Investigation of old damages in common ash stems | Pārnadžu bojājumu ietekme uz ošu stumbru kvalitāti
2003
Liepins, K., Latvian State Forest Research Inst. Silava, Salaspils (Latvia)
34 common ash trees stems were analysed to investigate the distribution of stem defects caused by old stem damages. Sample trees were collected in four districts- Jelgava, Bauska, Talsi and Daugavpils. Ash stems were divided in two meter long sections and cross-cut discs were cut from the butt at breast height (1.3 m) and in the middle of sections. Diameters and vertical distribution of black heart and decay were recorded. In cross-cut discs at the height of 1 m or 1.3 m the degree of damage as a proportion of damaged area to whole circumference length at the age of damaging was calculated. The ash trees are found to have excellent ability to overgrow scars of damage with sound wood even if over 70% of the cross-section is affected. In 80% of sample trees decay was found in the area of damage. The decay is restricted within the cross-section parameters of stem at the moment of inflicting the damage. In longitudinal direction the decay spreads comparatively slowly and commonly no more than 2-3 m high. No significant relationship between the presence of decay and the degree of damage as well as the age of damage was found. The ash black heart was recorded in all the sample trees except one. The distribution of black heart in both the cross-section and longitudinal directions is mostly confined to stem parameters at the moment the damage is inflicted. No correlation between the degree of damage and the longitudinal distribution of black heart was found. Although stem damages cause decay that adversely affects wood quality, destruction of such ash stands is not imminent.
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