Malinen, J., Maltamo, M. and Verkasalo, E. 2005. Stem and Wood Properties of Norway Spruce on Drained Peatlands and Mineral Forest Lands in Southern Finland. Baltic Forestry, 11 (1): 21-38

Norway spruce from drained peatlands is of growing importance for forestry and forest industries in Finland, Sweden and Norway, and it has an essential role in Baltic countries and Russia, as well. In this paper, the level of and between-tree, between-stand and vertical within-tree variations in the technical quality of stems and selected morphological and physical properties of wood were studied on mature Norway spruce in naturally regenerated stands on drained peatlands, compared to naturally regenerated and planted stands on mineral forest lands, in southern Finland. In the analysis, breast height diameter and sub-region (four of them) were considered the covariants. The properties were examined separately for the vertical sections of butt logs, other logs and small-sized saw logs. Concluded from the results, Norway spruce from drained peatlands provides at least a moderate technical potential in the butt log section for sawmill and plywood industries in southern parts of Finland. The issues of uncertainty concern mainly internal dry knots and compression wood, and possibly the heterogeneity of wood material within a log. The industrial value of upper log sections seems considerably lower. Sub-regional effects seem to be largely insignificant within the southern-finnish climatic conditions, after considering the main effects of tree size, soil type and way of regeneration.

Key words:  technical quality, wood properties, saw logs, peatlands, variation.