Traditionally, bogs have been seen as worthless, ugly pieces of land, holding little or no intrinsic value. Indeed, the phrase “bog standard” is used to denote anything that is basic, ordinary, unexceptional, or uninspiring. Bogs have such a serious image problem that, in Ireland and Scotland, the word bog has long been a slang term for toilet. “Going to the bog” is synonymous with “going to the bathroom.”
Bogs may not catch the eye in the way rainforests or coral reefs do, but they hold a subtler charm. In recent years, the negative image of bogs has started to be overturned. People are reassessing bogs and discovering that they are a fascinating ecosystem, vital in the fight against climate change. The principle reason for this change of view lies in the chief product of bogs: peat. In recent years bogs and mires have come to be known as peatlands in order to throw off the negative connotations associated with bogs.
What Is Peat?
Bogs have a variety of flora growing in them, the most famous of which are sphagnum mosses. Sphagnum has been credited as “the bog builder” by the Irish Peatland Conservation Council. It is capable of growing in the highly saturated, low-nutrient bog environment because it is able to absorb a vast amount of water, and does not need as much nutritional input as larger forms of vegetation.
Once bog vegetation dies, it decomposes at a much slower rate than vegetation found in other ecosystems. The slower decomposition happens because bog water is acidic and low in nutrients. This is the secret to how peat is formed. The decomposing bog vegetation slowly begins to form a new peat layer, storing large amounts of carbon and preventing it from making its way into the atmosphere. It is estimated that a metre of peat takes thousands of years to accumulate. Fresh layers of sphagnum mosses grow on top of the peat layer, and the cycle continues until a dome shape is formed at the top of the bog.
Peat has traditionally been used for a number of purposes. In European countries, including Ireland, Finland, and the Netherlands, peat was extracted to be used as a fuel source to heat homes. Peat was never a major source of fuel in North America. Instead, it is used in horticultural composts and starter soils. Indeed, the peat extracted from Burns Bog, Delta, BC, was used primarily for horticultural purposes.
Peat harvesting is now regarded as an unsustainable practice, due to the length of time peat takes to form, and the damage that can be done by extraction over a short period of time. Entire bogs can be erased over a period of just a few decades. The peat harvesting industry in Burns Bog only lasted from the 1940s to the 1980s, but in that time 40% of Burns Bog’s peat layers had been harvested to a depth of two meters, and huge damage was caused to the bog’s hydrology. Something that had taken ten thousand years to accumulate was almost wiped out in just four short decades.
In addition, peat extraction techniques cause enormous damage to the hydrology of peatlands. The harvesting techniques require the drainage of peatlands in order to gain easier access to the peat. This is achieved through digging ditches to release the water. As a result, peatlands are left with a much lower water table than is necessary for a viable future. Remember; peatlands/bogs are still primarily wetlands, and adequate hydrology is vital to their survival.
How Do Bogs Help Prevent Climate Change?
Peatlands help prevent climate change by permanently absorbing carbon dioxide from the atmosphere, and preventing the release of methane. Figure 1 demonstrates how a bog with a high water table can act as a carbon sink. Carbon dioxide is absorbed from the atmosphere by the vegetation growing on the surface of the bog. As the vegetation dies, it sinks under the water table and forms new layers of peat. Provided the water table remains high, the carbon dioxide and methane produced by the decomposition cannot be released into the atmosphere.
Contrast that with the low water table bog in Figure 2. Peatlands generally have a low water table as a result of human activities. The peat extraction and agricultural industries have traditionally dug ditches in order to lower the water table and dry out the peat. This makes it easier to extract the peat, or sow a different type of crop.
In Figure 2, the carbon dioxide absorbed from the atmosphere, is not trapped under the water table and turned into peat. As the vegetation dies, it releases methane (the most intensive greenhouse gas) into the atmosphere. The dry peat becomes aerobic, resulting in carbon dioxide making its way into the atmosphere. Instead of acting as a sink for greenhouse gases, the bog is now acting as a source.
The release of these harmful greenhouse gases contributes to the warming of our atmosphere and the changes in our climate. It is estimated that the peatlands in the northern hemisphere alone store up to 450 billion tons of carbon dioxide. Were this carbon to be released into the atmosphere, it would have catastrophic consequences for our climate.
What Can Be Done To Save Bogs?
Now that you are aware of the importance of peatlands in preventing climate change, you may be wondering what is being done to save these essential ecosystems. The short answer is, not enough. Many peatlands around the world are still being harvested, developed on, or drained for other purposes.
However, things are gradually beginning to change, and efforts are being made to preserve or restore many of our valuable peatlands. In many peatlands, including Burns Bog, efforts are being made to restore the water table and encourage the growth of sphagnum mosses. This is done through blocking the ditches that were dug when the peatlands were being exploited. Over time, results have shown that the water table in these damaged peatlands can return to a sustainable level. With the water table restored, conditions are right for sphagnum moss to again thrive. Indeed, in some bogs, sphagnum mosses have been planted to encourage quicker growth with positive results.
In addition, peat is declining as a fuel source, and there are many alternatives to peat in horticultural soils. So, really, there is no logical reason for continuing to destroy such a valuable resource. We do not need peat for fuel or compost, and by damaging peatlands we would ultimately be harming ourselves with a worse climate.
In his poem, Bogland, the great Irish poet, Seamus Heaney, marveled at the ability of peat to preserve historical artefacts for centuries. He referred to it as “kind black butter.” Perhaps, peat can perform its greatest act of kindness in preventing climate change.
Peat has a history of preserving our cultural past. Perhaps its next job is to ensure our future.
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Gerard John Cowan is a research and communications coordinator with the Burns Bog Conservation Society.
