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Impact factor 1.683
5-year impact factor 1.950
Silva Fennica 1926-1997
1990-1997
1980-1989
1970-1979
1960-1969
Acta Forestalia Fennica
1953-1968
1933-1952
1913-1932

Silva Fennica 1926-1997 no. 93 | 1957

Category: Article

article id 4675, category Article
Gustav Sirén. (1957). Kokemuksia raivaussahan käytöstä metsänhoitotöissä. Silva Fennica no. 93 article id 4675. https://doi.org/10.14214/sf.a9121
English title: Experiences of brush cutters in silviculture.

The aim of the study was to compare the newly introduced brush cutter to ordinary hand tools in clearing of cutting areas and thinning young birch (Betula sp.) and Scots pine (Pinus Sylvestris L.) stands. Working with a prototype of the brush cutter, Brushmaster, reduced the total working time by 15-20% compared to bush knife and axe, in spite of the cutter’s weight. At rainy weather the advantage of Brushmaster dissapeared because of clogging of the cutter’s air filter. The prototype proved to be more effective when clearing a cutting area, and hand tools seemed to be faster if damage to the remaining trees have to be avoided.

In addition, eight either lighter or more effective motor saws or brush cutters were compared mutually, and the effect of motor effect, weight, handiness, arrangement of suspenders and handles is discussed. With these improved types of the cutter it was possible to shorten the total working time in thinning of stands (mostly clearing of young stands) to 30-40% of the total working time compared to hand tools. The most modern saws appeared to be best adapted in clearing cutting areas.

The article includes an abstract in English.

  • Sirén, ORCID ID:E-mail:
article id 4673, category Article
M. T. Rogers. (1957). Vuosilustojen varjostus. Silva Fennica no. 93 article id 4673. https://doi.org/10.14214/sf.a9120
English title: Ring-shadows.

A picture of growth rings of a tree can be obtained on paper by placing it over a disc of a trunk or stump and rubbing it with a pencil. The ‘shadows’, while not yielding the complex data obtainable from the actual wood, do show the proportion of the growth rings composed of spring wood and the denser summer wood. It is possible to collect large amount of data by using an unexperienced staff cheaply and quickly, and the samples may be mailed at little expense. The method may be used to study the previous cuttings of a stand from stumps. The shadowing of tree rings is possible to do even from rather decayed stumps.

The article includes a Finnish abstract.

  • Rogers, ORCID ID:E-mail:
article id 4672, category Article
Leo Heikurainen. (1957). Lettoräme ja sen metsäojituskelpoisuus. Silva Fennica no. 93 article id 4672. https://doi.org/10.14214/sf.a9119
English title: Eutrophic pine bogs and their suitability for draining.

There are about 155,000 ha of fen-like pine swamps (eutrophic pine bogs) in Finland, major part of which are situated in Northern Finland. In the classification system for drainability of peatlands, this type of peatlands had been placed in the first class. The study presents a new evaluation for the peatland type, based on vegetation and tree growth.

According to a previous study, the vegetation of fen-like pine swamps can be characterised by distinctive plant communities that seem to reflect the fertility and high pH of the underlying soil. In this study, the fen-like pine swamps were divided in two subtypes based on the vegetation: proper fen-like pine swamps and fen-like pine swamps with ericaceous shrubs. Both have distinctive vegetation, which is described in the article. The distribution of the subtypes seems to be different: fen-like pine swamps with ericaceous shrubs are more common in eastern parts of Northern Finland. The two subtypes could be divided in different drainability classes according to tree growth, proper fen-like pine swamps belonging to class 1 and fen-like pine swamps with ericaceous shrubs to class 4.

The article includes a summary in English.

  • Heikurainen, ORCID ID:E-mail:
article id 4671, category Article
O. Leskinen, O. Vuorelainen. (1957). Tutkimus keskuslämmityslaitosten eri polttoaineiden taloudellisen käytön alueellisesta jakautumisesta Suomessa. Silva Fennica no. 93 article id 4671. https://doi.org/10.14214/sf.a9118
English title: A study on regional differences in economical use of different fuels in central heating boilers in Finland.

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.

  • Leskinen, ORCID ID:E-mail:
  • Vuorelainen, ORCID ID:E-mail:

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