Mining the British Isles oak tree-ring data set. Part A: Rationale, data, software, and proof of concept

Fowler, Anthony; Bridge, MC

doi:10.1016/j.dendro.2015.05.008

Cited by 8 publications

(6 citation statements)

References 13 publications

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“…The oak database used in this paper is essentially the same as that compiled by Fowler & Bridge (2015), supplemented by a few additional sites. The data consist of site chronologies from the British Isles, excluding inner-London and sites with fewer than three timbers (see Fowler & Bridge, 2015 for details).…”

Section: Methodsmentioning

confidence: 99%

“…Although it has earlier antecedents, the methodological roots of modern British dendrochronology can reasonably be traced to research undertaken from the late 1960s at Queen's University, Belfast (Baillie, 1982;Fowler and Bridge, 2015). By the early 1970s, the core elements of the "Belfast method" of statistical crossdating were established and had been made publically available in the form of the computer program CROS (Baillie and Pilcher, 1973 -BP73 hereafter).…”

Section: Introductionmentioning

confidence: 99%

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Empirically-determined statistical significance of the Baillie and Pilcher (1973) t statistic for British Isles oak

Fowler

Bridge

2017

Dendrochronologia

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The "Belfast method" of statistical crossdating has been widely used in the British Isles since public domain software was released by Baillie and Pilcher (1973). Although the conceptual merits of the approach are accepted, the details of the methodology have been severely criticised, including the fact that serially correlated tree-ring time series violate a fundamental requirement for the use of Students t statistic as a measure of statistical significance. An unfortunate consequence of this has been that t values are often published without reference to the associated probability of the specific value being obtained by chance. Here we present an empirical method for determining statistical significance from analysis of many misaligned inter-site correlations amongst over 2000 dated British Isles oak chronologies. Results indicate that a t value of 3.5 has a probability of about one in 600 for series lengths of 100+ years, but this declines (becomes less rare) as series length decreases.

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Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Empirically-determined statistical significance of the Baillie and Pilcher (1973) t statistic for British Isles oak

Fowler

Bridge

2017

Dendrochronologia

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“…Although underpinning much early crossdating of oak (Baillie and Pilcher 1973), the use of high-pass filtering using five-year moving averages induces phase shifts in the resulting series and can generate spurious dating outcomes (Fowler and Bridge 2017). Alternatively, cubic smoothing splines with a 50% frequency cut-off over eight years similarly reduce decadal-scale variability while avoiding the associated phase shifts (Fowler and Bridge 2015). Consistent with this latter approach, we indexed each of the panel-and portrait-level ring-width series using a smoothing spline with an eight-year frequency response.…”

Section: Crossdatingmentioning

confidence: 99%

“…Relative to that of continental Europe, Britain's climate exhibits a relatively high level of spatial inconsistency. That is, the relation between locations is relatively unstable and, as a consequence, site-level tree-ring chronologies contain a weaker geographic and relatively greater site-specific content than exhibited by European datasets (Fowler and Bridge 2015). Examples of living oak timbers correlating highly with locations far from their known origin (Bridge 2000a;Bridge 2012) illustrate this problem.…”

Section: Crossdating and Provenancingmentioning

confidence: 99%

Mapping Henry: Dendrochronological Analysis of a Sixteenth-Century Panel Painting Based Upon Synchrotron-Sourced X-ray Fluorescence Mapping

