This study was supported by the Slovenian Research Agency (ARRS) Program P4-0015 (Wood and lignocellulosic composites) and the Young Researchers&#39; Program.

1. Inspection and description of a stringed musical instrument&#160;-&#160;violin
NOTE: Violins are the most frequently investigated stringed instruments. Therefore, we describe the procedure on a violin.
<ol>
	<li>Examine the instrument and all its parts. Take detailed photos of the front (top), back, side, scroll, and label along with the measuring scale for the final report and the archive (Figure 1).</li>
	<li>Examine the top plate of the instrument to determine how it is constructed. If possible, remove the strings from the instrument to facilitate the analysis.</li>
	<li>Check whether the top plate is made of one, two, or more parts and how they are joined together. Here, the procedure is described for a top plate made of two parts, which is the most common case.</li>
	<li>On the radial board of the top plate (Figure 2A,C), examine the structure and orientation of the tree rings. They are seen as bands of annual growth layers, consisting of light-colored earlywood and darker latewood and delimited by the tree ring boundaries (Figure 2D).</li>
	<li>Based on the location and transition of earlywood to latewood, determine which side is the bark and which side is the pith (Figure 2C,G). In most cases, the most recently formed tree rings are located at the joint in the center of the top plate (when it consists of two parts; Figure 2C,D,F). These are the rings that were the nearest to the bark when the tree was still growing (Figure 2D,G). 
	NOTE: Since we need to look at the radial structure, the tree rings appear as bands and not rings. Nevertheless, the terms tree rings and tree ring width (TRW) are used in this protocol.</li>
</ol>
2. Selection of the locations for measurements on the musical instrument
<ol>
	<li>Inspect the widest parts on each piece of the top plate.</li>
	<li>Check for any damage, repairs, retouching, or dirt, and where the varnish is transparent enough to see the tree rings. If the instrument is opened (in the case of ongoing repairs or during restoration), measure the tree rings on the underside of the top plate, where no varnish is applied.</li>
	<li>Select the area with the greatest number of tree rings and check if the boundaries between the rings can be recognized (Figure 2C,D). The measurements can only be correct if the wood structure is clearly visible.</li>
	<li>Try to clearly see the tree rings that were near the bark as the tree was growing for an accurate identification of the end date (Figure 2D). Use a magnifying lens or stereo microscope for the observations.</li>
	<li>Mark the measuring line in the direction from the bark to the pith. Equip it with a measuring scale (Figure 2C). Place the scale (for instance, a commercially available paper measuring tape) on the board for this purpose.</li>
</ol>
3. Capturing digital images
<ol>
	<li>Capture images to measure the tree ring width with an image analysis system. Place the violin&#160;top plate side on the scanner and scan the parts selected for the tree ring measurement (Figure 2B). Select a resolution of 1,200 dpi or higher. Use a scanner that allows a high depth of field. 
	NOTE: Scanning is not the only way to capture images. A camera or other equipment can be used as well. If several images have to be captured, they must be stitched together properly. It is also possible to measure the tree ring width directly on the violin with the aid of a microscope and a special measuring device (e.g., a measuring table). This is especially useful in cases of poor visibility of the structure and if observation under a stereo microscope lens is needed. In this case, the images are valuable for further control of the measurements and for the archive.</li>
	<li>For editing the images, use a graphics editing program to check the quality of the image and adjust the color, brightness, and contrast to best see the annual growth rings and the boundaries between them. This step is useful when measuring tree rings with an image analysis system.</li>
	<li>To store the images, save the images in an adequate format (.tiff, .jpg).</li>
</ol>
4. Measurement of tree ring width
<ol>
	<li>Start an image analysis system, preferably one designed for the automatic and manual detection of tree rings and the measurement of TRW.</li>
	<li>Open the image and check or set the calibration manually by measuring the distance of a known length on the measurement scale that is part of the image (Figure 2C,D).</li>
	<li>Start the measurement by clicking on the tree ring boundaries so that the distance between them, representing the TRW, is recorded (Figure 2D). Note whether the first tree ring measured is closer to the bark or closer to the pith. For violins, click the tree ring boundaries manually, because the automatic detection of TRW is usually not possible or requires too many corrections.</li>
	<li>Measure all the TRWs along the measurement line. Save the data as the tree ring series (Figure 2E), with each TRW recorded for a specific relative year. Save the data in one of the widely used data formats. Perform more than one measurement on the same board for later verification. 
	NOTE: There are also other options (not described here) for the TRW measurements. Option 1: Use a general image analysis system, open and calibrate the image, measure the TRW, and note the measurements. Option 2: Using a 10x magnification lens with a built-in metric scale, measure the TRW directly on the violin and record the measurements. Option 3: Use a classic setup of dendrochronological equipment consisting of a movable measuring table, a stereo microscope, and a special program to record the measurement4,15. Place the violin on the table and observe it under a stereo microscope. Start the program for tree ring measurement and measure the TRW by clicking the tree ring boundaries.</li>
