Current issue: 56(2)
Under compilation: 56(3)
The effects of repeated fertilizer treatment on biomass production and nutrient status of willow (Salix ’Aquatica’) plantations established on two cut-away peatland areas in western Finland were studied over a rotation period of three years. Comparisons were made between single fertilizer applications and repeated annual fertilization.
The annually repeated fertilizer application increased the amounts of acid ammonium acetate extractable phosphorus and potassium in the soil as well as the concentrations of foliar nitrogen, phosphorus and potassium compared to single application. Depending on the fertilizer treatment and application rate, annual fertilizer application resulted in over two times higher biomass production when compared to single fertilizer application over a three-year rotation period. The effect of phosphorus fertilizer application lasted longer than that of nitrogen. The optimum fertilization regime for biomass production requires that nitrogen fertilizer should be applied annually, but the effect of phosphorus can last at least over a rotation of three years. Potassium fertilizer treatment did not increase the yield in any of the experiments during the first three years. The leafless, above-ground yield of three-year-old, annually NP-fertilized willow plantations was 9.5 t ha-1 and the total biomass, including stems, leaves, roots and the stump, averaged 17 t ha-1.
The effects of fertilized treatment on the soil nutrient concentrations, biomass production and nutrient consumption of Salix x dasyclados and Salix ’Aquatica’ were studied in five experiments on three cut-away peatland sites in western and eastern Finland during three years. Factorial experiments with all combinations of N (100 kg ha-1 a-1), P (30 kg ha-1 a-1) and K (80 kg ha-1 a-1) were conducted.
The application of P and K fertilizers increased the concentrations of corresponding extractable nutrients in the soil as well as in willow foliage. N-fertilization increased foliar nitrogen concentration. An increase in age usually led to decreases in bark and wood N, P and K concentrations and increases in bark Ca concentrations. N-fertilization increased the three-year biomass yield 1.5–2.7 times when compared to control plots. P-fertilization increased the yield only in those experimental fields whose substrates had the lowest phosphorus concentration. K-fertilization did not increase the yield in any of the experimental fields. The highest total biomass yield of NPK-fertilized willow after three growing seasons, 23 t ha-1, was distributed in the following way: wood 42%, bark 19%, foliage 17%, stumps 6% and roots 16%. As the yield and stand age increased, more biomass was allocated in above-ground wood. Three-year-old stands (above-ground biomass 18 t ha-1) contained as much as 196 kg N ha-1, 26 kg P ha-1, 101 kg K ha-1, 74 kg Ca ha-1 and 37 kg Mg ha -1. By far the highest proportion of nutrients accumulated in the foliage. The bark and wood contained relatively high proportions of calcium and phosphorus. With an increase in age and size, the amount of nitrogen and potassium bound in one dry-mass ton of willow biomass decreased while that of phosphorus remained unchanged.
For biomass forestry in the inland parts of Southern and Central Finland, the obvious choice of willow species is Salix myrsinifolia. However, selection of clones of indigenous species has not yet been completed and more research and selection is needed. In the Piipsanneva old peatland trial, indigenous species of willow, mostly clones of S. myrsinifolia and S. phylicifolia, were compared in terms of biomass production, coppicing, height growth and diameter distributions. In this trial, the mean annual biomass production was not particularly high; more important results were attained in the ranking of clones. The trial strengthens the hypothesis that, over the long-term, the biomass production of S. myrsinifolia is higher than that of S. phylicifolia. It was supposed that behind the highest yield there was a clone with uniform quality, one whose diameter distribution would be narrow and positively skewed. Comparisons of parameters of Weibull functions showed that the distributions of the best clones were wide, indicating that those clones use the whole growth space better than those with narrow distribution.
Growth and nutrition of 20 clones representing different species and interspecific hybrids of willows (Salix spp.) growing on an abandoned field were studied. There were highly significant differences between the clones as regards the survival, number of sprouts per stool, sprout mean height and diameter and stem biomass production per stool. The differences between the clones in the concentration of all nutrients in both the leaves and stems were highly significant.
This article summarises the importance of forest industry in the acquisition and consumption of wood-based energy in Finland. Opportunities to increase the efficiency of energy utilization further are discussed, as well.
The forest industry uses 25% of the total energy and 40% of the total electricity. It also generates considerable amounts of heat and electric power as by-products of wood-processing. Wood in different forms accounts for 64% of the fuels of the forest industry. Consequently, the need for outside, imported energy is minute. Black liquor of pulping is dominant as a source of wood-based energy. In addition, plenty of wood residues (bark, saw dust, planer shavings, grinder dust, screening reject of chips) and minor amounts of for wood processing unsuitable fractions obtained in conjunction with harvesting small-sized whole-trees, tree selections and logging residues are used for energy production.
The PDF includes an abstract in Finnish.
Linear programming was used to analyse the land use alternatives in the Debre Birhan Fuelwood Plantation area, in the central highlands of Ethiopia. The region represents a rural, high-altitude area, where the main land uses are grazing and cultivation of barley, wheat and pulses. To alleviate fuelwood shortage, large plantations of Eucalyptus globulus Labill. have been established. Livestock has traditionally used the major part of the production capacity of the sites. A decrease in the number of cattle would facilitate a considerable increase in the production of cereals, pulses, fuelwood and construction timber. The optimal share of the land for arable crops, grazing and tree plantations would be about 40, 45 and 15% respectively.
The PDF includes an abstract in Finnish.
The utilization of stump and root wood is analysed in this paper on the basis of literature from middle of 19th century to the present date. According to the information available, the utilization of pine stumps in tar production was small compared to that of peeled Scots pine stemwood in the 19th century. During the 1st and 2nd World War the utilization of stumps for tar production reached its highest levels. Other industrial utilization of stumps has been small up to the present time but now stumps are beginning to be used in the pulp industry.
