%0 Research article
%T Seed transfers of silver birch (Betula pendula) from the Baltic to Finland – effect on growth and stem quality
%A Viherä-Aarnio, Anneli
%A Velling, Pirkko
%D 2008
%J Silva Fennica
%V 42
%N 5
%R doi:10.14214/sf.226
%U https://silvafennica.fi/article/226
%X Silver birch (Betula pendula Roth) seed origins from the Baltic  countries, Finland and Russia were compared for survival, growth and  stem quality, and the effect of latitudinal seed transfer distance  examined in two provenance trials. The trials were located on moist  upland forest soils at Tuusula (60°21’N) in southern Finland and at  Viitasaari (63°11’N) in central Finland. The material consisted of 21  stand and single tree origins ranging from latitudes 54° to 63°N.  Survival, height, dbh, relative stem taper, stem volume/ha and the  proportion of trees with a stem defect (vertical branch or forked stem),  were assessed when the trees were 22 years old. Significant differences  were detected among the origins regarding all the measured traits in  both trials. Southern Finnish origins produced the highest volume per  unit area in central Finland, whereas Estonian and north Latvian stand  seed origins, as well as the southern Finnish plus tree origins, were  the most productive ones in southern Finland. The more southern the  origin, the higher was the proportion of trees with a stem defect in  both trials. The latitudinal seed transfer distance had a significant  but relatively small effect on survival, stem volume/ha and proportion  of trees with a stem defect. The proportion of trees with a stem defect  increased linearly in relation to the seed transfer distance from the  south. The relationship of both survival and stem volume/ha to the seed  transfer distance was curvilinear. Volume/ha was increased by  transferring seed from ca. 2 degrees of latitude from the south. A  longer transfer from the south, as well as transfer from the north,  decreased the yield.