Current issue: 58(5)
Needle fascicles of Scots pine (Pinus sylvestris L.) were rooted in a standard Jacobsen’s germination apparatus. The apparatus was found to be suitable for rooting at least on laboratory scale. The best rooting substrate was living Sphangnum, which remained sufficiently moist in the germination containers throughout the experiments. In a comparison of various growth substrate treatments, the best result was obtained with a combination of IAA (100 mg/l) and thiamine (5 mg/l). The rooting percentage using these growth substances with Sphagnum as the rooting medium was in the first experiment 30 and in the second 48.
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This study was carried out on behalf of the Central Association of Finnish Forest Industries (now Finnish Forest Industries Federation) in order to obtain information about the wood raw material situation, to serve, in turn, as a basis for the forest industries’ long-term planning. The study deals with the potential supply of roundwood, industrial residue and forest residue by the year 200 by five wood-supply areas. Examination of the situation during the period of 1972–80 is based on available balances and that concerning the period 1985–2000 in the estimated quantities available for industrial use.
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The paper describes an attempt to determine whether ammonium, nitrate and urea nitrogen are bound in peat used as a filling material in containerized seedling production, what is the effect of the nutrients on certain chemical properties in the peat, and what is the effect of the nitrogen fertilizers on the primary growth of containerized (paper-pot VH 608) Scots pine (Pinus sylvestris L.) seedlings in connection with planting out. The seedlings were fertilized with ammonium sulphate, potassium nitrate and urea.
The results show that none of the fertilizers used were bound in the peat. The nitrogen content in the above ground part of the seedlings increased clearly. Fertilization with ammonium sulphate resulted in the greatest increment and this increase appears to be permanent. The wintering process was somewhat delayed by the fertilization. The seedling mortality rate for all the treatments has been quite appreciable. However, fertilization particularly with ammonium sulphate on the poorer of the two sites studied has had a positive effect on seedling survival. Furthermore, it appears that fertilizer treatments have decreased growth after planting, but in the case of ammonium sulphate this decrease has changed into a clear growth increment.
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The photosynthetic rate of Pleurosium schreberi (Willd.), Hylocomnium splendens (Hedw.) and Dicranum undulatum (Sw.) grown in plastic containers was monitored with infrared gas analyser in open air under natural weather conditions. It proved that the photosynthetic rate of wet moss cushions was satisfactorily predicted by temperature and light intensity. In dry moss cushions this kind of model gave too high an estimate for photosynthetic rate. Water requirements of each moss species were found to be moderate, and water content of moss cushions limited photosynthetic rate only under serious water deficiency.
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This study forms part of a project designed to elucidate the total nutrient budget of a Scots pine (Pinus sylvestris L.) stand in Central Finland during the 1974 growing period. Precipitation has been divided up into precipitation, throughfall and stemflow.
The acidity of the rainwater was found to increase in the order – Precipitation, throughfall and stemflow. The electrolyte content of the rain water from throughfall and stemflow was higher than that of precipitation. The nutrient contents of precipitation were rather low. Throughfall and stemflow were found to leach some nutrient from the trees. This was most clear in the case of potassium. The total amounts of nutrients reaching the ground in throughfall were found to be smaller than those in precipitation. On the other hand, the amounts of potassium, calcium and magnesium in stemflow were clearly greater than those in precipitation.
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It has been in Finland discussed to replace the present straight piece rate by a time rate in forest work. The low earnings of aged forest workers, the health hazards, its tendency to cause conflicts and considerable income differences are the main drawbacks of the piece rate and the proneness to increase the labour costs is the essential fault of the time rate mentioned in the discussion. One possible solution for these problems is an efficiency bonus (prevents the labour costs from increasing and decreases the income differences) combined with a bonus for age (guarantees high incomes for aged wage earners), a maximum efficiency standard (prevents health hazards), and a group incentive (prevents conflicts).
