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| Registros recuperados: 188 | |
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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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| Souto,KCFL; Pereira,CD; Lomônaco,C. |
| The aim of this study was to comparatively characterize the monthly variation and the sex ratio of Euxesta stigmatias (Loew) and Euxesta sororcula (Wiedermann) populations from a natural reserve and from a guava orchard. It was also investigated whether density and the climate factors affected the individuals' size and fluctuating asymmetry (FA). In both environments, E. sororcula predominated over E. stigmatias. The number of individuals of E. sororcula collected in the ecological station was significantly lower than the number of individuals caught in the orchard. However, the number of captured individuals of E. stigmatias did not differ between environments. Significant sex ratio differences were detected between the collection sites. Female's... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Fluctuating asymmetry; Morphometry; Population dynamics. |
| Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1519-566X2011000600005 |
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| Heino, Mikko; Baulier, Loic; Boukal, David S.; Ernande, Bruno; Johnston, Fiona D.; Mollet, Fabian M.; Pardoe, Heidi; Therkildsen, Nina O.; Uusi-heikkila, Silva; Vainikka, Anssi; Arlinghaus, Robert; Dankel, Dorothy J.; Dunlop, Erin S.; Eikeset, Anne Maria; Enberg, Katja; Engelhard, Georg; Jorgensen, Christian; Laugen, Ane; Matsumura, Shuichi; Nussle, Sebastien; Urbach, Davnah; Whitlock, Rebecca; Rijnsdorp, Adriaan D.; Dieckmann, Ulf. |
| Biological reference points are important tools for fisheries management. Reference points are not static, butmay change when a population's environment or the population itself changes. Fisheries-induced evolution is one mechanism that can alter population characteristics, leading to "shifting" reference points by modifying the underlying biological processes or by changing the perception of a fishery system. The former causes changes in "true" reference points, whereas the latter is caused by changes in the yardsticks used to quantify a system's status. Unaccounted shifts of either kind imply that reference points gradually lose their intended meaning. This can lead to increased precaution, which is safe, but potentially costly. Shifts can also occur in... |
| Tipo: Text |
Palavras-chave: Biological reference points; Fisheries-induced evolution; Fisheries management; Population dynamics; Precautionary approach; Uncertainty. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00151/26228/24302.pdf |
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| Mili, S.; Jarboui, O.; Missaoui, H.. |
| Pour l’étude biométrique de la squille Squilla mantis, un échantillonnage régulier a été réalisé dans le golfe de Tunis, le golfe de Hammamet et le golfe de Gabès de janvier 2005 à décembre 2006. Les équations morphométriques de la squille, dans le golfe de Gabès, ont montré que la croissance relative du telson, celle de la masse totale et celle de la masse éviscérée par rapport à celle du céphalothorax sont caractérisées par une allométrie positive. Par contre, la longueur totale croît négativement par rapport à celle du céphalothorax. Pour le golfe de Hammamet, ces caractères ont une croissance marquée par une allométrie négative à part la masse éviscérée. Les équations morphométriques de la squille du golfe de Tunis ont montré une allométrie positive... |
| Tipo: Journal Contribution |
Palavras-chave: Biometrics; Comparative studies; Population dynamics; Population structure; Statistical analysis; Squilla mantis; Http://aims.fao.org/aos/agrovoc/c_46197. |
| Ano: 2008 |
URL: http://hdl.handle.net/1834/4241 |
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| Barraquand, F.; Picoche, C.; Maurer, Daniele; Carassou, L.; Auby, Isabelle. |
| Phytoplanktonic communities maintain a high diversity in a seemingly homogeneous environment, competing for the same set of resources. Many theories have been proposed to explain this coexistence despite likely competition, such as contrasted responses to temporal environmental variation. However, theory has developed at a faster pace than empirical evaluation using field data, which requires inferring drivers of community dynamics from observational time series. Here, we combine autoregressive models with a data set spanning more than 20 years of phytoplankton counts every two weeks, together with nutrients and physical variables. By comparing models dominated by nutrients or physical variables (hydrodynamics and climate), we first explore which abiotic... |
| Tipo: Text |
Palavras-chave: Competition; Diatoms; Dinoflagellates; Hydrodynamics; Interactions; MAR; Mutualism; Network; Population dynamics; Seasonality; Time series. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00461/57257/59285.pdf |
