"It's an ideal situation, because the development of the city has literally been happening as we watch," said ASU Life Sciences Professor Nancy Grimm, CAP LTER's other principal investigator. "We've made an assault on understanding the structure and function of the urban ecosystem on numerous fronts. From air quality to birds and bugs and plants to water quality and usage, to landscaping choices, climate, economics, zoning, pets we are considering everything that is part of the ecosystem."
One of the most interesting things that has been revealed is the special nature of the urban biota, which has a distinctive mixture of native and exotic plants and animals, but differs even further in the dynamics of how these organisms interact.
"We have been defining the Phoenix urban ecosystem, which, it turns out, functions very much like an ecosystem with bugs and birds and plants -- but in different sets of relationships, with much different abundances," said Redman. "The abundance of organisms is higher overall. If you just measure it, it is richer in town than in the desert."
The scientists note that the urban environment differs from the surrounding desert in that it has an ample, year-round supply of basic life resources such as water, that in the native environment is seasonal or highly localized. This leads to a larger and more consistent supply of growing plants, which are the base of the food chain, and ultimately to a greater number of animals, such as birds.
"If you know anything about abundances of birds in desert environments, you know that birds are concentrated along river corridors and riparian zones and that diversity also is concentrated there," said Grimm. "What Phoenicians have done is to take this river, which was one localiz
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Contact: James Hathaway
hathaway@asu.edu
480-965-6375
Arizona State University
3-Jan-2005