Wetland areas are known to contain vast amounts of methane trapped in swaps and flooded forests. They are considered as ecosystems that are crucial for the maintaining of stable concentrations of the gas in the atmosphere.
New research, conducted by Sunitha Pangala, a PhD student at The Open University, looks into alternative routes for this methane to escape from the soils where it is considered to be safely locked.
Analysing soils from peat swamp in Borneo, Pangala established that the concentrations underground have dropped. Together with her colleague, Sam Moore, the researcher conducted a series of ground-based measurements of soil, but also measured the tree stems.
The results were striking. It was noted that around 80% of all methane emissions are released through the trees.
In order to survive in waterlogged soils, trees develop lenticels, which are essentially large porous structures, inside their stems to allow air to enter the roots.
The study focused on eight species, which are commonly found in the Tropics. According to the researchers, this adaptation is very common in wetland trees, considering their living conditions. The study showed, that although the trees survive, the adaptation allows methane to escape.
Dr Gauci, the supervisor of Pangala, is certain that these findings will change the current models that predict the exchange of methane between wetlands and atmosphere.
The work will now be continued towards establishing whether the pattern is only characteristic for Tropical wetlands.