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In this study the area, 8 diameters, and 16 radii were measured of 174 discs representing aspen logs in a mill. The average difference between the largest and smallest diameter was 18 mm, or 7% of the longest diameter. The difference between the largest and smallest radius was 29 mm, or 22% of the longest radius. The diameter was on the average 2.4 mm longer than the two corresponding radii.
The exact area of each disc was measured using a planimeter. In comparison, the area based on the circle formula the diameter being the arithmetic mean of largest and smallest diameters overestimated the area by 1.7%. The results also indicated that the use of random direction in the measurement of diameter overestimated the cross-sectional area on the average by 1.8%.
The study is continuation of the earlier study where the bibliography is presented. As far as the results are comparable, they support each other.
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The aim of the study was to determine which characteristics of tree stands could be used in urban noise control and to develop guidelines for practical urban forestry. The attenuation of artificially produced noise was measured in various types of stands. The effect of tree stands on noise attenuation has been analysed using a model based on the physics of sound propagation.
The results show that the excess noise attenuation caused by trees can be in good situations 60% measured in energy units, compared with the attenuation caused by geometric spreading. This is 5–8 dB. The total amount of needles, leaves and branches of a stand proved to be the most important factors in noise attenuation. However, the density and height of a stand had rather high value in predicting the behaviour of noise in tree stands. Based on multiple regression between noise attenuation and tree species composition, density and height of a stand it was developed the nomograms with which the noise level at a certain point can be predicted when the tree stand characteristics, the distance and the noise level of the noise source are known and on the opposite way.
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In the study the proportion of branch samples of various diameter were studied. The branches were taken from small trees to be harvested by total tree chipping method. The material consisted of 1,056 branch samples of birch (Betula verrucosa, now B. pendula Roth, and Betula pubescens Erhr.), Norway spruce (Picea abies (L.) H. Karst.) and Scots pine (Pinus sylvestris L.) at intervals of 20 cm along each branch.
With exception of the basic density of bark, there was a relation between all the other properties which were studied and the diameter. Even when the effect of diameter was eliminated, in many cases the effect of the distance of the samples from the stem became apparent.
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The paper describes a method for the measurement of basic density of total tree chips. In the method the chips are placed in a container, which is immersed in a cylinder full of water, and the container is weighted at two levels. In the upper part of the cylinder the pressure against the air bubbles is smaller than in the lower level. In this method, the effect of air bubbles in the result can be eliminated. Besides this, due to homogenization of the material to be measured only small number of samples are needed for the estimation of the average basic density.
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The paper deals with variation in the nitrogen, phosphorus, potassium, calcium and magnesium content of vegetation and soil of young Scots pine (Pinus sylvestris L.) stand of Vaccinium site type situated in Central Finland. The material consists of sequential samples representing soil, ground vegetation and trees taken during summer 1974.
The amount of soluble nutrients in the humus layer decreased in June when maximum growth of trees and dwarf shrubs occurred. The nutrient content of this layer subsequently began to increase towards the end of the growing period.
The variation in the nutrient content of the bottom and ground layers followed a similar pattern. Nitrogen content increases at the beginning of the summer. After this phase it started to decrease and reached its lowest values by the end of growing period. Phosphorus and potassium content increased throughout the growing period.
The nutrient content of the needles and wood were positively correlated with tree height and negatively with the age of material. The highest values for the nutrient content were for new cells.
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The purpose of this study was to gain an insight into research problems and themes in multiple use of forests from a practical viewpoint. An inquiry concerning multiple use problems was sent to 597 organizations whose work related to multiple use of forests. Replies yielded 1,857 suggested research themes which were divided between different uses of forests. About half of the suggestions concerned the relations between timber production and the other uses of forests. The many propositions are due to the fact that timber production in its intensity has strong influence on the other uses of forests. The results of the study have been used in the planning of research in the multiple use of forests.
