Current issue: 53(2)

Under compilation: 53(3)

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

Articles containing the keyword 'metsäojitus'.

Category: Article

article id 7117, category Article
Leo Heikurainen. (1961). Metsäojituksen vaikutuksesta puuston kasvuun ja poistumaan hakkuusuunnitteiden laskemista varten. Acta Forestalia Fennica vol. 71 no. 8 article id 7117. https://doi.org/10.14214/aff.7117
English title: The influence of forest drainage on growth and removal in Finland. For estimations of allowable cut.

The Finnish forest industry is undergoing a vast expansion, which has raised questions of forest balance. This paper studies the possibilities to increase the amount available timber by means of forest drainage. About third of the Finnish land area is peatlands. The calculations of the investigation are based on Forestry Board districts. Based on earlier studies, there is estimated to be 3,042,000 ha of true drainable swamps, 973,000 ha of poor swamps, 1,381,000 ha of uplands in need of drainage, and 1,205,000 ha of drained peatlands. Therefore, the area of drainable and drained lands totals 6,6 million ha, and requirement of forest drainage 5,4 million ha. The drainage hardly reaches this extent, however. It can be assumed that part of the poor swamps is uneconomical to drain. In addition, a half of the paludified forest land will probably not be drained. Thus, it can be estimated that the area to be drained in the future is about 5 million ha. It seems possible that this area could be drained within about 50 years with the present draining capacity.

Draining of all objects of forests would increase the annual increment of our forests, in time, by about 10.5 million m3. This would signify an increase of 23% compared to the present growth of the forests. The increase in the growth consists mainly of softwood: 16% is birch, and the remaining 84% almost equally of Scots pine and Norway spruce. The increase of growth is relatively slow. Depending on the rate of the drainage program, the mean increase of growth will be reached in about 25–35 years. The increase in removal indicated by the increase in the mean increment will be reached in only 50–60 years.

The PDF includes a summary in English.

  • Heikurainen, ORCID ID:E-mail:
article id 7468, category Article
Leo Heikurainen. (1957). Metsäojien syvyyden ja pintaleveyden muuttuminen sekä ojien kunnon säilyminen. Acta Forestalia Fennica vol. 65 no. 5 article id 7468. https://doi.org/10.14214/aff.7468
English title: Changes in depth and top width of forest ditches and the maintaining of their repair.

The article deals with forest ditches dug by manual labour in drained peatlands in Central and Southern Finland, ranging in age from 16 to 25 years. The ditches have been allowed to develop in a natural state. A total 1,160 of randomly selected sample plots were studied.

The results show that the originally dug ditch depth has not been the decisive factor from the viewpoint of maintaining the ditch repair. Ditches dug in thick peat layer have maintained their repair better than those dug in thin peat layer. Apparently, the influencing factor is the type of soil, to a certain extent parallel to the thickness of peat layer. In ditches dug mainly in mineral soil, the type of soil has essentially contributed to maintaining the ditch repair. Ditches in coarse-grained soils maintained a better repair than those in fine-grained soils. Also, the steeper the gradient of the ditch the better the ditch repair has been maintained. There was no relationship between the thickness of peat and the filling up of ditch bottom, because of the influence of mineral soil. Filling up of a ditch seems to be mainly due to the sinking of peat. The filling up of ditch bottom was more pronounced in clay-silt soil than in other soil types. The filling up of ditch bottom by varying gradient is due to the fact that with a small gradient the speed of water is so slow as to permit the soil particles to sink to the bottom. Another factor affecting filling up of the ditches is wetness of the peatland. Deepening of ditches happens mainly through erosion, if the gradient is large enough. The study suggests that a 50-m spacing with about 60-cm ditchc depth would be most profitable.

The PDF includes a summary in English.

  • Heikurainen, ORCID ID:E-mail:
article id 7308, category Article
U. Metsänheimo. (1934). Havaintoja metsäojituksen kivitöistä. Acta Forestalia Fennica vol. 40 no. 31 article id 7308. https://doi.org/10.14214/aff.7308
English title: Observations on the removal of stones in drain digging of peatlands.

