Effect of Fungal Lesions on the Wood Density of Silver Fir ( Abies alba L.) in Ukrainian Carpathians

Abstract

The research has covered the biological wood resistance in terms of reducing its wood density of Silver fir growing in the Ukrainian Carpathians. Six Silver fir stands were placed in the State Enterprise Perechyn Forestry, in which were cut 54 model trees with varying decay stages. All qualitative characteristics of Silver fir wood were diagnosed by the European norms. Altogether, 1620 wood samples were studied. The start of biological damage to wood was defined as the cessation of cambial activity and drying of the tree crown, as well as diagnosed fungal lesions. As a result, there were significant differences in wood density with a different timeframe of decay stages of wood. The basic density of healthy wood varied from 362 kgm -3 to 457 kgm -3 with an average value of 392 kgm -3 , and the same figure for wood with significant damage ranged from 195 kgm -3 to 283 kgm -3 with an average value of 246 kgm -3 . This should be associated with the biological destruction of the cell wall affected by fungi from division Basidiomycota. Four significant decay stages of Silver fir stemwood taking the lesioned time by the equal variances estimated through Scheff & eacute;'s Method were set: (1) healthy wood without signs of biological damage by fungi; (2) initial wood damage caused by wood-staining fungi within up to 6 months; (3) medium wood damage caused by wood-destroying fungi within the timeframe from 0.5 to 2 years; and (4) substantial wood damage caused by wood-destroying fungi for more than 2 years.