The long-term effects of logging residue removal on forest floor nutrient capital, foliar chemistry and growth of a Norway spruce stand

This study compared the nutrient capital of the forest floor, the nutrient status of trees, and the growth of a stand of Norway spruce (Picea abies L. (Karst.)) planted on a whole-tree harvesting treatment (needles left on site) with a conventional stem-only harvesting treatment 30 years after clearcutting. No significant treatment effects were detected in the amount of organic matter, the amounts of nutrients in the forest floor, or the concentrations of foliar nutrients. The results indicate that whole-tree harvesting with the needles left on the site did not reduce the long-term nutrient capital of the forest floor or the nutritional status of trees. Whole-tree harvesting significantly reduced the height of dominant spruce compared to stem-only harvesting, however the stem volume of dominant spruce did not differ between the harvesting treatments. The greater height growth of the dominant trees in the stem-only harvesting treatment could be attributed to indirect factors other than changes in site resource availability (e.g. protection against frost damage), and hence the effect of whole-tree harvesting on potential site productivity was inconclusive due to the confounding effect of site factors. In the whole-tree harvesting treatment, the total stem volume of the stand and, consequently, the actual site productivity, was lower when compared to stem-only harvesting due to the lower density of naturally regenerated seedlings.