Christina Blebea

Through a secondary seed dispersal experiment in six long-term restoration sites in southern Costa Rica, we show that ants remove fewer seeds and disperse them shorter distances in naturally regenerating than in actively planted and reference forests. Our results demonstrate the importance of restoring plant-animal interactions.

Successfully establishing late-successional tree species in secondary forests can take centuries. Thus it is important to restore plant-animal interactions that can aid in ecosystem recovery. One fundamental interaction that is vital to restoring forests is seed dispersal. Ants are key secondary dispersers in tropical forests. Ants markedly impact plant spatial patterns and in turn forest recovery through directed dispersal. In this forest restoration study, we measured the number of seeds ants removed and the distance the seeds were carried for three species of mid- to late-successional trees. We conducted this experiment in six forests that were restored using active tree planting (plantations) and natural regeneration methods ≥ 17 years prior, as well as four remnant forests, in southern Costa Rica. Ants removed significantly fewer seeds in natural regeneration than plantation plots and reference forests. Seeds were also dispersed significantly shorter distances in natural regeneration compared to plantation and reference forest plots. Our study demonstrates that different restoration methods result in distinct vegetative structures and ant communities that impact late-successional tree dispersal.