Anna-Helena Purre - What Happens to a Bog Once We've Dried It?
Anna-Helena Purre, a doctoral student at Tallinn University explains what happens to the bogs where they used to extract peat, how do we maintain the carbon levels in them and how could they be used for the benefit of the environment.
Anna-Helena Purre, a doctoral student at Tallinn University explains what happens to the bogs where they used to extract peat, how do we maintain the carbon levels in them and how could they be used for the benefit of the environment.
Estonia has about a million hectares of peat bogs, which includes natural swamps, as well as swamps man has dried up. Dried up swamps have been used in agriculture, forestry, as well as peat extraction. Peat is formed when plants tie more carbon during photosynthesis than they exhale. In addition, dead plants do not decompose fully, which also keeps the carbon locked in.
Peat is an important resource for us; it is used in heating and gardening alike. In Estonia, over one million tonnes of peat was extracted in 2013 from around 20,000 hectares. Add to this area over 10,000 hectares, where they used to extract peat, but which have now been abandoned. What happens to these wetlands, where the extraction has stopped?
Peat extraction leaves behind apocalyptic fields – brown, crisp dry (on a dry summer day), and lifeless. These areas also produce carbon dioxide: over 400,000 tonnes in Estonia alone last year. While swamps in their natural state collect carbon, they become carbon producers themselves once they have been emptied.
To reduce the carbon footprint of Estonia and bring new life to these areas, it is important to sort out the former peat excavation sites. We could plant forests, create bodies of water, or grow berries and energy crops. From the viewpoint of carbon itself, the best option would be to restore the swamp with all its characteristics – high water levels, wetland plants, and a high concentration of peat moss, but also cranberries, cloudberries, heather, and cottongrass.
Regenerating the swamp on extraction sites is a time-consuming process, which has its ups and downs. To start the process, the water level must be raised close to the peat level, which allows the moss and other plants to reach the water. In large areas, the process could be accelerated by collecting moss from natural swamps and sowing it where necessary. The relocated moss should then be covered with mulch, which creates a pleasant environment for the plants. This way we can turn the carbon producers back to being carbon consumers and restart peat growth.
To decrease our carbon footprint we must turn a large proportion of former excavation sites into new swamps, with swamp plants, an abundance of water and peat that grows from the carbon in the atmosphere.