Successions in peatland types will mitigate warming-related increase of methane emissions

Submitted by kukkis on Tue, 06/15/2021 - 16:09
Wetland landscape. Photo: Kukka-Maaria Kohonen
Wetland landscape. Photo: Kukka-Maaria Kohonen

Climate change is likely to promote Sphagnum-establishments over brown mosses in many places of northern peatlands.

A recent study suggests that peatland type successions have significant impacts on methane (CH4) emissions. CH4 emissions from northern peatlands are projected to increase due to climate change, primarily because of projected increases in soil temperature. By investigating CH4 production and oxidation potentials at 5, 17.5 and 30 °C and their drivers of 14 peatlands (representing three peatland types – bogs, poor fens, and rich fens) in Finland, the authors observed a steeper temperature response of production in rich fens than in bogs and poor fens, but similar temperature response of oxidation between peatland types, which implies a potential different temperature response of CH4 emissions between peatland types. However, the authors also suggest that the accurate prediction of CH4 emissions also requires knowledge of, for example, CH4 transport by aerenchymous plants. The detected steeper temperature response of oxidation than production suggests that, at higher temperatures, CH4 oxidation might offset increased CH4 production. This offset could be stronger in bogs and poor fens where the temperature response of production was milder.