Observations on successional development and floristic composition were made in 25 plots (10x2 m) established in three contiguous secondary forest fragments of the Lankester Botanical Garden, Costa Rica. Human activities favored forest regeneration there by 1) protecting an abandoned farm and pasture area since 1970, and 2) planting and propagating plant species. Planting successfully growing native and introduced species can accelerate the succession process, avoid dominance of pioneer or invasive species, and increase species diversity faster than in common successional processes. Natural diversification slowed down as natural vegetation surrounding the secondary fragments was disappearing, with a consequent reduction or lost of seed input and other reproductive sources, such as spores and stalks. Introduced plant species became naturalized in these forests, their reproduction is successful, and some of them are invasive. This study proposes general paths to help Neotropical forest restoration processes by combining natural succession and planting of native species.
Keywords: secondary forest fragments, forest restoration, introduced plant species, natural succession, lankester Botanical Garden, Costa Rica