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This paper analyses the nutrient loses caused by whole-tree harvesting on the basis of the literature data. It has been considered that traditional stemwood harvesting does not lead to impoverishment of the soil because the nutrient content of the wood is quite low. The nutrient loss occurring in connection with heavy thinnings and whole-tree harvesting has been considered so great that it has to be compensated by fertilizer application. In comparison with harvesting unbarked stem timber, whole-tree harvesting has been found to increase the nutrient loss at the stage of final cutting as follows: N2 to 4 times, P 2 to 5 times, K 1.5 to 3.5 times and Ca 1.5 to 2.5 times. Depending on the conditions prevailing on the site, any one of these nutrients may be the limiting factor for tree growth during the next tree generation
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In the article some aspects concerning the measurement of environmental factors are discussed. Special attention is given to the following questions: The correct way of determining the active surface in a forest ecosystem, the time factor in measurement processes, and the mutual correlative relationships between the environmental factors. Analysis of the data is also taken into consideration.
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The article is a summary of a long-term research programme which has been prepared at the Finnish Forest Research Institute. The objective of the programme was to define and subdivide the field of multiple use research to be done at the institute, and so improve both the research planning and the coordination of the work in this field between the different research departments.
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The aim of the paper was to study the amount and distribution of rainfall in a virgin Norway spruce (Picea abies (L.) H. Karst.) stand. Special attention has been paid to the dependence of throughfall on the characteristics of the precipitation falling on an open area and the stand.
The throughfall was 62% of the precipitation in the open. The best independent variable as regards the throughfall was the amount of precipitation falling in the open. The heaviness of precipitation in the open gave no meaningful correlation. Horizontal layout of the stand was found to have some effect on the throughfall. The throughfall was also influenced by the tree species composition of the stand. Only 52% of the total variance of the amount of water caught by the rain gauges could be predicted with the characteristics of the precipitation in the open and the stand.
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The activation of CO2 exchange was monitored in two Scots pine (Pinus sylvestris L.) seedlings transferred from the field to the laboratory in December. Gas exchange was monitored by an URAS I infrared gas analyser in a so-called open IRGA-system with trap type chambers. Transpiration was also measured at the same time by weighing the potted seedlings twice a day. The measuring period lasted eleven days. During the period, the level of both transpiration and net photosynthesis increased about ten times. Furthermore, it was found that the level of photosynthesis at high temperatures was relatively lower at the beginning than at the end of the measuring period.
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This paper examines the changes in forest ownership and the farm properties for sale from a business economic standpoint. The changes in forest ownership are examined on the basis of statistics and literature. The empirical data both for farms for sale and farms sold are based on the purchases made by the National Board of Forestry in 1972.
There are a number of ownership groups actively buying and selling forest land, thus giving alternatives for ownership changes. The National Board of Forestry has been active in the market since 1960. For instance, in 1972 it purchased 60% of the forest estates it was offered. Of the forest area put up for sale, 75% originated from private individuals, and 20% from inheritance sales.
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In this study the width and height of 1,588 uniseriate and 454 fusiform rays were measured from tangential sections of four Scots pine (Pinus sylvestris L.) trunks. The samples represented various height levels and distances from the pith. The average width of the uniseriate rays was 19.7 μm and that of the fusiform rays, 51.9 μm. The average height of the uniseriate rays was 215.7 μm and that of the fusiform rays 406.2 μm. Due to this difference in height, it may be possible to develop an automatic system for distinguishing between uniseriate end fusiform rays on the basis of their height.
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Light intensity inside the canopy varies considerably both in space and time. A new apparatus was developed which is disturbed as little as possible by the above-mentioned variation. The construction is based on the linear relationships between light intensity (measured using silicon diodes) and photosynthesis. This procedure permits linear operations (summing and integration) to be carried out on the output of the diodes without any loss of accuracy. There are five diodes in each assimilation chamber. A model, in which the independent variables include ligth, measured with the present equipment, and temperature, fits the photosynthetic rates well even inside the canopy.
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The paper deals mainly with the effects of jolting of forest tractors and processors on the health and working capacity of the driver. The literature surveyed presents especially the following points of interest: Jolting of the machine may hamper the focusing of the eyes and mastery of the controls. Long-term exposure to jolting may result in reduced sympathetic nervous activity at rest, and may impair an already existing back problem. Workers exposed to vibration, get more frequently gastric changes and changes in reproductive functions than usual. Jolting, as also the other negative physical factors of working environment, must be minimized as early as possible during the design of the machines.
