Soil pH — Benchmark Detail

Benchmark Value

7.2 pH

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 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 detailed soil profile from a Salmon Gum (Eucalyptus salmonophloia) site within the GWW reports a topsoil (0-5 cm) pH value of 7.2, measured in a calcium chloride (CaCl2) solution.

Metric Definition:

Soil pH measured in a calcium chloride (CaCl2) solution in topsoil (0-5 cm)

Benchmark Definition:

This benchmark represents the soil pH measured in a calcium chloride solution in the topsoil of temperate semi-arid shrublands and open woodlands under production forestry in Australia.

Justification:

The benchmark is from a high-integrity TERN reference site, representing the 'best available condition' achievable under Ecologically Sustainable Forest Management (ESFM).

Sources (1)

Preview of Soil | Australia state of the environment 2021, accessed August 12, 2025,

Soil | Australia state of the environment 2021, accessed August 12, 2025, Journal

OzFlux-TERN GWW SuperSite presentation: Soil Chemical Properties

View Source

Supporting Sources (1)

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

Context

Region Australia
Biome Temperate Semi-Arid Shrublands & Open Woodlands
Land Use Production Forestry
Assessment Pristine Reference
Evidence Type ReferenceCondition

Lifecycle

Status Active
Version 1
Effective From 24 Mar 2026

Notes

The primary chemical degradation risk in this biome is acidification. There is no evidence for an Upper Detrimental Threshold caused by management; very high pH (>8.5) is a natural feature of calcareous or saline soils, where Electrical Conductivity (EC) becomes the more critical limiting factor.

Related Benchmarks

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