Biology researchers at Hope College will model changes in the global climate through new equipment being purchased with a grant from the National Science Foundation (NSF), hoping to better understand just what the world can expect as carbon dioxide levels continue to climb.

The $154,058, three-year grant will fund the purchase of four controlled-environment, plant-growth chambers. The chambers will enable the biologists to see how plants fare when they change light duration, light intensity, temperature, humidity and carbon dioxide levels.

Plant-growth chambers aren't new at the college-- Hope faculty and students have been conducting collaborative research using them for decades. The ability to factor carbon dioxide into the mix, however, is new--and particularly relevant, according to Dr. Thomas Bultman, who is principal investigator for the project and is also a professor of biology and chairperson of the department.

"It's quite clear that the percentage of carbon dioxide in the atmosphere has gone up in the last 100 years," Bultman said. "It's due to the Industrial Revolution and all the fossil fuels that we're burning."

Bultman noted that carbon dioxide levels have climbed from 316 parts per million in the atmosphere in 1960 to 370 parts per million currently. The increase, he said, is believed to contribute to the "greenhouse effect," since carbon dioxide in the atmosphere allows the suns rays to reach the earth but then serves as a shield that keeps them from leaving again.

On one level, Bultman said, more carbon dioxide could be a boon to plants, since they process the gas as part of their life cycle, producing oxygen. But altering the balance, he said, could change much.

"In ecological systems, everything is tied together. The question becomes: how do other things change when you change one thing?," he said. "Do all plants do better? Do some plants do better than others--competition? How are the insects affected that feed on these plants?"

Three members of the faculty will be directing research projects using the expanded modeling capability of the new chambers: Bultman; Dr. K. Gregory Murray, professor of biology; and Dr. Debbie Swarthout, assistant professor of biology. They will be conducting their work collaboratively with Hope students.

Bultman will consider the way that carbon dioxide and drought interact in a fungus and grass, and also how the changes affect insects. Murray will be seeking physiological explanations for changes in the distribution of tree seedlings within the cloud forests at Monteverde, Costa Rica. Swarthout will examine how the fungus alters the carbon-gaining capacity of the grass as carbon dioxide levels increase and nutrients and water decline.

The chambers each measure about eight feet long, three feet wide and six feet tall. They will be placed together in a single room, and linked by a computer network that will allow them to be controlled by the researchers from a variety of locations.

They will be installed in the Peale Science Center, ready for use when the building's renovation is complete a year from now.