</ol>
5. Data processing, cross-dating, and building the chronology of the instrument
NOTE: For cross-dating, a specialized program and suitable reference chronologies are needed.
<ol>
	<li>For data processing, open the data file. We describe here how to use the raw TRW series (i.e., TRWs (in mm) against years; Figure 2E). 
	NOTE: It is also possible to work with indexed data.</li>
	<li>For cross-dating a tree ring series of the same instrument, open the tree ring series to be cross-dated and another tree ring series of the same instrument to serve as a reference and run the cross-dating, which moves them into the synchronous (cross-dated) position.</li>
	<li>Check the tree ring patterns and the cross-dating parameters. If the measurement is correct, the tree ring patterns, especially those of the same board, are very similar (Figure 2E), and the cross-dating parameters are high.
	<ol>
		<li>Check for the following main cross-dating parameters used in studies of violins: the concordance coefficient Gleichl&#228;ufigkeit (Glk%), the Baillie and Pilcher t-value (TVBP), and the Hollstein t-value (TVH)20,21,22.</li>
		<li>Consider the parameters statistically significant if Glk &#8805;65%, TVBP &#8805;4.0, TVH &#8805;4.0. In the case of dating musical instruments, keep the criteria stricter and parameter values higher (e.g., TVBP &#8805;7.0).</li>
		<li>Consider the overlap (OVL), which indicates the overlapping period of two tree ring series, in years as well.</li>
	</ol>
	</li>
	<li>When the two tree ring series are on the same relative time scale, save the position of the series. Repeat this step until all the tree ring series of each board and instrument are cross-dated. 
	NOTE: The cross-dating is based on the comparison of (two) tree ring series by calculating the statistical similarity parameters and graphical comparison (matching) of the graphs. A good agreement between the tree ring series (of the same instrument) confirms the correctness of the measurement, which is compromised if the tree rings are very narrow or indistinct or if they are missing (i.e., did not form in a tree).</li>
	<li>For creating the chronology of the violin, when all the TRW series of the same board and instrument are cross-dated, look at their graphs. Then, select those that have no measurement errors and average them to form a chronology of the instrument. At this stage, the chronology is not yet dated.
	<ol>
		<li>For this purpose, produce at least two measurements from each part of the top plate. If the agreement between the series within the instrument is statistically significant, average all the tree ring series into one chronology of the instrument.</li>
	</ol>
	</li>
</ol>
6. Dating of the instrument
<ol>
	<li>Cross-date the chronology of the violin with the reference chronologies. Use several reference chronologies in this step. Perform the cross-dating, check the parameters of the agreement, and visually assess the proposed dating position.
	<ol>
		<li>For successful dating, ensure that the same end date is confirmed by multiple chronologies with statistically significant parameters, as well as by optical comparison of the sequences. Use additional techniques such as the formation of average chronologies from matching curves or the segmentation of longer series for additional confirmation of the dating. 
		NOTE: This is a very critical step because one needs proper reference chronologies for dating. Some reference data are available on the ITRDB14.</li>
	</ol>
	</li>
	<li>Report the end date, which is the final result of the dendrochronological analysis23. Estimate the number of years, which should be added to the end date to propose the potential date of manufacture of the instrument. For this purpose, use the information on the label (if original) and other sources about the potential age, geographic area, manufacturer, and organological characteristics of the instrument assessed by other experts.</li>
	<li>Try to confirm the assumptions about the age, maker, and area of origin as this helps to decide if the violin is authentic or not. 
	NOTE: The end date does not indicate the year in which the violin was made, and this must be estimated.</li>
	<li>Write a report that includes the dendrochronological end date and sufficient information about the investigation supported by information that may help in the interpretation of the dating. 
	NOTE: The most important steps of the protocol are illustrated in Figure 2.</li>
</ol>
<img alt="Figure 2" class="xfigimg" src="/files/ftp_upload/64591/64591fig02.jpg" /> 
Figure 2: Detailed representation of the steps of the protocol. (A) A violin with the top plate made of two resonance boards (bass and treble); (B) scanning of the top plate; (C) part selected for the tree ring width (TRW) measurement (precision 0.01 mm) and measurement direction from the bark to the pith (which were outside the board); (D) tree rings as bands on the radial board and the TRW measurement direction from the darker latewood to the light colored earlywood; asterisks indicate where the two boards with end dates of 2003 and 1995 are glued together; +1, +2, +3&#8230; denote the locations of the tree ring boundaries (+) and the tree ring numbers (1, 2, 3); scale bar = 1 cm; (E)&#160;tree-ring series of the treble and bass side of a violin in cross-dated position and end dates 2003 and 1995 indicated; (F) different end dates of the two boards due to different numbers of tree rings being removed during the manufacturing of the instrument; (G) orientation of the resonance board in the tree and the tree rings corresponding to the end date and the last tree ring below the bark formed before the tree was cut. <a href="https://www.jove.com/files/ftp_upload/64591/64591fig02large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>

