Forest fragmentation happens when one continuous forest breaks up into smaller islands of forests. Most forests are expected to be fragmented in the future due to human activities, and when forest fragmentation happens, there are various negative consequences on both plant and animal species that reside in those smaller forest fragments. I conducted my dissertation work in southern Costa Rica where I studied various aspects of forest fragmentation effects on animal-dispersed tree species. When a forest is fragmented, more edges are created relative to the forest interiors, where the environment is brighter, drier, and hotter. These effects are called ‘edge effects’. One of my projects assessed how edge effects impact various early life stages of tropical tree species. We found that edge effects can act substantially on very early stages, in a very short time frame (Sugiyama & Peterson 2013). This means that if you miss that specific stage, you might conclude that there are no negative impacts of forest fragmentation on species regeneration, while the reality might be completely opposite.
In transplant experiments, we assessed the relative importance of maternal origin, edge effects, light availability, and distance from reproductive conspecific trees on seedling performance. We found that seedlings from a particular maternal origin showed reduced growth in the greenhouse, but those same seedlings showed enhanced growth once they were transplanted in the forest, with one tree showing reduced performance when planted near its maternal tree (Sugiyama & Peterson, 2015). Taken together, if only specific life stages are assessed, negative effects could be missed and incorrect decisions might be made when these species are used for reforestation.