MODALITIES OF AERIAL SPACE OCCUPANCY BY H EMI-EPIPHYTES - ROLE OF SHOOT REITERATION

An architectural analysis of 3 Guianese species of hemi-epiphytes (Clu sia cuneata, Clusiaceae, Ficus nymphaeifolia and Coussapoa latifolia, Moraceae) has been undertaken in order to determine the role of shoot reiteration in hemiepiphyte plant construction and how it is related t o spatial relationship with the host-tree crown. Two different pattern s of shoot reiteration can ultimately be identified : arborescent form s (e.g. Ficus) or shrub-like ones (Coussapoa, Clusia). Each of these l ife-form categories allows the hemi-epiphytes here studied to use the available space differently. Thus, F. nymphaeifolia succeeds in oversh ading its host-tree; C. latifolia intercalates its branches inbetween those of its host-tree in a vertical way; and C. cuneata colonises emp ty spaces through a more or less horizontal direction. Reflections on the classical concept of hemi-epiphytism as a life form are given. Mor eover the evolutionary consequences of shoot reiteration in the transi tion from terrestrial to hemi-epiphytic forms are discussed.