In a time when an area of primary forest the size of a football field is lost approximately every six seconds, researchers have made an exciting new discovery concerning mature trees. According to a new study, old trees can increase their absorption of carbon dioxide if needed, meaning they are an invaluable weapon in the battle against climate change.
Researchers from the University of Birmingham, whose study was published in the Nature Climate Change journal, have turned their interest to mature trees in particular. Thanks to a group of 180-year-old English oak trees located on the premises of the university’s Free-Air Carbon Dioxide Enrichment (FACE) experiment in Staffordshire, they were able to get a good idea of how exactly those trees can adapt to changing circumstances.
For the experiment, the scientists plumbed in a network of pipes amongst the 40-metre-tall trees. Those pipes were then programmed to emit a certain dose of carbon dioxide (CO2) every day for seven years. That dose was the equivalent of the amount of CO2 we would all be exposed to in case no action is taken to reduce emissions.
After having observed the trees for seven years, the researchers have now come to the conclusion that the mature trees were actually able to up their production of wood by 10%, compensating for the increase in emissions by locking in the CO2. Alocating the absorbed carbon dioxide to growing trunks and branches was found to be the most efficient way, as the other two alternatives – more leaves and more roots – die off much faster and re-release the gas back into the atmosphere.
“I think it is a hopeful and positive story”, said Professor Rob MacKenzie, director of the Birmingham Institute of Forest Research and one of the authors of the study. “This is evidence in favour of careful management of established forests. The old forest is doing a huge amount of work for us. What we definitely should not be doing is cutting it down.”
Before this study, younger trees were already found to be able to up their carbon dioxide intake but it was unclear whether or not the same could be said for mature trees. The experiment will now be prolonged until 2031 to determine whether or not the increased intake will hold up over a longer period. The researchers will also try to conclude if the lifespan of the trees and the wildlife in the piece of woodland will change due to the different conditions.
According to the researchers, the study is one more reason to stop chopping down primary forests and to be more considerate about how we manage our woodlands in general. However, they also point out that no amount of trees would suffice to counterbalance the emissions from the current amounts of fossil fuel burned around the world.
