Wood Bark, and just a little nominative determinism

[SteamyTea]

From this weeks comic.

 

Tree bark microbiome has important overlooked role in climate

Tree bark has a total surface area similar to all of the land area on Earth. It is home to a wide range of microbial species unknown to science, and they can either take up or emit gases that have a warming effect on the climate

By James Woodford

8 January 2026

Melaleuca wetland forests in New South Wales, Australia, are hotspots for tree microbial life

Luke Jeffrey / Southern Cross University

 

The bark of a single tree can be home to trillions of bacteria, and these microbes may have an important but neglected role in controlling greenhouse gases in Earth’s atmosphere.

The total surface area of tree bark on the planet is thought to be around 143 million square kilometres, nearly as much as the world’s total land surface area. This surface makes up an immense microbial habitat known as the caulosphere, but the microbes that live there have received little attention from scientists.

 

“In a way it’s so obvious, but we have always overlooked tree bark,” says Bob Leung at Monash University in Melbourne, Australia. “We never thought of microbes on tree bark, but it makes sense, because bacteria are everywhere, and if we can find microbes in soils, on tree leaves, then most likely there will be microbes on bark.”

Leung and his colleagues began by studying a wetland species commonly known as paperbark (Melaleuca quinquenervia). They found that there were more than 6 trillion bacteria living in or on each square metre of bark, comparable to the volumes found in soil.

Genetic analysis of 114 of these bacteria showed that they mostly came from three bacterial families – Acidobacteriaceae, Mycobacteriaceae and Acetobacteraceae – but all of the species were completely unknown to science.

 

 

Remarkably, these microbes have one thing in common: they can use hydrogen, carbon monoxide and methane as fuel to survive. Hydrogen (H₂) isn’t itself a greenhouse gas, but through reactions with other molecules it can increase the warming effect of methane in the atmosphere.

The researchers then looked at the bark of another seven Australian tree species from a range of habitats, including casuarinas, gum trees and banksias, measuring, both in the field and in lab conditions, whether the bark of the different species absorbed or emitted greenhouse gases.

They found that all barks consumed hydrogen, carbon monoxide and methane in aerobic conditions when oxygen is available. But when trees are submerged in water and oxygen is limited, such as in swamps, bark microbes switched to producing the same gases.

 

The canopy of Melaleuca quinquenervia trees in an Australian forest

Luke Jeffrey / Southern Cross University

 

The team estimates that the total amount of hydrogen absorbed by bark microbes globally is between 0.6 and 1.6 billion kilograms each year, representing as much as 2 per cent of the total atmospheric hydrogen removed.

This is the first time scientists have attempted to assess the contribution of tree bark to atmospheric hydrogen, says team member Luke Jeffrey at Southern Cross University in Lismore, Australia.

“Discovering the hidden role of trees doing more than just capturing carbon dioxide in their wood is very important,” says Jeffrey. “They are active cyclers in other greenhouse gases. This is exciting, because H₂ affects the lifetime of methane in our atmosphere, therefore H₂ consumption in bark may help in reducing our growing methane problem.”

However, the global picture is highly uncertain, as the team has only sampled eight tree species from eastern Australia. “A lot of work now needs to be done across various forest types, tree species, microbial communities and site conditions,” says Jeffrey.

 

Brett Summerell at the Botanic Gardens of Sydney says the study highlights how little we know about the composition, diversity, abundance and role of microorganisms in bark. “How this might vary across a broader range of tree species, particularly in drier climates such as savannahs and woodlands, is interesting,” says Summerell.

It will also be important to understand the interactions between fungi and bacteria in bark, he adds.

 

Journal reference:

Science DOI: 10.1126/science.adu2182

[markc]

 

They found that all barks consumed hydrogen, carbon monoxide and methane in aerobic conditions when oxygen is available. But when trees are submerged in water and oxygen is limited, such as in swamps, bark microbes switched to producing the same gases.

This is interesting 🤔, 

[SteamyTea]

20 minutes ago, markc said:

This is interesting

Thankfully they are not submerged too often.

What I found interesting is the surface area they cover. A good reason to not put them in a wood burner.  Though it does raise questions about using timber in general.

[sgt_woulds]

It also calls into question the changes to UK building regulations to make it easier to destroy existing, old growth forests and other natural ammeneties and replace them elsewher with 'equivalent' planting. 

 

It takes milions of years to set up an intricate interconnected system of life, and a few minutes for Bloores and Barretts et al, to destry it to make way for better profit margins. 

 

 

[saveasteading]

14 minutes ago, sgt_woulds said:

changes to UK building regulations

I wasn't aware. can you point me towards this please? Presumably some government policy relaxation (to allow more building??) rather than a technical matter,

[FuerteStu]

This potentially opens up a whole new potential field of bio-mechanics to counteract climate change.. 

 

Surface area to volume, large trees are inefficient compared to other structures that could take up the same spaces. 

 

Just a thought

[SteamyTea]

20 minutes ago, FuerteStu said:

Surface area to volume, large trees are inefficient compared to other structures that could take up the same spaces. 

 

Just a thought

Quite a good thought.

As it is a new discovery, maybe someone will work out the optimum trunk radius to timber mass, which should help identify the best species to plant and at the ideal density, for different regions.

Would also be interesting how it affect other types of plant bark/skin.

 

Totally unrelated, but maybe not, I noticed that the main types of trees that got blown down last night were conifers, which are not indigenous to this area at all.  In fact, trees are not indigenous.