Stones can be removed in drain digging of peatlands by using explosives or hoisting devices. The report is based on observations, and time and motion studies on drainage sites in the state forests in Northern Finland in 1931‒1933. Dynamite has been previously the most common explosive used in drainage sites. The new explosives containing potassium chloride proved to be cheaper, and safer to handle and transport than dynamite. According to the time and motion studies, the use of hoisting devices to lift stones that are removable, was significantly cheaper than explosives.

The PDF includes a summary in English.

  • Metsänheimo, ORCID ID:E-mail:
article id 7096, category Article
P. Kokkonen. (1923). Tutkimuksia viemärien kuntoon vaikuttavista seikoista. Acta Forestalia Fennica vol. 27 no. 3 article id 7096. https://doi.org/10.14214/aff.7096
English title: Studies on the factors affecting the condition of forest drainage system.
Original keywords: ojitus; metsäojitus; oja; ojaverkosto; suo

Approximately 320,000 hectares of peatlands and paludified lands had been drained for agriculture and forestry purposes in Finland by 1920. The ditch network was not optimal in the early drained areas, and the condition of the ditches declined over time. In this study, the condition of drainage system, and the natural processes that affect them, was inspected in 18 drained peatlands.

Several processes can reduce of the size of the ditches. The process of crumbling of soil in the sides of the diches can last up to three years after the draining. Erosion of the main drains, caused by water flow can, however, continue longer. The ditches also sink when the peat dries. Soil frost can affect the ditches, but as the vegetation grows its effect gradually decreases. The vegetation that grows in the ditches may finally block the ditch completely.

The PDF includes a summary in English.

  • Kokkonen, ORCID ID:E-mail:
article id 5426, category Article
Juhani Päivänen. (1990). Pohjoisen havumetsävyöhykkeen suot ja niiden metsätaloudellinen hyväksikäyttö. Silva Fennica vol. 24 no. 2 article id 5426. https://doi.org/10.14214/sf.a15580
English title: Peatlands of the boreal zone and their utilization in forestry.

The paper is a review on utilization of peatlands in forestry in the countries of boreal zone: Finland, Norway, Sweden, Canada, the United States and the Soviet Union. First, the concept of peatlands, the types of peatlands throughout the zone are defined, and the use of natural peatlands is described. Finally, the drainage of peatlands for forestry purposes in the countries is reviewed. According to the statistics, a total of 13 million ha of peatlands have been drained in Fennoscandia and the Soviet Union.

  • Päivänen, ORCID ID:E-mail:
article id 5077, category Article
Eero Paavilainen, Kustaa Seppälä. (1980). Toimenpiteet vanhoilla ojitusalueilla. Suomalais-neuvosliittolaisen symposion esitelmät. Silva Fennica vol. 14 no. 2 article id 5077. https://doi.org/10.14214/sf.a15018
English title: Management of old forest drainage areas – papers presented in Finnish-Soviet symposium.

The forestry working group of the committee for scientific and technical cooperation between Finland and the Soviet Union initiated cooperation work between the two countries in the field of forestry almost ten years ago. The Finnish organizations the Department of Peatland Forestry, the Finnish Forestry Research Institute, and the Institute of Peatland Forestry of the University of Helsinki participated in the activity. From the Soviet Union the participants have been the Ministry of Forestry, the Russian Federation of USSR, and the Forestry Research Institutes of Leningrad and Estonia.

This paper includes the papers presented in the joint symposium arranged at the Forest Field Station of University of Helsinki on 17.9.1979. The 9 Russian lectures and the 8 Finnish ones, are presented either in their entirety or slightly condensed variably in Finnish, English or Russian. The summary of the seminar is presented in English and in Russian.

  • Paavilainen, ORCID ID:E-mail:
  • Seppälä, ORCID ID:E-mail:
article id 4891, category Article
Leo Heikurainen. (1973). Metsäojitustoiminta ja toimenpideraja. Silva Fennica vol. 7 no. 4 article id 4891. https://doi.org/10.14214/sf.a14729
English title: The profitability limit in forest drainage.

