Dendrochronomics

Tree-ring research revisited.

What is X-ray CT?

X-ray CT scanning is a non-destructive technique to visualize the internal structure of the object by using the power of X-rays to pass through matter. The technique has evolved at an incredible speed the last two decades, and is an important tool in research and development, as well as for industrial applications. UGent-Woodlab is part of the UGCT (UGent Centre for X-ray Tomography). You can find more info on the UGCT website regarding, among others, the available systems.

The video below shows you the process and result of high-resolution X-ray CT scanning of a rare butterfly. The scan is performed at the HECTOR scanner of UGCT.

Below you can find two surface renderings of submicron X-ray CT scans that can be manipulated when pressing the play button.

Quercus robur by Jan Van den Bulcke on Sketchfab

Pinus sylvestris by Jan Van den Bulcke on Sketchfab

X-ray CT & tree rings

The study of wood formation at different temporal and spatial scales is, clearly, in need of techniques enabling to capture sufficient multi-scale detail (Battipiglia et al. 2014). Both technological advances as well as related computational techniques will help in increasing our understanding of tree response in a changing climate and changing needs, supporting sustainable production of both timber and non-timber products. The aim of dendrochronomics is to develop a high-throughput multi-scale hard- and software platform to obtain and analyze continuous time series of multi-proxy data, with intra-annual resolution, on increment cores mainly. The platform comprises 3 essential breakthrough steps: high-throughput acquisition of multi-proxy tree-ring series, guided cross-dating and advanced time-aware analysis. The backbone of dendrochronomics is advanced multi-scale X-ray CT scanning (see example below for an increment core of Quercus spp.) at one hand and full imaging of long microtome cross-sections (see example below for Cedrela spp) at the other hand.

Download software

We offer free software for analyzing (i) 3D X-ray CT cores as well as (ii) flatbed/microscopy images to indicate tree rings. The toolboxes are built with MATLAB R2022b. You need to install the proper Matlab Runtime Version , which is free as well. Software and a test volume, used in the papers of Van den Bulcke et aL (2014), De Mil et al. (2016) and Van den Bulcke et al. (2019), De Ridder et al. (2011), can be downloaded here compiled for Windows. An older Mac version (credits to Prof. Kim Calders for compiling!) is available here , but hasn't been tested extensively (version from 2021, so install the MCR2021b for Mac in this case). Please cite the following papers if you use the software: Van den Bulcke et al. 2014, De Mil et al. 2016, Van den Bulcke et al. 2019. A short manual can be downloaded as well. Always check the latest version on this website.

  • Once the X-ray CT reconstructions are available, the CoreProcessor toolbox (in this video tutorial still called Densitometry toolbox) is used for extracting the virtual increment cores and converting them to absolute densities.

  • Tree rings need to be indicated then. See this short video tutorial . In this video tutorial RingIndicator is still called DHXCT.

  • Cores can be crossdated and parameters exported (CoreComparison). See this short video tutorial .

  • You are all set! Further analysis can be done in other tree-ring software, such as DPLR (Bunn et al. 2008) or the online platform XDateR .

Papers and projects

Ongoing projects related to dendrochronomics:

  • XINCAST: An X-ray view on the intra-seasonal dynamics of carbon storage in trees
  • XyloDynaCT: A game-changing perspective on intra-seasonal wood formation dynamics using high-resolution X-ray Computed Tomography to elucidate leaf senescence and autumn dynamics of temperate deciduous trees in Europe
  • ACTREAL: ACcurate Temperature REconstructions and climate change mapping in tree rings of Ancient bristlecone pines, the Longest-living trees in the world

Database

Within dendrochronomics, we also aim at the development of a database, both containing pith-to-bark density profiles based on 3D X-ray CT volumes as well as (partially annotated) pith-to-bark cross-sections. Currently, more than 5000 cores from locations in Africa, N- and S-America and Europe haven been X-ray CT scanned (see map below).


Following projects (number corresponds with 'projectnr' in the pop-up on the map) and associated people contributed to the database:

  1. IFS funded PhD Moses Libalah
  2. ITTO funded PhD dr. Agathe Dié
  3. VLIR-UOS funded PhD dr. Maaike De Ridder
  4. Master thesis Victor Deklerck
  5. ERC PASTFORWARD : Prof. Kris Verheyen, Sybryn Maes
  6. Special Research Scholarship Tom De Mil
  7. BELSPO BiosphereTraits project
  8. FRIA PhD project Yegor Tarelkin
  9. UCL Project Benoit Cassart
  10. BAEF Tom De Mil/NSF Will Tintor, Matt Meko, Connie Woodhouse, Valerie Trouet
  11. Ellen Janssen, Bart Muys, Nesibe Köse
  12. Lamarche, Dunwiddie, BAEF Tom De Mil, Matt Meko, Valerie Trouet
  13. Master thesis Siebe Puynen
  14. Master thesis Louis Veschuren
  15. MixForChange : Prof. Lander Baeten, dr. Haben Blondeel

Team

Collaborate with us

If you are interested in applying dendrochronomics in your work or you want to know more about X-ray CT scanning for tree-ring analysis or the database, feel free to contact us for collaboration. You can find additional information on the UGent-Woodlab website.