Institute of Ecosystem Studies

2008 BES Annual Meeting Presentation and Poster Abstracts

Using cross-system comparisons as an approach to study urban effects on soils: A case study of three urban metropolitan areas
Pouyat, Richard
Co-Authors: Ian D. Yesilonis, Katalin Szlavecz, Csaba Csuzdi, Elizabeth Hornung,Zoltan Korsós, Jonathan Russell-Anelli, Vincent Giorgio
Abstract: An overarching them in urban ecological theory implies that anthropogenic drivers will dominate natural drivers in the control of ecosystem response variables. We investigated the effects of a natural soil forming factor (parent material) vs. anthropogenic factors (urban environmental change) on the chemical properties of forest soils in the metropolitan areas of Baltimore, New York, and Budapest. We hypothesized that soils in forest patches in each city will exhibit changes in chemistry corresponding to environmental changes along urbanization gradients. Moreover, differences in parent material and development patterns would differentially affect the soil chemical response in each metropolitan area. Results showed that soil chemical properties varied with measures of urban land use in all three cities, including distance to the urban core. Moreover, the results showed that the spatial extent and amount of change was greater in New York than in Baltimore and Budapest for those elements that showed a relationship to the urbanization gradient (Pb, Cu, and to a lesser extent Ca). The spatial relationship of the soil chemical properties to distance varied from city to city. In New York, concentrations of Pb, Cu and Ca decreased to approximately background concentrations at 75 km from the urban core. By contrast, concentrations of these elements decreased closer to the urban core in Baltimore and Budapest. Moreover, a threshold was reached at about 75% urban land use above which concentrations of Pb and Cu increased by more than twofold relative to concentrations below this threshold. Results of this study suggest that forest soils are responding to urbanization gradients in all three cities, though characteristics of each city (spatial pattern of development, parent material, and pollution sources) influenced the soil chemical response.