Effects of slash and stump harvesting after final felling on stand and site productivity in Scots pine and Norway spruce

摘要

As a response to the increased market for biomass for energy in Sweden logging residues such as slash and stumps, previously left in the forest at stemwood harvest, have been targeted as a resource. Negative effects on site and stand productivity have been suggested as unwanted effects of this increased harvest intensity. Slash with its high nutrient content has the potential to impact forest production on nutrient limited northern forest sites. Stumps, with a lower nutrient content, may therefore be more favourable from a production point of view and the additional soil disturbance caused by the harvest may counteract the nutrient loss as a result of stimulated mineralization and reduced competition from the ground vegetation. Seedling survival is another critical factor that could be affected with potential effect on future stand productivity. Here stand and site productivity data from four long-term field experiments planted with, Scots pine (2 sites) and Norway spruce (2 sites) seedlings following (i) conventional stemwood harvest (5), (ii) stem and stump harvest (SS), and (iii) stem, stump, and slash harvest (SSS) is analysed and presented.