Experimental assessment of climatic adaptation of pine

This paper summarizes the content of three articles published in Studia Forestalia Suecica 80,81,82, 1970. A study of the annual grouuth rhythm on 2-, 3- and 20-year-old Pinus silvestris and 2-year-old Pinus contorta showed that the following methods can be used for experimental assessment of the climatic adaptation of populations and single trees: shoot- and needle elongation, bark colour onterminal, lignification of annual ring and water content of needles. It was established that the variation in rhythm within a population is so large that a portion of the trees within a stand progeny cannot be considered as adapted to the environment in which they were born. The annual rhythm was found to be correlated with the height growth of the single tree and with the survival, frost resistance and height growth of the population. It was shown that the regression of height on rhythm within a population may be used for assessment of the degree of adaptation to the testing environment. In tree breeding registration of the annual rhythm would improve the prediction of what environment a progeny is best adapted to and increase the precision in the evaluation of the potential growth capacity of the progeny.digitalisering@umu.s