TREE COMMUNITY DYNAMICS IN A HUMID SAVANNA OF THE IVORY-COAST - MODELING THE EFFECTS OF FIRE AND COMPETITION WITH GRASS AND NEIGHBORS

Humid savannas are often made of woody groves and grassy patches in which a few woody individuals develop. A simulation model has been built to explore: 1) the role of dispersal and individual growth in community structure; 2) the role of local-neighbourhood competition on seedling and adult survival; 3) the interaction between fire and vegetation structure. Competition for water in the upper horizons of the soil should be more efficient at limiting clump development. The average fire regime cannot prevent these savannas from being invaded by trees. Only a combination of strong competition between individuals and episodic fierce burning should regulate tree density in the long term. -from Authors