Abstract
Genetic resources from two willow species (Salix udensis and S. schwerinii) were collected in Hokkaido, and
their clones were preserved at the Hokkaido Regional Breeding Office, Forest Tree Breeding Center, Forestry and
Forest Products Research Institute. Clonal test sites were established to evaluate clonal characteristics by direct
plantation of stem cuttings to the test sites. A large variation was observed in the dry mass of the clone stems after
three growing seasons. Predicted values of the clonal stem dry mass were calculated via the best linear unbiased
prediction (BLUP) method. There was a 3.89-fold difference among the clones at a site. Here, we report the results
of clonal evaluations of the stem dry mass production and clonal selection based on their evaluations, with the goal
of improving woody biomass production using short rotation forestry for the willow species.
