Juvenile growth of provenances and open pollinated families of four Russian larch species (LarixMill.) in Swedish field tests

Four Russian larch species; (Larix sukaczewiiDyl., L. sibiricaLedeb., L. gmeliniiRupr. and L. cajanderiMayr.) were tested in combined provenance-progeny tests on three sites in Sweden. 29 provenances, two seed orchards and four seed stands-material were assessed for juvenile height growth and survival after five growing seasons in the field. Genetic parameters were also determined on the family level. The results show that provenances of L. sukaczewiioriginating from western Russia have the highest survival. Compared to the closely related L. sibirica, L. sukaczewiishow better adaptation, a pattern that has also been observed in Finland and Iceland. Provenances of L. gmeliniifrom the Russian Far East demonstrate best juvenile height growth on all three sites. L. cajanderifrom northern interior Siberia failed on all three sites. Both climatic and geographical variables showed strong correlation with survival and height. At this early evaluation it seems like provenances of L. sukaczewiican be transferred northward with satisfactory survival whereas southern transfer or transfer from strongly continental areas in Russia to the semi maritime climate in Sweden results in poor growth. CVAvalues suggested relatively high genetic variation in height for L. sukaczewiiand L. sibirica. The heritabilities for height growth and survival were at this early evaluation generally low (h2< 0.10) and often non-significant.