Study Questions Carbon Sequestration Capacity of Forests

Scientists have found that the ability of forests to store carbon dioxide from the atmosphere over long periods may be lower than previously thought. This discovery suggests that estimates of the role of forests in combating climate change may need to be reevaluated.Research has shown that trees continue to absorb carbon from the atmosphere even after they stop growing, but a significant portion of this carbon is not stored in the tree trunks for long periods. Scientists emphasize that increased carbon absorption does not always translate to increased carbon storage.Carbon sequestration refers to the process by which trees and other plants absorb carbon dioxide from the atmosphere and store it in their trunks, branches, roots, and soil for extended periods. This process reduces the amount of greenhouse gases in the atmosphere and helps slow global warming.Researchers analyzed 137 oak forests in the eastern United States and California. The study found that oak trees in the eastern United States primarily grow between May and July but continue to undergo photosynthesis until October. Approximately 36% of the annual carbon intake occurs after the trees stop growing.Similar results were found in California's oak trees, which stop growing earlier but continue to undergo photosynthesis, with about 26% of the annual carbon intake occurring after growth has ceased.Researchers noted that a significant portion of the carbon absorbed after growth has stopped is used for leaf, root, and other vital functions rather than thickening the trunk and branches. Therefore, not all the carbon absorbed from the atmosphere is stored in the tree trunks for decades.The study also found that the difference between photosynthesis and growth becomes more pronounced in years with frequent changes between dry and wet periods. Scientists suggest that climate change is expected to increase such weather conditions, which could impact future predictions of forest carbon sequestration capacity.