Do Janzen-Connell and distance from forest edge affect insect herbivory on tree seedlings?

The Janzen-Connell (JC) effect refers to the patterns that occur in predation among conspecific and heterospecific seedlings found under an adult tree, and is a means of regulating diversity. Seedlings’ conspecific status may often attract host-specific enemies to prey upon them, allowing for other species to establish under the adult tree. I conducted a study to determine if the joint efforts of the Janzen-Connell effect and forest position impact herbivory patterns of insects, using the temperate forest located on Bard College campus in Annandale-on-Hudson, New York. I studied 15 focal trees that varied in species identity and distance from the forest edge, selecting con- and heterospecific seedlings within a 3 m radius surrounding each focal tree to observe after three months; half of these were placed in small exclosures covered by garden fabric, while the other half were left in their exclosures uncovered. In early October 2021, I collected leaves from the observed seedlings, counting how many seedlings were conspecific or heterospecific near each tree, then measuring percent damage found on the leaves. I predicted that damage specifically from insect herbivory would be higher on conspecific seedlings than heterospecific seedlings, and higher on seedlings located at the forest’s edge than those located at the interior. I found no significant results, concluding that a larger sample size is needed in order to compare patterns of insect herbivory with differing Janzen-Connell strengths and forest positioning