ASU Research E-Magazine: Phoenix Under the Microscope

The Central Arizona-Phoenix Long-Term Ecological Research project (CAP-LTER) is a giant ecological study of Phoenix and the surrounding valley, much of it pristine Sonoran Desert. The ongoing project completed its first year in January. Researchers are studying the impact of urbanization in many forms.

In 1998, the large-scale study involved 50 ASU faculty members and more than 70 students. Individual projects ranged from determining the economic value of owning a home near an open area to the effects of urbanization on plants, animals, insects, and processes such as pollination. Many projects also involve community members, including elementary, middle, and high school students and their teachers.

CAP-LTER is part of a network of 30 ecological studies being conducted nationwide, but only one of two that focus on urban areas. Baltimore, Maryland is the second urban LTER site. All of the work is funded by the National Science Foundation.

Many scientific disciplines are involved. Nancy McIntyre is a scientist working at ASU’s Center for Environmental Studies, which serves as the coordinating unit for researchers. She says it is important to gather scientists together on a regular basis to share findings from their particular pieces of the giant project.

“We’re all adding little pieces of the overall puzzle,” she says.

McIntyre says each project collects a specialized type of data regarding urbanization. The collecting is being done over the long term. All information will be combined and made available to future city planners.

“We can’t stop urbanization. But we can try to ameliorate the effects of future urbanization so it has the least possible impact on the environment,” McIntyre says.

Results from first-year studies were presented at a special poster session held at ASU in February. One research group looked at whether water runoff from asphalt parking lots was a source of pollution in the area. A strong rain was simulated and all liquid runoff from the asphalt was analyzed.

Researcher Diane Hope says the results showed a high amount of nitrogen being washed off the pavement and onto nearby soil. The age of the asphalt surface also determined the amount of nitrogen being released into the soil.

“As pavement gets older we get more nitrogen runoff,” Hope says.

The overall impact of the finding is being studied. Scientists question whether the nitrogen is coming from the rainwater itself, or from oil and dirt congealed on the asphalt surface. The team also wants to determine what impact, if any, the extra nitrogen has in the soil.—Gary Campbell