A field-to-desktop toolchain for X-ray CT densitometry enables tree ring analysis

Abstract

Background and aims: Disentangling tree growth requires more than ring width data only. Densitometry is considered a valuable proxy, yet laborious wood sample preparation and lack of dedicated software limit the widespread use of density profiling for tree ring analysis. An X-ray computed tomography-based toolchain of tree increment cores is presented, which results in profile data sets suitable for visual exploration as well as density-based pattern matching.

Methods: Two temperate (Quercus petraea, Fagus sylvatica) and one tropical species (Terminalia superba) were used for density profiling using an X-ray computed tomography facility with custom-made sample holders and dedicated processing software.

Key results: Density-based pattern matching is developed and able to detect anomalies in ring series that can be corrected via interactive software.

Conclusions: A digital workflow allows generation of structure-corrected profiles of large sets of cores in a short time span that provide sufficient intra-annual density information for tree ring analysis. Furthermore, visual exploration of such data sets is of high value. The dated profiles can be used for high-resolution chronologies and also offer opportunities for fast screening of lesser studied tropical tree species.

Keywords: Cross-dating; Fagus sylvatica; Quercus petraea; Terminalia superba; X-ray CT; densitometry; high-resolution chronologies; pattern matching; tree ring analysis; wood anatomy; wood density.