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The authors have no conflicts of interest to disclose.

The presented protocol describes the procedure of the dendrochronological dating of a violin. The procedure includes several critical steps. The first one is to identify the tree rings in order to properly measure their width. This is critical because the tree rings are often very narrow or have unclear boundaries due to the small amount of latewood (step 1.3). The detection of tree rings can be complicated by aging of the wood, dark and opaque varnishes28, or damage, repairs, retouching, or dirt ...

An erratum was issued for:&#160;<a href="https://www.jove.com/t/64591">Dendrochronological Dating and Provenancing of String Instruments</a>. The Authors section was updated from:
Katarina &#268;ufar1 
Bla&#382; Dem&#353;ar2 
Micha Beuting3 
Angela Balzano1 
Nina &#352;krk1 
Luka Kr&#382;e1 
Maks Merela1 
1Department of Wood Science and Technology, Biotechnical Faculty, University of Ljubljana 
2University of Ljubljana 
3Universitat Hamburg
to:
Katarina &#268;ufar1 
Bla&#382; Dem&#353;ar2 
Micha Beuting2 
Angela Balzano1 
Nina &#352;krk1 
Luka Kr&#382;e1 
Maks Merela1 
1Department of Wood Science and Technology, Biotechnical Faculty, University of Ljubljana 
2Independent Scholar

An erratum was issued for:&#160;<a href="https://www.jove.com/t/64591">Dendrochronological Dating and Provenancing of String Instruments</a>. The Authors section was updated.

Erratum: Dendrochronological Dating and Provenancing of String Instruments

The goal of this study is to present a protocol for the dendrochronological analysis of tree rings on the top plate of a wooden musical stringed instrument. Dendrochronology is used as a method to determine the age of the wood of the instrument by determining the year in which the youngest tree ring on the plate was formed and after which the instrument was made (or before which the instrument could not have been made).
Dating a musical instrument (such as a violin) is an important step in its authentication1,2,3,4,5,6. It is a complex process that involves the year in which the instrument was made, as well as the maker or instrument-making school or geographical area. To do this, dendrochronology is often combined with other techniques, which include the study of the label on the instrument (which is often not reliable) and the inspection of the instrument and its parts such as the outlines, scroll, wood figure and aging, varnish, f-holes, and purfling (Figure 1). The authentication can only be done by experts5,6,7.
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/64591/64591fig01.jpg" /> 
Figure 1: The top of the violin and its parts. The wood of the top plate (also called the front plate, belly, or soundboard) made of Norway spruce (Picea abies) can be dated by dendrochronology. The characteristics and dimensions of other parts such as the scroll, f-holes, and purfling are studied by organologists and help to authenticate the instrument. Scale = 20 cm. <a href="https://www.jove.com/files/ftp_upload/64591/64591fig01large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
Dendrochronology is the science of dating tree rings in the wood, also called annual rings, growth rings, or growth layers, which are formed every year in the trees of temperate zones. Dendrochronology clarifies in which calendar year a particular tree ring was formed. By dating the outermost and most recently formed tree ring just below the bark, the last year of a tree&#39;s life before it was cut down can be determined.
Dendrochronology is based on the principle that annual variations in tree ring width (and other characteristics) are largely influenced by the environment, especially the climate, in which the trees grow. When conditions are similar over an area, trees of the same species show similar tree ring variations from year to year8. This means that the tree ring series (i.e., the temporal sequence of tree ring widths over time) is similar for trees of the same species in the same area.
The dating of wooden instruments follows the principles used for dating historical objects. In most cases, it is based on measuring tree ring width, creating tree ring series of the same object, cross-dating (to determine their matching position), and averaging them into a floating chronology of an object showing the tree ring series in relative time3,4,6.
Absolute dating (determining the calendar year of tree ring formation) is accomplished by cross-dating with one or more reference chronologies established for a particular tree species and geographic area4,6.&#160;The reference chronologies must be based on the tree ring widths of a sufficient number of trees (replication) and should be long enough to cover the period of interest.
Dendrochronology is regularly applied to determine the age of stringed instruments such as violins, violas, and cellos1,9,10,11,12,13. For stringed instruments, the wood of the top plates (also the front plate, belly, or soundboard) can be dated. They are usually made of Norway spruce (Picea abies) or silver fir (Abies alba)4,6,13. The measurements must be made in a non-invasive way directly on the instrument or by using images. The measurements are usually made at different locations on the top plate to establish a sequence for the instrument that can be dated with reference chronologies.
Dating is the most critical step because a reference chronology must be available for the species, geographic area, and time period of the instrument being studied. Many chronologies are available at the International Tree Ring Data Bank (ITRDB)14,&#160;but only a few are of Norway spruce or silver fir from the region covering the period of interest6; therefore, dendrochronology laboratories put a lot of effort into constructing reference chronologies. The likelihood of dating increases if a network of chronologies is available, including those from exactly defined forest sites, dated instruments, and instrument collections from various manufacturers like the Stradivari, Guarneri, and Amati families from Italy5,6,15,16, Jacob Stainer from Austria, as well as Joachim Tielke and members of the Hoffmann family from Germany17,18,19. The fine historical instruments made by the manufacturers in the 16th century to 18th century are most prized by musicians and collectors, although the importance of many less-known makers is also growing3,4,6,12.
Dendrochronology provides the end date, which must be considered the terminus post quem &#8211;&#160;the year after which the instrument was made. Dendrochronology is also used for dendroprovenancing, which helps to determine the geographic origin of the wood and to assign instruments to specific violin makers or violin-making schools3,4,6.
The dendrochronological end date almost never coincides exactly with the year the instrument was made, and the latter must, thus, be estimated, which requires a lot of supporting information and cooperation between experts of different fields.

