Approche méthodologique de la distribution spatiale des algues épiphytiques sur l’appareil foliaire d’Apium nodiflorum (L.) Lag. (Apiaceae)

Abstract

A microhabitat scale study of spatial epiphytic distribution of a common Apiaceae of karsfic mediterranean springs has been carried out, on the leaf system of Apium nodiflorum. Longitudinal and transverse zones along the leaf have been determined and separately analysed. In spite of a physiologic variability inherent in each sample, initial results, based on a 48 leaflets sample, for each stage, reveal a non-random distribution of epiphytes on different architectural elements of the host-plant. A homogeneity of algal communities is noted on the whole plant height from surface to base. The several scales necessary for this methodological study clearly show existence of microzones which are quantitatively and qualitatively representative for the whole epiphytic populations. These results, followed by later investigations on different plants must be useful as a technical approach for scientists and for water administrators in the river monitoring.