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Wood anatomy in relation to (tree)-ring ecology

The variation of wood anatomical features such as vessel or tracheid size and cell-wall thickness bears ecologically relevant information. Wood anatomical research at the WSL concentrates on the detailed analysis of these ecological traits as well as on the ability to measure long-term variations of these features back in time.

Analyzing single cells within annual rings of woody plants allows for a highly resolved, intra-annual reconstruction of past environmental conditions.

We do not exclusively analyze the anatomical structure of trees, but also that of shrubs, dwarf shrubs and even herbs. This rather new methodological approach enables us to go far beyond treeline to analyze environmental changes in high-alpine areas as well as in arctic regions.

To realize these detailed short- as well as long-term reconstructions, there is also a need to develop new preparation techniques (e.g., sample stabilization without embedding), analysis software (e.g., ROXAS) and devices (e.g., microtomes).


Shrubs growing on permafrost
Salix shrub Salix shrub: root section
Salix helvetica shrub growing on a rock glacier (Turtmanntal) Micro-section of a root of the same shrub. Note the very thick bark around the xylem.
Roots and slope stability:  Is the anatomical structure of roots influencing their tensile strength?
Root slope Root slope: root section
Exposed root system of a mountain maple planted in 1997 as part of an eco-engineering measure to stabilize a slope Micro-section of a single root of this tree
Root exposure
root exposure root exposure
Scarp of a landslide with exposed roots due to soil displacement. Micro-sections of exposed roots.
Upper section: change of cell structure due to exposure
Lower section: the distorted cells after the fourth ring indicate the time of disturbance.
Trees tilted (by avalanches, debris flows, landslides, etc.)
Trees tilted Trees tilted: root section
Conifers tilted and grown upright again covered by new depositions of a debris flow Compression wood (rounded cells in the lower part of the image) allows conifers to grow upright again

Recent publications

  • Gärtner H, Lucchinetti S, Schweingruber FH (2014): New perspectives for wood anatomical analysis in Dendrosciences: The GSL1-microtome. Dendrochronologia 32: 47-51 (pdf)
  • Gärtner H, Schweingruber FH (2013). Microscopic Preparation Techniques for Plant Stem Analysis. Verlag Dr. Kessel, Remagen. 78 p. (Illustrated extended summary, 22 pages, 1.5 Mb)
  • Fonti P, Bryukhanova M, Myglan V, Naumova O, Kirdyanov A, Vaganov E (2013). Temperature-Induced Responses of Xylem Structure of Larix sibirica Ldb. (Pinaceae) from Russian Altay. American Journal of Botany 100: 1332-1343. (pdf)
    (Link: )
  • von Arx G, Kueffer C, Fonti P (2013). Quantifying vessel grouping – added value from the image analysis tool ROXAS. IAWA Journal 34: 433-445. (pdf)



ROXAS is a tool for the quantitative analysis of xylem anatomy in microscopic images

Available languages: English 


One of the central topics in the further development of an ecologically based wood anatomy is the continuous improvement of preparation techniques. Two microtomes have been developed and are for sale at the wood anatomy lab of the WSL.

Available languages: German  English