Reproductive success in a tropical tree species, Virola surinamensis

The reproductive success of a species determines how successful that species will be in its environment. Many different processes can drive the reproductive success of a species. Fruit production, insect seed predation, and germination are important factors that affect the fitness of individual plants. Looking at these patterns helps us to further understand the many interactions that affect plant communities. My project focuses on assessing the forces driving variation in fruit production and insect seed predation rates in the tropical tree species, Virola surinamensis. I used transect and quadrat sampling techniques on ten focal trees to collect data about fruit production rates, insect seed predation, and germination to quantify the surrounding neighborhoods in a lowland tropical forest in Panama. Fruit production between individual trees was highly variable (735-17,265). When using a linear model, fruit production was found to be positively correlated with tree size. The proportion of seeds predated upon by insects also varied highly between trees (6.9-76.3%). Insect predation was not found to be statistically significantly correlated with seed availability; however a qualitative analysis of the data indicates that the level of insect predation increases with increasing seed availability to a peak, and then drops off. This is indicative of patterns of density dependence and insect predator satiation, and therefore these patterns may be playing a role in the reproductive success of the trees studied. Further research into the drivers of plant interactions in tropical environments will help to answer questions about biodiversity and inform conservation biology practices.Research Experience for Undergraduates (REU) supplement to National Science Foundation grant number DEB-1242622No embargoAcademic Major: Evolution and Ecolog