Current issue: 53(2)
Under compilation: 53(3)
An explorative study on wind conditions in a well-managed Scots pine (Pinus sylvestris L.) stand was made in Southern Finland. The wind velocity was recorded continually with two cup anomometers from April to August, 1964. The two levels used were 2 m and 9 m. The wind velocity was lower at 2 m than within the canopy at 9 m. The dependence on the absolute wind velocity at 9 metres was logarithmic. The wind velocity did affect the difference between daily minimum temperatures at the two levels; the difference in the maximum temperatures was affected only in May and August.
The PDF includes a summary in English.
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.