Trees’ respiration may adapt to climate change

New York Times : Plants take in carbon dioxide and then release it through a metabolic process known as respiration. Terrestrial plant life can release six times as much carbon dioxide as that found in the emissions from fossil fuel burning. Because studies had shown that warming temperatures can cause plants to increase their CO₂ output, scientists have been concerned over what effect that could have on climate change. To find out, a team of researchers monitored the respiration rates of 10 different North American tree species from boreal and temperate forests grown in two different conditions: ambient temperatures and 3.4 °C warmer than ambient temperature. The researchers also looked at how the trees responded by exposing some to short bursts of warmth, lasting minutes or hours, and allowing others to acclimate over time. They found that the trees allowed to acclimate were able to adjust their CO₂ output so that it increased by just 5%. The CO₂ output of trees exposed to rapid warming increased by 23%. Because the earlier studies had been conducted over shorter time scales, the researchers say that climate change may not cause plants to raise atmospheric CO₂ concentrations as much as previously thought.