Consulta: subjectFacets:"Relative abundance"
Registros recuperados: 11
Data/hora: 06/06/2024 01:10:37

Species richness, relative abundance, and habitat of reproduction of terrestrial frogs in the Triângulo Mineiro region, Cerrado biome, southeastern Brazil
Provedor de dados: 76
Autores: Giaretta,Ariovaldo A.; Menin,Marcelo; Facure,Kátia G.; Kokubum,Marcelo N. de C.; Oliveira Filho,Júlio C. de.
Based on field observations and pitfall sampling, we determined the species richness, relative abundance, and reproductive habitat of terrestrial frogs in three municipalities in the Triângulo Mineiro region, south Cerrado biome, in southeastern Brazil. We found thirty-two species of terrestrial frogs, belonging to the families Brachycephalidae, Bufonidae, Cycloramphidae, Dendrobatidae, Leiuperidae, Leptodactylidae and Microhylidae. Most of the species were found in open areas and reproduced in human-generated environments, such as artificial lakes (10 species) and ponds (14 species). Dominance was high, with Physalaemus cuvieri Fitzinger, 1826 (Leiuperidae) representing 48% of sampled frogs. A larger number of individuals was captured in the wet season,...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Reproductive habitat; Relative abundance; Richness; Triângulo Mineiro; Southeastern Brazil.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0073-47212008000200002

Exploring Change in the Relative Abundance of Marine Megafauna in the Bay of Biscay, 2004-2016
Provedor de dados: 5
Autores: Authier, Matthieu; Doremus, Ghislain; Van Canneyt, Olivier; Boubert, Jean-jacques; Gautier, Gerard; Doray, Mathieu; Duhamel, Erwan; Masse, Jacques; Petitgas, Pierre; Ridoux, Vincent; Spitz, Jerome.
Conservation has moved from species-centered to ecosystem-based approaches: the Marine Strategy Framework Directive requires the maintenance or restoration of ‘Good Environmental Status’ of all European marine waters. Monitoring biodiversity at the scale of whole ecosystems is salient, but challenging owing to the large spatial scale involved and the large spatio-temporal heterogeneity of marine ecosystems. We capitalized on the integrated ecosystemic PELGAS survey carried out in spring in the Bay of Biscay to document patterns of change in marine megafauna relative abundance at the community level over more than a decade (2004-2016). The relative abundance of the twenty three most frequently sighted species (6 cetaceans and 17 seabirds) was estimated by...
Tipo: Text
Palavras-chave: Marine megafauna; Relative abundance; MSFD; Ecosystemic surveys.
Ano: 2018
URL: http://archimer.ifremer.fr/doc/00403/51405/51981.pdf

Species Diversity and Relative Abundance of Fisheries Resources Found in Beach Seine along the Central Coast of Ghana
Provedor de dados: 20
Autores: Aggrey-Fynn, J.; Sackey-Mensah, R.
The diversity and relative species abundance of fisheries resources were studied from Winneba to Cape Coast on the central coast of Ghana during December 2007 to May 2009. Samples of organisms were collected at random from beach seine landings during the study period. The fishes were counted and identified to the family and species levels. Ecological indices such as Shannon-Wiener diversity index, equitability and Sørenson’s similarity index were used to analyse the data. Specimens from Winneba, Saltpond and Cape Coast comprise 56 species belonging to 30 families. Carangidae, Haemulidae, Clupeidae and Sciaenidae were some of the families, where key species occurred during the study. The relative abundance of key organisms in the beach seine landings...
Tipo: Report
Palavras-chave: Fish; Biodiversity; Relative abundance; Coastal fisheries; Carangidae; Haemulidae; Sciaenidae; Marine resources.
Ano: 2012
URL: http://hdl.handle.net/1834/5323

