Australian researchers have discovered a hidden climate superpower of trees. Their bark harbours trillions of microbes that help scrub the air of greenhouse and toxic gases.<\/p>\n
It\u2019s long been known that trees fight global warming by consuming carbon dioxide (CO2) through photosynthesis. But a new study published in\u00a0Science\u00a0shows their microbial partners take up vast amounts of other climate-active gases too.\u00a0<\/p>\n
The study, conducted primarily by\u00a0Dr Bob Leung<\/a>\u00a0at Monash University\u2019s Biomedicine Discovery Institute (BDI), and\u00a0Dr Luke Jeffrey<\/a>\u00a0at Southern Cross University\u2019s Faculty of Science and Engineering, rewrites our understanding of how trees and their resident microbes shape the atmosphere.\u00a0<\/p>\n \u201cEach tree hosts trillions of microbial cells on its bark,\u201d said Dr Leung, a co-first author. \u201cYet their existence and roles have been overlooked for many decades until now.\u201d<\/p>\n The researchers spent five years sampling trees across eastern Australia, including wetland, upland, and mangrove forests.<\/p>\n They then used advanced genomic and biogeochemical techniques to determine, for the first time, the identities, capabilities and activities of the microbes living in their bark.\u00a0<\/p>\n \u201cRemarkably, most of these microbes are tree-adapted specialists that feed on climate-active gases,\u201d Dr Leung said. \u201cThey consume methane, hydrogen, carbon monoxide, and even volatile compounds released by the trees themselves.\u201d<\/p>\n Dr Jeffrey, also a co-first author, said the scale of this hidden process was staggering.<\/p>\n \u201cCounting all trees on Earth, the total global surface area of bark covers an area roughly the same as all seven continents combined,\u201d he said. \u201cThis microbial activity across this massive \u2018bark continent\u2019 is potentially removing millions of tonnes of climate-active gases every year.<\/p>\n \u201cThese gases can come from the atmosphere or from within tree stems. By consuming these unwanted gases, microbes in bark are essentially cleansing our air and enhancing the benefits of trees in multiple ways.\u201d\u00a0<\/p>\n The BDI\u2019s\u00a0Professor Chris Greening<\/a>, who co-led the study with Southern Cross University\u2019s\u00a0Professor Damien Maher<\/a>, said there was much long-term potential to use these findings for climate action.<\/p>\n \u201cWe now know different trees host different microbes,\u201d Professor Greening said. \u201cIf we can identify the trees with the most active gas-consuming microbes, they could become priority targets for reforestation and urban greening projects.\u201d<\/p>\n Professor Greening added that the discovery could benefit both climate and human health. \u201cIn addition to being a climate-active gas, carbon monoxide is also a toxic air pollutant,\u201d he said. \u201cTree microbes are helping scrub it from the air and so improve air quality.\u201d<\/p>\n Professor Maher said there were many more discoveries to be made in this research area. \u201cThis research is really the tip of the iceberg in terms of expanding our understanding of how trees and microbes interact,\u201d he said.<\/p>\n \u201cThe diversity of microbes that we found living in the bark of these trees suggests that we may need to rethink how trees and forests control Earth\u2019s climate now and into the future\u201d.<\/p>\n The tree species included\u00a0paperbark (Melaleuca quinquenervia),\u00a0Swamp box (Lophostemon suaveolens) and Swamp oak (Casuarina glauca) from freshwater wetland forest; Banksia (Banksia integrifolia) and\u00a0Golden wattle (Acacia longifolia) from coastal heath forest;\u00a0Mangrove (Avicennia marina) from mangrove forest; Grey ironbark (Eucalyptus siderophloia) and Grey Gum (Eucalyptus propinqua) from upland forest.\u00a0<\/p>\n