Determination of wood type

Wood species identification is carried out using microscopic transmitted light analyses, whereby the different types of wood can be identified to species or genus level using over 100 anatomical structural and identification features.

To determine the type of wood, thin sections of the samples are produced using a razor blade or microtome and then analysed at up to 500x magnification.

Thin sections from three different cutting directions are required for the taxonomic determination: Transverse, radial and tangential sections. The wood species is then determined with the aid of the relevant identification literature (e.g. Schweingruber 1990) or with reference comparisons (reference collection / Xylothek). Microscopic identification features relevant to wood anatomy include the distribution and size of tracheae and tracheids, the formation of vascular perforations, the width and height of medullary rays, as well as the presence of resin canals, screw thickenings of the tracheae and spotted arteries.

Charcoal, on the other hand, is analysed using a binocular and reflected light microscope at 10 to 500x magnification. The same characteristics are used to determine the type of wood as for classic microscopic wood species identification. However, as reflected light microscopes are used, no sectional specimens are produced, but the charcoals are broken accordingly so that fresh and clean tangential, radial and transverse fractures are available. These can then be used to analyse the wood anatomical features relevant to the determination in reflected light.