Articles containing the keyword 'regulation'

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, E-mail: wc@mm.unknown

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, E-mail: rh@mm.unknown
• Hari, E-mail: ph@mm.unknown

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, E-mail: rh@mm.unknown
• Ellefson, E-mail: pe@mm.unknown

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, E-mail: il@mm.unknown
• Hari, E-mail: ph@mm.unknown
• Kellomäki, E-mail: sk@mm.unknown
• Väisänen, E-mail: ev@mm.unknown

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, E-mail: no@mm.unknown

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, E-mail: ek@mm.unknown

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, E-mail: ek@mm.unknown

The EU’s influence on national forest policies is growing, and the implementation of forest-related policies proposed by the Commission will affect the practice of forestry in Europe. For instance, the Nature Restoration Law sets concrete areal goals for restoring forest ecosystems and for conservation, the Deforestation Regulation requires meticulous tracking of wood’s origin, and the renewed Renewable Energy Directive (RED III) sets new criteria to sustainable forest biomass procurement. So far there have been no studies that have looked into the impacts from the economic and operational point of view. In this study, structural systems analysis was first performed to discover the relevant variables (and their functioning) associated with the roundwood harvesting operations and the operating environment. A scenario approach was then applied to capture the potential levels of implementation of the EU’s forest-related policies. Finally, using different scenarios (low-, moderate- and high-impact) and a systems analysis framework, the impact of alternative levels of implementation was quantified in terms of harvesting costs, measured in € m^–3. The results indicate that with the low- and moderate-impact scenarios the harvesting costs would increase by less than 10% from the current levels in three different regions in Finland. Such an increase (less than 10%) could be tolerated over a period of a few years, but a sudden increase is likely to lead to challenges to the running of businesses. With the high-impact scenario the harvesting costs would increase by between 15% and 18%, depending on the region. This magnitude of increase (of approximately a sixth) corresponds to a severe change in the roundwood harvesting operations and operating environment.

• Ahtikoski, Natural Resources Institute Finland (Luke), Tekniikankatu 1, FI-33720 Tampere, Finland https://orcid.org/0000-0003-1658-3813 E-mail: anssi.ahtikoski@luke.fi
• Väätäinen, Natural Resources Institute Finland (Luke), Yliopistonkatu 6, FI-80100 Joensuu, Finland https://orcid.org/0000-0002-6886-0432 E-mail: kari.vaatainen@luke.fi
• Anttila, Natural Resources Institute Finland (Luke), Latokartanonkaari 9, FI-00790 Helsinki, Finland https://orcid.org/0000-0002-6131-392X E-mail: perttu.anttila@luke.fi
• Laitila, Natural Resources Institute Finland (Luke), Yliopistonkatu 6, FI-80100 Joensuu, Finland E-mail: juha.laitila@luke.fi
• Mutanen, Natural Resources Institute Finland (Luke), Yliopistonkatu 6, FI-80100 Joensuu, Finland https://orcid.org/0000-0003-0533-9356 E-mail: antti.mutanen@luke.fi
• Lindblad, Natural Resources Institute Finland (Luke), Yliopistonkatu 6, FI-80100 Joensuu, Finland https://orcid.org/0009-0003-6766-6587 E-mail: jari.lindblad@luke.fi
• Sikanen, Natural Resources Institute Finland (Luke), Yliopistonkatu 6, FI-80100 Joensuu, Finland E-mail: lauri.sikanen@luke.fi
• Routa, Natural Resources Institute Finland (Luke), Yliopistonkatu 6, FI-80100 Joensuu, Finland https://orcid.org/0000-0001-7225-1798 E-mail: johanna.routa@luke.fi

• Kaitera, Finnish Forest Research Institute, Northern Finland Regional Unit, FI-91500 Muhos, Finland E-mail: juha.kaitera@metla.fi
• Nuorteva, Finnish Forest Research Institute, Southern Finland Regional Unit, FI-01301 Vantaa, Finland E-mail: hn@nn.fi

• Mäkinen, Finnish Forest Research Institute, Vantaa Research Centre, P.O. Box 18, FIN-01301 Vantaa E-mail: pekka.makinen@metla.fi

• Linkosalo, University of Helsinki, Department of Forest Ecology, Unioninkatu 40 B, P.O. Box 24, FIN-00014 University of Helsinki, Finland E-mail: tapio.linkosalo@helsinki.fi