Etude des Successions Vegetales des Forets Brulees du Tampoketsa D'Ankazobe pour la Restauration de la Foret D'Ankafobe
Mirana Arilala Robisoa
Ankafobe is one of the largest fragments of forest in Tampoketsa, district of Ankazobe. One part of this forest was exposed to fire and to some other perturbations like most of the vegetations in this area. However, Ankafobe has its own particularity; it is a vestige of natural forests among those in the high lands of Madagascar. The forests play a very important role for the regulation of “biogeochemical” cycle and serve home and shelter for rare species like Schizolaena tampoketsana or “sohisika”, one of the endemic species in this area. The project of ecological restoration should intervene to reestablish the integrity of ecology in the parts of forest destroyed by fire, or even in the whole massif. Yet, the plan for this restoration requires knowledge based on scientific data. Therefore, the principal objective of this research is to collect some necessary information about the succession of burned forests in Tampoketsa in order to suggest some strategies of restoration adapted to the forest of Ankafobe. A synchronic approach, permitting simultaneous analysis of vegetations having different ages after the fire, is then adopted by following the trajectory of vegetal succession. In this way, after the passage of fire, a stage of herbaceous colonization appears in about one to two years; then a stage of cover pioneer succeeds this first stage (3 to 10 years); and finally, there is a sequence of pre- forest which lasts more than ten years after perturbation. Therefore, in the scale of twenty years, it was deducted that the vegetations succeeding the burned forest in Tampoketsa can re-form naturally to a structure more or less the same to the state of a real forest in which the inside of Ankafobe, if there won’t be fire repetition. The reference is in fact the forest ecosystem to what the path of plants succession will be directed to the accomplishment of the restoration. Hence, this research will serve as referential tools to accomplish the project of ecological restoration for Ankafobe.
Complete article is in French.