Notions sur les structure et dynamique des forêts tropicales humides

Abstract

Dense tropical rainforests are the most complex type of terrestrial ecosystem on the planet. They are currently the topic of much debate in connection with a number of major issues e.g., the sequestration of carbon arising from atmospheric pollution and the greenhouse effect, and the depletion of the pool of diversity they represent, with the concomitant loss of molecules whose properties are still largely unknown. As a result, understanding their dynamics with a view to better management has become a priority research area for reasons beyond just scientific curiosity. This brief presentation begins with a description of some of the essential features in the structuring processes of the arborescent population - non spatial parameters (diameter class distribution, density, basal surface), spatial structures (vertical and horizontal, overall and specific), wealth and incidence of species. The second part describes a number of mechanisms at work in the forest dynamics and then focuses more specifically on the variations brought about by the heterogeneity of the environment and on the time and space scales of the processes involved.