Pruning Lift Height to HDB Green Crown

Audit requested pruning lift against existing live crown geometry and caller retained-crown constraint; not existing crown ratio alone, stem-quality prediction or a pruning recommendation.

Description

Pruning lift changes live crown length only above the current crown base.

Pruning lift changes live crown length only above the current crown base. A retained-crown fraction constraint must account for that existing geometry.^[1]

Audit requested pruning lift against existing live crown geometry and caller retained-crown constraint; not existing crown ratio alone, stem-quality prediction or a pruning recommendation.

When to use Pruning Lift Height to HDB Green Crown

Use this tool to audit requested pruning lift against existing live crown geometry and caller retained-crown constraint; not existing crown ratio alone, stem-quality prediction or a pruning recommendation.

Gather the tree inventory, plot measurements or model parameters. Check diameter, area, time and moisture conventions; keep paired observations aligned.

How to use Pruning Lift Height to HDB Green Crown and understand its results

Gather the tree inventory, plot measurements or model parameters. Check diameter, area, time and moisture conventions; keep paired observations aligned.
Enter totalTreeHeightsM, currentLiveCrownBaseHeightsM, requestedPruningLiftHeightsM, callerMinimumRetainedLiveCrownFractions using the field table and calculation rules, then run the tool.
Read postPruningLiveCrownFractions, maximumLiftUnderCallerCrownConstraintM, aboveCallerLiftConstraintFlags. 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
totalTreeHeightsM	Total tree heights m	list of number	Required
currentLiveCrownBaseHeightsM	Current live crown base heights m	list of number	Required
requestedPruningLiftHeightsM	Requested pruning lift heights m	list of number	Required
callerMinimumRetainedLiveCrownFractions	Caller minimum retained live crown fractions	list of number	Required

Pair positive tree heights, nonnegative base/lift heights not above total, and minimum fractions in [0,1]. Return post-pruning fractions, nominal maximum lift height×(1−minimum) and flags where actual retained fraction is below its minimum.

Paired lists must be nonempty and have equal lengths.

post fraction=[height−max(current crown base,requested lift)]/height

Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.

Output field	Meaning	Value type
postPruningLiveCrownFractions	Post pruning live crown fractions	list of number
maximumLiftUnderCallerCrownConstraintM	Maximum lift under caller crown constraint m	list of number
aboveCallerLiftConstraintFlags	Above caller lift constraint flags	list of number

json

{
  "input": {
    "totalTreeHeightsM": [
      10,
      20
    ],
    "currentLiveCrownBaseHeightsM": [
      2,
      5
    ],
    "requestedPruningLiftHeightsM": [
      5,
      15
    ],
    "callerMinimumRetainedLiveCrownFractions": [
      0.4,
      0.4
    ]
  },
  "output": {
    "postPruningLiveCrownFractions": [
      0.5,
      0.25
    ],
    "maximumLiftUnderCallerCrownConstraintM": [
      6,
      12
    ],
    "aboveCallerLiftConstraintFlags": [
      0,
      1
    ]
  }
}

Limitations and assumptions

An already insufficient crown can fail even with a low requested lift. This audit does not prescribe pruning or predict stem quality.

Numeric inputs and returned numeric values must be finite; an unrepresentable returned value produces an error. 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 Shelterwood Overstory Retention Percent: Summarize matched original/retained overstory basal-area inventories and represented area; not single-tree basal area, canopy cover or a regeneration guarantee. For a complementary task, use Ice Storm Canopy Retained Severity Percent: Audit measured retained live crown volume after storm against matched prestorm inventory and caller loss cutoff; canopy volume differs from shade/cover and observations do not establish future tree survival.

References

Pruning Lift Height to HDB Green Crown — tool.io

Similar or alternative tools

Shelterwood Overstory Retention Percent
Summarize matched original/retained overstory basal-area inventories and represented area; not single-tree basal area, canopy cover or a regeneration guarantee.
Ice Storm Canopy Retained Severity Percent
Audit measured retained live crown volume after storm against matched prestorm inventory and caller loss cutoff; canopy volume differs from shade/cover and observations do not establish future tree survival.