Strategies d'echantillonnage et fluctuations naturelles dans des ecosystemes benthiques. Deux exemples en milieu tropical

Two benthic tropical environments were sampled in two different ways, raising a methodological problem: the suitability of a given sampling plan for any ecological problem. On the Ivory Coast the sampling schedule consists of transects, stations being distributed in relation to hydroclimatical conditions. In Madagascar, because of the environmental complexity, stations were arranged geographically on a grid pattern. The analysis of results suggest that the character of informations which are introduced by means of the "stratifier" (sampling plan criterion) influences the character of the results. In the authors' cases, the results appear as a distribution in terms of hydroclimatical and sedimentological conditions on the Ivory Coast and in terms of geographical marks in Madagascar.