X-ray imaging and computed tomography of conifer tree rings for climatological purposes

S L Bondarenko,A V Batranin,S V Smirnov,S G Stuchebrov

doi:10.1088/1755-1315/211/1/012044

Abstract

This paper presents images of wood structure for various measurement regimes of X-ray microtomography. This is done by obtaining tomographic slices (iSee, CTvox), averaging them with the help of a statistical script called Adobe Photoshop, converting the average images into multidimensional data sets, and then averaging the image profiles (OriginCalc) to finally obtain a two-dimensional array of dendrochronological series of tree-ring density. The results of measurements are checked by a weight method to confirm the reliability of the data processing algorithm. For dendrochronological measurements of the ring density, it is shown that, depending on the width, two modes can be used: 80-μm (for wide rings) and 30-μm (for narrow rings). A measurement mode of less than 10-μm is used to display the structure of the wood inside a ring. The results of XCT-density measurements performed with an 8-μm resolution are given to assess the daily changes in wood density during the growing season.

Highlights

To analyze the correlation between solar activity and wood growth, tree-ring characteristics were first used by A
Frittsin [2] in particular, showed that environmental conditions greatly affect the tree growth, and tree rings were found to be an effective indicator of climatic changes
The X-ray computed tomography (XCT) technique implies mathematical reconstruction of the inner three-dimensional structure of an object based on measurements of X-ray absorption under multiple irradiation of an object in different intersecting areas [11, 12]

Summary

Methods

The XCT technique implies mathematical reconstruction of the inner three-dimensional structure of an object based on measurements of X-ray absorption under multiple irradiation of an object in different intersecting areas [11, 12]. The radiation absorption depends on the density of the substances that form the internal structure of an object. For visual and quantitative evaluation of the X-ray density R, the scale in Hounsfield Units (HU) is used to indicate the degree of radiation attenuation in the materials. The scale shows the ratio of radiation attenuation in the air to that in distilled water, the X-ray density of these being equal to 0 and 1000 HU, respectively, at standard pressure and temperature. Water air where , water and air are the linear attenuation coefficients for the material, water, and air under normal conditions, respectively. Negative R values indicate substances with less density as compared to water, and positive R values refer to those of higher density

Results

Discussion

Conclusion