Browsing by Subject "puun laatu"

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  • Tolvanen-Sikanen, Tiina; Sikanen, Lauri; Harstela, Pertti (The Finnish Society of Forest Science and The Finnish Forest Research Institute, 1995)
    The first aim of this study was to develop a simulation model describing the flow of different timber qualities to different firms. The second aim was to study preliminarily the factors which affect timber distributions. In addition, we tested the hypothesis that in a small sawmill firm the traditional way of organizing timber procurement does not direct effectively good quality logs to the special production. The game theoretic approaching and the principles of Monte-Carlo simulation were applied in developing of the simulation model. The most important factors of the model were tried to find for further studies with sensitive analyses. Empirical validation brought forth promising results in the area of one municipality. The buyer’s awareness of a marked stand, the seller’s willingness to sell a marked stand, the buyer’s ability to pay for wood and the proportion of first quality pine logs in a marked stand affected the distribution of pine logs. The results also supported the hypothesis that the traditional system, in which sawmills or their own forest department procure themselves all timber needed, is not the most effective way to direct enough good quality timber to the special production.
  • Pukkala, Timo; Karsikko, Jari; Kolström, Taneli (Suomen metsätieteellinen seura, 1992)
  • Walldén, Paul (Suomen metsätieteellinen seura, 1933)
  • Vuoristo, Ilmari (Suomen metsätieteellinen seura, 1937)
  • Persson, Anders (The Finnish Society of Forest Science and The Finnish Forest Research Institute, 1994)
    Independent of genotype, increased spacing results in increased branch diameter of Scots pine (Pinus sylvestris L.), but on different levels for different genotypes. Frequency of defects like spike knots and crooked stems are under stronger genetic than silvicultural control. Simultaneous improvement of rate of growth and timber properties is feasible. Deteriorating of both factors can happen rapidly at a negative selection. This needs consideration when selecting seed trees for natural regeneration. A defect like stem cracking of Norway spruce (Picea abies (L.) Karst.) only manifests itself under drought stress when certain genetic and environmental prerequisites are present, like high fertility and wide spacing. This emphasize the fact that new silvicultural methods may reveal genetic weaknesses.
  • Lappi-Seppälä, M. (Suomen metsätieteellinen seura, 1937)
  • Lassila, I. (Suomen metsätieteellinen seura, 1934)
  • Laitakari, Erkki (Suomen metsätieteellinen seura, 1937)
  • Haapanen, Matti; Velling, Pirkko; Annala, Marja-Leena (The Finnish Society of Forest Science and The Finnish Forest Research Institute, 1997)
    Estimates of individual heritability and genetic correlation are presented for a set of 10 growth and quality traits based on data from 16 Scots pine (Pinus sylvestris L.) progeny trials in Finland. Seven of the traits (tree height, stem diameter, crown width, Pilodyn value, branch diameter, branch angle and branch number) were objectively measured, whereas three traits (stem straightness, branching score and overall score) were assessed visually. The genetic correlations were mostly moderate or low, and favorable from the tree breeder’s point of view. All variables related to tree size correlated relatively strongly and positively. Tree height exhibited a more favorable genetic relationship with the crown form traits than diameter, the latter showing positive correlation with branch diameter. Except for the slight negative correlation between branch angle and branch diameter, the branching traits were not notably correlated. The pilodyn value was positively correlated with stem diameter, reflecting negative correlation between diameter growth and wood density. The highest genetic correlations occurred among the two visually evaluated quality scores and branch diameter. All of the heritabilities were less than 0.4. Overall score, Pilodyn, branch angle, branching score and tree height showed the highest heritability.
  • Pöntynen, V. (Suomen metsätieteellinen seura, 1929)
  • Heiskanen, Veijo (Suomen metsätieteellinen seura, 1966)
  • Lassila, I. (Suomen metsätieteellinen seura, 1931)