Effect of spacing on growth, especially predetermined and free shoot growth of Norway spruce (Picea abies (L.) Karst.)

Four year old Norway spruce stecklings of 12 clones in total (4 clones each of 3 provenances) were grown at 22 x 22, 35 x 35, 50 x 50, and 65 x 65 cm for two years in the nursery. Shoot growth was distinctively larger on densely spaced trees while diameter growth was reduced. Free growth occurred much more frequently and also predetermined growth elongated more and quicker on densely spaced trees, although at the different spaces an equal number of primordia had been initiated (at least in the first year of the experiment). Denser spacing caused the trees to flush earlier. Between clones in provenances and provenances differences in several characters were found. There seem to be different modes of adaptation.