Nov 05, 2008. /Lesprom.com/. Noble hardwoods constitute only 15 % of all forests in Sweden, but due to a warming climate the proportion can increase in the future, The Nordic Forest Owner's Association. Not only oak and beech count among noble hardwoods. Ash, elm, maple, basswood, hornbeam and wild cherry are also included in this category. The unique properties of noble hardwoods are due to their different density, aptitude for shrinking, durability and hardness. These properties make them suitable for various purposes from basswood sculptures to hard ash floors. Beech researchers at Swedish University of Agricultural Sciences have ascertained that acorn years, which are suitable for beech forest regeneration, have become more frequent and abundant during the last 35 years. After 1983 the time span between acorn years has never exceeded three years, probably due to climate warming. However, many things may happen after acorns fall to the ground in late autumn. Voles, insects and fungi attack the acorns already before sprouting and saplings suffer from cold, draught and from fungus attacks. Acorns may also be eaten by browsers. At least 500,000 acorns per hectare are needed in order attain a sufficient amount of beech saplings.