<table><tbody><tr><td>CDendro</td><td>Cybis Elektronik &amp;amp; Data AB</td><td>https://www.cybis.se</td><td>program CoDendro for dendro data management and crossdating</td></tr><tr><td>CooRecorder</td><td>Cybis Elektronik &amp;amp; Data AB</td><td>https://www.cybis.se</td><td>program CooRecorder to measure tree ring widths on images</td></tr><tr><td>TSAP-Win</td><td>RINNTECH</td><td>https://rinntech.info/products/tsap-win/</td><td>Time series analysis software</td></tr></tbody></table>

dendrochronological dating and provenancing of string instruments

Dendrochronology, the science of dating tree rings in the wood, defines in which calendar year a particular tree ring was formed. The method can be used to determine the age and authentication of wooden musical instruments. We present a protocol describing how to perform a dendrochronological analysis on stringed instruments and how to interpret the dating. The protocol describes the basic steps in the analysis of top plates, which are usually made of Norway spruce (Picea abies) or, more rarely, silver fir (Abies alba). First, the top plate is carefully inspected, and then the tree ring widths are measured directly on the instrument using high-resolution images. After completing the measurements, a tree ring sequence of the instrument is created, and, in the next step, dating is performed with a number of reference chronologies of the tree species from different geographical areas and instruments. The specialists who date the instruments also invest work in creating reference chronologies. The dendrochronological report provides the dating of an instrument as a calendar year (end date), indicating the year in which the last (most recent) tree ring on the top plate was formed when the tree was still alive. The end date represents the terminus post quem, the year after which the instrument was made or before which it could not have been made. To estimate the year of manufacture, one must consider the time required for wood drying and storing and the number of tree rings removed during wood processing. This protocol is intended to help those commissioning such an analysis to better understand how the analysis is performed and how to interpret the dendrochronological reports in terms of the age, origin, maker, and authenticity of the instrument.

A typical case in which a dendrochronological study was requested is a violin allegedly made by Andrea Guarneri of Cremona belonging to the family/school that produced numerous valuable instruments16,24. The violin in question contained two labels. One stated that the instrument was made by Andrea Guarneri of Cremona in 1747, while the other stated only 1867. However, the organological examination of the violin (Figure 3) suggested t...

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Dendrochronological Dating and Provenancing of String Instruments

The dendrochronological analysis of a stringed instrument requires inspecting the top plate, measuring the tree ring widths, establishing the chronology of the instrument, and dating through determining the end date-the year of the formation of the most recent tree ring.

