How is spruce wood distinguished?

Dietger Grosser
The wood of the fir - properties and use - LWF knowledge 45

The fir ([i] Abies alba Mill. [/ I]) - also called white or silver fir because of the white to silver-gray color of its bark - is one of the ripening trees or "trees with light heartwood". Their sapwood and heartwood cannot be distinguished from one another in terms of color. Fir wood is matt, mostly yellowish-white to almost white in color. It is not uncommon for it to have a gray-violet or bluish sheen. Under the influence of light it darkens noticeably and takes on a yellowish-brown age tone.

Figure: Cross section through fir wood

As with all native conifers, the annual rings are clearly separated from each other. Within the annual rings, the transition from the light, whitish early wood to the darker reddish yellow late wood usually takes place gradually (illustration). The clear color difference between early wood and latewood causes distinctive flat spots (tangential cut) or stripes (radial cut) on the longitudinal surfaces. Resin channels, which are characteristic of spruce, pine, larch and Douglas fir, are missing.

Therefore, fir wood has no resin odor. The wood of the fir is very similar to that of the spruce and not always easy to distinguish based on the color, even for the expert. The most essential feature for the macroscopic differentiation of the two types of wood are the resin channels, which - as mentioned - only occur in the spruce and can be seen there as small bright points on clean brain surfaces under the magnifying glass. The resin pockets, which are quite common in spruce wood, are also missing. Furthermore, spruce is usually characterized by a more yellowish color and a silky sheen. The more whitish wood of the fir tree, on the other hand, remains dull or dull.

The branch position offers another clue for the differentiation of the species. In the fir, the knotters are almost horizontal to the trunk axis, while in the spruce they are oriented more diagonally upwards. Accordingly, the incision in the fir tree results in approximately round,

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