Soil Phosphorus

AUS-TSR-CON-SOP General Moderate confidence

Benchmark Value

No specific value — see range
Range: 10 to 60 mg/kg
Thresholds: Lower: 10, Upper: —
Optimal Range: 10 to 60
Direction: Higher is desirable ↑
Form: OptimalRange

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 7 benchmarks together — the OptimalRange form drives the primary score, while 6 guard(s) constrain the result.

Contributing Benchmarks

OptimalRange Primary MaximumOnly Guard OptimalRange Guard MinimumOnly Guard MaximumOnly Guard OptimalRange Guard MinimumOnly Guard

Evidence & Context

Indicator Name: Soil Phosphorus Reference Value: 10 - 60 Unit: mg/kg Source Title: Plant-soil nutrient relationships in the wet tropical rainforests of north Queensland, Australia (Maycock 1998); Nutrient relationships of tree species in a New South Wales Subtropical rainforest (Turner & Lambert 1990); Tool 2.8: Soil nutrient critical limits (Meat & Livestock Australia 2020) Source URL or DOI: (Maycock 1998); (Turner & Lambert 1990); (MLA 2020) Confidence Level: Moderate

Metric Definition:

Available Phosphorus (Colwell P or equivalent) measured or inferred in the topsoil (0-10 cm) of undisturbed, high-integrity rainforest conservation areas.

Benchmark Definition:

This benchmark represents the range of Available Phosphorus measured in the topsoil of undisturbed, high-integrity rainforest conservation areas in Australian tropical and subtropical rainforests.

Justification:

The confidence is Moderate, as the value is based on high-quality field data but requires inference for some soil types due to data anomalies in primary sources.

Sources (2)

Preview of Nutrient relationships of tree species in a New South Wales Subtropical rainforest (Turner & Lambert 1990)
Nutrient relationships of tree species in a New South Wales Subtropical rainforest (Turner & Lambert 1990) GreyLiterature

Tool 2.8: Soil nutrient critical limits (Meat & Livestock Australia 2020)

View Source
Preview of Plant-soil nutrient relationships in the wet tropical rainforests of north Queensland, Australia (Maycock 1998)
Plant-soil nutrient relationships in the wet tropical rainforests of north Queensland, Australia (Maycock 1998) Journal

Plant-soil nutrient relationships in the wet tropical rainforests of north Queensland, Australia (Maycock 1998)

View Source

Context

  • Region Australia
  • Biome Tropical & Subtropical Rainforests
  • Land Use Conservation / Protected Natural Areas
  • Assessment Pristine Reference
  • Evidence Type ReferenceCondition

Lifecycle

  • Status Active
  • Version 1
  • Effective From 25 Mar 2026

Notes

Lower Critical Threshold: 10 mg/kg. The natural phosphorus status varies by soil parent material, creating a fertility spectrum from oligotrophic to eutrophic systems. Phosphorus enrichment above natural ranges is detrimental.

Related Benchmarks

Other benchmarks in the AUS-TSR-CON-SOP family.

100 mg/kg Moderate
Conservation / Protected Natural Areas · Pristine Reference
Point Active v2
10 mg/kg Moderate
Conservation / Protected Natural Areas · Pristine Reference
MinimumOnly Active v1
20 mg/kg Moderate
Conservation / Protected Natural Areas · Pristine Reference
MaximumOnly Active v1
60 mg/kg Moderate
Conservation / Protected Natural Areas · Pristine Reference
MaximumOnly Active v1
3030 mg/kg Moderate
Conservation / Protected Natural Areas · Pristine Reference
Point Active v1
— mg/kg Moderate
Conservation / Protected Natural Areas · Pristine Reference
OptimalRange Active v1
1300 mg/kg Moderate
Conservation / Protected Natural Areas · Pristine Reference
Point Superseded v1