Abstract:
There is a need to understand how anthropogenic influences affect urban and periurban
forest diversity at the regional scale. This study aims to compare urban and periurban tree
composition along a geographic gradient, and test hypotheses about species composition and
ecological homogeneity. We paired urban forest (UF) data from eight cities across the southeastern
US with periurban forest (PF) data from the USDA Forest Service Forest Inventory and Analysis
program. We found that tree diversity, as well as both observed and estimated species richness values
were greater in UF versus PF. Community size structure analysis also indicated a greater proportion
of large trees and greater numbers of non-native, invasive, and unclassified tree species in the UF
versus the PF, regardless of location. Both forest type and ecological province had a significant effect
on community species composition, with forests closer together in space being more similar to each
other than those more distant. While land use change and management has been associated with
ecological homogenization in human dominated landscapes, we found that species composition
was more dissimilar along latitudinal lines than compared to between forest types, refuting this
hypothesis, at least in terms of tree diversity