Ecological homogenization of urban America

Why do the places we live in all look the same, with a similar mix of lawn, shrubs, trees, ponds, streams and pavement?  What human values and desires lead us to ecologically homogenize the areas where we live?  What are the effects of this homogenization on plant diversity, microclimate and soil processes? How does this homogenization with density (urban, suburban, exurban), socio-economic status and life stage in cities across the U.S.?  How can this coupled socio-ecological phenomenon be studied?  Can we use results from our studies to improve environmental quality, the quality of life and the sustainability of human settlements?