The effect of wide espacement on wood density in Sitka spruce.

Abstract

In modern plantation forestry wide espacement is attractive because it leads to lower establishment costs, it dispenses with uneconomic thinnings, it gives greater individual tree vigour and it concentrates the final volume production on a smaller number of more uniform trees. Numerous reports (Ward and Gardiner, 1976; Brazier, 1970; Cown, 1973) have suggested that one of the effects of vigorous tree growth is to cause a decrease in wood density as vigour of growth increases. The evidence for this is, however, conflicting since some investigators (Maeglin, 1967; Paul, 1963) have reported that within the limits of normal silvicultural practice, initial spacing has very little effect on the density of the wood produced. Furthermore, it has been shown (Larson, 1969) that when species such as pines and spruces are pruned artifically, they produce wood of a non-uniform quality, characterised by a rapid increase in latewood percentage with increasing age...