Yield of Larix sukaczewii Dyl. and larch hybrids in northern Scandinavia

Yield of bulk collected provenances of Larix sukaczewii was compared to first generation Russian larch hybrids and three other tree species native to Scandinavia. The hybrids were full sib families of selected European and Russian larch (L. decidua x L. sukaczewii) or Japanese and Russian larch (L. kaempferii x L. sukaczewii). Two provenances of L. sukaczewii were compared. The results after 50 years show that the provenance from Arkhangelsk produced more volume and had better height growth on five of six sites in northern Sweden compared to a provenance from the central Ural Mountains, Sverdlovsk. The hybrid L. decidua x L. sukaczewii which is present in two of the sites have produced 24-71% more stem volume than the best growing pure Russian larch provenance. The dominant height was between 29 and 30.5 meter at the age 51 in the two best growing hybrids. This is between 5 and 6.5 m taller than the expected dominant height for Norway spruce (Picea abies) grown on farm land at the same age. The volume production could be overestimated due to edge effects but indicate a very high production potential in these hybrids. In a 40 year old species trial in central Sweden yield of L. sukaczewii was compared to four other species (Larix decidua, Pinus sylvestris, Picea abies, and Betula pendula). L. decidua showed best volume production of the compared species. L. sukaczewii was second best with a mean growth that was significantly higher than that of Norway spruce and silver birch. A comparison of the yield of the Raivola larch provenance (L. sukaczewii) growing at two sites, one with a strong maritime influence at Lat. 67 deg 04 min N and the other site located in a local continental climate at Lat. 60 deg 54 min N, reveal a very wide ecological niche in this provenance.