Dendrochronology, the science of dating tree rings in the wood, defines in which calendar year a particular tree ring was formed. The method can be used ...

dendrochronological-dating-and-provenancing-of-string-instruments

Research

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Environment

2.4K Views.  University of Ljubljana. Dendrochronologie is de wetenschap van boomringen in het hout. Het kan worden gebruikt om de leeftijd en oorsprong van houten muziekinstrumenten, zoals een viool, te bepalen. Dendrochronologie verduidelijkt in welk kalenderjaar een bepaalde boomring werd gevormd.We kunnen inschatten wanneer de boom is gekapt, waar hij groeide en wanneer de viool werd gemaakt. Dit protocol zal u helpen om beter te begrijpen hoe de dendrochronologische analyse wordt uitgevoerd, hoe u het rapport moet int...

Video: Dendrochronological Dating and Provenancing of String Instruments

A Technical Perspective in Modern Tree-ring Research - How to Overcome Dendroecological and Wood Anatomical Challenges

Dendroecological research uses information stored in tree rings to understand how single trees and even entire forest ecosystems responded to environmental changes and to finally reconstruct such changes. This is done by analyzing growth variations back in time and correlating various plant-specific parameters to (for example) temperature records. Integrating wood anatomical parameters in these analyses would strengthen reconstructions, even down to intra-annual resolution. We therefore present a protocol on how to sample, prepare, and analyze wooden specimen for common macroscopic analyses, but also for subsequent microscopic analyses. Furthermore we introduce a potential solution for analyzing digital images generated from common small and large specimens to support time-series analyses. The protocol presents the basic steps as they currently can be used. Beyond this, there is an ongoing need for the improvement of existing techniques, and development of new techniques, to record and quantify past and ongoing environmental processes. Traditional wood anatomical research needs to be expanded to include ecological information to this field of research. This would support dendro-scientists who intend to analyze new parameters and develop new methodologies to understand the short and long term effects of specific environmental factors on the anatomy of woody plants.

Here we present a protocol outlining how to sample wooden specimens for the overall assessment of their growth structures. Macro- and microscopic preparation and visualization techniques necessary to generate well-replicated and highly resolved wood anatomical and dendroecological dataset, are described are described.

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Alternative Method of Removing Otoliths from Sturgeon

Extracting the otoliths (ear bones) from fish that have very thick skulls can be difficult and very time consuming. The common practice of making a transverse vertical incision on the top of the skull with a hand or electrical saw may damage the otolith if not performed correctly. Sturgeons (Acipenseridae) are one family in particular that have a very large and thick skull. A new laboratory method entering the brain cavity from the ventral side of the fish to expose the otoliths was easier than other otolith extraction methods found in the literature. Methods reviewed in the literature are designed for the field and are more efficient at processing large quantities of fish quickly. However, this new technique was designed to be more suited for a laboratory setting when time is not pressing and successful extraction from each specimen is critical. The success of finding and removing otoliths using this technique is very high and does not compromise the structure in any manner. This alternative technique is applicable to other similar fish species for extracting the otoliths.

The goal of the protocol is to show an effective method to extract the otoliths from sturgeon carcasses.

Extracting the otoliths (ear bones) from fish that have very thick skulls can be difficult and very time consuming. The common practice of making a ...

Laboratory and Field Protocol for Estimating Sheet Erosion Rates from Dendrogeomorphology

Sheet erosion is among the crucial drivers of soil degradation. Erosion is controlled by environmental factors and human activities, which often lead to severe environmental impacts. The understanding of sheet erosion is, consequently, a worldwide issue with implications for both environment and economies. However, the knowledge on how erosion evolves in space and time is still limited, as well as its effects on the environment. Below, we explain a new dendrogeomorphological protocol for deriving eroded soil thickness (Ex) by acquiring accurate microtopographic data using both terrestrial laser scanning (TLS) and microtopographic profile gauges. Additionally, standard dendrogeomorphic procedures, dependent on anatomical variations in root rings, are utilized to establish the timing of exposure. Both TLS and microtopographic profile gauges are used to obtain ground surface pro&#64257;les, from which Ex is estimated after the threshold distance (TD) is determined, i.e., the distance between the root and the sediment knickpoint, which allows de&#64257;ning the lowering of the ground surface caused by sheet erosion. For each profile, we measured the height between the topside of the root and a virtual plane tangential to the ground surface. In this way, we intended to avoid small-scale impacts of soil deformation, which may be due to pressures exerted by the root system, or by the arrangement of exposed roots. This may provoke small amounts of soil sedimentation or erosion depending on how they physically affect the surface runoff. We demonstrate that an adequate microtopographic characterization of exposed roots and their associated ground surface is very valuable to obtain accurate erosion rates. This finding could be utilized to develop the best management practices designed to eventually halt or perhaps, at least, lessen soil erosion, so that more sustainable management policies can be put into practice.