Brookhouse

Ives

Dredge

et al. 2020

Studies in Conservation

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The study of materials that comprise artworks significantly contributes to understanding of age and provenance. While dendrochronology is a particularly valuable and well-established technique for panel paintings comprising oak timber, conventional practices of resurfacing endgrains to reveal tree rings is becoming less acceptable because it removes material, modifying the painting. Recently, application of non-destructive X-ray fluorescence (XRF) spectroscopy to a portrait of Henry VIII held by the Art Gallery of NSW (AGNSW) revealed tree-ring boundaries in the resulting high-resolution elastic scatter XRF map. In this study, we examine the dendrochronological potential of that mapping with the aim of contributing to resolving the relation of the AGNSW portrait to similar paintings elsewhere. Examination of the timber revealed affinities with Quercus petraea (Matt.). We measured tree-ring widths along multiple paths in the XRF scatter map and crossdated the resulting 81-year XRF ring-width (XRF portrait ) series against master chronologies of English, western European, and Baltic origin. Rather than an arbitrarily defined threshold, we used a Bonferroni correction to determine a minimum significance level for crossdating. While the XRF portrait series did not crossdate with the continental European chronologies, we identified a single significant (α = 3.4 x 10 -6 ) dating position with the English chronology (1400-1480 CE). Cross-matching with site-level chronologies revealed a cluster of high t-values in central-southern England. The earliest date of felling precedes the documented date of completion for the AGNSW and two similar Tudor portraits of Henry VIII held by the National Portrait Gallery (NPG), London and one at the Society of Antiquaries, London. While, the apparent British provenance of timber used in the AGNSW portrait contrasts to Baltic origin of timbers used for the two NPG portraits and the majority of English panel paintings, it is consistent with the provenance of the timber used for the Society of Antiquaries portrait.

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“…The reference chronologies are established from cross-dated samples of ring-width measurements that are thought to represent local tree-growth. The location of the provenance is then approximated by the geographical area in which best matches between the ring-width patterns of a candidate series and the reference chronologies are found [ 16 ]. Generally, best matches are determined statistically using the same methods as for the (cross-)dating of ring-width series [ 17 , 18 ].…”

Section: Introductionmentioning

confidence: 99%

Assessing site signal preservation in reference chronologies for dendro-provenancing

Gut

2020

PLoS ONE

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Regional differences in tree growth can be used to approximate the geographical provenance of ring-width series ('dendro-provenancing'). This method relies on cross-dated ringwidth series (reference chronologies) that are thought to represent the radial growth signal of trees in a given region. Reference chronologies are often established from ring-width series of living tree populations. Frequently, they are too short to allow for investigating the provenance of historical wood. Thus, references are extended by ring-width series from buildings and art-historical objects that exhibit best matching growth patterns with the living tree references. Yet, series from other provenances may erroneously be included. Thereby the local or regional growth signal of the references is progressively contaminated, but this has received little attention to date. I investigate this contamination risk using a simulation approach that allows for generating pseudo site chronologies that preserve the relevant statistical properties of the real site chronologies. While the exact provenance of historical wood is unknown, for simulated ring-width series the provenance is unambiguous. Hence, pseudo reference chronologies may be established while monitoring the signal mixture. Specifically, 15 site chronologies of Norway spruce (Picea abies (L.) H. Karst.) from northeastern Switzerland were used to generate 15 pseudo site growth signals that span 1000 years. The simulation demonstrates that quasi uncontaminated references can be established in ideal circumstances for the study area. However, the thresholds for the similarity in between-series correlation must be very high. Even then, contaminated pseudo references occurred in rare cases during the simulation. Yet, elevation-specific pseudo references were established with lower thresholds. Simulation currently offers the only approach for assessing the contamination risk of reference chronologies, and it allows for elucidating the conditions under which acceptable levels of contamination can be guaranteed. Therefore, the present approach paves the way towards a practical simulation tool for dendroprovenancing.

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Mining the British Isles oak tree-ring data set. Part A: Rationale, data, software, and proof of concept

Cited by 8 publications

References 13 publications

Empirically-determined statistical significance of the Baillie and Pilcher (1973) t statistic for British Isles oak

Empirically-determined statistical significance of the Baillie and Pilcher (1973) t statistic for British Isles oak

Mapping Henry: Dendrochronological Analysis of a Sixteenth-Century Panel Painting Based Upon Synchrotron-Sourced X-ray Fluorescence Mapping

Assessing site signal preservation in reference chronologies for dendro-provenancing

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