Since the last ice age, peatlands have stored huge amounts of atmospheric carbon within their peat layers. However, because of human actions and a rise in global temperatures over the last two hundred years, peatlands are about to release the carbon back to the atmosphere – unless we do something quickly.
Here in Finland we have about 100 different peatland types, with their own specific characteristics. As a peatland researcher and enthusiastic berry picker, I have seen many of them and I must admit that the ones that have been recently restored don’t belong in my top ten list.
Our country is known for its plentiful peatlands, even by its name: Suomi = suomaa or Finland = fenland, and we truly have a lot of them. Even though peatlands cover a mere three percent of the land of the globe, the amount of carbon stored within their peat is close to the amount of carbon present in the atmosphere. Thus, you can imagine the importance of the carbon stored in the numerous peatlands in our country. The carbon in peat is not active in the global carbon cycle and therefore helps to cool our climate.
Carbon bursts ahead?
However, we have used the land efficiently, and in Finland, more than half of the original peatland area has been drained for forestry or agriculture. As the plants growing in peatlands depend on wet, anaerobic conditions, as does the carbon accumulation, drainage has caused dramatic changes in our peatlands.
Peatlands are not only under threat from this direct anthropogenic activity but also from climate change. The predictions are that a warmer climate and annual shifts in precipitation regimes will bring about more droughts. Drainage and drought increase carbon release from the peat as decomposition is faster when the soil is dry and filled with air, rather than with water. In addition, plant species composition may change, which in turn will affect the productivity. As a result, the once stored carbon may be burst back to the atmosphere.
Can we fix the damages we have caused to nature?
Recent global and national policies have recognized that protection of natural ecosystems is not enough. In order to safeguard the satisfactory level of biodiversity and other ecosystem services, we also need to restore degraded ecosystems. Carbon storage is one of the most significant ecosystem services that peatlands provide, and therefore actions that support this service are of high importance. There are already attempts to combine peatland restoration and carbon markets as a means of decreasing countries’ greenhouse gas emissions. However, there have only been a few studies on the subject, and we need more numbers to quantify how much restoration actually reduces these emissions.
Embrace your imagination when visiting restored peatlands
With my colleagues from the Finnish Natural Resources Institute (LUKE) we went to Siikajoki, on the coast of Bothnia Bay, and restored young peatlands. In this instance, restoration meant cutting most of the trees and filling the ditches with peat so that the soil becomes wet again. Then we spent several years following what happened to the vegetation and greenhouse gas fluxes. Greenhouse gases such as carbon dioxide, methane and nitrous oxide (laughing gas) are the ones that keep our atmosphere warm and cause global warming. Whether a peatland has a cooling or a warming effect on the climate depends on the balance between how much carbon dioxide plants take from the air and how much is released back to the air by soil microbes as carbon dioxide and other gases. To our delight the peatland plants, especially the sedges that are the key species of young peatlands, reacted quickly to the increased moisture and light and took over the space from plants more common to forests. In addition, the greenhouse gas flux rates of the restored peatlands were similar to those that we measured from pristine peatlands nearby.
Therefore, we conclude that peatland restoration is a means to go forward. Even though the “rough” scenery immediately after restoration activities may not appeal to the eye, we just have to be patient. Eventually, after the peatlands have recovered, we will see picturesque moss covered bogs filled with cloudberries and cranberries. In the meantime, we might even experience special summers such as 2016, when Cotton Grass covered the restored peatlands with its white fluffy duvet.
Last updated: 28.9.2017