Average Tree Ring Width
Calculate mean measured radial growth per represented year including multi-year measurements; not an unweighted width mean when measurements cover unequal time.
Description
Measured ring growth may cover unequal numbers of years.
Measured ring growth may cover unequal numbers of years. Dividing total measured radial growth by total represented years gives an annual rate on a consistent exposure basis.1
Calculate mean measured radial growth per represented year including multi-year measurements; not an unweighted width mean when measurements cover unequal time.
When to use Average Tree Ring Width
Use this tool to calculate mean measured radial growth per represented year including multi-year measurements; not an unweighted width mean when measurements cover unequal time.
Prepare the artifact, site or survey measurements and any independently established calibration or model choices. Keep paired observations aligned and confirm units and coordinate conventions.
How to use Average Tree Ring Width and understand its results
- Prepare the artifact, site or survey measurements and any independently established calibration or model choices. Keep paired observations aligned and confirm units and coordinate conventions.
- Enter ringWidthsMm, representedYearsPerMeasurement using the field table and calculation rules, then run the tool.
- Read totalMeasuredRadialGrowthMm, totalRepresentedYears, averageGrowthMmPerYear. The explanation below defines the units, signs, ordering and any flags or placeholder values.
- If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.
| Input field | Meaning | Value type; see rules below | Requirement |
|---|---|---|---|
| ringWidthsMm | Ring widths mm | list of number | Required |
| representedYearsPerMeasurement | Represented years per measurement | list of number | Required |
Pair nonnegative measured widths in mm with positive integer represented years. Return total radial growth, total represented years and their ratio in mm/year. For a multi-year measurement, the width is its total growth rather than an annual width to be multiplied again.
Paired lists must be nonempty and have equal lengths.
annual mean growth = Σ measured widths/Σ represented years Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.
| Output field | Meaning | Value type |
|---|---|---|
| totalMeasuredRadialGrowthMm | Total measured radial growth mm | number |
| totalRepresentedYears | Total represented years | number |
| averageGrowthMmPerYear | Average growth mm per year | number |
{
"input": {
"ringWidthsMm": [
1,
2,
3
],
"representedYearsPerMeasurement": [
1,
2,
1
]
},
"output": {
"totalMeasuredRadialGrowthMm": 6,
"totalRepresentedYears": 4,
"averageGrowthMmPerYear": 1.5
}
}Limitations and assumptions
The result does not detrend ring widths, cross-date specimens or account for missing and false rings. Each represented interval is assumed correctly identified.
Numeric inputs must be finite. Follow the calculation-specific rules for overflow, underflow and exceptional cases. Numeric lists are limited to 100,000 entries; the rules above may require smaller limits. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors.
Alternative or Complementary methods
Use Dendro Ring Count Tool: Count measured dendro rings with explicit inferred missing-ring and outer-loss assumptions; calendar anchors are supplied, not independently dated by counting. For a complementary task, use Dendro Master Curve Match Checker: Scan all whole-ring offsets using signed Pearson correlation on supplied sequences, first offset breaking ties; candidate correlations and a caller cutoff are not a statistically validated dendro date.
References
-
Average Tree Ring Width — tool.io
Similar or alternative tools
- Dendro Ring Count Tool
Count measured dendro rings with explicit inferred missing-ring and outer-loss assumptions; calendar anchors are supplied, not independently dated by counting.
- Dendro Master Curve Match Checker
Scan all whole-ring offsets using signed Pearson correlation on supplied sequences, first offset breaking ties; candidate correlations and a caller cutoff are not a statistically validated dendro date.