21. Influence of Urbanization on Herbivore-Induced Leaf Damage

Abstract

As humanity expands, urbanization of natural habitats can stress ecosystems. Fragmentation and habitat degradation greatly affect the interactions of populations within communities. In the event that urbanization excludes larger predators, herbivory may proceed unchecked. We purposed this research with determining how urbanization alters the amount of damage inflicted on trees by herbivores. We examined the leaves of Acer sp. and Quercus sp. for evidence of herbivore damage at two locations on the UNG Gainesville campus. We chose trees and branches at random and scored a minimum of 20 leaves before moving to the next tree or branch. We used contingency tables and x² tests to determine the significance of any differences. Although data implied little difference in the frequency of damage in general, they showed significant differences in the prevalence of each individual type of damage between sites. We observed more instances of mining and scraping at the Tumbling Creek reserve, while hole feeding, margin feeding, skeletonization, and oviposition tended to manifest mostly within the campus hub. This study suggests that the trees’ proximity to more urbanized areas has little bearing on the frequency of damage; however, it greatly influences the occurrence of individual damage types.

Keywords: Herbivory, Urbanization, Leaf, Acer, Quercus, Trophic Interactions, Herbivore