Ocotea oblonga: A Gynodioecious Tree

Ocotea oblonga (Meisn.) Mez (Lauraceae) is unusual among tree species in having a gynodioecious breeding system, meaning some plants are female (bearing only female flowers) and some plants are hermaphrodites (bearing bisexual flowers). Despite its large geographic range, the ecology and evolution of this species remain largely unexplored. In the population on Barro Colorado Island (BCI), 30% of reproductive adults are female, and female trees produce more fruits than hermaphrodites. The species is moderately abundant on BCI, including on the 50-ha Forest Dynamics Plot, which provides demographic data for hundreds of individuals over the past 40 years. Associated multispecies studies show that O. oblonga is relatively gap dependent, has relatively high growth and mortality rates, and is significantly more common in the moister slope habitat of the plot. The unusual breeding system of this species combined with the extensive preexisting data on BCI provide excellent opportunities for future research.