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 wetland types: fen, marsh and bog was undertaken. Incorporating organic soil parameters resulted in a significant improvement in turbulent flux estimates for the vascular dominated fen and marsh wetlands, yet non-vascular bog-type wetlands are relatively poorly modelled Bog surfaces were treated as bare soil surfaces in this testing procedure since the non-vascular nature is not readily incorporated within the current CLASS model vegetation categories. CLASS does not contain a method for moisture transfer from vegetation other 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 table already introduced, and an additional non-vascular vegetation category, if should be possible to model accurately the range of wetland types with CLASS.