Upscaling of peatland-atmosphere fluxes of methane: Small-scale heterogeneity in process rates and the pitfalls of “bucket-and-slab” models

摘要: Most models of carbon balance processes in northern peatlands were developed to apply at the scale of small peatland features such as hummocks and hollows, which may have linear extents of 100–101 m, or at the scale of individual peatlands (up to 104 m). However, many have been applied at the much larger scale of cells in land surface schemes (typically, 1 latitude× 1 longitude or larger), which are linked to global circulation models. In these larger representations, as with the scale for which the models were originally developed, they take some account of vertical variability through the peat profile but ignore horizontal variability in vegetation and peat properties. That is, they contain a single vegetation type, a horizontally uniform slab of peat, and predict a single water table position: they represent the peatland as a “bucket and slab.” In this chapter, we examine the accuracy of assuming that carbon balance …