February 9, 2009

High CO2 hikes soybean plant respiration

U.S. scientists say they've determined soybean leaves grown at the high carbon dioxide levels predicted for 2050 respire more than under current CO2 levels.

Researchers at the University of Illinois and the U.S. Department of Agriculture said their finding will help fine-tune climate models and could point to increased crop yields as CO2 levels rise.

The scientists said plants draw CO2 from the atmosphere and make sugars through the process of photosynthesis. But they also release some CO2 during respiration as they use the sugars to generate energy for self-maintenance and growth. How elevated CO2 affects plant respiration will therefore influence future food supplies and the extent to which plants can capture CO2 from the air and store it as carbon in their tissues.

The research, led by Professor Andrew Leakey, appears in the Proceedings of the National Academy of Sciences.