Silva Fennica vol. 27 no. 3 | 1993
Category : Article
The paper discusses the principles of forest management in the state forests of Finland, and the contradictions in choosing between the different land uses. These principles of the forest management are sustainable use of natural resources, economic and effective management, and taking in account nature conservation, protection of environment, recreation services and employment issues in all activities of the Forest Service. Even regional policy affects the management planning in the state forests.
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Kotimäki,
E-mail:
tk@mm.unknown
Forests have been economically important for Finnish private forest owners at all times, but the use of forests has changed markedly since 1920s, when forests were mainly used for collecting household timber, and the cuttings were often exploitative because of the farmer’s need for money. The present situation is totally different. Need for household timber is marginally small, and private forestry produces mainly timber for sale. The sales of timber have increased, but due to better forest management the growing stock in the private forests has increased. The article discusses how the changes in values of forest owners has and will affect the stage of private forestry.
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Järveläinen,
E-mail:
vj@mm.unknown
The paper discusses how the general trend towards increasing growth and productivity in the European societies is expressed also in forestry. It is reflected, for instance, in the increasing production and productivity of forest industries. Technological progress and call for economic growth require great flexibility from all resources. These pressures for effectiveness and production also concern Finnish forestry and forest management. Industrialization, urbanization and development of forestry have increased the pressure to use forests in recreation, preserving human environment and nature conservation in addition to production of timber. Through the development the definition of sustainability has become wider.
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Vehkamäki,
E-mail:
sv@mm.unknown
The paper deals with the application of forest dynamics. Reference is made to two studies, which have been carried out at a national level. The simulations of forest decline as well as the production of exceedingly thick timber of spruce and fir provide various examples of the major problems of forest simulation and of some possible solutions. It is pointed out that the statistical analysis of empirical data is most important for modelling and it might bring about even more valuable results than the ultimate simulation itself.
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Sekot,
E-mail:
ws@mm.unknown
There is some evidence to support the hypothesis that crown form of Scots pine (Pinus sylvestris L.) can be inherited either mono- or polygenically. In Finland, a narrow, horizontal whorl-layer structure is striking in about one half of the offspring of a genotype E 1101, ”Kanerva pine”. The offspring are characterized by a narrow crown, short and thin branches at an angle of 90° to the stem, minimal tapering and by numerous long, lateral shoots, long needles and the common occurrence of three-needled fascicles among the dwarf shoots. These features are connected to a high growth rate, a high harvest index and to tortuosity of the stem. It is suggested that this complex of characters is determined by a single dominant gene.
In this study, several offspring of the E 1101 were classified into three form types in seven sets of progeny test data, including progenies of various ages having E 1101 as either maternal or paternal parent as well as open pollinated progenies of second-generation offspring. A segregation close to 1:1 was found both in the first and in the second-generation progenies when wilds and intermediates were combined and compared with Kanervas. The result indicates that the three types of Kanerva form can be due to a single dominant allele (K). Kanervas are heterozygous (Kk) for the allele and wilds are recessive homozygotes (kk) resulting 1:1 segregation in their progenies. However, there were also remarkable deviations from the expected distribution. The differences as well as the inheritance pattern are discussed.
The PDF includes an abstract in Finnish.
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Pöykkö,
E-mail:
tp@mm.unknown
- Velling, E-mail: pv@mm.unknown
Coniferous and non-coniferous fine root and rhizome production was measured after one growing season using the ingrowth bag method in Scots pine (Pinus sylvestris L.) stands differing in ages from 7 to 105 years in Southern Finland. Total fine-root production decreased from the 7-year to 20-year-old stands, and then increased slightly in the 85- to 105-year-old stands. Most of the total fine-root biomass in the youngest age groups came from non-conifer species, whereas most of the total fine-root biomass in the three older age groups came from conifer species. The maximum coniferous fine-root production was found to occur at crown closure in the 11- to 13-year-old stands. Rhizome production was the lowest and highest in the 20- and 85- to 105-year-old stands, respectively. The increase in rhizome production in the 85- to 105-year-old stands was associated with an abundant understory cover of Vaccinium myrtillus and V. vitis-idaea and an increase in light penetration. The ingrowth bag method was found to be useful in assessing the relative fine-root production among species-group and successional stages of Scots pine stands.
The PDF includes an abstract in Finnish.
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Messier,
E-mail:
cm@mm.unknown
- Puttonen, E-mail: pp@mm.unknown
Yield of Cupressus lusitanica Mill. was modelled by predicting the diameter distribution of trees at given stand ages. The beta distribution was used as a theoretical distribution. The models used for the calculation of diameter distribution were based on 66 temporal sample plots with varying age, site and stand density. The growing sites of Cupressus lusitanica were divided into four classes on the basis of age and dominant height. Using the stand models developed in the study, the yield and profitability of different thinning schedules was evaluated by a simulation technique. In the simulated treatment regimes, the mean annual increment varied from 6.6 m3/ha in the poorest site class to 16.6 m3/ha in the best class with rotation lengths ranging from 25 years (best sites) to 34 years (poorest sites). With typical planting densities (1,600 trees/ha), thinnings increase the total harvest by a few percentage points and improved the profitability of plantation forestry.
The PDF includes an abstract in Finnish.
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Pohjonen,
E-mail:
vp@mm.unknown
- Pukkala, E-mail: tp@mm.unknown
Mixed linear models were constructed to describe the height development of Norway spruce (Picea abies (L.) H. Karst.) and Scots pine (Pinus sylvestris L.) advance growth after release cutting. The models related density of the overstory, time elapsed since release cutting and tree size with annual height increment. Parameters of preliminary models were estimated from a limited data set to judge the feasibility of the approach for further studies.
The PDF includes an abstract in Finnish.
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Koistinen,
E-mail:
ek@mm.unknown
- Valkonen, E-mail: sv@mm.unknown