Current issue: 54(2)
The dependence of elastic and tensile properties of coniferous trees on the share of summer wood can be presented as linear functions, if the soft wood is considered as a statically indefinite structure. By eliminating the share of summer wood by a certain function presented in the article, the elastic and tensile properties are the linear functions of density.
The functions are proved right by conducting strength tests on pine. Practical implications of the derived functions in rating the quality of wood are also presented.
The PDF contains a summary in Finnish.
There are three theories regarding the stem form of trees. The stem form plays a role in ability of the tree to resist wind and wind breaks. This article presents the theory and experiments about mechanic stem form theory. The wind velocity in a forest stand and the coefficient of resistance at the tree crone and at the tree stem are calculated. The hypothesis about the point when the tree stem breaks is discussed. The approximate values of different calculations are presented.