Soil Phosphorus

AUS-AMR-FOR-SOP General Moderate confidence

Benchmark Value

20 mg/kg
Thresholds: Lower: —, Upper: 20
Direction: Higher is desirable ↑
Form: UpperThreshold

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 16 benchmarks together — the OptimalRange form drives the primary score, while 15 guard(s) constrain the result.

Contributing Benchmarks

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

Evidence & Context

Upper Detrimental Threshold: A Colwell-P level of > 20 mg/kg is considered detrimental to the ecological integrity of the native forest system.

Metric Definition:

Upper detrimental threshold for available soil phosphorus (Colwell-P) above which ecological integrity is harmed.

Benchmark Definition:

Upper detrimental threshold for available soil phosphorus (Colwell-P) above which ecological integrity is harmed.

Justification:

Negative effects begin to appear at lower concentrations (e.g., >15 mg/kg), but 20 mg/kg is the critical ceiling for ecological harm.

Sources (1)

Preview of Synthesis of peer-reviewed literature and government technical reports on soil phosphorus dynamics in managed Australian native ecosystems.
Synthesis of peer-reviewed literature and government technical reports on soil phosphorus dynamics in managed Australian native ecosystems.
View Source

Supporting Sources (1)

Additional references from the underlying research that informed this benchmark.

Preview of (PDF) Too much of a good thing: phosphorus over-fertilisation in ..., accessed July 30, 2025,
(PDF) Too much of a good thing: phosphorus over-fertilisation in ..., accessed July 30, 2025,
Direct Evidence Journal

Review of fertiliser use in Australian forestry - Forest & Wood ..., accessed July 30, 2025,

View Source

Context

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

Lifecycle

  • Status Active
  • Version 1
  • Effective From 24 Mar 2026

Notes

Corresponds to the 'High' and 'Very High' classifications and indicates a condition inconsistent with ecologically sustainable forest management.

Related Benchmarks

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

— mg/kg Moderate
Production Forestry · Pristine Reference
OptimalRange Active v2
5 mg/kg Moderate
Production Forestry · Pristine Reference
LowerThreshold Active v1
— mg/kg Moderate
Production Forestry · Pristine Reference
OptimalRange Superseded v1