Peatlands store large amounts of carbon. However, when they are drained, they can become substantial sources of the greenhouse gas carbon dioxide (CO₂).
Peatlands store large amounts of carbon. However, when they are drained, they can become substantial sources of the greenhouse gas carbon dioxide (CO₂). An international research team led by the University of Münster has now used the largest international dataset on CO₂ budgets of northern peatlands to show how water level and temperature effects are linked. The lower the water table, the more strongly CO₂ emissions respond to rising temperatures. A higher water table can therefore dampen this effect. The results have been published in the journal Nature Communications.
Peatlands develop in areas with permanently or temporarily waterlogged soils. Under oxygen-poor conditions, dead plant material decomposes only slowly, allowing peat to accumulate over long periods of time and store large amounts of carbon. When a peatland is drained, more oxygen enters the peat. Microorganisms then break down the organic material more rapidly, releasing CO₂, among other gases. “Water level has long been recognised as an important factor controlling the CO₂ balance of peatlands. Our analyses show, however, that its importance cannot be considered independently of temperature,” explains Nicolas Behrens, first author of the study and a researcher at the Institute of Landscape Ecology at the University of Münster.
For the study, the team analysed measurements from 276 so-called site-years covering a total of 114 peatlands in temperate and boreal regions. These were located, among other places, in Germany, Estonia, France, the United Kingdom and North America. A site-year refers to measurements from a particular site over the course of one year. The researchers examined both natural fens and bogs as well as croplands, grasslands and former peat extraction sites.
Read More: University of Münster
Image: For almost four years, this monitoring station in the Amtsvenn-Hündfelder Moor near by Gronau has been recording the fluxes of several greenhouse gases and water vapour. (Credit: Biosphere-Atmosphere Interaction research group)
