Spatial occupation of Cyathea muricata Willd. (Cyatheaceae) in Guadeloupean tropical rain forest. I - At the individual level

A study of the spatial occupation of Cyathea muricata Willd. has been made in Guadeloupe at 300 m altitude in the tropical rain forest. We have consid ered the occupied space at the level of the individuel during the growth. T hanks to the measure of the height, stipe diameter. length and number of fr onds for some seventy tree-ferns, we demonstrated that there were two phase s in the growth of Cyathea muricata. During the first phase, or establishme nt one, the diameter of the stipe and the length of the fronds attain their maximum whereas the height of tree-fern increases just a little, Then, the occupied space during this phase corresponds to an inverted cone with 30 c m of height and a radius, at his base, equal as the maximum length of the f ronds. During the second phase or adult phase, only the augmentation of the height is effective : the diameter of the stipe and the length of the fron ds remain stables. Then, the occupied space corresponds to a cylinder whose radius is equal as the maximum length of the fronds.