A Tool for Estimating Nutrient Fluxes In Harvest Biomass Products for 30 Canadian Tree Species.

Published information on nutrient concentrations in four tree biomass components (stem bark, stem bole, branches, foliage) were compiled from existing databases and form the literature for the 30 most important Canadian tree species. This database was linked to a series of allometric biomass equation that have been validated at the national scale to generate estimates at the tree or at the stand level of biomass and nutrient export upon stem-only or whole tree harvesting. Confidence interval s are provided for each component. An analysis of how these nutrient fluxes vary with tree species, stand basal area and components of biomass harvested (branch, bark, trunk, foliage) was performed. There was a clear distinction between deciduous and coniferous species for nitrogen content but large overlaps for other elements, in particular phosphorus. Calcium and magnesium contents are correlated within deciduous species.  The calcium content of coniferous species is generally lower than that of deciduous with the exception of Thuja species showing the greatest concentrations. This database could help defining sites that are vulnerable to intensive biomass extraction and help with the selection of species better suited to given site conditions.