Curly birch (Betula pendula f. carelica Sok.) is characterized by large variations in stem form and the internal structure of the wood, and is generally divided in to four types on the basis of visible external stem characteristics. First plantation experiments in Finland in the 1920’s in experimental areas of the Finnish Forest Institute, had become ripe for cutting and were felled. The study material of this study consists of one 52-year old and three 42–43 -year old stands of curly birch.
The yield suitable for plywood manufacture from the oldest stand was 34,777 kg/ha and that of curly grained branch wood 39,452 kg/ha. The corresponding figures of the other stands were, on average 24,219 and 57,271 kg/ha. The yield from the stands were sold at the present-day price. The result was economically better than from any other forest tree species grown in Finland. The younger stands were obviously cut too early. It was concluded that the genetic quality of the seedlings used in the plantations in the 1920’s and 1930’s was not very high.
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The aim of this paper was to study the nature of the relative areal differences in the Finnish forests in respect of timber yield, intensity of exploitation and stumpage prices. The yield index is the most inconsistent and the source of the greatest regional differences. The differences arise even in Southern Finland, as the yield in the South-West is only 80 % of that obtained in Eastern Häme. The areal variations in the wastage index are of the order of only 10 % at most, and the stumpage price index is relatively constant, remaining within the 10 % limit, as far north as the southern boundary of the province of Oulu.
Indices for the forest yield and final forest returns suggest that the further one goes in Finland the greater the discrepancy between the two, as a consequence of the increase in stumpage price differences. Thus, whereas the yield per hectare in North-Eastern Finland is about 20 % of that in Eastern Häme, the stumpage price is similarly only just over 50 % of that prevailing in the latter area. This, the resulting returns per hectare are only 10 % of those obtainable in the more southerly area. When the return per hectare for the Forestry Board District of Eastern Häme is represented by the index 100, one then obtains corresponding return indices of 21.0 for the Northern Ostrobothnia and Kainuu area, 13.0 for Lapland and 10.0 for North-Eastern Finland. Thus, it may be said that roughly 10 hectares of forest land in Lapland, 5 in Northern Ostrobothnia or Kainuu, or 2 in Northern Karelia or the coastal area of southern and central Ostrobothnia would be required to produce the same returns as 1 hectare in Eastern Häme. This represents an extremely wide range of variation within the borders of one country.
This work provides a clear and sufficiently accurate impression of the order of magnitude of the areal differences in returns from the Finnish forests, and may thus serve as an adequate basis for the taking of decisions in this field.
The PDF includes a summary in English.