Consulta: subjectFacets:"Spatial variation"
Registros recuperados: 20
Data/hora: 16/06/2024 10:58:06

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

Spatial and long-term changes in the functional and structural phytoplankton communities along the French Atlantic coast
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: David, Valerie; Ryckaert, Mireille; Karpytchev, Mikhail; Bacher, Cedric; Arnaudeau, Vanessa; Vidal, Nadia; Maurer, Daniele; Niquil, Nathalie.
Spatial and interannual variations of phytoplankton diversity were characterized along the French Atlantic Coast in relation to physical factors and large-scale climatic indices using phytoplankton surveys conducted from 1993 to 2010 in four geographical areas. This study relates phytoplankton diversity to oyster recruitment success by comparing a 'specific' versus a 'functional' diversity approach. Functional diversity was represented by functional groups of different phytoplanktonic functional traits (size, shape, toxicity), relevant for oyster feeding during growth, reproduction and larval development. Phytoplankton diversity patterns along the French Atlantic coast corresponded to a geographical distribution mainly driven by a latitudinal gradient and...
Tipo: Text
Palavras-chave: Phytoplankton; Long-term variation; Spatial variation; Climate; Atlantic coast.
Ano: 2012
URL: http://archimer.ifremer.fr/doc/00093/20376/19677.pdf

Latitudinal influence on gametogenesis and host–parasite ecology in a marine bivalve model
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Mahony, Kate E.; Lynch, Sharon A.; Egerton, Sian; Laffan, Rebecca E.; Correia, Simão; De Montaudouin, Xavier; Mesmer‐dudons, Nathalie; Freitas, Rosa; Culloty, Sarah C.
Reproduction and parasites have significant impacts on marine animal populations globally. This study aimed to investigate the associative effects of host reproduction and a host–parasite interplay on a marine bivalve, along a geographic gradient of latitude. Cockles Cerastoderma edule were sampled from five European sites (54°N to 40°N), between April 2018 and October 2019. A histological survey provided data on trematode (metacercaria and sporocyst life stages), prevalence, and cockle stage of gametogenesis to assess the influence of a latitudinal gradient on both interplays. Sex ratios at the northernmost sites were skewed toward females, and spawning size was reduced at the lower latitudes. Trematode infection did not follow a latitudinal gradient....
Tipo: Text
Palavras-chave: Boom and bust; Cockles; Fisheries; Latitude; Parasite–host interactions; Reproduction; Shellfish; Spatial variation; Trematodes.
Ano: 2021
URL: https://archimer.ifremer.fr/doc/00691/80352/83454.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

Diversity of springtails (Hexapoda) according to a altitudinal gradient
Provedor de dados: Pesquisa Agropecuária Brasileira
Autores: García-Gómez,Arturo; Castaño-Meneses,Gabriela; Palacios-Vargas,José G.
The objective of this work was to elevate gradient effect on diversity of Collembola, in a temperate forest on the northeast slope of Iztaccíhuatl Volcano, Mexico. Four expeditions were organized from November 2003 to August 2004, at four altitudes (2,753, 3,015, 3,250 and 3,687 m a.s.l.). In each site, air temperature, CO2 concentration, humidity, and terrain inclination were measured. The influence of abiotic factors on faunal composition was evaluated, at the four collecting sites, with canonical correspondence analyses (CCA). A total of 24,028 specimens were obtained, representing 12 families, 44 genera and 76 species. Mesaphorura phlorae, Proisotoma ca. tenella and Parisotoma ca. notabilis were the most abundant species. The highest diversity and...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Collembola; Canonical correspondence analysis; CO2; Mesofauna communities; Spatial variation.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2009000800016

