KILDARE WILDLIFE COLUMN: Bogs store twice as much carbon as forests
Nuala Madigan from the Bog of Allen Nature Centre
Did you know that the United Nations consider peatlands, also known as bogs, to be the largest terrestrial store of carbon in the world, storing twice as much carbon as all the worlds forests?
People often comment to me that while they had heard of the value that peatlands offer in supporting climate mitigation plans, they do not actually know how peatlands store carbon.
Peatlands are wetlands with a water table that fluctuates between 10-20cm from their surface. Peat is the soil type of bogs and it is made up of an accumulation of dead plant material over thousands of years.
The high water table on a bog means that the peat is not exposed to oxygen and decomposition is limited. Bogs started to form peat at the end of the last ice age.
Since then the wetland plants have grown through the process of photosynthesis, absorbing carbon dioxide (CO2) which we know today as a greenhouse gas.
The plants don’t need the oxygen so they release it and store the carbon in their bodies.
Once they have enough energy they can produce their flowers, which are then pollinated, producing seeds for reproduction.
With the start of winter the plants hibernate letting their leaf litter containing carbon sink to the bottom of the lake.
Each spring the plants emerge and repeat the process. Eventually these lakes would fill and as the peatland growth continued Sphagnum mosses began to thrive. Growing upwards this plant can hold ten times its own weight in water ensuring to keep the peatland wet.
On the surface of the bog today the peatland plants continue to grow through the process of photosynthesis, storing carbon and releasing oxygen.
They also continue to hibernate leaving their leaf litter, containing carbon on the surface of the bog which eventually becomes peat as the Sphagnum mosses grow upwards and bury the leaf litter under the surface of the bog.
Over thousands of years the lack of decomposition and build of peat, the dead plant material containing carbon, have made peatlands the largest terrestrial store of carbon in the world.