Variabilidad temporal de la fauna acompañante del camarón Farfantepenaeus notialis en el Golfo de Ana María, Cuba
Provedor de dados: 20
Autores: Valdés, E.; Villafuerte, V.; Domínguez, H.; Pérez, A.
Se analizó la diversidad de la fauna acompañante del camarón en la pesquería del Golfo de Ana María (plataforma suroriental cubana), en términos de la variabilidad temporal de los grupos taxonómicos que la integran y la abundancia relativa de las especies presentes, en particular de la ictiofauna. En el período 2002-2009, los peces fueron el principal integrante de la fauna acompañante del camarón en 82 %, seguido en orden por los crustáceos, moluscos, poríferos y equinodermos con cifras bajas. Resultó poca variabilidad entre los niveles de representatividad de los grupos taxonómicos del período 2002-2008 respecto al 2009. Se determinaron nueve especies de peces representativas (85 % de la captura), siendo dominantes la mojarra (Gerres cinereus), la...
Tipo: Journal Contribution
Palavras-chave: Variability; By-catch; Relative abundance.
Ano: 2011
URL: http://hdl.handle.net/1834/4647

Abundancia, distribución y dimensionamiento de la pesquería del Cangrejo rojo Geryon quinquedens Smith, 1879 en el Atlántico Sudoccidental
Provedor de dados: 20
Autores: Defeo, Omar; Barea, Luis; Niggemeyer, Fernando; Little, Virginia.
Un estudio cuantitativo del cangrejo rojo Geryon quinquedens (Smith, 1879) fue realizado en la Zona Común de Pesca Argentino-Uruguaya en primavera de 1985 y verano de 1986, entre las latitudes 35º00´S y 36º40´S y en un rango de profundidad comprendido entre 300 y 900 m. Como arte de captura fue empleada una nasa de tipo troncofónica. El área fue relevada en base a un muestreo sistemático, con estaciones ubicadas cada 20 millas y a razón de una cada 100 m de profundidad. Un crucero adicional de caminamiento acústico fue dirigido a efectos de cuantificar la superficie relevada. Las estimaciones de stock se llevaron a cabo en base a la propuesta de Arena et al. (en prensa). La abundancia relativa de G. quinquedens fue mayor entre los 400 y 700 metros de...
Tipo: Report
Palavras-chave: Red crab fisheries; Relative abundance; Fishing gear; Capture fisheries; Geryon quinquedens.
Ano: 1992
URL: http://hdl.handle.net/1834/5292

On the relative abundance of natural populations
Provedor de dados: 27
Autores: Heip, C.H.R.
The constant and similar statistical variability shown by various aquatic populations is postulated to be a result of competition for space. When competition for space occurs, numbers of species should form a series of abundance in which two adjacent species differ by a factor which at closest packing is 1.27. This hypothesis is tested by comparing different communities where competition for space is expected to occur (marine phytoplankton) or not (brackish water copepods).
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Natural populations; Relative abundance.
Ano: 1976
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3549

Elevated Atmospheric CO2 and Drought Affect Soil Microbial Community and Functional Diversity Associated with Glycine max
Provedor de dados: 90
Autores: Wang,Junfeng; Wang,Yuhui; Song,Xinshan; Wang,Yuan; Lei,Xiaohui.
Abstract Under the background of climate change, the increase of atmospheric CO2 and drought frequency have been considered as significant influencers on the soil microbial communities and the yield and quality of crop. In this study, impacts of increased ambient CO2 and drought on soil microbial structure and functional diversity of a Stagnic Anthrosol were investigated in phytotron growth chambers, by testing two representative CO2 levels, three soil moisture levels, and two soil cover types (with or without Glycine max). The 16S rDNA and 18S rDNA fragments were amplified to analyze the functional diversity of fungi and bacteria. Results showed that rhizosphere microbial biomass and community structure were significantly affected by drought, but effects...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Enzyme activities; Microbial functional diversity; Fungi and bacteria; Relative abundance.
Ano: 2017
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832017000100430

