Spatio-temporal dynamics of the tropical rain forest

Mechanisms which drive the dynamics of forest ecosystems are complex, from seedling establishment to pollination, and seed dispersal by animals, runni ng water or wind. These processes are more complex when the ecosystem shelters a large number of species and of vegetative forms, as it is the case in the tropical rain forest. To take them into account, we must develop and use models. I present a review of the fundamental mechanisms for the of a natural fores t dynamics - photosynthesis, tree growth, recruitment and mortality - as we ll as a description of the past and of the present of tropical rainforests. This information is used to develop a spatially-explicit and individual-bas ed forest model. Simplified models are deduced from it, and they serve to a ddress more specific issues, such as the resilience of the forest to climat e disturbances, or savanna-forest dynamics. The last topic is related to the spatio-temporal description of tropical pl ant biodiversity. A detailed introduction to the problem is provided, and m odels accounting for the maintenance of diversity are compared. These model s include non spatial as well a spatial approaches (branching anihilating r andom walks and voter model with mutation).