Low-site class black spruce and jack pine nutrient removals after full-tree and tree-length logging

An old, merchantable, low-site class black spruce (Piceamariana (Mill.) B.S.P.) stand growing on a Lithic Humo-Ferric Podzol overlying a granite bedrock, and a younger but merchantable low-site class jack pine (Pinusbanksiana Lamb.) stand growing on a Ferro-Humic Podzol overlying a deep coarse sand near Baie Comeau, P.Q., were analysed for stand biomass and macronutrient contents of both stand and soil. The magnitude of the depletions of macronutrients from the site, in full-tree and tree-length methods of logging, are compared with their available and total quantities in the soil. The range of values from the literature for nutrient inputs are presented and discussed in relation to logging losses. The results suggest that full-tree logging in the dry jack pine stand could cause a severe loss of potentially mineralizable N supply; P, K, and Mg deficiency problems owing to export are not apparent, but a Ca balance problem is apparent. The implication is that full-tree logging should be avoided on such sites.