[en] Minimal sampling areas have been determined for marine Bangiophyceae and Cyanophyceaee epiphytic on Cladophora prolifera and Halopteris scoparia in Calvi, Corsica. This was done by observing the stabilization of species/area curves and of qualitative and quantitative similarity coefficients between samples of increasing size. For Cyanophyceae (studied only on Cladophora) the minimal sampling area is in the order of 15 - 38 mm2, depending on the method used. The sampling area is smaller when the quantitative similarity coefficient is used, apparently because of the rather homogeneous distribution of a few abundant taxa. For the same reason the quantitative similarity coefficient stabilizes at a high value (75 %). For Bangiophyceae on Cladophora, the area is of the order of 7 - 10 mm2, but a larger area is necessary for the quantitative than for the qualitative coefficient. The stabilized value of the quantitative coefficient is relatively low (66 %), despite the fact that the qualitative coefficient reaches 94 %. On Halopteris, by counting only on medium sized ramifications (about 100 um in diameter), one can use a sampling area as low as 0.1 - 0.5 mm2 and obtain a qualitative similarity coefficient of 100 % and a quantitative one of 80 %. This study demonstrates that techniques used for macrophytic vegetation can be applied with success to microscopic epiphytes.
Centre Interfacultaire de Recherches en Océanologie - MARE ; STARESO ; Centre d'Ingénierie des Protéines - CIP