PLANT-TRANSPORT AND METHANE PRODUCTION AS CONTROLS ON METHANE FLUX FROM ARCTIC WET MEADOW TUNDRA

The roles of plant transport and CH4 production in controlling CH4 flux from wet meadow tundra communities were investigated. Plant transport was the dominant pathway of CH4 flux from this ecosystem. Most CH4 production (measured with in situ anaerobic incubations) occurred well below the water table, and C supply (estimated by anaerobic CO2 production) was the best single predictor of CH4 production rates. Plant transport of CH4 was controlled both by CH4 supply and the plant species. Eriophorum angustifolium transported substantially more CH4 than did Carer aquatilis, due to differences in size and structure of the two species. The composition of the plant community was a greater control on CH4 flux from the site than either water table height (which varied only slightly) or CH4 production rates, indicating the importance of species-specific plant dynamics in controlling CH4 flux from arctic wetlands.