XVI International Botanical Congess

Early colonizing shrubs play an important role in succession in temperate oldfields, yet there has been little study of the effects of shrubs on succession in the extensive areas of abandoned tropical pasture. I compared different stages of tree seedling establishment in areas of shrubs and grasses in abandoned pasture in southern Costa Rica. Results demonstrated: (1) seed dispersal was higher below shrubs compared to under grasses, (2) seed predation was higher below shrubs, (3) seed germination rates were similar below shrubs and grasses, and (4) early seedling survival and growth was higher below shrubs. Although shrubs have both positive and negative effects at different stages of tree seedling establishment, overall shrubs enhance establishment in the abandoned tropical pasture studied. Therefore, seeding shrubs may serve to accelerate forest recovery in abandoned tropical pastures.