Characterizing erosion from dendrogeomorphology has usually focused on accurately finding the starting time of root exposure, by examining macroscopic or cell level changes caused by exposure. Here, we offer a detailed description of different novel techniques to obtain more precise erosion rates from highly accurate microtopographic data.

Sheet erosion is among the crucial drivers of soil degradation. Erosion is controlled by environmental factors and human activities, which often lead to ...

Using Tree-Rings to Reconstruct Fire History Information from Forested Areas

Annual tree-ring patterns are a source of ecological and environmental information including the history of fires in forested areas. Tree-ring based fire histories include three fundamental phases: field collection, laboratory methods (preparation and dating), and data analysis. Here we provide step-by-step instructions and issues to consider, including the process for selecting the study area, sampling sites, plus how and which fire-scarred trees to sample. In addition, we describe fire-scar sample preparation and dating which are done in the laboratory. Finally, we describe basic analysis and relevant results, including examples from studies that have reconstructed fire history patterns. These studies allow us to understand the historical fire frequency, changes in those frequencies related to anthropogenic factors, and analyzes of how climate influences fire occurrence over time. The description of these methods and techniques should provide a greater understanding of fire history studies that will benefit researchers, educators, technicians, and students interested in this field. These detailed methods will allow new researchers to this field, a resource to start their own work and achieve greater success. This resource will provide a greater integration of tree-ring aspects within other studies and lead to a better understanding of natural processes with forested ecosystems.

This work explains the most appropriate techniques and methods for conducting a fire history study from beginning site selection to final analysis of fire-climate relationship.

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How to Extract Climate Variability from Tree-Rings

Tree rings have been used to reconstruct climatological variables in many locations around the world. Moreover, tree-rings can provide valuable insights into climatic variability of the last few centuries and, in some areas, several millennia. Despite the important development, that dendrochronology has had in recent decades to study the dendroclimatic potential of a large number of species present in different ecosystems, much remains to be done and explored. In addition to this, in the last few years more people (students, teachers and researchers) around the world are interested in implementing this science to extend the timeline of climate information backwards and understand how climate has changed on scales of decades, centuries or millennia. Therefore, the objective of this work is to describe the general aspects and basic steps needed to conduct a tree-ring climate reconstruction, from site selection and field sampling to laboratory methods and data analysis. In this method's video and manuscript, the general basis in tree-ring climatic reconstructions is explained so newcomers and students can use it as an available guide into this field of research.

Tree-ring climate reconstructions can be helpful to better understand past climate variability beyond instrumental records. This protocol shows how to reconstruct past climate using tree rings and meteorological instrumental records.

Tree rings have been used to reconstruct climatological variables in many locations around the world. Moreover, tree-rings can provide valuable insights ...

Advanced Workflow for Taking High-Quality Increment Cores - New Techniques and Devices

In dendroecological research, precise dating of each single growth ring is a basic requirement for all studies, focusing on ring-width variations only, chemical or isotope analyses, or wood anatomical studies. Independent of the sampling strategy for a certain study (e.g., climatology, geomorphology), the way samples are taken is crucial for their successful preparation and analyses.
Until recently, it was sufficient to use a (more or less) sharp increment corer to obtain core samples that could be sanded for further analyses. Since wood anatomical characteristics can be applied to long time series, the need to obtain high-quality increment cores has taken on a new meaning. Essentially, the corer needs to be sharp(ened) when used. When coring a tree by hand, there are some problems in handling the corer, resulting in the hidden occurrence of micro cracks along the entire core: When starting to drill by hand, the drill bit is strongly pressed against the bark and the outermost ring until the thread has fully entered the trunk. At the same time, the drill bit is moved up and down as well as sideward. Then, the corer is drilled all the way into the trunk; however, it is necessary to stop after each turn, change the grip, and turn again. All these movements, as well as the start/stop-coring, puts mechanical stress on the core. The resulting micro cracks make it impossible to create continuous micro sections, as they fall apart along all these cracks.
We present a protocol to overcome these obstacles by applying a new technique using a cordless drill to minimize these problems when coring a tree, as well as its effect on the preparation of long micro sections. This protocol includes the preparation of long micro sections, as well as a procedure to sharpen corers in the field.

Here, we present a protocol on how to avoid micro cracks in increment cores by applying a cordless drill with a torque multiplier to minimize problems when coring trees, as well as its effect on preparing long micro sections. This protocol also includes a procedure to sharpen corers in the field.

In dendroecological research, precise dating of each single growth ring is a basic requirement for all studies, focusing on ring-width variations only, ...

