A test of the Canadian Land Surface Scheme (CLASS) for a variety of wetland types

The validation of the Canadian Land Surface Scheme (CLASS) for several wetl and types: fen, marsh and bog was undertaken. Incorporating organic soil pa rameters resulted in a significant improvement in turbulent flux estimates for the vascular dominated fen and marsh wetlands, yet non-vascular bog-typ e wetlands are relatively poorly modelled Bog surfaces were treated as bare soil surfaces in this testing procedure since the non-vascular nature is n ot readily incorporated within the current CLASS model vegetation categorie s. CLASS does not contain a method for moisture transfer from vegetation ot her than transpiration by the vascular pathway of root, stem and leaf while evaporation of water from moss and lichen dominated surfaces found in bogs is presently Not included. With improved parametrization of the water tabl e already introduced, and an additional non-vascular vegetation category, i f should be possible to model accurately the range of wetland types with CL ASS.