Barking up the right tree

MICROBES IN BARK REMOVE METHANE FROM THE ATMOSPHERE

Trees have long been lauded for their ability to benefit the climate by removing carbon dioxide from the air but, according to a recent UK study (published on 24th July in the journal 'Nature'), microbes hidden within tree bark can also absorb methane, a powerful greenhouse gas, from the atmosphere making forests even more effective against climate collapse than was thought.

An international team of researchers led by the University of Birmingham has shown for the first time that microbes living in bark or in the wood itself are removing atmospheric methane. Methane is responsible for around 30% of global warming since pre-industrial times and emissions are currently rising faster than at any point since records began around 40 years ago.

Up until now it was thought that soil was the only terrestrial sink for methane as it absorbs the gas and breaks it down for use as energy, but researchers have now shown that trees may be as important. In the study, the researchers investigated upland tropical forests in the Amazon and Panama, temperate broadleaf trees in the UK, and boreal boreal coniferous forests in Sweden.

The methane absorption was strongest in the tropical forests, probably because microbes thrive in the warm wet conditions found there. On average the newly discovered methane absorption adds around 10% to the climate benefit that temperate and tropical trees provide. Their findings indicate that the climate benefits of tropical and temperate forest protection and reforestation may be much greater than previously assumed.

Lead researcher on the study, Professor Vincent Gauci and his colleagues are now planning a new research program to find out if deforestation has led to increased atmospheric methane concentrations. They also aim to understand more about the microbes themselves, the mechanisms used to take up the methane and will investigate if this atmospheric methane removal by trees can be enhanced.

To read the study in full visit the Nature website.