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This paper includes the answer of professor Pentti Hakkila for professor Mikko Kantola who in this issue of Silva Fennica gives some critical points on professor Hakkila’s earlier article (Silva Fennica vol. 9, no. 4 in 1975) on the status and future prospects of forest work science in the Finnish Forest Research Institute. He emphasises that the worry about the forest work reseach presented in his earlier article was not directed towards the research work but towards the financing of forest work science in Finland.
This article is a comment on a previous article in Silva Fennica (vol. 9, no.4) published in 1975, written by professor Pentti Hakkila, titled ‘The status and future prospects of forest work science at the Finnish Forest Research Institute’. It aims at giving some further aspects on the choice of research fields and subjects, and the concepts of result, opinion and research work.
The Finnish Society of Forest Science arranged on 15 January 1976 a research seminar concentrating on forest research policy under a theme of goal orientation and forest sciences. About 70 interested persons participated the day-long seminar. This paper includes the speeches and their summaries, and couple of examples of the results of the workshops.
The area of Koilliskaira, situated in the eastern part of Finnish Lapland, is a popular venue for hikers. The present work examines the change of vegetation around 35 refuge huts in the area. The indigenous vegetation was found to conform to the various heath forest types common to forests in Lapland and continental subalpine mountain birch forest types, principally dry or fairly dry heath forest.
According to the study, the change in vegetation showed a clear positive correlation with the number of summer visitors. The dwarf shrubs and lichens were the most susceptible to trampling, and the grasses the least so. Both resilient and susceptible species were to be found among the mosses. The incoming hemerophilous flora was seen to consist principally of species known to accompany Lappish settlement in the area, and only occasional cases of alien species were noted.
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In this article, information about tree growth which was familiar to the learned men in the old days is presented. The time when different tree species start growing, the different growth rate of various tree species, the age of trees, their resistance to injury etc. are discussed.
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The study was carried out in order to find out the changes taking place in germination of seeds in certain tree species as a function of gamma irradiation, the height growth of the seedlings produced and the types of phenotypic mutants possibly found in the generation that had received radiation. The tree species studied were Pinus sylvestris L., Picea abies (L.) H. Karst., Betula verrucosa (Betula pendula Roth), B. Pubescens Ehrh., Alnus glutinosa (L.) Gaertn. and Alnus incana (L.) Moench.
Soaked seeds that had received a rather small dose of radiation germinated usually better than storage-dry seeds, B. pubescens being an exception. The damages observed in germination, height growth and the relative number of mutants were greater the higher the irradiation doses. The LD50 dose (germination, 28 days) was as follows in the case of the different tree species (storage dry/soaked): P. Sylvestris 1,500-2,000/2500-3,000, P. abies 1,000-1,500/4,000-4,500, B. pendula 9,500-10,000/7,000-7,500, B. pubescens >10,000/7,500-8,000 and A. Glutinosa 10,000/8,500-9,000 rad. Mass production of different mutants of deciduous trees for ornamental purposes, for example, appears to be easy using gamma-irradiation. On the other hand, the possibility of increasing tree growth remains open for further study.
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The main forest research institutes in USSR as well as schools for higher education in forestry are presented in this article, on the basis of observations made during study tours and the relevant literature. Research in forest genetics, tree physiology and related fields i stressed. The State Forestry Committee leads the regional units of forestry administration and also governs a number of research institutes. Among these, the All-Union Forest Research Institute near Moscow has a central position. Regional institutes as well as those specializing in a particular field within forest research may belong to this category, too. Basic research, on the other hand, is conducted under the auspices of the Academy of Sciences, the Academy of Agricultural Sciences or academies of sciences of the Soviet republics. This type of institute also includes those devoted purely to forestry. Forest education at the university level takes place in schools usually called institutes of forest technology.
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