dendrochronology

Annual increment basis

Record the evidence that visible growth boundaries represent annual increments in this taxon and setting.

1. What evidence supports annual ring formation for this taxon at its known or proposed growth location? provenance
2. Which anatomical or growth conditions make annual boundary recognition uncertain? boundary

Coverage and sampling constraints

Record specimen origin, radii, preserved extent, and constraints on obtaining better dating evidence.

1. Which cores, sections, or timbers represent distinct trees, and which may share a source tree? provenance
2. Would another radius or specimen resolve the identified weakness, and is that sampling permitted? action

Ring anomalies

Track suspected false and locally absent rings and the comparisons used to resolve them; these anomalies can defeat simple ring counting. See [University of Arizona ring-anomaly examples](https://www.ltrr.arizona.edu/skeletonplot/ringanomalies.htm).

1. Where are boundaries ambiguous, duplicated, locally absent, or obscured by damage? measurement
2. What comparison with another radius or tree supports each proposed insertion, exclusion, or reassignment? provenance

Measured ring series

Retain measurement paths, units, resolution, preparation details, and corrections separately from dating interpretations.

1. Which specimen path, ring boundaries, instrument, units, and resolution produced the recorded values? measurement
2. Which values were remeasured or corrected, and what observation justified each change? provenance

Candidate match evidence

Record visual agreement, statistical diagnostics, overlap, preprocessing, and alternative offsets for each proposed match.

1. What overlap, diagnostic values, and distinctive ring patterns support each candidate offset? measurement
2. Which alternative placements and mismatching intervals were examined before accepting this alignment? boundary

Anchor and year convention

Record the anchor evidence, reference chronology version, and convention for assigning growth seasons to calendar years.

1. What evidence anchors this sequence to calendar years, and which reference or independently dated ring supplies it? provenance
2. How are cross-calendar-year growing seasons and any BCE/CE dates represented? definition

Processing and membership

Record included and excluded series, transformations, detrending when used, and aggregation choices. Raw measurements and growth-index chronologies are distinct products in the [NOAA tree-ring archive](https://www.ncei.noaa.gov/products/paleoclimatology/tree-ring).

1. Which dated series contribute, and why were other candidate series excluded? provenance
2. What transformations and aggregation methods produced the chronology, and where are the original measurements retained? provenance

Weak intervals and reference fitness

Identify sparsely supported intervals, dependence on individual trees, and the justified range of reference use.

1. How many independent trees and measured series support each interval, and how consistent are their patterns? measurement
2. Which intervals or target growth contexts require additional evidence before this chronology is used for dating? boundary

Preserved edge and event inference

Record pith and outer-edge preservation, any estimated missing growth, and assumptions connecting growth to felling or use.

1. Are pith, sapwood, bark, or waney edge preserved, and what limits do missing portions place on the conclusion? boundary
2. What separate evidence supports translating the last preserved ring date into a felling, construction, or deposition date? provenance

Qualified dating decision

Retain the decision, reviewer rationale, unresolved alternatives, and dependencies that may require reassessment.

1. Is the placement accepted, provisional, rejected, or unresolved, and for which intended use? boundary
2. What remeasurement, independent comparison, or reference revision would trigger reconsideration, and which dependent results would need review? action

Kinds and varieties

Reported by the breadth pass; each item needs checking against its source before it becomes normative.

• Archaeological and historic-building dendrochronology (felling dates of structural timber)
• Dendroclimatology (temperature, drought and precipitation reconstructions from ring width, density or isotopes)
• Dendroecology (fire, insect outbreak, stand release and disturbance histories)
• Dendrogeomorphology (dating landslides, floods, debris flows and glacier advances from living and killed trees)
• Dendroprovenancing (geographic origin of timber by matching to regional chronologies)
• Art-historical and organological dating (panel paintings, sculptures, musical instruments)
• Radiocarbon calibration and wiggle-matching on tree-ring-dated wood (IntCal-type series)
• Isotopic and chemical dendrochronology (δ¹⁸O, δ¹³C, trace elements in cellulose or wood)

1. Which of these kinds and varieties hold for the sense of dendrochronology this model covers, and on what evidence? provenance

Identifiers and schemes

Reported by the breadth pass; each item needs checking against its source before it becomes normative.

• Wikidata - Q128110 - Item for dendrochronology as a dating and environmental method.
• Library of Congress Subject Headings - Dendrochronology - Established LCSH used in library and heritage catalogues.
• NOAA ITRDB site/series code - typically a 2-3 letter region prefix plus a numeric site number (e.g. AZ033), with ring-width files in Tucson/decadal .rwl form - De facto public identifier for archived tree-ring measurement series in the International Tree-Ring Data Bank.

1. Which of these identifiers and schemes hold for the sense of dendrochronology this model covers, and on what evidence? provenance

Standards and regulation

Reported by the breadth pass; each item needs checking against its source before it becomes normative.

