Uncertainties modelling CH4 emissions from northern wetlands in glacial climates: the role of vegetation

The PEATLAND-VU methane (CH4) model has been used to simulate emissions from continental Europe under different climatic conditions during the last glacial (LG) and modern climates. Such emissions are reactive to hydrology and the results presented by this paper demonstrate high sensitivity to vegetation parameters. Vegetation influences natural CH4 emissions and thus affects its modelling. In wetlands ecosystems various interactions between plants and CH4 do take place and each type of plant is able to affect fluxes in its own way. However, effects of vegetation factors are rarely properly assessed in detail for large scale emission models. Consequently, modelling of CH4 fluxes is currently suffering from lack of information regarding vegetation processes and parameter quantification, thus explaining uncertain estimations. Modelled wetland CH4 emissions during glacial climates are highly uncertain regarding the extent and type of vegetation cover. Paleobotanical data indicate that past (glacial) northern wetland plants associations differed considerably from present moss-rich tundra vegetations. This study examines the effects of wetland vegetation on CH4 emissions, aiming at more plausible flux estimation as well as identifying the sources and the processes governing CH4 emissions.