Highlights • Annual growth is 287 million m 3 in the forests of the Nordic and Baltic countries. • Growth can be increased by new tree species, tree breeding, high-productive management systems, fertilization and afforestation of abandoned agricultural land. • We predict a forest growth increment of 50-100% is possible at the stand scale. • 65% of annual growth is harvested today.

No abstract

Due to practical need to improve the accuracy of measurement of wood electrical resistance via creating multivariate calibration models the study of electrode effects was carried out. The experiments were made in DC mode and five types of electrode effects were measured: electrical resistance of the galvanic contact between the measuring electrode and wood, corrosion of measuring electrodes in wet wood, polarization and depolarization of the double layer forming on the surface of the measuring electrodes, residual polarization voltage between measuring electrodes and effect of repeated use of measuring electrodes. For multi-channel measurement mode effect of neighbouring electrodes was measured. Behind each of these factors is a complex transfer mechanism of free and bounded charge carriers from wood to measuring electrodes. Among the factors, polarization and depolarization have an immediate effect (duration of the processes in seconds) while resistance of electrode/wood contact, corrosion of electrodes and residual polarization have a slow effect (duration of processes in hours). For pine sapwood, coefficients of the Stamm formula were found in moisture contents (MC) above the fibre saturation point. It was determined that wood polarization and depolarization indicators are dependent on wood moisture content as is the case with wood electrical resistance. Compared to wood electrical resistance, wood polarization proved approximately four times and depolarization approximately eight times less sensitive to moisture content variation.

Irdla, M., Padari, A., Kurvits, V., Muiste, P. 2017. The chipping cost of wood raw material for fuel in Estonian conditions. -Forestry Studies | Metsanduslikud Uurimused 66, 65-74. ISSN 1406-9954. Journal homepage: http://mi.emu.ee/forestry.studies Abstract. In Estonia up to now the producers of wood fuels have not yet adequately analysed the production and transport costs although it is known that the share of these costs form up to half of the fi nal price of wood chips or hog fuel. With this in mind the goal of the case study was defi ned -to analyse the price formation of comminuted wood fuels in Estonian conditions. Within one year of the survey the initial data was collected from the company SLG Energy. Different types of machines (7 in total) were observed -wood chippers Jenz HEM 561, Jenz HEM 582, Heinola 910ES, and Doppstadt DH 608. All machines were equipped with a GPS tracking device which recorded the route and the fuel consumption and during the observation period all costs and revenues related to the concerned machines were accounted. It was determined that due to frequent repairs the maintenance costs of older machines were higher and productivity lower compared with new machines. The biggest item of expenditure turned out to be the fuel consumption. The second was the cost of repairs in the case of older machines and price in the case of new machines. Also the type of chipper had an impact on the production cost. Under the cumulative effect of various factors the production cost turned out to vary widely from 1.03 to 2.38 €/m l 3 .

No abstract