The study describes the relationships between a method developed by the author for the calculation of the profitability of forest drainage and the old biological method. The calculations were based on empirical data, and they aimed at finding out the effect of a variation in the profitability limit in the areas in hectares to be drained, and on the profitability of drainage. The study deals also with the profitability of present-day drainage activities. The results showed that the profitability coefficient (the ratio between the discounted increase in returns and the costs of drainage) averages 3.04 for the whole country. The corresponding value was 5.68 for Southern Finland, 3.19 for Central Finland and 1.67 for Northern Finland.

The PDF includes a summary in English.

  • Heikurainen, ORCID ID:E-mail:
article id 4829, category Article
Juhani Numminen. (1970). Metsäojituksen kannattavuuden alueittainen vaihtelu. Silva Fennica vol. 4 no. 4 article id 4829. https://doi.org/10.14214/sf.a14618
English title: Regional variation of the profitability of forest drainage in Finland.

The study attempts to establish to what extent the present regional allocation of the forest improvement subsidies equalize the profitability of forest drainage in Finland. The benefit/cost ratio has been used to describe the regional variation of the profitability

The study revealed that the forest improvement subsidies granted in 1968, even the highest possible subsidies, did not equalize the profitability of forest drainage. According to the results, the northern regions are at a disadvantage compared to the southern parts of the country. To fully equalize the profitability of forest drainage the average subsidies granted in 1968 should have been raised in the second financing zone from 22 to 32%, in the third zone from 32 to 60%, and in the fourth, northernmost zone from 43 to 86%. The study also suggests that the boundary lines of the financing zones should run, at least in Central and Northern Finland, from southeast to northwest instead from east to west, as it is now.

The PDF includes a summary in English.

  • Numminen, ORCID ID:E-mail:
article id 4716, category Article
Leo Heikurainen, Matti Keltikangas, Kustaa Seppälä. (1963). Kustannusten jakaminen yhteisissä metsäojitushankkeissa. Silva Fennica no. 115 article id 4716. https://doi.org/10.14214/sf.a14274
English title: Allocation of costs in joint forest drainage undertakings.

One forest drainage undertaking in Finland often consists of woodlots belonging to several owners, and over hundred owners may be involved. In the present paper a method for allocation the costs to different owners in a joint drainage undertaking is worked out. The problem has been emphasised by the new Waterways Law, which enables also such drainage projects to be undertaken to which some of the land owners oppose. In those cased the costs must be allocated according to the benefit driven by each owner from the project.

The method attempts to assess the benefits to be driven from the forest drainage, those costs of the drainage that are joint and thus subjected to allocation, and what is the area affected by drainage as used as a basis for cost allocation.

The joined costs are apportioned in the following manner. The area of peatland adjusted to differences in the benefit obtained by drainage is ascertained by the land holder by multiplying the index number by the corresponding areas. In the case of cultivated agricultural land, also an index showing the need for drainage is used in computing the adjusted area. Each topographic unit in the map is provided with a notation of its apportionment area. Joined costs are allocated to different land owners in relation to their adjusted land areas.

The PDF includes a summary in English.

  • Heikurainen, ORCID ID:E-mail:
  • Keltikangas, ORCID ID:E-mail:
  • Seppälä, ORCID ID:E-mail:
article id 4643, category Article
Paavo Yli-Vakkuri. (1954). Aikatutkimuksia metsäojitusten kivitöistä. Silva Fennica no. 84 article id 4643. https://doi.org/10.14214/sf.a9105
English title: Time studies on stone work done in forest drainage.

When ditches are dug in forest drainage, smaller stones are removed by hand, but the larger ones require the use of explosives or stone lifting machinery. Use of explosives have been a more common method for the larger stones. Due to development of detonation methods, it has also been used for smaller stones than earlier.

The investigation was a time study comparing five different stone lifting machines. Time needed for different stages of the work was measured. The stages lasted approximately as long for all of the machines. However, the effectivity of the machines could not be determined, because the stones removed were not similar enough. Stone lifting machine Pekka appeared slightly more effective than the other four machines. It was also easy to assemble, disassemble and move.

The article includes a summary in German.

  • Yli-Vakkuri, ORCID ID:E-mail:
article id 4635, category Article
Paavo B. Mansner. (1953). Suometsien hoito. Silva Fennica no. 80 article id 4635. https://doi.org/10.14214/sf.a14051
English title: Forest management of peatland forests.

