UK study claims trees in wetland areas are biggest 'vents' of Methane gas

A recent study by the researchers at the University of Birmingham unveiled that the majority of methane gas emitted from Amazon wetlands regions is discharged into the atmosphere through tree root systems. The study's results which have been released in the journal 'Philosophical Transactions A' of the Royal Society further stated that a considerable quantity of methane emissions happens even when the ground is not flooded.

The researchers discovered indications stating that trees thriving on floodplains in the Amazon basin produce significantly more methane than trees grow in soil or surface water and that this happens in both wet and dry situations. To the atmosphere, wetlands provide a significant amount of methane which is considered to be the second most important greenhouse gas.

'Methane usually ingested by the soil when there are no trees'

Although there is a lot of study going on to figure out how much methane is emitted this way, most models believe the gas is only created when the ground is entirely inundated and underwater. As per the study, when there are no trees in the wetland region, methane would usually be ingested by the soil in its direction to the surface. However, researchers believe that in the forested wetland region, the tree root system could act as a transportation network for the gas, carrying it up to the surface where it could emit the gases into the atmosphere through the tree trunks.

However, even when methane is created in soil and water many metres below ground level, it can escape through this channel. As a result of this, existing models might be greatly misrepresenting the probable magnitude of methane leaks in wetland areas like the Amazon basin. To put this idea to the test, the scientists measured three sites on the floodplains of three main rivers in the central Amazon basin.

Research conducted to analyse methane emissions in the central Amazon basin 

The scientists measured three sites on the floodplains of three main rivers in the central Amazon basin to put the idea to the test. The same trees were observed at each plot at four different times throughout the year to see how they responded to the yearly flood's fluctuating water levels. Methane emissions were quantified using a transportable greenhouse gas analyser, and the results were then scaled out over the Amazon basin using equations.

Further, the researchers estimate that trees are responsible for over half of global tropical wetland methane emissions, with the surprising conclusion that trees are particularly essential for emissions when the floodplain water table is below the soil's surface.

Talking about the findings of the study, lead author Professor Vincent Gauci of the University of Birmingham's School of Geography, Earth and Environmental Sciences said, “Our results show that current global emissions estimates are missing a crucial piece of the picture. We now need to develop models and methods that take into account the significant role played by trees in wetland methane emission," as per the Science Daily website.

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