New research finds methane-eating bacteria in a common Australian tree - National Tree Day Blog

New research finds methane-eating bacteria in a common Australian tree

The benefits of trees are well understood. Often referred to as ‘the Earth’s lungs,’ they produce oxygen, store carbon dioxide, provide shade, promote diversity, and the list goes on. Now researchers have discovered the bark of paperbark trees provides a unique home for bacteria that feeds on methane.

It may come as a shock to learn, but trees are capable of emitting a greenhouse gas called methane, which is far more potent than carbon dioxide*. New research published in Nature Communications has found bacterial communities living in the common Australian tree species, paperbark (Melaleuca quinquenervia), that consume the methane and convert it into carbon dioxide.

The bacteria made up to 25% of the total microbial communities living in the bark and were consuming around 36% of the tree’s methane.

‘These microbial communities were abundant, thriving, and mitigated about one third of the substantial methane emissions from paperbark that would have otherwise ended up in the atmosphere,’ researchers wrote in The Conversation

Tree methane, also known as “treethane”, is a relatively new discovery. It was first reported within cottonwood trees in 1907. Francis Bushong, a chemistry professor, cut down some cottonwood trees and observed the formation of bubbles in the sap. When he struck a match, the gas ignited in a blue flame, which he then replicated in a lab and confirmed the presence of methane. 

For almost a century it was overlooked until 2018, when a tree methane review was published, exploring methane production and emissions in trees and forests. Soon after a research blueprint was put forward labelling this as “a new frontier of the global carbon cycle.” Studies are now happening in several countries around the world to understand the full impacts of this finding.

The discovery will revolutionise the way in which we view methane emitting trees and the novel microbes living within them. By understanding why, how and where trees emit methane, it will help us plant forests more effectively and draw down carbon dioxide while avoiding unwanted methane emissions. 

Read the full article in The Conversation.

*Over a 20-year period methane is 84 times more potent as a heat absorbing gas than carbon dioxide. 

Jennifer McMillan

Jen worked as a vet nurse while studying environmental science and completing her master's degree in Journalism. She loves bushwalking, storytelling, caring for baby animals, Australian birds and river red gums. Jen works on the National Tree Day and National Recycling Week campaigns.