Older Trees Can Help in Fight Against Climate Change
Older trees have a major role to play in the fight against climate change, according to a recent study from the UK.
Researchers at the University of Birmingham have found that older trees respond to increased levels of carbon dioxide in the atmosphere by absorbing more of it with increased wood production. Previously, it was thought that only younger trees could do this.
The scientists studied data from an experiment run by the University of Birmingham's Institute of Forest Research (BIFoR) in a forest in central England. This forest mainly consists of oak trees that are over 180 years old.
To understand the impact of the changing climate on trees, scientists put a network of pipes in the forest that fed the area a stream of carbon dioxide. This created a local atmosphere of increased carbon dioxide — something we might see everywhere if nothing is done to reduce global emissions.
After seven years of running the experiment, it was found that, in response to a 40% increase in carbon dioxide levels, the trees had increased their production of wood by nearly 10%.
Trees convert carbon dioxide into oxygen, which they release into the air, and carbon, which is used to produce wood, leaves and roots.
Leaves and roots can die quite quickly, and when they do, they release carbon dioxide back into the atmosphere. Wood, however, acts as a long-term carbon store. So when the BIFoR trees made more wood, they were keeping carbon dioxide out of the atmosphere for many years to come, and stopping it from warming our atmosphere.
Speaking to the BBC, Rob MacKenzie, the director of BIFoR and one of the authors of the study, described the findings as "hopeful and positive," and said we should carefully manage older forests.
"The old forest is doing a huge amount of work for us," he said. "What we definitely should not be doing is cutting it down."
