Mature Trees Prove Crucial in Absorbing CO2, Offering Hope in Climate Fight

Scientists at the University of Birmingham have discovered that older trees can significantly accelerate their absorption of carbon dioxide (CO2), a major contributor to global warming. Over seven years, a forest of mature oak trees exposed to elevated CO2 levels showed an increase in wood production, effectively locking in more of the greenhouse gas and reducing its potential to warm the planet.

This research highlights the critical role mature forests play in combating climate change, emphasizing the importance of preserving these ecosystems rather than cutting them down.

The study was conducted as part of the Free-Air Carbon Dioxide Enrichment (FACE) experiment, located in a 52-acre forest in Staffordshire. The experiment involved a network of pipes that released streams of CO2 among 180-year-old oak trees, simulating future atmospheric conditions if CO2 emissions continue unchecked.

After seven years, the trees demonstrated a nearly 10% increase in wood production, which is a long-term carbon storage method, preventing the immediate re-release of CO2 into the atmosphere.

The research found that most of the absorbed CO2 was converted into woody biomass, a form that can store carbon for decades.

This challenges previous assumptions that mature forests are less adaptable in increasing CO2 absorption compared to younger forests. The study’s findings underscore the global significance of mature tree cover, as older trees make up a substantial portion of the world’s forests and play a crucial role in carbon sequestration.

However, the researchers caution that this discovery should not be seen as a solution to allow continued fossil fuel use without reducing emissions. Professor Rob MacKenzie, one of the study’s authors, stresses that while the results are promising, they do not provide a “get out of jail free card” for fossil fuel consumption.

The study shows that while forests can help mitigate climate change, they cannot fully counteract the effects of unchecked CO2 emissions.

The FACE experiment will continue until 2031 to monitor whether this increased productivity in older trees persists over time. The researchers aim to further explore how elevated CO2 levels might affect tree lifespan and biodiversity, including potential impacts on insect populations observed during the study.

The long-term continuation of this experiment is seen as essential for understanding the future dynamics of mature forests under changing climate conditions.