This study describes forest cover changes and the current vegetation in the area surrounding the Joyuda Lagoon in western Puerto Rico. Forest cover increased from 22 ha to 87 ha between 1930 to 1997. This increase is the result of mangrove forest expansion and the abandonment of a former coconut plantation. Three mangrove species occupy the areas closest to the lagoon water. The abandoned coconut plantation is dominated by several exotic tree species typically planted along the coasts of Puerto Rico. Comparisons with previous accounts of the composition of this plantation and with the vegetation of another abandoned coconut plantation elsewhere in Puerto Rico suggest that this tree assemblage is still developing towards a community type that is very different than that of other areas having similar physical and climatic conditions.