Pine forests are rich in spruces, which are permanently weakened by atmospheric factors. Frayed roots are easily infected by harmful fungus and insects. The most damaging is honey mushroom, with edible specimen, which grows in pulp, between the bark and timber, causing the death of tree. The other damaging fungus is bracket fungus, which destroys roots and trunks from the inside. The honey mushroom devastates the tree within a few months, and the bracket fungus, within a few years, as a result of mechanic changes in wood-structure.