Silva Fennica : quarterly issues : 33(3) : sa333225.htm

Anneli Viherä-Aarnio & Pirkko Velling. 1999.

Growth and stem quality of mature birches in a combined species and progeny trial

Silva Fennica 33(3): 225–234

The growth and stem quality of silver birch (Betula pendula), downy birch (B. pubescens) and paper birch (B. papyrifera) were compared in a 32-year-old field trial in southern Finland. The material consisted of different unselected stand origins and progenies of phenotypically selected plus trees of silver and downy birch from southern Finland and differing stand origins of paper birch from the North-West Territories, Canada. Growth, yield and a number of stem quality traits, including taper, sweep, stem defects, heights of different crown limits and length of the veneer timber part of the stem were measured or observed. The native Finnish silver and downy birches were superior to paper birch in terms of both yield and stem quality, silver birch being the best. Progenies of silver birch plus trees were better than the stand origin, indicating that the former are able to reach high quality veneer log size in a shorter time than unselected material. The cultivation of paper birch can not be considered viable in Finland.

Keywords
Betula pendula Roth, Betula pubescens Ehrh., Betula papyrifera Marsh., progeny, growth, stem quality, timber production

Addresses
The Finnish Forest Research Institute, Vantaa Research Centre, P.O. Box 18, FIN-01301 Vantaa, Finland. Fax +358 9 8570 5711, E-mail anneli.vihera-aarnio@metla.fi

Received 21 August 1997 Accepted 1 July 1999
ISSN 0037-5330

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