An autecological study of Palicourea riparia Bentham as related to rain forest disturbance in Puerto Rico

Summary The present study is an attempt to understand biology of Palicourea riparia Bentham relative to the process of recovery following disturbance in a tropical rain forest in Puerto Rico. In this species seed germination and seedling maintenance are favored by environmental conditions associated with disturbance, yet germination and seedling persistence are significant in undisturbed forest conditions. The pattern of seed germination indicates that (1) the seeds possess a dormancy mechanism, (2) dormany is not evenly distributed within a seed population, and (3) some seeds can remain viable if buried in the soil for at least three years. Results from reciprocal transplant studies indicate that there has been no differentiation into growth ecotypes in this species. Photosynthetic rates are very low under both field and laboratory conditions. In the laboratory, photosynthetic rates are consistently enhanced by increases in light intensity. It is concluded that P. riparia is a species of wide ecological amplitude that acts as a gap opportunist.