Longévité des graines et contraintes à la survie des plantules d'afzelia africana Sm. dans une savane boisée du Burkina faso

Abstract

The viability of seeds and the survival of seedlings in natural conditions are key factors for sexual regeneration of woody species. The constraints of sexual regeneration of Afzelia africana were studied in laboratory, nursery and under natural conditions. The experiments consisted of germination tests in laboratory, monitoring of the seedling growth in rhizotron and assessment of the factors of mortality of seedlings under natural conditions. When seeds water content is about 8% (on the fresh weight basis), they can be stored in ambient conditions for at least 33 months after collection, without a significant reduction of the germination rate. The seedlings have a deep-root system with precocious lateral ramifications. However, the seedlings are still very sensitive to fire, browsing and drought. To grow well, the seedlings of A. africana need to be protected against these constraints.