Correlation of physical and chemical attributes of soil with sugarcane yield
Provedor de dados: Pesquisa Agropecuária Brasileira
Autores: Cerri,Domingos Guilherme Pellegrino; Magalhães,Paulo Sérgio Graziano.
The objective of this work was to evaluate the correlation between sugarcane yield and some physical and chemical attributes of soil. For this, a 42‑ha test area in Araras, SP, Brazil, was used. Soil properties were determined from samples collected at the beginning of the 2003/2004 harvest season, using a regular 100x100 m grid. Yield assessment was done with a yield monitor (Simprocana). Correlation analyses were performed between sugarcane yield and the following soil properties: pH, pH CaCl2, N, C, cone index, clay content, soil organic matter, P, K, Ca, Mg, H+AL, cation exchange capacity, and base saturation. Correlation coefficients were respectively ‑0.05, ‑0.29, 0.33, 0.41, ‑0.27, 0.22, 0.44, ‑0.24, trace, ‑0.06, 0.01, 0.32, 0.14, and 0.04....
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Saccharum officinarum; Precision agriculture; Soil sampling; Spatial variation; Variation structure.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2012000400018

Determinants of Geographic Variation in U.S. Food Prices
Provedor de dados: Research in Agricultural & Applied Economics (AgEcon Searh)
Autores: Leibtag,   Ephraim S.; Todd,   Jessica E.; Mancino,   Lisa.
Text and tables
Tipo: Conference Paper or Presentation
Palavras-chave: Food prices; Spatial variation; QFAHPD; Agricultural and Food Policy; Consumer/Household Economics; Demand and Price Analysis.
Ano: 2010
URL: http://purl.umn.edu/61023

Occurrence and distribution of larval lanternfish (Myctophidae) from the southwest Atlantic Ocean
Provedor de dados: Revista Brasileira de Zoologia
Autores: Castro,Márcia S. de; Richards,William J.; Bonecker,Ana Cristina T.
This study analyzes the occurrence and distribution of lanternfish (Myctophidae) larvae along the Brazilian coast (12-22ºS) between 200 m and the surface. Three cruises were conducted during the spring/1998, winter/1999 and autumn/2000. A total of 3,394 lanternfish larvae were identified representing 27 species and Lepidophanes guentheri (Goode &amp;amp; Bean, 1896) was the most abundant. Most of the identified taxa were in the postflexion stage. Myctophid larvae were more numerous during the winter. Most taxa were distributed widely from 12-22ºS, including some seamounts, and occurred mainly outside the 1,000 m isobath. Although there was no difference in the myctophid community among the coastal, oceanic and seamount regions it was significantly...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Brazilian coast; Larval mesopelagic fish; Myctophidae; Spatial variation; Tropical region.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-46702010000400006

Diet and trophic guilds of fish assemblages in two streams with different anthropic impacts in the northwest of Paraná, Brazil
Provedor de dados: Revista Brasileira de Zoologia
Autores: Bonato,Karine Orlandi; Delariva,Rosilene Luciana; Silva,Jislaine Cristina da.
In the present study, we describe the diets of the fish assemblages in two streams in the Maringá region of Paraná that are under the influence of different anthropic impacts. We also evaluate how the origin and use of food resources varies temporally and spatially and how the trophic organization of the fish assemblages differs between the two streams. Fish were collected every two months from October 2006 to October 2007 using sieves, seining and closing nets along two 50 m stretches of each stream. We used the volumetric method to analyze the stomach contents of 599 fish belonging to 15 species. We then employed ANOSIM, SIMPER, NMDS and cluster analyses (using the Bray-Curtis index) to examine how different factors (species, stream, sampling site and...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Food resources; Seasonality; Spatial variation; Urbanization.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-46702012000100004

Spatial distribution of the estuarine ichthyofauna of the Rio Formoso (Pernambuco, Brazil), with emphasis on reef fish
Provedor de dados: Revista Brasileira de Zoologia
Autores: Paiva,Andréa C. G. de; Lima,Marina F. V.; Souza,José R. B. de; Araújo,Maria E. de.
The objectives of the present study were to identify species of reef fish that use the Rio Formoso estuary (northeastern Brazil) as a refuge and natural nursery and to describe the spatial distribution of the estuary fish fauna in rainy and dry seasons. A total of 5475 specimens, across 78 species and 39 families, were analyzed; 51.3% of the species were of reef origin. Among these, Eucinostomus melanopterus (Bleeker, 1863), E. gula (Cuvier, 1830), and Sphoeroides testudineus (Linnaeus, 1758), in this order, were the most abundant in the upper estuary; S. greeleyi Gilbert, 1900, E. melanopterus, and Lutjanus synagris (Linnaeus, 1758) were the most abundant in the mid estuary; and E. gula and Albula vulpes (Linnaeus, 1758) in the lower estuary. The...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Connectivity; Estuary; Fish community; Reef fishes; Spatial variation.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-46702009000200009

