By MORGAN SIMMONS, simmonsm@knews.com
September 25, 2005

OAK RIDGE - An 8-foot-high fence made from chicken wire surrounds Gregory Crutsinger's study plot.

Outside the enclosure the abandoned field is choked with ironweed, Joe Pye weed, and wingstem - the familiar wildflowers of later summer and early fall.

Inside the fence, there is only goldenrod. Lots and lots of goldenrod.

Crutsinger, a 25-year-old graduate student in the department of ecology and evolutionary biology at the University of Tennessee, is growing different varieties of goldenrod to determine how insects respond to subtle genetic differences in the plant.

His research has earned him an EPA STAR Fellowship, one of the most competitive grant programs funded by the Environmental Protection Agency. Only about 100 fellowships were awarded this year to some 4,500 applicants nationwide.

Crutsinger said his research will explore how genetic variations within a single goldenrod species (Solidago canadesis, or tall goldenrod) can affect insect populations, and ecosystems as a whole.

But for now, he's looking at a lot of hot, painstaking work.

"We've been out here all summer," Crutsinger said. "This project is basically the biggest garden I've had in my entire life, and I don't get to eat any of it."

Last winter Crutsinger propagated 21 varieties of goldenrod in a greenhouse. In late April he transplanted the plants to his study site, which is located on U.S. Department of Energy land adjacent to Melton Hill Lake. The goldenrod grows in well-manicured rows. The fenced-in plot measures 120 feet by 70 feet, and the visual impact of the plume-like, yellow flowers is stunning.

Helping Crutsinger is Kerri Crawford, an undergraduate student at UT who is studying gall midges, one of the most common insects associated with goldenrod. Together, they count every insect they find on the goldenrod plants. It takes them about 21 hours to visually survey the insects on each plant. They take photos, and send the pictures back to UT's ecology lab for positive identification.

Crutsinger said his goldenrod study plot is home to 130 different species of insects and spiders.

"Any kind of system is going to have different genotypes, or varieties," he said. "In agricultural systems, you have different varieties of apples and corn. Some apples taste better to us than others. Insects can tell a difference, too."

Crutsinger is quick to point out that ragweed, not goldenrod, is the culprit when it comes to hay fever in the fall.

"Goldenrod pollen is heavy and sticky - not wind dispersed like ragweed," he said. "They bloom at the same time, so it's guilt by association."

Crutsinger is studying how the different goldenrod varieties compare in terms of insect damage, and he's collecting leaves to determine how genetic diversity effects the leaves' decomposition, which in turn could affect the leaf litter.

The most leaves he and Crawford have counted in a single day is 60,000. He said he expects the project will take him another four or five years, and that he isn't looking forward to the day when Crawford graduates and he has to find new help.

"I can't say it's glamorous work," Crutsinger said. "It's hard to find someone willing to count goldenrod leaves in the hot sun all day. I try to buy Kerri a lot of ice cream."

Morgan Simmons may be reached at 865-342-6321.

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