Site Index From Height Age Calculator
Explicit caller calibrated Hossfeld h(t)∝t²/(a+bt+ct²) reference-age normalization, distinct from existing Chapman–Richards site index, no universal species constants. Caller independently verifies units, applicability and matching conditions; no operational recipe, safety certification, causal efficacy or legal/resource classification is inferred.
Description
A Hossfeld-style height curve provides a chosen age–height relationship for a site-index comparison.
A Hossfeld-style height curve provides a chosen age–height relationship for a site-index comparison.1
Scaling a measured height to reference age is conditional on independently applicable coefficients and age definitions. Use this tool to calculate site index from height age from the supplied measurements and assumptions.
When to use Site Index From Height Age Calculator
Use this tool to calculate site index from height age from the supplied measurements and assumptions. Establish the species/site, survey protocol, units, sampled area or exposure, and the independently chosen reference or model.
How to use Site Index From Height Age Calculator and understand its results
- Establish the species/site, survey protocol, units, sampled area or exposure, and the independently chosen reference or model.
- Enter observedDominantHeightM, observedStandAgeYears, callerReferenceAgeYears, callerHossfeldShapeA, callerHossfeldShapeB, callerHossfeldShapeC, using the field meanings and rules below, then run the tool.
- Read hossfeldNormalizedSiteHeightM. Interpret the fields using their units, signs and evidence conventions below.
- If input validation fails, correct the reported field and run again. Before applying the result, check reference scope, model assumptions and any missing evidence or placeholder values.
| Input field | Meaning | Value type | Requirement |
|---|---|---|---|
| observedDominantHeightM | Observed dominant height m | number | Required |
| observedStandAgeYears | Observed stand age years | number | Required |
| callerReferenceAgeYears | Caller reference age years | number | Required |
| callerHossfeldShapeA | Caller hossfeld shape a | number | Required |
| callerHossfeldShapeB | Caller hossfeld shape b | number | Required |
| callerHossfeldShapeC | Caller hossfeld shape c | number | Required |
Require positive observed height, observed age, reference age and coefficient a, with b and c nonnegative. Evaluate h(t)=t²/(a+bt+ct²) at both ages and multiply observed height by h(reference)/h(observed). Return the modeled reference-age height in the observed height unit. No calibration fit or species-specific coefficients are installed.
referenceHeight=observedHeight×[tRef²/(a+btRef+ctRef²)]/[tObs²/(a+btObs+ctObs²)] Use the exact units, boundary rules, ordering and missing-evidence conventions above.
| Output field | Meaning | Value type |
|---|---|---|
| hossfeldNormalizedSiteHeightM | Hossfeld Normalized Site Height M; follow the units, sign, ordering and evidence convention stated above | number |
{
"input": {
"observedDominantHeightM": 20,
"observedStandAgeYears": 20,
"callerReferenceAgeYears": 40,
"callerHossfeldShapeA": 100,
"callerHossfeldShapeB": 0,
"callerHossfeldShapeC": 1
},
"output": {
"hossfeldNormalizedSiteHeightM": 23.52941176470588
}
}Limitations and assumptions
Scaling a measured height to reference age is conditional on independently applicable coefficients and age definitions. Interpretation depends on the units, sampling scope and exact model described above.
All listed fields require explicit values. Unexpected fields, incorrect types, nonfinite numbers and sparse evidence arrays fail validation; the specific bounds and alignment requirements are stated above. Extremely large inputs or outputs can also be rejected. An input error is distinct from a successful result reporting false, no matches or missing evidence.
Alternative or Complementary methods
Use Yield Class Lookup for this related task: A yield class refers to productivity under a particular species, region and management reference.
Use Bavarian Volume Table Lookup when its separate inputs and assumptions fit the question: Regional timber-volume conventions associate measurement factors with a named reference method.
References
-
Site Index From Height Age Calculator — tool.io
Similar or alternative tools
- Yield Class Lookup
A yield class refers to productivity under a particular species, region and management reference.
- Bavarian Volume Table Lookup
Regional timber-volume conventions associate measurement factors with a named reference method.