High-Throughput Tree Ring Analysis and Density Estimation

Tree Core Analysis with X-ray Computed Tomography

An X-ray computed tomography (CT) toolchain is presented to obtain tree-ring width (TRW), maximum latewood density (MXD), other density parameters, and quantitative wood anatomy (QWA) data without the need for labor-intensive surface treatment or any physical sample preparation. The focus here is on increment cores and scanning procedures at resolutions ranging from 60 &#181;m down to 4 &#181;m. Three scales are defined at which wood should be looked at: (i) inter-ring scale, (ii) ring scale, i.e., tree-ring analysis and densitometry scale, as well as (iii) anatomical scale, the latter approaching the conventional thin-section quality. Custom-designed sample holders for each of these scales enable high-throughput scanning of multiple increment cores. A series of software routines were specifically developed to efficiently treat three-dimensional X-ray CT images of the tree cores for TRW and densitometry. This work briefly explains the basic principles of CT, which are needed for a proper understanding of the protocol. The protocol is presented for some known species that are commonly used in dendrochronology. The combination of rough density estimates, TRW and MXD data, as well as quantitative anatomy data, allows us to broaden and deepen current analyses for climate reconstructions or tree response, as well as further develop the field of dendroecology/climatology and archeology.

Author Spotlight: Advancements in X-ray CT Tool Chain for Tree Core Analysis

Here we show how to process tree cores with an X-ray computed tomography toolchain. Except for chemical extraction for some purposes, no further physical lab treatment is needed. The toolchain can be used for biomass estimations, for obtaining MXD/tree-ring width data as well as for obtaining quantitative wood anatomy data.

An X-ray computed tomography (CT) toolchain is presented to obtain tree-ring width (TRW), maximum latewood density (MXD), other density parameters, and ...

Protocol for Field to Lab Tree Ring Digitization in Dendroecological Studies

A New Workflow for Sampling and Digitizing Increment Cores

Here we present a new workflow from taking increment cores in the field, storing and transporting them to the lab, to digitizing their tree rings for further analyses for subsequent dendroecological analyses. The procedure involves the use of new sample carriers for increment cores. These new G&#228;rtner Schneider Core (GSC) holders are designed using three-dimensional (3D) modeling software and finally printed with a 3D printer. Using these mounts from the beginning in the field, the cores can directly be cut with a core microtome, and their surface can then be digitized without further rearrangement using a new high-resolution image-capturing system. They are thus available for direct analysis. This system allows digitizing tree rings from cores and disks, and also taking images from long micro sections (up to 40 cm) using transmitted light. This feature is of special interest for dendroecological and geomorphic applications to identify the onset of any disturbance in micro sections cut with a core-microtome.

Author Spotlight: Innovative Device Development for Advancing Dendroecology and Wood Anatomy Research

We present a protocol to use 3D-printed mounts to fix increment cores in the field without the necessity of unpacking and gluing them on wooden mounts. The new GSC holder allows placing the cores in a core microtome to cut their surface and directly transfer them to digital image capturing.

Here we present a new workflow from taking increment cores in the field, storing and transporting them to the lab, to digitizing their tree rings for ...

Artificial Thermal Ageing of Polyester Reinforced and Polyvinyl Chloride Coated Technical Fabric

Architectural fabric AF9032 has been subjected to artificial thermal ageing to determine changes of the material parameters of the fabric. The proposed method is based on the accelerated ageing approach proposed by Arrhenius. 300 mm x 50 mm samples were cut in the warp and fill directions and placed in a thermal chamber at 80 &#176;C for up to 12 weeks or at 90 &#176;C for up to 6 weeks. Then after one week of conditioning at ambient temperature, the samples were uniaxially tensioned at a constant strain rate. Experimentally, the parameters were determined for the non-linear elastic (linear piecewise) and viscoplastic (Bodner&#8211;Partom) models. Changes in these parameters were studied with respect to the ageing temperature and ageing period. In both cases, the linear approximation function was successfully applied using the simplified methodology of Arrhenius. A correlation was obtained for the fill direction between experimental results and the results from the Arrhenius approach. For the warp direction, the extrapolation results exhibited some differences. Increasing and decreasing tendencies have been observed at both temperatures. The Arrhenius law was confirmed by the experimental results only for the fill direction. The proposed method makes it possible to predict real fabric behavior during long term exploitation, which is a critical issue in the design process.

Here, we simulate accelerated thermal ageing of technical fabric and see how this ageing process influences the mechanical properties of the fabric.

