Soil Phosphorus

AUS-TSR-CON-SOP General Moderate confidence

Benchmark Value

1300 mg/kg
Direction: Higher is desirable ↑
Form: Point

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 2 benchmarks together — the Point form drives the primary score, while 1 guard(s) constrain the result.

Contributing Benchmarks

Point Primary MaximumOnly Guard

Evidence & Context

Total P Benchmark: The undisturbed granitic site at Mt Spec, North Queensland, has a mean Total P of ~1300 mg/kg.

Metric Definition:

Total Phosphorus (Total P): This measures the entire stock of phosphorus in the soil, including mineral, organic, and occluded forms.

Benchmark Definition:

This benchmark represents the total phosphorus stock in granitic soils of undisturbed rainforest at Mt Spec, North Queensland.

Justification:

This value represents the measured reality in a protected, mature rainforest and is comparable to the mesotrophic sites.

Sources (1)

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

Supporting Sources (1)

Additional references from the underlying research that informed this benchmark.

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)
Contextual Support GreyLiterature

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

View Source

Context

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

Lifecycle

  • Status Superseded
  • Version 1
  • Effective From 25 Mar 2026
  • Effective To 25 Mar 2026

Notes

Rainforests on granitic soils exist at the lower end of the biome's fertility spectrum. While described as having comparatively low fertility, they are still functional, high-integrity ecosystems. No upper detrimental threshold — higher values are always better up to natural saturation.

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
— mg/kg Moderate
Conservation / Protected Natural Areas · Pristine Reference
OptimalRange 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