Harvesting effects on long-term changes in nutrient pools of mixed oak forest

The effects of sawlog harvesting (SAW) vs. whole-tree harvesting (WTH) on C and nutrient budgets of a mixed oak forest near Oak Ridge, TN, were assess ed by sampling soils and vegetation just prior to and 15 yr after harvestin g. Fifteen Sears after harvest, large woody residues in the SAW treatment l ost >80% of their mass and nutrient content. Greater concentrations of Ca, K, and Mg were Pound in both foliage and soils in the SAW treatment than in the WTH treatment, but there were no signs of deficiency in these nutrient s and no differences in growth due to treatment. There were no declines in exchangeable Ca2+ in the WTH treatment, and the increases in soil exchangea ble Ca2+ pools in the SAW watersheds were approximately equal to the amount of Ca2+ released by decomposing residues. On the other hand, no treatment effects on soil C, vegetation biomass, species composition, vegetation N or P concentration, soil bulk density, or soil N were found 15 Jr after treat ment. Contrary to what has been speculated on regarding the basis of nutrie nt budgets, this study showed no detrimental effects of WTH on productivity or soil nutrient status (i.e., reductions from preharvest conditions). The results did show, however, that nutrients (especially Ca) from logging res idues are largely retained in soils and reflected in elevated foliar nutrie nt concentrations.