Architectural fabric AF9032 has been subjected to artificial thermal ageing to determine changes of the material parameters of the fabric. The proposed ...

Engineering

Radioactive Decay and Radiometric Dating

Radioactivity is a spontaneous disintegration of an unstable nuclide and is a random process, as all the nuclei in the sample do not decay simultaneously. The number of disintegrations per unit time is called the activity (A), which is directly proportional to the number of nuclei in the sample. The decay constant (λ) is an average probability of decay per nucleus in unit time.
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The SI unit for activity is the becquerel, which is one disintegration per second. Another unit of activity is the curie, which is equal to 37 billion becquerels. Plotting activity vs time for different radionuclides indicates different decay rates. The time required for the activity to fall from any value to half of that value is one half-life, indicated as t1/2.
As the activity is proportional to the number of radioactive atoms, it decreases with time as the amount of sample diminishes. Mathematically, the activity of a radionuclide is indicated by an exponential equation:
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Thus, when activity is reduced to half, rearranging the equation provides a way to calculate the half-life, which is inversely proportional to the decay constant.
<img alt="DNA replication process diagram with labeled polymerase enzyme, leading and lagging strands." src="/files/ftp_upload/11447/11447_Equation_3.png" style="text-align: center; height: 110px;" data-altupdatedat="1747908711000" data-alt="Eq3">
A half-life is an intrinsic property of a radionuclide, and any single atom of an unstable nuclide has the same half-life regardless of whether it is completely alone in a vacuum or in a sample with many other atoms of that nuclide. The half-lives of radionuclides vary widely: radon-220 has a half-life of 1 minute: one million nuclei decay down to half a million in a minute and further decay to one fourth of a million in another minute. However, thorium-232 has a half-life of 14 billion years.
Several radioisotopes have half-lives and other properties that make them useful for purposes of “dating” the temporal origin of objects such as archaeological artifacts, formerly living organisms, or geological formations.
Carbon-14, a radionuclide with a half-life of 5730 years, provides a method for dating objects that were a part of a living organism. This method of radiometric dating is accurate for dating carbon-containing substances that are up to about 30,000 years old and can provide reasonably accurate dates up to a maximum of about 50,000 years old.
Naturally occurring carbon consists of three isotopes: carbon-12, which constitutes about 99% of the carbon on earth; carbon-13, about 1% of the total; and trace amounts of carbon-14. Carbon-14 forms in the upper atmosphere by the reaction of nitrogen atoms with neutrons from cosmic rays in space.
All isotopes of carbon react with oxygen to produce CO2 molecules. Thus, living plants and animals have a ratio of carbon-14 and carbon-12 identical to the atmosphere. But when the living plant or animal dies, replenishment of carbon stops, and the carbon-14 to 12 ratio starts diminishing as the radioactive carbon-14 continuously decays. For example, if the carbon-14 to carbon-12 ratio in a wooden object found in an archaeological dig is half what it is in a living tree, this suggests that the object was made from wood cut down 5730 years ago. Highly accurate determinations of carbon-14 to carbon-12 ratios can be obtained from very small samples (as little as a milligram) using a mass spectrometer.
Radioactive dating can also use other radioactive nuclides with longer half-lives to date older events. For example, uranium-238, which decays in a series of steps into lead-206, can be used for establishing the age of rocks (and the approximate age of the oldest rocks on earth). Since uranium-238 has a half-life of 4.5 billion years, it takes that amount of time for half of the original uranium-238 to decay into lead-206. In a sample of rock that does not contain appreciable amounts of lead-208, the most abundant isotope of lead, we can assume that lead was not present when the rock was formed. Therefore, by measuring and analyzing the ratio of U-238:Pb-206, we can determine the age of the rock. This assumes that all of the lead-206 present came from the decay of uranium-238. If there is additional lead-206 present, which is indicated by the presence of other lead isotopes in the sample, it is necessary to make an adjustment. Potassium–argon dating uses a similar method. Potassium-40 decays by positron emission and electron capture to form argon-40 with a half-life of 1.25 billion years. If a rock sample is crushed and the amount of argon-40 gas that escapes is measured, determination of the Ar-40:K-40 ratio yields the age of the rock.
This text is adapted from <a href="https://openstax.org/books/chemistry-2e/pages/21-3-radioactive-decay">Openstax, Chemistry 2e, Section 21.3: Radioactive Decay.</a>

Radioactive Decay, Activity Units, Half-life & Radiometric Dating

Radioactivity is a spontaneous disintegration of an unstable nuclide and is a random process, as all the nuclei in the sample do not decay simultaneously. ...

Dendrochronological Dating and Provenancing of String Instruments

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