Seed phenology and germination of Ghanaian forest trees
Seed production and germination of some timber tree species were studied in Ghana for possible prediction of seed yield and natural regeneration. Seed phenology in 13 species was monitored for two years, using permanent seed traps in two forest sites. Seed germination tests were conducted in neutral, green shade and dark in shade houses for 20 species. In the forest, germination was tested in forest gaps receiving different irradiances. Fruiting frequency ranged from twice in each year to supra-annual fruiting. Fruiting periods for species were consistent between years. Fruiting synchrony was higher among individuals of a population than between sites for the same species. Fecundity differed between years for the majority of species and between sites for species common to both sites. Premature fruit abscission was quite common. Maximum seed weight and percentage germination occurred during peak fall of mature seeds. Seeds of the majority of species germinated equally in light and dark and also in neutral and low red: far red ratio. These included some species previously classified as pioneers. In the forest germination was depressed in a large clearing for the majority of species. The use of photoblastic germination alone to define pioneers leads to a smaller group of pioneer species than is presently recognised. Large gaps due to logging may discourage natural regeneration.