Default | NEWS

3/19/2008

Study: Insects bounce back faster from summer burns
Rice undergraduates pair up on two peer-reviewed journal articles

BY JADE BOYD
Rice News staff

Controlled fires are often used to keep trees from slowly taking over prairies, but they also indirectly affect insect communities that keep prairies healthy. New research from Rice University suggests that landowners can help insect populations rebound faster by burning fields in the summer rather than the winter.

The research, which is slated to appear in the June issue of Southwestern Naturalist, was conducted by two undergraduate students in early 2007 at the Lady Bird Johnson Wildflower Center in Austin, Texas. The researchers found that the timing of prescribed burns affected not only the overall number of insects in test plots but also the balance of insect species, with 60 percent more species in the summer- versus winter-burn plots.

Research  by Katherine Horn and Sally Johnson found that the timing of prescribed burns affected not only the overall number of insects in test plots but also the balance of insect species, with 60 percent more species in the summer- versus winter-burn plots. JEFF FITLOW

"We presumed we would find some differences, but we were surprised at the how significant some of the differences were," said study co-author Sally Johnson, a Jones College senior.

Today, many U.S. land managers burn fields in the dormant winter months. While prior studies had looked at how the burns affected the diversity of plant species on summer- versus winter-burn plots, Johnson and co-author Katherine Horn, a graduate student who was a senior at the time the research was conducted, said there was no data on how seasonal burns affected insects.

Horn and Johnson chose to tackle the problem for their final project in last spring's Insect Biology course and lab. Course instructor Jennifer Rudgers, Rice's James H. and Deborah T. Godwin Assistant Professor of Ecology and Evolutionary Biology, said several teams from the class carried out research at the Lady Bird Johnson Wildflower Center, but Johnson and Horn's work proved exceptional.

"The fact that their work was accepted by a peer-reviewed journal speaks for itself," Rudgers said. "It is rare for undergraduates to be listed as the first authors on peer-reviewed scientific papers, and what's even more exceptional is that this is the second first-authored paper that Katherine and Sally have had accepted for publication."

Johnson and Horn's other paper, which has been accepted by the journal Wetlands, was written as a project for a fall 2006 ecology class taught by Evan Siemann, associate professor of ecology and evolutionary biology. That project examined the susceptibility of the eggs of apple snails to submersion in water and cannibalism by adults. The fist-sized South American snails are a problematic invader in several Houston-area bayous.

Horn and Johnson said converting their class projects into publishable research did create extra work, but it didn't interfere with their course work. Working together on the papers only became a problem last summer, when internships carried the pair to opposite ends of the Earth. Horn was doing fieldwork in Mexico's remote Sonora Desert with Nat Holland, assistant professor of ecology and evolutionary biology, and Johnson was on an internship in Samoa with Ph.D. candidate Amy Savage.

"We were getting the changes back from the editors on both of these papers at the same time, and we barely had access to the Internet," Horn said. "Until a research station near our site installed wireless Internet, I had to go to an Internet café in a neighboring town just to check my e-mail."

Communication was even more problematic in the Pacific. "We were two towns away from the village that had Internet," Johnson recalled. "So we either walked there or took the bus 45 minutes into town, which was definitely a different experience than taking a bus somewhere in the U.S."

Both Johnson and Horn said their research experience with Rudgers, Siemann, Holland and Savage have cemented their decision to attend graduate school and helped them determine the types of research they'll pursue in the future. Horn is now working toward a master's degree with Siemann.

"I never thought insects were very interesting until we did the work in Central Texas," Johnson said. "I'm much more interested in that now."