Physical and biological barriers can delay natural regeneration in degraded ecosystems. Tropical tree plantations can contribute to restore soils and accelerate forest regeneration. In a program on ecosystem rehabilitation in three regions of Latin America, about 50% of a total of 29 tree species tested had positive effects on soils and good growth, making them attractive to farmers for reforestation. In plantations with indigenous tree species in the humid lowlands of Costa Rica, tree regeneration was higher under plantations than in abandoned pastures. Tree regeneration was high under mixed-species plantations. Open pastures had the highest proportion of wind-dispersed seeds, while bird and bat seed dispersal was predominant in the plantations. High litter accumulation on the plantation floor diminished grass growth and encouraged woody invasion.