Density and richness of leaf litter frogs (Amphibia: Anura) of an Atlantic Rainforest area in the Serra dos Órgãos, Rio de Janeiro State, Brazil
Provedor de dados: 103
Autores: Siqueira,Carla C.; Vrcibradic,Davor; Almeida-Gomes,Mauricio; Borges-Junior,Vitor N. T.; Almeida-Santos,Patrícia; Almeida-Santos,Marlon; Ariani,Cristina V.; Guedes,Diego M.; Goyannes-Araújo,Pablo; Dorigo,Thiago A.; Van Sluys,Monique; Rocha,Carlos F. D.
Data on species composition, richness, and density are presented for the leaf litter frog assemblage of an area of Atlantic Rainforest at the Serra dos Órgãos mountain range, in the state of Rio de Janeiro, southeastern Brazil. Three sampling methods were used: plot sampling, visual encounter surveys, and pitfall traps. The local assemblage of leaf litter frogs was composed of 16 species, with the direct-developing species, Euparkerella brasiliensis (Parker, 1926), being the most abundant. The estimated density of the local leaf litter frog assemblage based on plot sampling was 17.1 ind/100 m² and the estimated overall leaf litter frog mass was 684.2 g/ha. The estimated density of leaf litter frogs at the present study is the highest currently reported for...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Amphibian survey; Relative abundance; Tropical forest.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-46702009000100015

Calliphoridae (Diptera) from wild, suburban, and urban sites at three Southeast Patagonian localities: Calliphoridae (Diptera) de ambientes no habitados, suburbanos y urbanos en tres localidades del sudeste patagónico
Provedor de dados: 99
Autores: Mariluis,Juan C.; Schnack,Juan A.; Mulieri,Pablo P.; Patitucci,Luciano D.
Species composition, relative abundance, sex ratio and habitat preference of blowflies (Diptera: Calliphoridae) from Caleta Olivia, Puerto Deseado, and Puerto San Julián (Santa Cruz Province, Argentina) were studied during late spring and summer in 2004-2005. Results showed a higher prevalence of the exotic species, Calliphora vicina (Robineau-Desvoidy) and Phaenicia sericata (Meigen) at urban sites over the natives, Compsomyops fulvicrura (Robineau-Desvoidy) and Sarconesia chlorogaster (Wiedemann), which shows a strong preference for those sampling sites either not inhabited or less influenced by human activities. Sex ratio was female biased for all species, except for Sarconesia chlorogaster, which exhibited a male prevalence over females.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Calliphoridae; Species composition; Relative abundance; Synanthropy; Southeastern Patagonia.
Ano: 2008
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S0373-56802008000100010

Trophic categories in a mammal assemblage: diversity in an agricultural landscape
Provedor de dados: 49
Autores: Dotta,Graziela; Verdade,Luciano M.
Mammals play an important role in the maintenance and regeneration of tropical forests since they have essential ecological functions and can be considered key-species in structuring biological communities. In landscapes with elevated anthropogenic pressure and high degree of fragmentation, species display distinct behavioral responses, generally related to dietary habits. The landscape of Passa-Cinco river basin, in the central-eastern region of São Paulo State, shows a high degree of anthropogenic disturbance, with sugar cane plantations, eucalyptus forests, native semideciduous forest remnants and pastures as the key habitat types in the region. We surveyed medium to large mammals in those habitats and determined species richness and relative abundance...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Species richness; Relative abundance; Feeding guilds; Agroecosystems.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1676-06032007000200031

Four seasons abundance changes of Zalophus californianus californianus (Lesson 1828), Allen, 1880, in the Gulf of California, Mexico
Provedor de dados: 52
Autores: Maravilla-Chávez,M. Octavio; Zavala-González,Alfredo; Ortega-Rubio,Alfredo.
This paper describes for the first time the relative abundance, population structure and numeric variation of California sea lions in the Gulf of California, Mexico, during four different seasons. The relative abundance estimates varied from the highest 17,162 sea lions in July of 1990 (summer) to a minimum 7,470 in February of 1992 (winter), representing a reduction of 10,000 sea lions. Hypotheses about the migration of part of the population to the Pacific Ocean were compared and discussed against their residency inside the Gulf, and seasonal dispersion of individuals along this inner sea.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Zalophus californianus californianus; Seasonal variations; Relative abundance; Migration; Gulf of California; Mexico.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132006000100013