The greatest amounts of stumps have been utilized by the rural population. Stumps were used as fuel. In the thirties, the yearly amount used was over 200,000 m3 (solid measure), and even in the sixties over 100,00 m3. No industrial utilization method has yet reached these levels.
The PDF includes a summary in English.
As Finland has neither coal nor oil resources, it has had to resort to large-scale imports dependant on foreign relations and especially maritime connections. When the outbreak of World War II broke these connections, the state had to institute comprehensive controls and measures to ensure the supply of fuels. The present article deals with the measures taken by the authorities at that time.
Although the danger to Finland of interruption in fuel imports had been pointed out, the Finns had made hardly any preparations to manage on their own. In autumn 1939 there was no reserve stocks and particularly vulnerable was the question of motor fuels and lubricants.
When the Winter War ended in spring 1940, it was realised that special measures were needed. A law was enacted that concerned both the revival of production and regulation of consumption. For instance, every forest owner was notified of his share of the fuelwood logging. The wood processing industry had been accustomed to maintain stocks of wood covering two years’ requirements, but these inventories, too, were depleted by 1944. The law for safeguarding the supply of timber, enacted in early 1945, invested far-reaching powers in the authorities, and the logging plans were exceptionally large in 1945-47. Controls governing forestry and the forest industry were discontinued in 1947.
In Finland it is necessary to maintain a state of preparedness. This applies above all to fossil fuels and particularly oils.
The PDF includes a summary in English.
The purpose of the study was to find out the most economical fuel for central heating boilers in different parts of Finland. The most common central heating fuels and boilers used in Finland were compared in the study.
The present consumption of different fuels and the regional distribution of the boilers of a few main types was investigated. The costs were calculated according to the costs level of February 1957. To be able to compare the costs, both variable costs and fixed costs were calculated. The heat output produced annually in the different boilers was studied to divide the fixed costs into costs per heat unit.
Comparison of the total costs per heat unit showed that cost of wood or imported fuels (oil, coke, coal etc.) was about on the same level in the coastal areas close to import harbours, but wood was the cheapest fuel for central heating in inland.
The article includes an abstract in English.
Fuel shortage during and after the Second World War compelled the Government of Finland to improve the fuel supply. In 1948 the Government appointed a Committee to draft a proposal on use of domestic and imported fuels. Special attention was placed on how to develop use of peat as fuel.
In rural districts, firewood billets and waste wood accounted for 45% of fuel consumption. For other users than the rural population, coal and coke consisted 25%, industrial waste wood 11% and billets 18% of the total consumption in 1938. After the war the use of coal and coke increased and the use of billets decreased.
Due to the decreased demand of billets, their price in the towns fell lower than the production and transport costs from the most remote areas where the wood was harvested. The demand for small sized timber is important for silvicultural reasons, and wood harvesting creates jobs for the rural population, therefore, the Committee proposes that the state supports the production of billets. This could be done by improving the effectiveness of firewood loggings, and by building truck roads and railways.
Small-sized birch is used predominantly as fuel. The Committee considers the growing stock of birch to be the largest unutilized wood reserve. Supported by technological research, it may become a new raw material for sulphate cellulose industry. Use of industrial waste wood as fuel and improvement of heating equipment would improve the competitiveness of fuelwood and peat against other fuels. For the possible interruptions in imports, stocks of foreign fuels should be maintained.
The article includes a summary in English.
A questionnaire was sent to the steamship owners to investigate the annual fuelwood consumption of the steamships in Finland in 1927‒1929. Most of the steamships used split spillet as fuel, and the share of coal and waste wood remained low. The fuelwood consumption of cargo ships, passenger ships and tugboats was calculated for different kinds of steamships, and by the engine power of the ships and by the fuelwood type. The annual fuelwood consumption of cargo ships was 22,768‒27,390 m3, passenger ships 24,738‒33,616 m3 and tugboats 76,764‒113,791 m3 in 1927‒1929.
The PDF includes a summary in German.
This paper deals with fuelwood consumption in the city of Monrovia (Liberia) in 1965. Buyers of fuelwood were interviewed at market places, relevant data were recorded, and the average size of fuelwood bundles was measured by applying Archimedes Law.
The results showed that the annual average consumption of fuelwood per caput was 1.3 solid m3, and by household 6.5–6.6 solid m3. The average annual per caput expenditure on fuelwood was $ 9.7. This corresponds to a household of about 5 persons and means a household (family) expenditure of slightly less than $ 50 per annum, which is about 8% of the total household costs. Applying the Monrovia data to the whole of Liberia, it was estimated that fuelwood consumption in the whole country was 1.62 million m3 in 1965.
The PDF includes a summary in Finnish.
Industrial chipping is becoming increasingly popular, as the result of a growing demand for woody biomass. Industrial chippers are large, powerful machines that generate much noise and vibration. This study explored some factors that may affect exposure to noise and vibration, namely: feedstock type (branches vs. logs), work station characteristics (truck cab vs. separate cab) and knife wear (new knives vs. blunt knives). Exposure to noise was significantly affected by all three factors, and it was higher for branch feedstock, separate cabs and blunt knives. The higher exposure levels recorded for the separate cab were especially insidious, because they were below and above the hearing threshold and would elude immediate perception. Exposure to whole-body vibration (WBV) was significantly higher for branch feedstock and for the separate cab. Knife wear seemed to determine an increase in WBV, but this effect had no statistical significance and the result could not be taken as conclusive. Among the three factors studied, work station characteristics had the strongest effect. Further studies may extend the comparison to a wider range of options, as well as explore the use of exposure variation for machine diagnostics.