Cell structures in tree rings: Novel methods for preparation and image analysis of large cross sections

A new method for the preparation of wood samples for high-resolution reflected-light microscopy in combination with a species-specific image analysis system is introduced. The method is based on an ultraprecise single-point diamond flycutter equipped with air bearings and functions on the basis of a rotating diamond edge. Extensive and very smooth surfaces can be produced on increment cores as well as entire cross sections. Hence, this technique provides the prerequisites for a continuous microscopic analysis across large tree-ring sequences, or entire cross sections. Patching or sub-sectioning is not required. The high-resolution analysis of cell structures of spruce and oak presented here introduces new approaches for describing and predicting reactions of diameter growth to various environmental events.