Conservation assessment of Playa Delfín Rainforest Reserve and Research Station, Costa Rica

Résumé

Playa Delfín is located in southwestern Costa Rica on the Golfo Dulce coast across from the Osa Peninsula, and occupies an area of 115 ha with elevations ranging up to 145 m. The reserve is privately owned by Patrick and Anne Weston, and was purchased in 1988 to protect one of the last remaining tracts of primary forest in the region. A two-week botanical survey in 2011 aimed at assessing the conservation value of the site resulted in the documentation of 138 taxa of chiefly woody plants. Of these 101 were trees, 24 were shrubs, 6 were lianas, and 7 were herbs. Included in the list are twelve species considered to be rare or of restricted ranges, as well as three species representing first reports for the Osa Peninsula/Golfo Dulce region. Four major habitats are described along with typical species associated with each community. Primary forest occurred in the uplands and stream corridors while the lowland section was more disturbed but still contained a number of large trees. Five non-native species were documented in the lowlands but only Gmelina arborea was particularly invasive. These results suggest that a rich flora occurs at Playa Delfín, and, as it was also known to harbor a rich fauna, provides additional evidence of the high conservation value of the site. Already a part of Costa Rica’s private forest reserve system, Playa Delfín received additional government protection as a result of this and other studies documenting the biological resources at the reserve.