The natural succession of boreal coniferous forest after
forest fire, storm or clearcut of managed forests is shown in
Fig. 2. The natural mortality of trees varies between 25 and
40% in 100 years in an unmanaged stand depending on tree
species. This means that a regularly managed stand can
produce about 20% more volume to be utilized than an
unmanaged stand. The difference is much higher in
economic terms, if the time factor is taken into account by
discounting the costs and revenues of the management to the
beginning of the rotation (Valsta, 1992).