Harvesting Effects on Long-Term Changes in Nutrient Pools of Mixed Oak Forest
1998
Johnson, D. W. | Todd, D. E.
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 assessed by sampling soils and vegetation just prior to and 15 yr after harvesting. Fifteen years after harvest, large woody residues in the SAW treatment lost >80% of their mass and nutrient content. Greater concentrations of Ca, K, and Mg were found in both foliage and soils in the SAW treatment than in the WTH treatment, but there were no signs of deficiency in these nutrients and no differences in growth due to treatment. There were nod eclines in exchangeable Ca²⁺ in the WTH treatment, and the increases in soil exchangeable 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 yr after treatment. Contrary to what has been speculated on regarding the basis of nutrient 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 residues are largely retained in soils and reflected in elevated foliar nutrient concentrations.
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