Current issue: 58(5)
Silva Fennica vol. 12 no. 1 | 1978
Category : Article
About 100 years old larch (Larix sibirica Lebed. And L. decidua Mill.) trees were felled and the basic density samples taken from the stump level were determined. The number of trees was 21 and number of samples 378. The maximum basic density was reached at the age of 40–60 years, as counted from the pith. The basic density decreased as the width of the growth rings increased or the amount of heartwood decreased. The average basic density of the whole disc was 543 kg/m3 in L. sibirica and 497 kg/m3 in L. decidua. The basic densities of bark were 328 kg/m3 and 286 kg/m3, respectively.
The PDF includes a summary in English.
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Kärkkäinen,
E-mail:
mk@mm.unknown
The distribution of the dry matter and nutrients in Scots pine (Pinus sylvestris L.) tree stock growing on a Vaccinium type site, ground vegetation, and humus were determined in the study. The greatest part of the dry matter in the tree was found in the stemwood. The living branches, roots, bark, needles and dead branches decreasing order of magnitude made up the rest of the biomass. The trees contained over 90%, the field layer vegetation 3% and the bottom layer vegetation 2% of the dry matter in the tree stand. The tree stock contained 86–95% of the total amount nutrients in the stand. The field layer vegetation contained less nutrients than the bottom layer vegetation. Nitrogen, however, was an exception, the amount being approximately the same in both vegetation layers.
The PDF includes a summary in English.
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Lehtonen,
E-mail:
il@mm.unknown
In this study two methods of determining the basic density of total tree chips are compared. The method of Mäkelä (1977) is based on the volumes of Scots pine, Norway spruce, birch, and alder in a logging area, and the age of the trees. In the other method the basic density of total tree chips is measured by the common displacement method. The correlation was 0,730 in the material of 22 logging areas. Besides this it was found that the basic density of chips increases as the size of the chip particles increases with the exception of the smallest particles.
The PDF includes a summary in English.
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Kärkkäinen,
E-mail:
mk@mm.unknown
In this paper the system of collective timber price agreement in Norway is described. The history of »collective behaviour» in the roundwood market can be tracked far back in history, with different degrees of importance, and it has totally dominated the price-formation of roundwood from the 1950’s until the present. In trying to answer the question »What has been the effect of the collective price agreements» a few theoretical market models are used and the empirical data are also employed. Both the theoretical discussion and the empirical data seem to indicate that the forest owners are better off with collective price agreements than with a situation where there are no organized price-negotiations.
The PDF includes a summary in English.
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Høsteland,
E-mail:
jh@mm.unknown
The concepts central to ergonomic research connected with the amount of strain caused by work was studied. A model was made to describe the process of strain. The model includes the following concepts: load or stress, human input, worker, strain, renewal of human resources, output and their hierarchical units. Based on the quality of human input, the forest work was roughly divided into two categories: (1) work demanding primarily muscle activity and (2) neuro-sensory work. In the first group, especially in cutting work, the main part of the human input is intensive consumption of muscle energy. In addition, work load causes accidents, wear of skeletal and muscular systems and processes by noise, vibrations, and climate. Correspondingly, when operating forest machines, the human input is mainly neuro-sensory functions of the central nervous system. Work load causes directly the effects of low frequency vibration and of other work conditions. The model was tested on data from research of forest work.
The PDF includes a summary in English.
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Harstela,
E-mail:
ph@mm.unknown
During the 1970’s an average of 4 million Betula pendula (Roth) seedlings have been planted annually in Finland. The activities connected with the planting of this tree species, the selection of forestation sites, site preparation, planting out the seedlings and follow-up work on the forestation sites are briefly reviewed in the article. The manuscript is based on the studies into the breeding, seedling production and planting techniques of B. pendula started by the Finnish Forest Research Institute already in 1960’s, as well as on practical observations made at the planting sites. A list of some of the Finnish studies concerning B. pendula which have been published in English and studies with a summary in English is included.
The PDF includes a summary in Finnish.
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Raulo,
E-mail:
jr@mm.unknown
The success of certain Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) H. Karst.) provenances from Northern Finland was studied in a tree damage area occasioned by air pollution in the town of Oulu over the period of 1972-76. The pine strains from more northerly and easterly areas and the spruce strains from the immediate vicinity of the site itself were being observed to thrive best. The results point in a similar direction to those of other comparable experiments, except that the mortality rate amongst the saplings was exceptionally high and the proportion of healthy saplings in good condition was found to be unusually low. Structural properties suggestive of resistance to pollution were observable selectively in certain provenances, these including the xeromorphy of needles or thickness of the epidermis. The chief cause of mortality amongst the saplings was found to be the damage inflicted by pollution during the winter, while that arising in the summer months was relatively slight.
The PDF includes a summary in Finnish.
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Huttunen,
E-mail:
sh@mm.unknown
