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Silva Fennica 1926-1997
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Acta Forestalia Fennica
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Articles containing the keyword 'regulation'.

Category: Research article

article id 149, category Research article
Juha Kaitera, Heikki Nuorteva. (2010). Effects of Melampyrum extracts on the growth of axenic cultures of Cronartium flaccidum and Peridermium pini. Silva Fennica vol. 44 no. 2 article id 149. https://doi.org/10.14214/sf.149
For 3–6 months, mycelial colonies cultured from 5 isolates of each of two pine stem rusts (Cronartium flaccidum and Peridermium pini) were grown on nutrient-rich agar supplemented with Melampyrum extracts. Non-autoclaved extracts of M. pratense significantly reduced the growth of P. pini. The growth of C. flaccidum isolates was slightly stimulated after the second month of incubation but after that was inhibited during incubation months 4–6. We observed considerable variation in colony growth, a significant component of which was explained by incubation time, isolate, growth medium and their interaction. Rust species (C. flaccidum or P. pini) was not an important factor in growth variation. While sterilized extracts of M. pratense, M. sylvaticum and M. nemorosum did not significantly affect growth, colonies of C. flaccidum were slightly stimulated, whereas colonies of P. pini were slightly inhibited. Generally, isolates of P. pini grew better and showed a slower rate of degeneration than C. flaccidum on all media.
  • Kaitera, Finnish Forest Research Institute, Northern Finland Regional Unit, FI-91500 Muhos, Finland ORCID ID:E-mail: juha.kaitera@metla.fi (email)
  • Nuorteva, Finnish Forest Research Institute, Southern Finland Regional Unit, FI-01301 Vantaa, Finland ORCID ID:E-mail:
article id 589, category Research article
Pekka Mäkinen. (2001). Competitive strategies applied by Finnish timber carriers following deregulation. Silva Fennica vol. 35 no. 3 article id 589. https://doi.org/10.14214/sf.589
The present study examines the success of timber carriers and the factors involved in their success immediately following deregulation. In Finland in 1991 the timber trucking sector was deregulated. Means testing was changed to suitability testing, which meant that the Ministry of Transport and Communications, provincial authorities and the trucking association could no longer regulate the entry of new entrepreneurs to the sector. The present research material contains two successful enterprise groups. In the strategically more successful group, good results were obtained with a moderate labour input by the entrepreneurs. The strategic position of this group was considered to be successful because the operating hours of the trucks were fairly high but the work loads imposed on the entrepreneur remained reasonable. The profitability of these enterprises was so good that it was possible to use hired labour to drive the trucks. The work load of close to half of the unsuccessful entrepreneurs had been large or extremely large. In some cases, the obvious reason for failure was their inadequate transportation rates. Others had seemingly satisfactory haulage rates when compared to the average, but still their enterprises performed poorly. In these cases, the explanation lay in the inefficiency of operations or excessive debts, the latter caused, for example, by earlier operations. The results of this study do not support the view that a lot of hard work generally means success in entrepreneurship. The results support the view that both entrepreneurs’ work and management inputs have a significant impact on the success of the enterprise, and that high tariffs alone are not a guarantee of success.
  • Mäkinen, Finnish Forest Research Institute, Vantaa Research Centre, P.O. Box 18, FIN-01301 Vantaa ORCID ID:E-mail: pekka.makinen@metla.fi (email)
article id 647, category Research article
Tapio Linkosalo. (1999). Regularities and patterns in the spring phenology of some boreal trees. Silva Fennica vol. 33 no. 4 article id 647. https://doi.org/10.14214/sf.647
Phenological time series of flowering and bud burst of Populus tremula (L.) and Betula sp., and the flowering of Pinus sylvestris (L.), Alnus glutinosa (L.) and Alnus incana (L.) were constructed from data collected in Finland during the period 1896–1955. The resulting combined time series were examined with two aims in mind: first, to determine the phenological regularities between different species and, second, to detect patterns of spring advancement over a geographically large area. The results indicate that the geographical pattern of spring advancement is rather uniform from year to year, and between different species. Furthermore, the mechanisms regulating the timing of phenological events in different species seem to function in a similar way, suggesting an unanimous optimal response to climatic conditions.
  • Linkosalo, University of Helsinki, Department of Forest Ecology, Unioninkatu 40 B, P.O. Box 24, FIN-00014 University of Helsinki, Finland ORCID ID:E-mail: tapio.linkosalo@helsinki.fi (email)

Category: Article

article id 7435, category Article
Esko Kangas. (1954). On the possibility of pests being conveyed in export timber : survey of biological requirements. Acta Forestalia Fennica vol. 61 no. 23 article id 7435. https://doi.org/10.14214/aff.7435

Many countries have enacted plant protection laws or statutes that consist timber imported into a country, both raw wood and processed timber. This has caused some inconvenience to the international timber trade. Necessary protection against the spread of pests via export is fully acceptable, but the protection should be based on actual need.
When considering processed or barked raw timber, the problem concerns only species that pass their development in the wood. The four most important biological requirements affecting the risk are 1) the tree species of the importing country and affinity of the pest, 2) climatic conditions of the importing country and the pest’s range and adaptability to the climate, 3) biological factors regulating the population, and 4) suitability of the individual development of the pest for transmission. These risks are discussed in the article.

It is concluded that it is possible largely to eliminate the species that might be conveyed via export timber. It is often possible to decide in advance what danger threatens the importing country from species that might be conveyed via export timber. This would make it possible to adapt plant protection regulations to suit the relation between the exporting and importing countries.

The Acta Forestalia Fennica issue 61 was published in honour of professor Eino Saari’s 60th birthday.

