In northern Finland tree growth is limited by short growing seasons and low temperatures. The development of the timberline zone is also affected by such facts as how long the snow cover lasts, wind speed and the amount of packed snow on the trees. The age classes of the trees show, that there was no reproduction during the 19th centenary cold period. The tree-line zone has moved upwards following the warm period in the 1930's. June temperatures are more significant for Norway Spruce than those of July but for Scots Pine the reverse is true.
Strong winds cause asymmetrical tree growth and mechanical stress.
Last modified on November 27 th , 1995.