Species composition in northern wetlands may influence greenhouse gas fluxes

Global temperature has increased 0.6 degrees C over the last century due to a continuous increase in the concentration of greenhouse gases in the atmosphere. Although the largest sources of greenhouse gases are anthropogenic, wetlands account for 25% of the total emission of the important greenhouse gas methane (CH4) making them the single largest natural source (75%) of this gas to the atmosphere. Through studies in southern and northern Sweden and in Greenland, we have shown that wetland plants have species-specific effects on the amount of methane that is emitted to the atmosphere. Our results point toward a direct and very important link between plant species diversity and the functioning of wetland ecosystems, and indicate that changes in species composition may alter important processes relating to controls on and interactions between greenhouse gas fluxes. This will have significant implications for feedback mechanisms in a changing climate.