Wetland methane fluxes : upscaling from kinetics via a single root and a soil layer to the plot.

In the last decade, knowledge of methane production and methane consumption has increased considerably. This increased knowledge has been used to support the descriptive models mentioned above and to develop process models [Cao et aL, 1995; 1996; Walter et al, 1996; Watson et al, 1997]. However, these process models require fit procedures or intensive on site measurement of parameters which are as variable as methane fluxes, which limits their applicability for understanding and developing general relationships between methane fluxes and environmental variables. To improve the process models in this respect the knowledge of methane production and methane consumption is reviewed and it is investigated how this knowledge could be used to establish quantitative relations between the rates of both processes and environmental variables...