Reducing the nitrogen load: Whole-tree harvesting. A literature review

Where nitrogen deposition is high, nitrogen will accumulate in forest ecosystems and with time affect the environment negatively. By removing forest felling residues for fuel, it appears possible to strongly counteract the effects of nitrogen deposition. Felling residues contribute considerably to the soil's organic nitrogen reserve. They also influence the soil climate and processes, frequently resulting in increased mineralization, nitrification and leaching of nitrogen and other nutrients from clearcut areas. Removal of felling residues will reduce the leaching of nitrogen on the clearcut and counteract nitrogen accumulation. The value of the critical load for nitrogen also becomes much higher if felling residues are removed, in comparison with when they are left on the site. Extensive removal of felling residues, however, requires that losses of mineral nutrients are compensated. NOx-emissions during combustion of the biomass can be restricted to about 5% of the fuel's nitrogen. 82 refs, 5 figs, 1 tab