Photo by Daniel Beltra

ScienceDaily (Nov. 29, 2009) — Peatlands, especially those in tropical regions, sequester gigantic amounts of organic carbon. Human activities are now having a considerable impact on these wetlands. For example, drainage projects, in combination with the effects of periodic droughts, can lead to large-scale fires, which release enormous amounts of carbon dioxide (CO2) into the atmosphere, and thus contribute to global warming. Using laser-based measurements, Professor Florian Siegert and his research group at Ludwig-Maximilians-Universität (LMU) in Munich have now estimated the volume of peat burned in such fires with unprecedented accuracy.

The new data imply that, in 2006, peatland fires in Indonesia released up to about 900 million metric tons of CO2. This is more than the total amount of CO2 emitted in Germany in that year, and represents about 16 % of the emissions associated with deforestation worldwide. "Our work once again underlines the decisive role played by acutely endangered tropical wetland ecosystems in the context of global warming," says Siegert. "The study also provides important data for the upcoming World Climate Conference in Copenhagen. One of the goals of that meeting is to reach agreement on how financial and other incentives can be employed for the protection of tropical wetlands, and so help preserve their enormous capacity for carbon storage. (PNAS online, 26 November 2009)

Over the course of millions of years, plant material can be converted into coal. The first step in this process leads to the formation of peat, an organic material that is combustible and is harvested for heating purposes in many parts of Europe. As a condensed form of plant mass, peat is also an important storage form of carbon at near-surface levels. "It is estimated that, in the tropics, peat swamps cover an area of 30 to 45 million hectares," says Professor Florian Siegert from the GeoBio-Center of the LMU Munich. "This corresponds to about 10% of the total area of peatlands in the world, and means that tropical peatlands represent one of the largest near-surface storage sites for organic carbon that we have." — And almost half of this reservoir is located in a single country, Indonesia.

Many of the coastal peatlands on Borneo formed over 20,000 years ago. Since that time — as in most tropical peatlands — convex domes of peat, up to 20 metres thick, have developed. They serve as the basement layer of tropical peat swamp forests and possess a huge capacity for storing carbon. Indeed, the total amount of carbon locked in the peatlands of Indonesia alone is thought to be more than 50 gigatons. However, these areas are in imminent danger. Left in their natural state, they are simply too wet to burn. But drainage measures and deforestation disturb their ecological equilibrium and make them vulnerable to fire, which is almost always caused by human activities. Private companies often exploit fires to prepare the ground for the establishment of large-scale plantations for the production of wood pulp and palm oil,.

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