Nov 27 2009
Peatlands or wetlands in tropical regions remove large amount of organic carbon. But, now-a-days, human activities have an impact on these wetlands. Large-scale fires, triggered by drainage projects in combination with repeated droughts, can release large amount of carbon dioxide into the atmosphere, which ultimately leads to global warming. Prof. Florian Siegert and his research group at GeoBio-Center, Ludwig-Maximilians-Universitat (LMU) have estimated the volume of peat burned in fires with accuracy, with the help of laser-based measurements.
According to the new data collected in the year 2006, in Indonesia, the peatland fires released about 900 million metric tons of carbon dioxide. This amount is more that the total amount of carbon dioxide emitted in Germany in the year 2006, and it represents 16% of the emission related with deforestation worldwide. Siegert remarks that the research study undertaken by him and the team specifies the major role played by endangered tropical wetland ecosystems in relation to global warming. The study has also provided data for the forth coming World Climate Conference in Copenhagen. Reaching an agreement on finding out how financial and other types of incentives can be utilized for protecting the tropical wetlands, and help to preserve the capability of wetlands to store carbon will be one of the goals in the meeting.
In the course of millions of years, plant material will be converted into coal. The first step in this process is the formation of peat, which is an organic material that is combustible. This peat is utilized for heating purpose in many parts of Europe. Peat is a condensed form of plant mass, and it is an important form of carbon stored at near-surface levels. According to Prof. Florian Siegert, peat swamps cover a vast area of 30 to 45 million hectares in the tropical lands, and this covers up to 10% of the total area of peatlands available in the world. This once again proves that tropical peatlands are the largest near-surface organic carbon storage sites in the world, and half of this is located in Indonesia.
The coastal peatlands found on Bornea was formed over 20,000 years ago. From that time onwards, convex domes of peat with the thickness of 20m have developed. These domes of peat form the basement layer of tropical peat swamp forests and have the capacity to store carbon to a greater extent. More than 50 gigatons of carbon is found in the peatlands of Indonesia. Drainage measures and deforestation disturb these peatlands and they are easily affected by the fires caused due to human activities.
The fires produced by human activities in the peatlands contain large amount of aerosols and toxic gases, which can lead to health problems in Southeast Asia. Apart from this, the organic carbon found in the soil is transformed into carbon dioxide, which has a main role in global warming. The combustible rate of the peat in the peatlands is aggravated by the periods of aridity. During the year 1997-98, due to drought related with the El Nino phenomenon, 2.57 gigatons of carbon was released from the peatland found in Indonesia.
Siegert and his team have used a direct method to measure the exact amount of peat absorbed during fire. The team used LIDAR (Laser Detection and Ranging) method to measure the peat. The team used this method to calculate the measurements from a helicopter as direct access to the peatlands is difficult. LIDAR utilizes a laser that will emit high-frequency optical signals. Echoes are produced and the team recorded when the signals hit the ground, which helped to determine the level of the surface with precision to centimeter. The instrument has helped the team to show that the fires in the year 2006 destroyed the layer of peat upto a depth of 0.3m. The derived value helped the team to conclude that from a study area of 2.79 million hectares, 180 million tons of carbon dioxide was released. The precision data collected show that forest fires in the peatlands of Indonesia has made it as one of the largest producer of atmospheric carbon dioxide in the world, and it also emphasized the factor that burning of peat can be a leading factor of global warming.
Source: http://www.uni-muenchen.de/