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| Diserud, Oh. |
| In this paper, I present a method developed to detect 'extra', or novel, changes in diversity in a naturally fluctuating environment. When comparing samples in order to evaluate changes in community structure, the sampling procedure will inevitably induce randomness in observed species composition and abundance, so two samples may show considerable differences, even if they come from exactly the same community. Sometimes the effort put into the sampling varies as well, leading to the expectation of a further increase in difference. Finally, if there were a temporal distance between the samples, we would like to correct for variations in species abundance occurring naturally due to fluctuating environmental conditions. The test method presented here... |
| Tipo: Text |
Palavras-chave: Structure des communautés; Diversité; Variance environnementale; Dynamique des populations; Modèle d'abondance d'une espèce; Community structure; Diversity index; Environmental variance; Population dynamics; Species abundance model. |
| Ano: 2001 |
URL: http://archimer.ifremer.fr/doc/00322/43345/42881.pdf |
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| Gaudy, R.; Guerin, J.p.. |
| Following are results obtained in our laboratory during breeding experiments with an harpacticoid copepod, Tisbe holothuriae. In small size volumes (200 ml), the potential production appears to be higher when an artificial compound food of animal substances is used instead of a vegetal diet. In medium volume experiments (100 l) the production is related to the surface available for animals in breeding tanks, Breeding in complete cycles can be obtained using various foods, but the quality of diet may markedly affect the characteristics of the vital cycle, such as the length of the fertility period and fecundity. Temperature has a crucial effect, chiefly on dynamic preoccesses, that is to say, developmental rate and average generation time. With different... |
| Tipo: Text |
Palavras-chave: Production; Dynamique des populations; Biomasse; Composition chimique élémentaire; Bilan énergétique; Copépodes harparcticoïdes; Production; Population dynamic; Biomass; Chemical elementary composition; Energy balance; Hapacticoïd copepods. |
| Ano: 1979 |
URL: http://archimer.ifremer.fr/doc/00306/41672/40881.pdf |
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