Silva Fennica Issue 80 includes presentations held in 1952 in the 7th professional development courses, arranged for foresters working in the Forest Service. The presentations focus on practical issues in forest management and administration, especially in regional level. The education was arranged by Forest Service.

This presentation describes the factors that limit growth of trees in peatlands, and principles of draining of peatlands.

  • Mansner, ORCID ID:E-mail:
article id 4622, category Article
O. O. Tirkkonen. (1952). Suomen metsäojitus 1900-luvun alkupuoliskolla. Silva Fennica no. 72 article id 4622. https://doi.org/10.14214/sf.a9094
English title: Peatland drainage in Finland in the first half of 20h century.

According to the second National Forest Survey, peatlands covered before the World War II 11,156,000 hectares, 32% of the land area of Finland. The early drainage of peatlands in 1700th century had aimed at preventing frost and increasing area of agricultural land. The experiences proved that drainage of wet forests was lucrative also in the point of view of forestry. The drainage of state-owned forest lands was promoted by the Crown Forest Committee in its report in 1900. The systematic drainage work in state lands begun in 1909. In the end of 1920s 500-700 km of ditches was dug annually.

The drainage of private lands begun after 1928, when forestry promotion work in private forests begun. By the end of 1950, 4,815 forest drainage projects had been approved by the Forest Service in the private lands. In addition, 286,000 ha of peatlands was drained on work organized by the central forest associations in 1930-1950, and 239,272 ha by timber companies in 1902-1950. The drained area totalled 755,892 ha. The area of drainable and drained peatland was estimated to be 4.4 million ha.

The article includes an abstract in English.

  • Tirkkonen, ORCID ID:E-mail:
article id 4607, category Article
U. Metsänheimo. (1951). Metsäojitustoiminnasta Perä-Pohjolan valtionmetsissä. Silva Fennica no. 69 article id 4607. https://doi.org/10.14214/sf.a14003
English title: Forest drainage in state forests in Northern Finland.

Silva Fennica Issue 69 includes presentations held in 1948-1950 in the fourth professional development courses, arranged for foresters working in the Forest Service. The presentations focus on practical issues in forest management and administration, especially in regional level. The education was arranged by Forest Service.

This presentation describes the history and present stage of forest drainage in Northern Finland. The first peatlands were drained in the area in 1909. About 6% of the 600,000 hectares of peatlands suitable for drainage was drained at the time in Perä-Pohjola. The areas to be drained are characteristically very large.

  • Metsänheimo, ORCID ID:E-mail:
article id 4517, category Article
U. Metsänheimo. (1937). Metsäojituksen vaikutuksesta vesitalouteen. Silva Fennica no. 42 article id 4517. https://doi.org/10.14214/sf.a14095
English title: Effects of forest draining on water management.

Silva Fennica issue 42 includes presentations held in professional development courses, arranged for foresters working in public administration in 1936. The presentations focus on practical issues in forest management and administration, especially in regional level. The education was arranged by Forest Service

This presentation describes the effects of draining of peatlands on water management in the peatland and the surrounding area.

  • Metsänheimo, ORCID ID:E-mail:
article id 4491, category Article
A. J. Cautón. (1937). Kuivaustöitten suorittamisesta metsänkasvattamista varten. Silva Fennica no. 39 article id 4491. https://doi.org/10.14214/sf.a13901
English title: Practices of forest drainage work.

Silva Fennica Issue 39 includes presentations held in professional development courses in 1935 that were arranged for foresters working in public administration. The presentations focus on practical issues in forest management and administration, especially in regional level.

This presentation gives guidelines for draining of peatlands.

  • Cautón, ORCID ID:E-mail:
article id 4482, category Article
O. J. Lukkala. (1937). Soiden ojituskelpoisuudesta. Silva Fennica no. 39 article id 4482. https://doi.org/10.14214/sf.a13892
English title: Peatlands’ suitability to draining.

Silva Fennica Issue 39 includes presentations held in professional development courses in 1935 that were arranged for foresters working in public administration. The presentations focus on practical issues in forest management and administration, especially in regional level. The education was arranged by Forest Service.

This presentation describes different kinds of peatlands and their suitability to draining and forestry.

  • Lukkala, ORCID ID:E-mail:

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