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| SILVA, G. V.; PINTO, N. S.; SANTOS, R. S.; DAUD, R. D.. |
| No presente estudo foi avaliado o efeito temperatura sobre a dinâmica populacional de Tenuipalpus heveae Baker em cinco clones de seringueira. O estudo foi conduzido de novembro de 2018 a janeiro de 2019 no jardim clonal de seringueiras do campo experimental da Embrapa Acr,e Rio Branco, estado do Acre, nos clones CPAA C18, FDR 5788, FX 3899, PB 312 e RRIM 600. Semanalmente foram retiradas, aleatoriamente, oito folhas do terço inferior da copa de quatro plantas de cada clone. Os ácaros coletados foram montados em lâminas de microscopia em meio de Hoyer. A relação entre a temperatura média e a abundância de T. heveae foi testada por meio de um modelo linear generalizado com distribuição de Poisson. Foi amostrado um total de 2.909 ácaros em 6.720 folíolos... |
| Tipo: Artigo de periódico |
Palavras-chave: Tenuipalpus heveae; Ruber tree; Plagas de plantas; Temperature resistance; Dinámica poblacional; Granjas de demostración; Embrapa Acre; Rio Branco (AC); Acre; Amazônia Ocidental; Western Amazon; Amazonia Occidental; Seringueira; Hevea Brasiliensis; Caucho; Praga de Planta; Resistência a Temperatura; Dinâmica Populacional; Ácaro; Campo Experimental; Tenuipalpidae; Acari; Plant pests; Mites; Population dynamics; Demonstration farms. |
| Ano: 2021 |
URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/1137786 |
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| MIRANDA, E. M. de; SILVA, E. M. R. da; SAGGIN JUNIOR, O. J.. |
| O objetivo deste trabalho foi identificar e estimar a diversidade de comunidades de fungos micorrízicos arbusculares (FMAs) autóctones associados ao amendoim forrageiro (Arachis pintoi), em monocultivo e consorciado com outras forrageiras. A amostragem foi realizada em sete áreas, em Rio Branco, AC, sendo coletadas quatro amostras de solo em cada área, na profundidade de 0-10 cm, nas estações seca (junho de 2004) e chuvosa (janeiro de 2005). As áreas cultivadas com A. pintoi foram: monocultivo, consórcio com pastagens de gramíneas e outras leguminosas e como cobertura do solo em cafeeiro, além de capoeira e mata adjacentes como testemunhas. Foi verificada a ocorrência de 21 espécies de FMAs nas duas estações, sendo 18 espécies no período seco e 16 no... |
| Tipo: Artigo de periódico |
Palavras-chave: Amendoim forrageiro; Fungo micorrízico arbuscular (FMA); Rio Branco (AC); Acre; Amazônia Ocidental; Biología del suelo; Fertilidad del suelo; Dinámica poblacional; Hongos mycorrhizales.; Biologia do solo; Fertilidade do solo; Monocultura; Consorciação de cultura; Leguminosa forrageira; Fungo; Flutuação populacional; Estimulante de crescimento vegetal; Soil biology; Soil fertility; Mycorrhizal fungi; Population dynamics; Arachis pintoi.. |
| Ano: 2010 |
URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/657810 |
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| Desprez, M; Ducrotoy, J; Elkaim, B. |
| In this paper, the results collected since 1978 on the cockle (Cerastoderma edule) in the Bay of Somme have been recapitulated. A synthesis is brought up about causes of the bivalve population collapse which was portended as early as 1982 from the animal cinetics study. In order to back up the discussion, the main results dealing with the biology and ecology of the species are recalled in illustrated form. A review of the international literature leads to a comment upon the diagrams. A comparison with data from European estuaries tends to take climatic and oceanic disturbances into account as well as local pollution such as eutrophication which is probable on the littoral of Picardy. |
| Tipo: Text |
Palavras-chave: Clam fisheries; Stock assessment; Recruitment; Population dynamics; Marine mollusks. |
| Ano: 1985 |
URL: http://archimer.ifremer.fr/doc/1985/publication-1783.pdf |
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| Ducrotoy, J; Desprez, M; Elkaim, B. |
| The recent collapse in the landings of cockles (Cerastoderma edule) from the Bay of Somme (France) required to investigate if a change in the environmental factors was liable for the drop of the bivalve populations. This project has led to a preliminary assessment of the situation and has been drawn up from the data collected by the Groupe d'Etude des Milieux Estuariens et Littoraux since 1978. It relies on the survey of the spatio-temporal changes of bio-facies. it is suggested that the impact of changes in sediment characteristics is important as well as competition with species as Pygospio elegans (Polychaeta). The above parameters are assessed as essential in the fluctuations of the cockle numbers but they do not explain entirely the collapse in the... |
| Tipo: Text |
Palavras-chave: Landing statistics; Clam fisheries; Stock assessment; Population dynamics; Marine mollusks. |
| Ano: 1985 |
URL: http://archimer.ifremer.fr/doc/1985/publication-1784.pdf |
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| Registros recuperados: 188 | |
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