Oral Abstract Details

Author(s):
Amy Stephens Davis and Ross K. Meentemeyer

Affiliation:
Center for Applied Geographic Science at UNC Charlotte

Presentation Type:
Oral

Topic Area:
Evaluating changes to ecosystem goods and services along urban-rural gradients

Abstract Text:
Land use change and invasions by exotic species are widely recognized as the primary drivers of biodiversity loss. However, few studies have focused on how landscape structure of rapidly urbanizing regions is impacting the spread of exotic plant species and persistence of native plant diversity. Using the rapidly growing metropolitan region of Charlotte, North Carolina as a case study, we examine the hypothesis that landscape structure of the built and natural environment are linked to patterns of native and exotic plant diversity in forests along the urban to rural gradient. We sampled 105 randomly located plots for woody species presence and abundance at 25 forested sites stratified across three land use types (urban, suburban and rural). We investigated multi-scale effects of building and road density on landscape patterns of woody species diversity using linear regression analyses and controlling for spatial autocorrelation. Road density within 1 km negatively influences native diversity. Building density within 1 km positively influences exotic abundance in urban sites (r2= .473), and building density within 200 m for suburban sites (r2=.340). Native richness and diversity are highest in rural areas and decrease with increasing urbanization. Unexpectedly, we found that mean exotic abundance is significantly higher at rural sites as compared to urban and decreases with increasing urbanization. We hypothesize that historical factors such as past agricultural land use and patterns of forest connectivity over time influence native diversity and exotic species distributions potentially confounding the effects of contemporary landscape heterogeneity. We have mapped land cover at multiple time steps from 1938 to 2006 at each forest sampling site to examine the influence of historical landscape structure and composition on the persistence of native diversity and exotic abundance and will report the results of our analysis. One anticipated outcome of this work is a better understanding of how landscape legacy vs. contemporary landscape heterogeneity affect exotic species spread and plant species diversity.