Methane emission from a wetland plant:: the role of CH4 oxidation in Eriophorum

The importance of plant-mediated CH4 transport was studied in a northern wetland. CH4 transport through Eriophorum, a dominant sedge, was found to be the major pathway for CH4 fluxes. Mean emission from Sphagnum lawns was low (34 mu g CH4 m(-2) h(-1)) and significantly higher from tussocks of Eriophorum vaginatum (974 mu g CH4 m(-2) h(-1) U-test, p < 0.05). Mean flux from single tillers of Eriophorum angustifolium was 92 mu g CH4 h(-1) In contrast to other ecosystems, no CH4 oxidation was associated with Eriophorum. Hence, the lack of oxidation is one reason for the high emission rates from these ecosystems. This finding is a caveat for models of CH4 emission and may also have consequences for carbon flow models of northern wetlands.