Soil pH — Benchmark Detail

Benchmark Value

No specific value — see range

Range: 7.5 to 8.5 pH

Optimal Range: 7.5 to 8.5

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.

Evidence & Context

For landscapes within the biome that are defined by calcareous parent materials, a naturally higher pH is expected and represents the healthy state for that specific context. The GWW soil profile itself shows pH increasing with depth to 8.5, indicating the presence of alkaline subsoils.

Metric Definition:

Optimal functional range for soil pH in calcareous soils measured in calcium chloride (CaCl2) solution

Benchmark Definition:

This benchmark represents the optimal soil pH range in calcareous soils measured in calcium chloride solution, reflecting natural conditions in temperate semi-arid shrublands and open woodlands under production forestry in Australia.

Justification:

Reflects the natural conditions reported for calcareous systems.

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

High pH is a natural characteristic of these soils. No evidence of a detrimental pH threshold from management. [Migration] Original wider evidence range: 6.5 – 9 (retained OptimalRange: 7.5 – 8.5)

Related Benchmarks

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