A Conceptual Model Of The Movement And Effects Of Toxic Chemicals In Urban Ecosystems (presentation)

DIAMOND, M. L. and R. V. Pouyat

A conceptual model will be presented to explain the movement of toxic chemicals through urban ecosystems in contrast to relatively undisturbed ecosystems. The model is based on the multimedia urban model (MUM) that quantifies the movement of chemicals between air, impervious surfaces, vegetation, soil, surface water, and sediments. To test the relationships in the conceptual model, we propose to quantify and compare inter-media fluxes and the direction of these fluxes along an urban-rural gradient, e.g., between air, and vegetative, soil and impervious surfaces. We expect that a better understanding of these interactions would allow for: 1) prediction of the effects of contaminants and nutrients on terrestrial and aquatic plant and animal communities and ecosystem functioning; 2) quantification and assessment of human exposure to contaminants; and 3) development of conceptual and mathematical models of chemical fate in urban and suburban ecosystems. These research activities will benefit the efforts of urban planners and natural resource managers in reducing human exposure and ecological damage due to contaminants and nutrients in developed areas and will allow for the evaluation of realistic scenarios in watersheds undergoing urban and suburban development.