ibclogo XVI International Botanical Congess


Abstract Number: 3907
Session = 16.7.2


THE PALM ASTROCARYUM SCIOPHILUM, A LONG-LIFE" STRATEGY IN A POOR LIGHTENERGY ENVIRONMENT


P. Charles-Dominique*, A. Brunner#, J. Chave^, B. di Pietro#, M. A. Dubois^, B. Riéra* and C. Vezzoli*, *UMR8571 CNRS/MNHN, Laboratoire d'Ecology Generale, 4 avenue du Petit Château 91800 Brunoy France, ^SPEC DRECAM, CEA, L'Orme des Merisiers, Centre de'Etudes de Saclay, 91191 Gif sur Yvette, France, #University of Milano, Italia


The undergrowth of tropical rain forest provides a microclimate characterized by a practically constant high humid and worm milieu. However, plants which achieve their complete cycle in these conditions have to develop adaptations in reaction to two main ecological constraints : 1) the low light energy attaining the ground, 2) the relatively frequent « bombing » of the undergrowth by falling branches and trunks. The palm Astrocaryum sciophilum live in such conditions, reaching when adult, a funnel like shape up to 8 m in diameter. Due to low light energy, new leaves are produced every 12 - 19 months, with a very low size increasing. Different measurements of the growth gave an estimation of 160 to 200 years before the first fructification, then 200 to 350 years of adult stage. Because a short seed dispersal (rodents) the colonization of the species is particularly slow, offering a good model in order to study the events having affected tropical forest during the last millenaries. Different isolated subpopulations show a phase of colonization in there margins, evoking a present-day recolonization of the forest from zones having probably acted as refuges.


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