Birch Plantations Research Articles

Decay and discoloration in a birch (Betula maximowicziana) plantation (I) : A case study of damage at Hitsujigaoka, Sapporo, Northern Japan

Decay and discoloration in a birch (Betula maximowicziana) plantation (I) : A case study of damage at Hitsujigaoka, Sapporo, Northern Japan

Birch production and utilization for energy

Natural birch stands represent a significant biomass resource since birches are one of the most common deciduous genera in cool temperate regions, even in places ranging up to the forest line. Many characteristics of birch make it highly suited for short rotation forestry. However, growing birch in very short rotations (less than 10 years) in northern climates is not worthwhile on the basis of biomass production and economics. Rotations of 15 to 20 years may give good results everywhere. The intensive culture of birch plantations has largely remained untested, but it is very likely that the yield levels can be increased significantly by using cloned material as well as improved silvicultural treatments, fertilization and pest control. Birch feedstock, compared to material of many other tree species, is of even quality. Moisture content is low and basic density high. Branches and bark are also suitable for energy use. Birch plays an important part in the energy budget of entire nations, particularly of Finland and Sweden

Resistance breeding against voles in birch: possibilities for increasing resistance by provenance transfers1

Voles (mainly Microtus agrestis) are major pests in Nordic birch plantations. No feasible measures are known for controlling the damage due to voles during cyclic peak years. The results presented here indicate that there are large differences in palatability between different origins of one‐year‐old birch seedlings. These differences in resistance could not be explained by the success of the winter‐hardening process. The voles shunned very small seedlings, but after the seedlings reached normal dimensions, there was no correlation between palatability and plant size. Contrary to predictions, seedlings from a greenhouse with higher growth temperatures were more susceptible to vole damage. The prospects for breeding for resistance are considered promising because the seedlings of the most resistant V. Koski and J. Tahvanainen provided valuable comments on the manuscript. The English was checked by J. von Weissenberg. P. Manninen carried out the measurements and E. Matikainen drew the figures.