Soil Structure & Compaction

AUS-AMR-FOR-SSC General Moderate confidence

Benchmark Value

No specific value — see range

Thresholds: Lower: 1500, Upper: 3500

Direction: Lower is desirable ↓

Form: MinimumOnly

Scoring Curve

This curve shows how a field measurement for this indicator would score across all available benchmark forms in this context. The scoring engine uses 13 benchmarks together — the OptimalRange form drives the primary score, while 12 guard(s) constrain the result.

Contributing Benchmarks

OptimalRange Primary MinimumOnly Guard MinimumOnly Guard UpperThreshold Guard MaximumOnly Guard MaximumOnly Guard MaximumOnly Guard OptimalRange Guard MinimumOnly Guard Point Guard MaximumOnly Guard OptimalRange Guard LowerThreshold Guard

Evidence & Context

The upper detrimental threshold is defined by penetration resistance values greater than 3500 kPa, marking the point of near-complete cessation of root growth and ecosystem degradation.

Metric Definition:

Penetrometer resistance (PR) measured at field capacity indicating severe ecosystem degradation and cessation of root growth.

Benchmark Definition:

Penetrometer resistance threshold indicating severe soil degradation and loss of ecosystem function in production forestry soils.

Justification:

Based on evidence of mechanical failure and cascading negative biogeochemical and microbial shifts above this value.

Sources (1)

Preview of The Influence of Compaction and Soil Strength on the Establishment of Four Australian Landscape Trees | Arboriculture & Urban Forestry

The Influence of Compaction and Soil Strength on the Establishment of Four Australian Landscape Trees | Arboriculture & Urban Forestry Journal

Australia's State of the Forests Report, accessed May 15, 2025

View Source

Supporting Sources (1)

Additional references from the underlying research that informed this benchmark.

Preview of RELATIONSHIPS BETWEEN CONE PENETRATION RESISTANCE, BULK DENSITY, AND MOISTURE CONTENT IN UNCULTIVATED, REPACKED, AND CULTIVATED, accessed July 30, 2025,

RELATIONSHIPS BETWEEN CONE PENETRATION RESISTANCE, BULK DENSITY, AND MOISTURE CONTENT IN UNCULTIVATED, REPACKED, AND CULTIVATED, accessed July 30, 2025,

Direct Evidence Journal

Relationships between cone penetration resistance, bulk density, and moisture content in uncultivated, repacked, and cultivated hardsetting and non-hardsetting soils from the coastal lowlands of south-east Queensland, Australia

View Source

Context

Region Australia
Biome Arid Mountain Ranges & Uplands
Land Use Production Forestry
Assessment Pristine Reference
Evidence Type DegradationThreshold

Lifecycle

Status Active
Version 2
Effective From 21 Mar 2026

Notes

Includes anaerobic conditions, altered greenhouse gas fluxes, and degraded microbial communities. ConsistencyResolver applied 2026-03-23 00:19 UTC: BenchmarkValue 3500 → (check: MinAboveOptimalHigh, rationale: Clear BenchmarkValue to avoid duplication since the threshold is now set in UpperThreshold.) ConsistencyResolver applied 2026-03-23 00:19 UTC: LowerThreshold → (check: MinAboveOptimalHigh, rationale: Ensure LowerThreshold is null to avoid conflicting threshold definitions.) ConsistencyResolver applied 2026-03-23 00:20 UTC: UpperThreshold → 3500 (check: MinAboveOptimalHigh, rationale: The Notes and EvidenceStatement indicate that 3500 kPa is an upper degradation threshold (values above 3500 cause severe degradation). Moving this value to UpperThreshold will auto-correct the form from MinimumOnly to MaximumOnly, resolving the contradiction.) ConsistencyResolver applied 2026-03-23 00:20 UTC: LowerThreshold → 1500 (check: MinAboveMax, rationale: The Notes for 1500 kPa indicate a conservative target for best condition, consistent with a MinimumOnly lower threshold. Setting LowerThreshold=1500 resolves the contradiction.)

Related Benchmarks

Other benchmarks in the AUS-AMR-FOR-SSC family.