• NOAA NCEI International Tree-Ring Data Bank (ITRDB): contribution rules and Tucson (decadal) measurement-file format for archived ring-width and density series.
• Historic England / English Heritage, Dendrochronology: Guidelines on producing and interpreting dendrochronological dates - heritage practice for sampling buildings and reporting felling versus construction dates.
• IntCal working group (published in the journal Radiocarbon): tree-ring-dated wood is the backbone of Holocene radiocarbon calibration; laboratories follow IntCal rather than a product-safety statute.
• Disciplinary crossdating conventions (Tree-Ring Society / European oak labs): measurement to 0.01 mm; a calendar match commonly requires a Baillie-Pilcher t-value of about 3.5 or higher, often much higher for short series.

1. Which of these standards and regulation hold for the sense of dendrochronology this model covers, and on what evidence? provenance

Real-world use

Reported by the breadth pass; each item needs checking against its source before it becomes normative.

• Dating the felling year of oak or conifer timbers in standing buildings, ships, wells and pile dwellings, often to a calendar year when bark or waney edge is present.
• Assigning a terminus post quem to panel paintings, altarpieces and musical instruments whose boards retain a measurable ring sequence.
• Reconstructing past drought, growing-season temperature, streamflow and wildfire from living trees and remnant wood, including millennial bristlecone, oak and kauri series.
• Calibrating radiocarbon (IntCal) by measuring ¹⁴C in wood that already has a dendrochronological calendar date.
• Checking whether timber was imported or reused by seeing which regional master chronology it matches (dendroprovenancing, including illegal-logging cases).

1. Which of these real-world use hold for the sense of dendrochronology this model covers, and on what evidence? provenance

Typical measurements

Reported by the breadth pass; each item needs checking against its source before it becomes normative.

• Annual ring width - about 0.2-5 mm yr⁻¹ in temperate trees (suppressed rings can be ~0.01 mm; release rings can exceed 10 mm) - mm
• Ring-width measurement resolution - 0.01 (standard stage micrometer or image-analysis increment) - mm
• Maximum latewood density (MXD) - roughly 0.4-1.0 - g cm⁻³
• Series length needed for a unique calendar match - commonly ≥50-80 rings for European oak; shorter series are often only dated with a strong regional master and high t-value - years (rings)
• Baillie-Pilcher t-value against a master chronology - candidate matches typically ≥3.5; many labs treat ≥5 as a working oak threshold - dimensionless
• Expressed population signal (EPS) of a site chronology - 0.85 often used as a replication threshold for climate work - dimensionless

1. Which of these typical measurements hold for the sense of dendrochronology this model covers, and on what evidence? provenance

Failure modes and hazards

Reported by the breadth pass; each item needs checking against its source before it becomes normative.

• Missing rings (especially drought years in conifers) and false or intra-annual rings, which shift the counted sequence unless caught by crossdating.
• Complacent series with little year-to-year variation cannot be uniquely matched to a master chronology.
• Many tropical, and some Mediterranean, woods do not form reliable annual rings, so a calendar date is not available.
• Reused, stockpiled or imported timber: the ring date is the tree's growth/felling history, not the construction or painting date.
• No bark or waney edge: the outermost measured ring is only a terminus post quem for felling, not a felling year.
• Short sequences can lock onto the wrong interval of a long chronology.
• Destructive coring or sectioning of heritage objects; climate reconstructions can also be biased if age trend, competition or disturbance is treated as climate.

1. Which of these failure modes and hazards hold for the sense of dendrochronology this model covers, and on what evidence? provenance

Regional variation

Reported by the breadth pass; each item needs checking against its source before it becomes normative.

• Northwest Europe: dense archaeological oak (Quercus) chronologies for buildings and artefacts; practice centres on waney-edge felling dates and high t-value matches.
• Western North America: living and remnant conifers used mainly for climate and fire history; Great Basin bristlecone pine supplies multi-millennial series.
• East Asia: hinoki, sugi and related temple timbers in Japan; different species masters than European oak.
• Southern Hemisphere: opposite seasonal timing; long records from species such as kauri, Fitzroya and Nothofagus rather than oak.
• Tropics: annual-ring dendrochronology is possible only for certain taxa (e.g. some teak and dry-forest species) and is not the default method.

1. Which of these regional variation hold for the sense of dendrochronology this model covers, and on what evidence? provenance

Neighbouring kinds and how to tell them apart

Reported by the breadth pass; each item needs checking against its source before it becomes normative.

• Dendrology - Dendrology is the identification and classification of trees; dendrochronology is calendar dating and environmental inference from annual rings of already identified wood.
• Radiocarbon dating of wood - ¹⁴C on a bulk or single-ring sample yields a calibrated age range; dendrochronology, if the series crossdates and bark/waney edge is present, can give a calendar felling year. The two are complementary: tree-ring-dated wood calibrates ¹⁴C.
• Sclerochronology - The same idea of annual growth bands, but in molluscs, corals or otoliths rather than tree xylem; the organism and the archive differ.
• Varve chronology - Annual layers in lake or marine sediment, not in wood; a varve year is a deposition year in a basin, not a cambial growth year of a tree.
• Wood anatomy / xylology - Identifies taxon, structure and sometimes season of last growth; it does not by itself assign a calendar year. Dendrochronology uses anatomy then crossdates the ring sequence.
• Lichenometry - Ages a surface from lichen thallus size with large uncertainty; it does not produce a ring-by-ring calendar match to a master chronology.

1. Which of these neighbouring kinds and how to tell them apart hold for the sense of dendrochronology this model covers, and on what evidence? provenance