Articles containing the keyword 'merchantable timber'

The purpose of this investigation was to study the felling volume and its structure in the State forests of Finland. Special attention was paid on the proportion of waste wood within the felling volume. This information was in demand for the general plan of the State forests that was being prepared at the same time. The survey was performed using a sampling method, and it represented the districts in the northernmost Finland, Ostrobothnia, Eastern Finland and Western Finland of the Forest Services.

The proportion of merchantable timber of the total felling volume was lowest in the northernmost Finland, less than 2/3 of the total cut. In Ostrobothnia the share was ¾, Eastern Finland 4/5 and in Western Finland 5/6. When the tree species were compared, the proportion of waste wood was largest in broadleaved trees, especially in the Northern Finland, while for Scots pine it was lowest. For Norway spruce the share of merchantable timber is markedly lower in the northernmost part of the country, where, for instance, decay increases the proportion of waste wood. For birch, demand of wood influences most the proportion of waste wood.

In general, the proportion of waste wood and merchantable timber in the felling volume was influenced by changes in the demand of timber, structure of the stands, and the felling method. The demand of the timber assortment affects most in the amount of waste wood. The more valuable the timber assortment is, the less waste wood is left in the cutting area.

The PDF includes a summary in German.

• Kangas, E-mail: yk@mm.unknown

The effect of different kinds of injuries in the amount of merchantable timber was studied in 57 sample plots in the northernmost Finland. Without any injuries the yield of timber would have been 72.3% in Scots pine (Pinus sylverstris L.) and 89.9% in Norway spruce (Picea abies (L.) H. Karst.). Butting, and removal of parts of the stems due to Injuries decreased the volume by 10.4% in pine and 13.5% in spruce. The main cause for butting of pine was fire wounds, and butt rot in spruce. Also pine blister rust (Peridermium pini and Cronartium flaccidum) causes injuries in Scots pine. The better the forest site type, the smaller is the timber discarded due to injuries. In pine 54% and in spruce 53% of the trees and were healthy. The forests in the northernmost Finland are over-mature which increase the occurrence of fire wounds and decay. Thus, forest fire control and the felling or thinning of over-mature stands will improve the quality of the timber in the long run.

The PDF includes a summary in German.

• Tikka, E-mail: pt@mm.unknown