, Brazilian Amazon
Provedor de dados: Anais da Academia Brasileira de Ciências
Autores: Pereira,Luci C.C.; Monteiro,Marcela C.; Guimarães,Danielly O.; Matos,Jislene B.; Costa,Rauquírio M. da.
Bragança's socioeconomic situation is highly dependent on estuarine and marine biological resources that are influenced by tidal cycles and climatology. Field measurements (hydrological, hydrodynamic and microbiological variables) were taken in the most urbanized zone from Caeté estuary to characterise the quality of the local environment. During the dry period, the estuary was more eutrophic and presented the highest temperature (30.5 °C in Oct./06), salinity (17 psu in Feb./07), pH (8.24 in Feb./07) and fecal coliform (&gt; 1000 MPN/100 ml in Dec./06 and Feb./07) values. The phytoplankton Cyclotella meneghiniana, Coscinodiscus centralis and other r-strategist species were observed. The lack of basic hydric canalization was responsible for the local...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Equatorial estuary; Temporal variation; Eutrophication; Northern Brazil.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652010000200022

Spatial variability studies in São Paulo, Brazil along the last twenty five years
Provedor de dados: Bragantia
Autores: Vieira,Sidney Rosa; Dechen,Sonia Carmela Falci.
Soil properties vary in space due to many causes. For this reason it is wise to know the magnitude and behaviour of the variability for adequate data analysis and decision making. Our work on spatial variability of soil properties in São Paulo, Brazil began in 1982 with a very simple soil sampling in a small field. Much progress has been made since then on sampling designs, field equipment and methods, and mostly on computation equipment and softwares. This paper reports the results corresponding to some aspects of this progress, as far as the field, analysis and computation work are concerned. The objective of this study was to illustrate the use of geostatistics in data analysis for three sampling conditions on long term no-tillage system. The analysis...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Geostatistics; Semivariogram; Temporal variation; Grain crop yield.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87052010000500007

Temporal and spatial variation on heavy metal concentrations in the bivalve Perna perna (LINNAEUS, 1758) on the northern coast of Rio de Janeiro State, Brazil
Provedor de dados: Brazilian Archives of Biology and Technology
Autores: Ferreira,Alexandre Gomes; Machado,André Luís dos Santos; Zalmon,Ilana Rosental.
Heavy metal (Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn) concentrations were studied in Perna perna from three beaches (Barra do Furado, Buena and Ponta do Retiro) on the northern coast of Rio de Janeiro State by ICP-AES. The average concentration was 0.3 ± 0.04 (Cd); 1.9 ± 0.6 (Cr); 6.1 ± 0.7 (Cu); 1,130 ± 113 (Fe); 22 ± 3.2 (Mn); 9.3 ± 4.6 (Ni); 0.4 ± 0.2 (Pb); 44 ± 5.8 (Zn) µg.g-1 dry weight. There were no significant difference for almost all the studied metals in relation to sex. Although, significant spatial variations (p &lt; 0.05) occurred for Cr, Pb and Ni with higher values for Barra do Furado. Temporal variations were significant (p &lt; 0.05) at the three beaches, however, no trends of accumulation were observed. The metal concentrations were similar to...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Heavy metals; Mollusk; Spatial variation; Temporal variation.
Ano: 2004
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132004000200020