Wood identification using non-destructive confocal laser scanning microscopy

Abstract

Exact wood identification is usually based on observation of wood features under the microscope. For this, we have to take a sample of the wood from the object and cut thin slides, possibly of all three anatomical sections. Such destructive sampling is often not possible on valuable historical objects, and therefore there is a need for non-destructive approaches. The objective of the study is to present the potential of Confocal Laser Scanning Microscopy (CLSM) using an Olympus LEXT OLS5000 for the identification of wood. We present work on an example of a gothic sculpture, “St. George Defeating the Dragon”. Conventional sampling and microscopical wood identification showed that St. George is made of Norway spruce (Picea abies), and the dragon of poplar (Populus sp.) or willow (Salix sp.). We present crucial features needed for the identification of these species and the limitations with identification if the samples are too small. Finally, we demonstrate the possibility of wood identification of the abovementioned species using CLSM on wood samples without special preparation of the surfaces. CLSM enabled us to observe all the features needed for wood identification.