Distinguishing root- and stem-wood of Picea abies

In archaeology, palaeobotany and dendrochronology, it can be important to distinguish between root- and stem-wood. Although numerous studies have described the root-wood of various species in great detail, there is, as yet, no quick and generally accepted wood anatomy-based method to distinguish Norway spruce root- from stem-wood. This study compared the anatomical characteristics of Norway spruce root- and stem-wood, and found it was possible to distinguish these two parts of the tree by differences in the average number of rows of ray tracheids as viewed in radial section, and in the frequency of rays per mm2 as viewed in tangential section. The reliability of these criteria was verified in a double-blind trial. Finally, a cross-comparison between Norway spruce and European larch root- and stem-wood characteristics was carried out, and it was determined that spruce root-wood can be distinguished from larch stem- or root-wood.