  • Kangas, ORCID ID:E-mail:
article id 5462, category Article
Wladyslaw Chalupka. (1991). Usefulness of hormonal stimulation in the production of genetically improved seeds. Silva Fennica vol. 25 no. 4 article id 5462. https://doi.org/10.14214/sf.a15620

Application of growth regulators, primarily gibberellins, has become an efficient method of flowering regulation in many coniferous forest trees. In this paper some results are discussed with respect to various genetic processes in seed orchards. It is concluded that there are still several unsolved problems in the regulation of flowering in forest seed orchards. These problems are related to different genetic processes occurring in the seed orchards and they should be taken into account in endeavouring to produce genetically improved seeds. 

  • Chalupka, ORCID ID:E-mail:
article id 5462, category Article
Wladyslaw Chalupka. (1991). Usefulness of hormonal stimulation in the production of genetically improved seeds. Silva Fennica vol. 25 no. 4 article id 5462. https://doi.org/10.14214/sf.a15620

Application of growth regulators, primarily gibberellins, has become an efficient method of flowering regulation in many coniferous forest trees. In this paper some results are discussed with respect to various genetic processes in seed orchards. It is concluded that there are still several unsolved problems in the regulation of flowering in forest seed orchards. These problems are related to different genetic processes occurring in the seed orchards and they should be taken into account in endeavouring to produce genetically improved seeds. 

  • Chalupka, ORCID ID:E-mail:
article id 5348, category Article
Risto Häkkinen, Pertti Hari. (1988). The efficiency of time and temperature driven regulation principles in plants at the beginning of the active period. Silva Fennica vol. 22 no. 2 article id 5348. https://doi.org/10.14214/sf.a15505

The distribution of the minimum temperatures after the beginning of the active period (one temperature for each spring) have been calculated for each principle using daily meteorological data collected during the years 1883–1980. The efficiency criterion is the variance of the minimum temperature distributions and the length of the active period. The most efficient regulation principle is found to be based on the temperature sum which includes a feedback component.

The PDF includes a summary in Finnish.

  • Häkkinen, ORCID ID:E-mail:
  • Hari, ORCID ID:E-mail:
article id 5296, category Article
Russell K. Henly, Paus V. Ellefson. (1986). Cost and effectiveness of legal mandates for the practice of forestry on private land. Silva Fennica vol. 20 no. 4 article id 5296. https://doi.org/10.14214/sf.a27752

Comprehensive state laws regulating the practice of forest management on private lands are in effect in seven of the United States. Established to protect a wide range of non-timber forest resources and to ensure reforestation after harvest, these laws may impose significant administrative costs on states and significant compliance costs on landowners and timber operators. Total state administration costs for 1984 are estimated at $10.1 and total private sector compliance costs are estimated at $120.5 million, for a total regulation cost of $130.6 million.

The resource protection effectiveness of state forest practice regulation is difficult to quantify. However, agreement is strong that regulation has led to significant improvements in forest resource conditions and has helped to increase reforestation.

  • Henly, ORCID ID:E-mail:
  • Ellefson, ORCID ID:E-mail:
article id 4959, category Article
Irja Lehtonen, Pertti Hari, Seppo Kellomäki, Eero Väisänen. (1977). On control of daily structural matter production in population of Avenella flexuosa (L.) Parl. Silva Fennica vol. 11 no. 1 article id 4959. https://doi.org/10.14214/sf.a14810

In the boreal zone, the environmental control of growth rate, i.e. the rate of irreversible change in shoot dimensions, is assumed to be dominated by temperature. Promnitz (1975) emphasises that in boreal and temperate zones storage of photosynthetic products is an essential part of the growth process, and thus direct interaction between growth rate and radiation is not evident. The aim of the present study was to investigate the control of daily structural matter production in populations of Avenella flexuosa (L.) Drejer. Special attention was paid to the role of temperature and radiation in addition to the self-regulation of the plants themselves.

Temperature and self-regulation were found to explain over 90% of the daily variation of growth rate. Introduction of radiation into the analysis did not increase the explanatory power of the growth model based on temperature and self-regulation.

The PDF includes a summary in Finnish.

  • Lehtonen, ORCID ID:E-mail:
  • Hari, ORCID ID:E-mail:
  • Kellomäki, ORCID ID:E-mail:
  • Väisänen, ORCID ID:E-mail:
article id 4809, category Article
N. A. Osara. (1969). Polttoaineiden ja puutalouden säännöstely Suomessa toisen maailmansodan aikana ja sen jälkeen. Silva Fennica vol. 3 no. 4 article id 4809. https://doi.org/10.14214/sf.a14597
English title: Government control of fuels and forestry in Finland during World War II.

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.

  • Osara, ORCID ID:E-mail:
article id 7649, category Article
Eeva Korpilahti. (1988). Photosynthetic production of Scots pine in the natural environment. Acta Forestalia Fennica no. 202 article id 7649. https://doi.org/10.14214/aff.7649

The dependence of the rates of photosynthesis and transpiration are studied on the environmental factors and on the control of the plant metabolism with Scots pine (Pinus sylvestris L.) in the natural environment. The importance of the different environmental factors to the photosynthetic production are evaluated. In modelling the dependence of the rates of photosynthesis and transpiration on the environmental factors and on the control processes, a dynamic system analysis approach is applied. Irradiance, temperature and water are explored during the annual cycle. Field measurements of the CO2 exchange and environmental factors over three years are used in the analysis of the rate of the photosynthesis. The effect of different environmental factors on photosynthetic production is evaluated by model estimations using weather data in a 20-year period.

The PDF includes a summary in Finnish.

  • Korpilahti, ORCID ID:E-mail:

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