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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