The Wild Life of American Cities
One of America’s hottest cities and one of its coldest may have more in common than you would guess. In places like Phoenix and Minneapolis, scientists think that cities are starting to look alike in ways that have nothing to do with the proliferation of Starbucks, WalMart or T.G.I Fridays. It has to do with the flowers we plant and the fertilizers we use and the choices we make every spring when we emerge from our apartments and homes and descend on local garden centers.
“Americans just have some certain preferences for the way residential settlements ought to look,” Peter Groffman, a microbial ecologist with the Cary Institute of Ecosystem Studies in Millbrook, N.Y., recently told me. Over the course of the last century, we’ve developed those preferences and started applying them to a wide variety of natural landscapes, shifting all places — whether desert, forest or prairie — closer to the norm. Since the 1950s, for example, Phoenix has been remade into a much wetter place that more closely resembles the pond-dotted ecosystem of the Northeast. Sharon Hall, an associate professor in the School of Life Sciences at Arizona State University, said, “The Phoenix metro area contains on the order of 1,000 lakes today, when previously there were none.” Meanwhile, naturally moist Minneapolis is becoming drier as developers fill in wetlands.