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| Registros recuperados: 145 | |
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| Marandel, Florianne; Lorance, Pascal; Trenkel, Verena M.. |
| The thornback ray (Raja clavata) in the Bay of Biscay is presumed to have declined during the 20th Century. To evaluate this decline and estimate biomass trajectories, a hypothetical catch time series was created for the period 1903-2013. A Bayesian state-space biomass production model with a Schaefer production function was fitted to the hypothetical catch time series and to a shorter research vessel Catch Per Unit Eeffort (CPUE) time series (1973-2013, with missing years). A censored likelihood made it possible to obtain biomass estimates without a CPUE time series or only with an estimate of biomass depletion. A simulation-estimation approach showed a high sensitivity of results to the prior for the intrinsic growth rate. The model provided biomass... |
| Tipo: Text |
Palavras-chave: Population dynamics; Stock assessment; Data poor; Censored data; Bayes; Thornback ray; State-space model. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00359/47032/46947.pdf |
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| Fabré, N.N.. |
| Los lenguados constituyen un importante recurso pesquero en el Mar Argentino. Más que en los volúmenes desembarcados (9 .731 t en 1991), esta importancia se centra en su elevado valor de comercialización debido a la alta calidad de su carne. Atendiendo a los desembarques totales realizados en el Mercado de Concentración Pesquera de Mar del Plata, los lenguados ocupan el octavo lugar. Estos desembarques están compuestos principalmente por especies de porte mediano a grande pertenecientes al género Paralichthys, y por ejemplares de tamaño mediano o pequeño de las especies Xystreuris rasile, y en menor proporción, Paralichthys isosceles. Este recurso es explotado, en el sector bonaerense, por las flotas de rada o ría y costera, mientras que la flota de altura... |
| Tipo: Theses and Dissertations |
Palavras-chave: Geographical distribution; Population dynamics; Population structure; Growth; Reproduction; Mortality; Environmental effects; Ecosystems; Marine fish. |
| Ano: 1992 |
URL: http://hdl.handle.net/1834/5158 |
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| Cacho, Oscar J.; Hester, Susan M.; Spring, Daniel. |
| The detectability of invasive organisms influences the feasibility of eradicating an infestation. Search theory offers a framework for defining and measuring detectability, taking account of searcher ability, biological factors and the search environment. In this paper, search theory concepts are incorporated into a population model, and the costs of search and control are calculated as functions of the amount of search effort (the decision variable). Simulations are performed on a set of weed scenarios in a natural environment, involving different combinations of plant longevity, seed longevity and plant fecundity. Results provide preliminary estimates of the cost and duration of eradication programs to assist in prioritising weeds for control. The... |
| Tipo: Article |
Palavras-chave: Bioeconomics; Invasive species; Operations research; Population dynamics; Weed control; Resource /Energy Economics and Policy. |
| Ano: 2007 |
URL: http://purl.umn.edu/118522 |
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| Loretto,Diogo; Vieira,Marcus Vinícius. |
| Despite the great diversity of Brazilian Atlantic forest small mammals, natural history of most species is unknown due to their cryptic and nocturnal habits, but also due to the inadequacy of methods to capture some species, especially those of arboreal habits. A new technique, based on the use of artificial nests (AN) to record arboreal marsupials, is presented. Artificial nests were combined with traditional live traps to study the population ecology of four didelphid marsupial species. After 62 months of monitoring, 119 individuals were recorded 243 times (total success = 5.2%). Only 26 individuals (22%) were recorded by both AN and live trap methods, and two of the four species were never captured by live traps, only by AN. Live traps alone would have... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Didelphidae; Mark-recapture; Live trapping; Population dynamics; Marsupials. |
| Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-46702011000300013 |
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| OLIVEIRA, C. M. de; RESCK, D. V. S.; FRIZZAS, M. R.. |
| RESUMO: Este trabalho objetivou avaliar a influência de sistemas de preparo de solo e de rotação de culturas e pastagem na abundância e dinâmica de artrópodes edáficos. O experimento, instalado em Planaltina, DF, foi composto por 17 tratamentos que corresponderam a sistemas de preparo de solo (convencional e direto) e a rotação de culturas, pastagem e vegetação nativa (Cerrado). Realizaram-se amostragens de solo em três profundidades (0-5 cm, 5-10 cm e 10-20 cm) e em quatro épocas do ano (fevereiro, maio, agosto/setembro e outubro/novembro) entre 2003 e 2006. Os artrópodes foram extraídos em funil de Berlese-Tüllgren e identificados com relação à ordem. Coletaram-se artrópodes pertencentes a três classes: Insecta, Arachnida e Collembolla. Observou-se que... |
| Tipo: Boletim de Pesquisa e Desenvolvimento (INFOTECA-E) |
Palavras-chave: Entomologia; Dinâmica Populacional; Inseto; Gramínea; Leguminosa; Manejo do Solo.; Grasses; Entomology; Legumes; Population dynamics; Soil management.. |
| Ano: 2006 |
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/570260 |
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| Leite,Germano Leão Demolin; Picanço,Marcelo; Jham,Gulab Newandram; Moreira,Márcio Dionízio. |
| Kale Brassica oleracea var. acephala is attacked by whitefly Bemisia tabaci, aphid Brevicoryne brassicae and Thrips tabaci. One of the main reasons for extensive insecticide application is the lack of information about factors that control insect population. The objectives of this study were to investigate the relationships between predators and parasitoids, organic compound leaves, levels of leaf nitrogen and potassium, total rainfall, relative humidity, sunlight and median temperature on the abundance of whitefly, aphid, and thrips in kale genotype "Talo Roxo". The beating tray method, direct counting and magnifying lens were used to estimate the number of these pests, predators and parasitoids. Median temperature, sunlight and relative humidity... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Population dynamics; Nonacosane; Climatic factors; Braconidae. |
| Ano: 2005 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2005000300001 |
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| Ba, I.S.. |
| Résumé: Cette étude traite de la biologie et de la dynamique des populations d’anchois (Engraulis encrasicolus) des côtes mauritaniennes. Après un bref rappel des conditions climatiques et hydrobiologiques de la région, une tentative de mise en évidence de race ou population locale a montré que cette espèce pourrait être rattachée à la population méridionale atlantique du Golfe de Gascogne. En Mauritanie, l’Anchois n’est pêché que de façon accessoire. Les captures les plus abondantes sont réalisées de mai à Septembre essentiellement dans la zone nord où l’on observe un upwelling permanent. Pour évaluer la taille du stock, des estimations de biomasse par échointégration ont été effectuées, mais celles-ci n’ont pas permis de donner un ordre de grandeur... |
| Tipo: Theses and Dissertations |
Palavras-chave: Anchovy fisheries; Upwelling; Population dynamics; Mortality. |
| Ano: 1988 |
URL: http://hdl.handle.net/1834/676 |
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| Registros recuperados: 145 | |
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