Cities are growing in area and population as urbanization is happening at record rates. Known as urbanization, this brings about the clearance of urban forest ecosystems to accommodate development. Urbanization affects ecological functions, structures, and systems by impacting the distribution of very important ecosystem services. For the natural environment and urban populations, the removal of urban forest ecosystems presents serious implications. Ecosystem services and ecologies are disrupted as urban forests are in a current state of decline. For this research, urban ecology and ecosystem services are studied based on a context which quantifies urban forest presence or absence. Specifically, the ecosystem service of particulate matter (PM2.5) removal by tree cover and the human ecology service of park walkability is measured. Assessing the urban tree canopy metrics of two American cities will provide information on urbanization’s effect on urban forests, ecosystem services, and human ecology. Furthermore, underlying social factors such as the history of the area, culture, and demographics provide a framework to interpret why there is inequity in urban forest distribution. The cities of Pittsburgh, Pennsylvania and New York, New York will serve as backdrops to answer the following question: In urban settings, how does the presence or lack of urban forest ecosystems affect human ecology and the distribution of ecosystem services, in turn affecting surrounding populations?
