June 5 (UPI) -- New research suggests plants begin to take up more carbon once they're acclimated to warmer temperatures.
In order to improve carbon cycle models, researchers at Purdue University measured the rates at which plants absorb carbon during prolonged periods of different temperatures.
"Models have good representations of short-term changes in temperature, but few data exist for incorporating longer-term responses," Nick Smith, an adjunct professor of forestry and natural resources at Purdue, said in a news release. "Plants are currently the only way that carbon dioxide is removed from the atmosphere on land. The way plants are represented in these large-scale models is really important."
In his experiments, Smith allowed 22 plant species to acclimate to different temperature levels, ranging from 59 to 95 degrees Fahrenheit, for seven days. After the acclimation period, Smith and his colleagues tracked the photosynthetic and respiratory rates of the different species -- the rates at which carbon is pulled from and released back into the atmosphere.
The findings -- detailed in the journal Global Change Biology -- suggest plants, once acclimated, take up more carbon at higher temperatures.
Researchers also exposed plants to sudden increases in temperature. They found plants increase their photosynthetic rates -- and thus, their carbon intake -- up to an inflection point. Past the inflection point, photosynthesis becomes less efficient. Interestingly, Smith found plants acclimated to high temperatures had higher inflection points.
As other studies have pointed out, there are several climatic reasons why forests and vegetation may not perform as efficiently as Smith's study suggests. Warmer temperatures could promote disease and drought, for examples, which would affect plant health and carbon absorption.
In the absence of mitigating factors, however, Smith's research makes it clear plants can become more efficient absorbers of carbon, once acclimated to warmer conditions. And at current warming rates, plants should continue to become more efficient, not less, absorbers of carbon.
"Our study suggests that at least under the range that we measured, the plants aren't hitting this inflection point," Smith said. "We shouldn't expect a decrease in photosynthesis or uptake of carbon based on temperature alone."