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

New record of Trichodesmium thiebautii Gomont ex Gomont (Oscillatoriales - Cyanophyta) for the continental shelf of northeastern Brazil
Provedor de dados: Acta Botanica Brasilica
Autores: Monteiro,José Juarez Ferreira; Leça,Enide Eskinazi; Koening,Maria Luise; Macedo,Silvio José de.
This study reports the first occurrence of Trichodesmiumthiebautii Gomont ex Gomont on the coast of northeastern Brazil. Samples were gathered during the rainy season (July 2005) and the dry season (November 2006) at six stations distributed along two perpendicular profiles of the coast of Pernambuco (8º18'S - 34º56'W and 8º32'S - 35º00'W). T. thiebautii was found during both periods of the year and at the six collection stations, forming colonies in the form of clusters or more rarely, bundles, with straight cylindrical trichomes, quadratic or slightly longer cells, with widths between 5-10 µm and heights of 3-15 µm. The hydrological variables presented small variations, contributing to wide distribution of the species.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Taxonomic characters; Annual variation; Spatial variation; Pernambuco.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-33062010000400027

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

Spatial variations in the zooplankton community from the Corumbá Reservoir, Goiás State, in distinct hydrological periods - DOI: 10.4025/actascibiolsci.v31i3.4132
Provedor de dados: Acta Scientiarum: Biological Sciences
Autores: Takahashi, Erica Mayumi; UEM; Lansac-Tôha, Fábio Amodêo; UEM; Dias, Juliana Déo; UEM; Bonecker, Claudia Costa; UEM; Velho, Luiz Felipe Machado; UEM.
This study evaluated the spatial variations in species richness and abundance of zooplankton over a hydrological cycle, and also verified the influence of physical and chemical water variables and chlorophyll-&amp;alpha; concentrations on the abundance of these organisms. The tested hypothesis was that the zooplankton community presents higher species richness in lotic environments and higher abundance in lentic ones. One hundred forty species were identified, distributed among rotifers (88), testate amoebae (35), cladocerans (13) and copepods (4). Higher values of species richness and abundance were observed during the dry period. During both hydrological periods, the copepods presented high abundance values, due to the contribution of young stages,...
Palavras-chave: 2.00.00.00-6    Ciências Biológicas zooplankton; Tropical reservoir; Spatial variation; Dry and rainy periods ecologia zooplankton; Tropical reservoir; Spatial variation; Dry and rainy periods.
Ano: 2009
URL: http://periodicos.uem.br/ojs/index.php/ActaSciBiolSci/article/view/4132

Trophic structure of fish assemblages associated with macrophytes in lakes of an abandoned meander on the middle river Purus, brazilian Amazon
Provedor de dados: Acta Scientiarum: Biological Sciences
Autores: Suçuarana, Monik da Silveira; Virgílio, Lucena Rocha; Vieira, Lisandro Juno Soares.
The trophic structure of fish assemblages associated with banks of aquatic macrophytes in abandoned meander lakes on the river Purus is investigated. Comparisons between lakes and between different periods of the hydrological cycle are undertaken. Fish samples were collected in six lakes during the rainy (February), ebb (May) and dry (September) season in 2012. Fish stomach contents were analyzed by frequency of occurrence and volume methods, combined in the Feeding Index (IAi). Fish species were included in nine trophic categories, based on IAi rates. The richness and abundance of fish species, by trophic category, was influenced by temporal variations, with no significant spatial variation. Some species changed their diets and were included in different...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: 2.05.02.00-1 Ecologia diet; Neotropical ichthyofauna; Spatial variation; Temporal variation Ecologia.
Ano: 2016
URL: http://periodicos.uem.br/ojs/index.php/ActaSciBiolSci/article/view/28973

