RESPROUTERS VS RESEEDERS IN SOUTH-AFRICAN FOREST TREES - A MODEL-BASED ON FOREST CANOPY HEIGHT

1. We expect tree species that regenerate primarily by sprouting to pr oduce fewer seedlings than co-occurring species that regenerate mainly from seedlings, because of the trade-off between allocating resources either to ensuring vegetative reproduction (e.g. protective bark/late nt buds) or to sexual reproduction (e.g. seeds). 2. Furthermore, respr outing species, because of their multi-stemmed nature, should be at a relative disadvantage, and therefore relatively infrequent, in tall fo rests, This is because a resprouting individual allocates resources to a number of basal branches/stems and buds rather than maximizing vert ical extension of a single leader, as is the case in a seeder. Also, m any tall stems arising from the same multi-stemmed base, as is the cas e in resprouters, will be relatively poorly supported in comparison to the single stem of a reseeder. 3. To test these two ideas we surveyed a number of plots in a range of South African forests and thicket com munities. We noted the numbers of seedlings and resprouts for each spe cies and determined a mean for each site, 4. Short forests and thicket s were dominated by multi-stemmed species and there was an almost tota l absence of seedlings. In contrast, tall forests were dominated by si ngle-stemmed reseeding species and were accompanied by seedlings.