Seed production and soil seed bank in three evergreen woody species from aneotropical savanna

Results of a 3-y study on the populations of three evergreen woody species (Byrsonima crassifolia, Palicourea rigida and Bowdichia virgilioides), from a regularly burnt savanna, in Venezuela, are reported. Tree density, size structure, fruit-seed production per tree of different size classes and soi l seed bank were estimated. Viable seed production was one order of magnitu de higher in B. crassifolia, which was also the only species with a permane nt soil seed bank. Seeds of B. virgilioides germinated readily after disper sal, whilst seeds of P. rigida showed an innate dormancy synchronously rele ased after a year. Both of the latter species seemed to maximize the first growth season by germinating at the beginning of the favourable season. In B. crassifolia, germination proceeds with an early small burst of germinati on, possibly followed by a second peak at the beginning of the next rainy s eason and little or no germination thereafter. The results showed that desp ite the high fire frequency, the studied species produce a substantial numb er of viable propagules, and have the capacity to germinate in field condit ions (readiness depending on the species). Sexual reproduction is expected, therefore, to play an important role, as suggested by their reproductive i nvestment, in longterm population maintenance.