so as to
hamper the natural regeneration process. Here, spruce
trees, because of little thinning in the younger stages,
have low mechanical stability. Besides Armillaria infections,
in the 1980s, clearcuts were carried out in
some stands, heavily damaged first by Cephalcia arvensis
(Hymenoptera, Pamphiliideae) and then by
Coleoptera Scolytidae (Battisti et al. 1994).