The effect of a teak (Tectona grandis) plantation on the establishment of native species in an abandoned pasture in Costa Rica

Many tropical forest plantation projects, particularly those funded through governmental or development agencies are designed to provide secondary social or environmental benefits in addition to timber. The research reported here examined the ecological effects of establishing a teak (Tectona grandis) plantation on an abandoned pasture in southwestern Costa Rica. The 10-year-old plantation's understory was evaluated using a nearby non-planted area as a baseline for potential local recruitment of native tree species. The native trees in the teak plantation were significantly less abundant, less diverse, and more restricted to the lower height classes than the trees in the abandoned pasture. Furthermore, trees with shrubby growth forms dominated the plantation's understory, whereas larger species were more common in the unplanted abandoned pasture. Several aspects of teak's biology may contribute to the species' exclusion of native trees. The primary goal of nearly all forest plantations is the production of timber. However, for those managers secondarily interested in the goal of providing habitat for native forest species, teak appears to be a poor choice of crop tree. (C) 2002 Elsevier Science B.V. All rights reserved.