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Undergraduate research reveals lichen's secrets

March 01, 2007

With summer just around the corner, undergraduate life sciences students can look forward to a unique work experience through the Research Experience for Undergraduates (REU) program in the School of Life Sciences . Students are hired to participate in ongoing School of Life Sciences research projects and are paid to spend 10 weeks of their summer conducting full-time, hand-on studies at the bench or in the field. By arming their futures with a competitive edge, a walk in the park and a stroll with a Xanthoparmelia never looked so good.

Xanthoparmelia is a genus of lichen commonly found on rocks in Arizona and was the focus of research for Thomas Zambo, a senior with a major in life sciences in the Department of Integrated Natural Sciences at ASU's West campus. He was participating in a survey of lichen in and around 28 study sites in Maricopa County to see if concentrations of airborne heavy metals, such as copper, lead, zinc, nickel and aluminum, had changed in the last 10 years.

“Lichen are long-lived and remarkably good indicators of air quality,” Zambo says. “This is a result of their unique nutrient uptake – from the air. Because nutrient levels are so low in the air, lichen are very efficient accumulators.”

According to Zambo, this means that as the lichen take up airborne nutrients, they take up pollutants. Over time, findings from the study of lichen can be compared to local industry's toxic release inventories to generate a very complete pattern of regional air pollution, one that also takes into account unrecorded heavy metal releases, like the vanadium, nickel and chromium that are released from car tire wear.

Zambo's work is part of ongoing research directed by mentors Thomas Nash, professor in the School of Life Sciences , and curator of the ASU lichen herbarium, and his graduate student, Ken Sweat, who also is a lecturer at the West campus. Zambo presented his work in the REU poster session last summer, but his work has continued to expand. In January, he participated in the Central Arizona-Phoenix Long Term Ecological Research Project poster symposium with a presentation on “Geographic Patterns of Mercury Deposition using the Lichen Xanthoparmelia in Maricopa County , AZ. ”

REU appointments commonly include a summer stipend of roughly $3,000, with support for housing and travel if needed. Students also receive six hours of course credit and a tuition waiver.

For more information about School of Life Sciences ' undergraduate research programs, visit: The deadline to apply for summer 2007 REU research is April 4.