Soil Structure & Compaction

AUS-TDG-CON-SSC General High confidence

Benchmark Value

2300 kPa

Direction: Lower is desirable ↓

Form: MaximumOnly

Scoring Curve

This curve shows how a field measurement for this indicator would score across all available benchmark forms in this context.

Evidence & Context

The critical soil strength (measured with a cone penetrometer) above which woody plant root elongation is severely restricted is in the vicinity of 2.3 MPa, depending on soil type and plant species (Day and Bassuk 1994).

Metric Definition:

Cone penetrometer penetration resistance at field capacity representing critical soil strength for woody species.

Benchmark Definition:

Degradation threshold for severe root elongation restriction in woody perennials in temperate woodlands.

Justification:

This literature synthesis specifically analyzes the biophysics of root restriction in woody perennial species, which is highly applicable to the woody overstorey component of temperate woodlands.

Sources (1)

Compacted Soil as a Permeable Impediment Journal

Compacted Soil as a Permeable Impediment

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Supporting Sources (4)

Additional references from the underlying research that informed this benchmark.

(PDF) The effect of soil compaction on germination and early growth ..., accessed August 4, 2025,

Direct Evidence Journal

The effect of soil compaction on germination and early growth of Eucalyptus albens and an exotic annual grass

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Changes to soil physical properties after grazing exclusion

Irrelevant

Changes to soil physical properties after grazing exclusion

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SOIL CARBON EDITION - North Central Catchment Management Authority, accessed July 28, 2025,

Direct Evidence Government

Detecting soil compaction

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Soil penetration resistance and tree root development | Request PDF - ResearchGate, accessed May 16, 2025,

Direct Evidence Journal

Soil penetration resistance and tree root development

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Context

Region Australia
Biome Temperate Dry Woodlands & Native Grasslands
Land Use Conservation / Protected Natural Areas
Assessment Conservation Target
Vegetation Woodland
Evidence Type DegradationThreshold

Lifecycle

Status Active
Version 1
Effective From 20 Jun 2026

Notes

Woody species root tips show severe cell division and elongation restrictions when physical resistance exceeds this threshold, limiting recruitment and structural development.

Related Benchmarks

Other benchmarks in the AUS-TDG-CON-SSC family.