Carbon and nitrogen cycling in North American boreal forests. II. Biogeographic patterns

Test forests included black spruce Picea mariana, white spruce Picea glauca, white birch Betula papyrifera, balsam fir Abies balsamea and jack pine Pinus banksiana stands located in 5 different bioclimatic regions. Test comparisons of simulated and actual data included aboveground tree biomass, basal area, density, litter fall, and moss and lichen biomass as well as forest floor biomass, turnover, thickness, N concentration, and N mineralization. The model correctly simulated 60 (76%) of the 79 variables tested; c42 of the incorrectly simulated variables occurred in one forest. Major recurring errors included inaccurate moss and lichen biomass and low moss N concentrations. -from Author