Soil Phosphorus

AUS-AMR-FOR-SOP General Low confidence

Benchmark Value

20 mg/kg

Direction: Higher 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. The scoring engine uses 14 benchmarks together — the OptimalRange form drives the primary score, while 13 guard(s) constrain the result.

Contributing Benchmarks

OptimalRange Primary MinimumOnly Guard MaximumOnly Guard Point Guard OptimalRange Guard MinimumOnly Guard MaximumOnly Guard Point Guard MinimumOnly Guard OptimalRange Guard MaximumOnly Guard Point Guard MinimumOnly Guard MaximumOnly 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:

Available soil phosphorus measured as Colwell-P, indicating the maximum critical level above which ecological harm occurs.

Benchmark Definition:

This benchmark defines the critical upper threshold of available soil phosphorus above which ecological toxicity and biodiversity loss occur in production forestry of arid mountain ranges and uplands in Australia.

Justification:

Supported by rehabilitation and ecotoxicology studies showing toxicity to native species and shifts in community composition at elevated phosphorus levels.

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. Journal

(PDF) Too much of a good thing: phosphorus over-fertilisation in ...

View Source

Supporting Sources (1)

Additional references from the underlying research that informed this benchmark.

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

Direct Evidence Journal

(PDF) Soil and vegetation response to thinning White Cypress Pine ...

View Source

Context

Region Australia
Biome Arid Mountain Ranges & Uplands
Land Use Production Forestry
Assessment Not Stated
Evidence Type DegradationThreshold

Lifecycle

Status Active
Version 1
Effective From 10 Jun 2026

Notes

Represents a clear ecological harm boundary; management should avoid exceeding this level to maintain ecosystem integrity. AssessmentContext defaulted to 'Not Stated' because the source document did not state one.

Related Benchmarks

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