Interior Forest Edge Ratio From Patch Size
Evaluate rectangular patch interior/edge areas under a caller uniform inward edge-depth model; no coordinate buffers, patch shape inference or biodiversity outcome; absent interior makes edge/interior ratio undefined.
Description
A rectangular forest patch loses modeled interior when a uniform edge influence extends inward.
A rectangular forest patch loses modeled interior when a uniform edge influence extends inward. An edge/interior ratio is undefined if all patches have zero interior.1
Evaluate rectangular patch interior/edge areas under a caller uniform inward edge-depth model; no coordinate buffers, patch shape inference or biodiversity outcome; absent interior makes edge/interior ratio undefined.
When to use Interior Forest Edge Ratio From Patch Size
Use this tool to evaluate rectangular patch interior/edge areas under a caller uniform inward edge-depth model; no coordinate buffers, patch shape inference or biodiversity outcome; absent interior makes edge/interior ratio undefined.
Gather the tree inventory, plot measurements or model parameters. Check diameter, area, time and moisture conventions; keep paired observations aligned.
How to use Interior Forest Edge Ratio From Patch Size 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 rectangularPatchLengthsM, rectangularPatchWidthsM, callerEdgeInfluenceDepthM using the field table and calculation rules, then run the tool.
- Read interiorPatchAreasM2, pooledInteriorAreaFraction, pooledEdgeToInteriorAreaRatio. 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 |
|---|---|---|---|
| rectangularPatchLengthsM | Rectangular patch lengths m | list of number | Required |
| rectangularPatchWidthsM | Rectangular patch widths m | list of number | Required |
| callerEdgeInfluenceDepthM | Caller edge influence depth m | number | Required |
Pair positive rectangular lengths/widths and nonnegative caller edge depth in meters. Sum interior and total areas, require positive pooled interior and return patch interiors, pooled interior fraction and edge/interior ratio.
Paired lists must be nonempty and have equal lengths.
interior=max(0,length−2depth)max(0,width−2depth) Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.
| Output field | Meaning | Value type |
|---|---|---|
| interiorPatchAreasM2 | Interior patch areas m2 | list of number |
| pooledInteriorAreaFraction | Pooled interior area fraction | number |
| pooledEdgeToInteriorAreaRatio | Pooled edge to interior area ratio | number |
{
"input": {
"rectangularPatchLengthsM": [
100,
50
],
"rectangularPatchWidthsM": [
100,
20
],
"callerEdgeInfluenceDepthM": 10
},
"output": {
"interiorPatchAreasM2": [
6400,
0
],
"pooledInteriorAreaFraction": 0.5818181818181818,
"pooledEdgeToInteriorAreaRatio": 0.71875
}
}Limitations and assumptions
No geographic buffering or biodiversity outcome is computed. Rectangular geometry and uniform influence depth are assumptions.
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 Class-Level Contagion Fragmentation Metric: Compute named class contagion from supplied class proportions and directed adjacency counts, omitting zero probability log terms; no raster processing/geodesy and adjacency counting convention must remain consistent. For a complementary task, use Snag Wildlife HSI: Aggregate caller independently calibrated snag-habitat component scores by weighted geometric mean, retaining limiting zero components; not species presence probability or validated habitat suitability.
References
Similar or alternative tools
- Class-Level Contagion Fragmentation Metric
Compute named class contagion from supplied class proportions and directed adjacency counts, omitting zero probability log terms; no raster processing/geodesy and adjacency counting convention must remain consistent.
- Snag Wildlife HSI
Aggregate caller independently calibrated snag-habitat component scores by weighted geometric mean, retaining limiting zero components; not species presence probability or validated habitat suitability.