The Swiss Federal Institute for Forest Snow and Landscape Research WSL

Dating accurately

Climatic conditions, injuries and other environmental factors affect the size and wall thickness of wood cells. Accordingly, these characteristics vary from year to year.

Cells also differ within a tree ring: large and thin-walled in earlywood, flattened and thick-walled in latewood.

We can therefore date past events to within a season using microscopic images of wood thin sections