Soil pH — Benchmark Detail

Benchmark Value

No specific value — see range

Range: 6 to 8 pH

Optimal Range: 6 to 8

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

Contributing Benchmarks

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

Evidence & Context

A benchmark range of pH(w) 6.0 – 8.0 is proposed as the reference for best available condition.

Metric Definition:

Soil pH measured in water (pHw) as an indicator of soil acidity or alkalinity affecting ecosystem health.

Benchmark Definition:

This benchmark represents the natural pH range of healthy native woodland soils in the Arid Mountain Ranges & Uplands biome under production forestry land use, indicating a safe operating range for ecosystem function.

Justification:

The confidence level is Low due to the complete absence of established, sustainable Production Forestry operations within the Arid Mountain Ranges & Uplands biome, necessitating the use of a scientifically-derived proxy.

Sources (2)

Preview of Peppermint Box (Eucalyptus odorata) Grassy Woodland of South Australia, accessed August 9, 2025,

Peppermint Box (Eucalyptus odorata) Grassy Woodland of South Australia, accessed August 9, 2025, Journal

Northern Mount Lofty Ranges and Southern Flinders Ranges soil descriptions.

View Source

Peppermint Box (Eucalyptus odorata) Grassy Woodland of South Australia, accessed July 30, 2025, GreyLiterature

Peppermint Box (Eucalyptus odorata) Grassy Woodland of South Australia, accessed July 30, 2025,

View Source

Supporting Sources (3)

Additional references from the underlying research that informed this benchmark.

Government of South Australia, Department for Environment and Water. (n.d.). Soil Health and Condition.

Direct Evidence Government

Soil acidity - Department for Environment and Water, accessed July 30, 2025,

View Source

Soil acidity is starting to emerge in the Southern Mallee on certain soils types. - GRDC, accessed July 30, 2025,

Direct Evidence

Soil acidity is starting to emerge in the Southern Mallee on certain soils types. - GRDC, accessed July 30, 2025,

View Source

Soil pH - SA | Fact Sheets | soilquality.org.au

Direct Evidence Government

Soil pH - SA | Fact Sheets | soilquality.org.au, accessed July 30, 2025,

View Source

Context

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

Lifecycle

Status Active
Version 1
Effective From 25 Mar 2026

Notes

This range reflects the natural variability of soils from slightly acidic to moderately alkaline and represents a safe operating space for resilient ecosystem function. It is bounded by a lower critical threshold of pH(CaCl₂) < 5.0 and an upper detrimental threshold of pH(w) > 8.2.

Related Benchmarks

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