In the longest-running study of its kind, researchers in Maryland and Florida are trying to piece together how plants will cope in 50 years — when the air is thicker with the products of our lifestyle.
Scientists with the Smithsonian Environmental Research Center have spent 17 years tracking how higher levels of carbon dioxide — a “greenhouse” gas produced by cars, factories and power plants — are affecting vegetation.
“We’re measuring as many of the effects of carbon dioxide on an ecosystem as possible,” said Bert Drake, a plant pathologist at SERC.
Drake’s work, funded largely by the Department of Energy, focuses on two plants — spartina grass and sedges — grown in a marsh on a 10-acre site near the Rhode River in Edgewater, Md., and encased in 30 polyester chambers. Carbon dioxide is pumped into the chambers, doubling the concentration of the gas the plants are exposed to.
Monitors record a range of data about each plant’s life cycle, including the amount of nitrogen and methane given off and growth rates.
“It’s not a question of whether plants will respond to carbon dioxide. We know they do. The question is how do they respond to these other factors — things like rainfall, the availability of nitrogen, salinity,” Drake said.
So he and other scientists are trying to figure out which plants will thrive and which will disappear if the world’s appetite for fossil fuels continues unabated.
Although politicians argue about the effect, scientists agree that increases in greenhouse gases are warming the planet. And one gas in particular — carbon dioxide — has been rising steadily since the Industrial Revolution began in the 19th Century. Carbon dioxide levels are now at 400 parts per million, a huge increase in the past 100 years, experts say.
The rate of future increases will depend on whether alternative power sources are developed, such as hydrogen-powered vehicles. But scientists expect carbon dioxide levels to nearly double by 2100, and an understanding of the effects of that increase remains elusive.
For example, studies over the past decade have shown that rising carbon dioxide produces increased vegetation, which in turn might absorb much of the carbon dioxide being pumped out by the world’s cars and industries.
At the University of Illinois, researchers found higher carbon dioxide levels increased growth rates for corn and soybeans, but they also increased pest infestations.