Microbial, physical and chemical properties of irrigation water in rice fields of Southern Brazil
Provedor de dados: Anais da Academia Brasileira de Ciências
Autores: RECHE,MARIA HELENA L.R.; MACHADO,VILMAR; SAUL,DANILO A.; MACEDO,VERA R.M.; MARCOLIN,ELIO; KNAAK,NEIVA; FIUZA,LIDIA M.
ABSTRACT This paper presents the results of the statistical analysis of microbiological, physical and chemical parameters related to the quality of the water used in rice fields in Southern Brazil. Data were collected during three consecutive crop years, within structure of a comprehensive monitoring program. The indicators used were: potential hydrogen, electrical conductivity, turbidity, nitrogen, phosphorus, potassium, calcium, total and fecal coliforms. Principal Component and Discriminant Analysis showed consistent differences between the water irrigation and drainage, as the temporal variation demonstrated a clear reduction in the concentration of most of the variables analyzed. The pattern of this reduction is not the same in the two regions - that...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Agrosystems; Irrigation; Rice field; Spatial variation.
Ano: 2016
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652016000100361

Spatial and temporal distribution of stream macroalgae in a tropical river basin
Provedor de dados: Biota Neotropica
Autores: Tonetto,Aurélio Fajar; Peres,Cleto Kaveski; Hirata,Rafael Taminato; Branco,Ciro Cesar Zanini.
Spatial and temporal distribution of stream macroalgae in streams from southeastern Brazil were assessed for one year. The fluctuations in macroalgal species composition and environmental factors were monitored monthly. The region exhibit a tropical climate, with defined rainy and dry seasons. Nineteen species were found, with a predominance of Chlorophyta (52.7% of the species), followed by Cyanobacteria (26.3%), Ochrophyta and Rhodophyta (10.5% each). Scytonema arcangeli had the highest number of records (63.6%), while Mougeotia capucina occurred in all sampling sites. Community structure had low similarity (20-26%) and the environmental factors showed a weak contribution to the distribution pattern observed. Despite this, the light availability at the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Species distribution; Spatial variation; Temporal dynamics; Stream macroalgae; Rarity.
Ano: 2015
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1676-06032015000400102

Distribution and abundance of shorebirds in tidal flats of Sanquianga National Natural Park and the mouth of Iscuandé, Nariño (Colombia), between 2009 and 2020
Provedor de dados: Boletín de Investigaciones Marinas y Costeras (INVEMAR)
Autores: Johnston-González,Richard; Eusse-González,Diana; Valencia-Martínez,Natasha.
ABSTRACT 11 % of shorebirds using the American Pacific Flyway are declining and an additional 46 % have no information to estimate their population status. To understand the magnitude of these changes and their causes, baseline information is required especially at sites of concentration like the mouth of Iscuandé River (IS) and the Sanquianga National Natural Park (SNNP). To characterize the composition of shorebird communities there, ten years of standardized counts were analyzed. Using proportional abundance, prevalence and mean density of each location, it was evaluated differences between sites with a different marine influence of the Patía River. IS contributed to 63 % of the average abundance in the study area, where 80 % were small shorebirds....
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Shorebirds; Tidal flats; Spatial variation; Colombian Pacific.
Ano: 2020
URL: http://www.scielo.org.co/scielo.php?script=sci_arttext&pid=S0122-97612020000300073

Increase in microplastic pollution in the surface waters of Buenaventura Bay, Colombian Pacific
Provedor de dados: Boletín de Investigaciones Marinas y Costeras (INVEMAR)
Autores: Vidal,Laura; Molina,Andrés; Duque,Guillermo.
ABSTRACT Microplastic (MP) pollution in coastal ecosystems is a serious problem throughout the world. In Colombia, there is little information on this issue, especially for the Pacific coast. For these reasons, the density, distribution, and types of MP on the surface of the water were studied in the bay of Buenaventura estuary, Colombia’s main seaport. A total of 36 samples were collected in two estuarine areas: the inner estuary (IE), closest to the main urban area and river mouths, and the external estuary (EE), further away from both areas, during three seasons: rainy, transition, and dry, in 2015 and 2019. On average, the density of the MP increases annually by 28.7 % in the surface waters of Buenaventura Bay. It was also found that the highest...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Buenaventura Bay; Microplastics; Spatial variation; Climate seasons; Monitoring.
Ano: 2021
URL: http://www.scielo.org.co/scielo.php?script=sci_arttext&pid=S0122-97612021000200113

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