Alternate Strip Clearcutting in Upland Black Spruce: IV. Projected Nutrient Removals Associated with Harvesting

Nutrient removals associated with conventional, full-tree, and whole-tree harvesting on 100-year rotations in an upland boreal black spruce stand in northern Ontario were estimated. Conventional (stems only) logging would remove 219 kgha −1 of Ca, 62 of N, 36 of K, 18 of Mg and 9 of P from the site. Increased utilization of phytomass during full-tree harvesting, in comparison with conventional logging, could result in as much as a 400% increase in N removal and a 60% increase in Ca removal. Estimates of projected N and K removals by full-tree harvesting may be conservative, relative to those in other black spruce stands because of the low foliar mass of this forest. The forest floor contained 51% to 72% of the soil's reserves of nutrients, except for P, within the effective rooting zone. Post-harvesting site preparation methods should be restricted to those that ensure that forest floor nutrient reserves are retained on site.