CO2 Emissions and Plants: New Research


Black Rock Forest was included in a global study on plant respiration and climate change, published in the journal Proceedings of the National Academy of Sciences (PNAS) in April 2016. Researchers measured respiraton in 231 plant species, across Alaskan tundra and Texan to Australian savannahs, in boreal, temperate and tropical forests. The Consortium's president, Dr. Kevin L. Griffin of Columbia University, was a co-author of the study and postdoctoral fellow Dr. Mary Heskel was lead author. 
When plants photosynthesize they take up carbon dioxide (CO2), a gas that contributes to global warming. But when plants respire, they release CO2 back to the atmosphere, and they release more when the temperature rises. Overall, plant respiration puts much more CO2into the atmosphere than all human sources combined. Dr. William Schuster, executive director for the Consortium, said that the April PNAS study "discovered global limits to plant respiration that actually result in less than the expected increase with temperature." 
The study found that all plants have the same internal controls regulating the response of respiration to temperature, and the same curve describes this response across all surveyed habitats and plant types. "What we thought was a steep curve in some places is actually a little gentler," said Dr. Griffin. "With this new model, we predict that some ecosystems are releasing a lot less CO2 through leaf respiration than we previously thought. All this adds up to a significant amount of carbon." 
"We now have a better way to estimate one process, but it's only one process," Dr. Griffin added. "The whole system is quite complicated; a small change in the balance between one part and another could produce a really big result. That's the challenge we face when we think about the earth as a whole." 
"Black Rock Forest Consortium's mission is to learn from nature using the most appropriate means, whether high tech or low tech," said Dr. Schuster. "We need accurate, unbiased predictions of what the future holds. This new paper highlights limits to how much respiration can increase with temperature that will make forecasting models more accurate."