Soil Electrical Conductivity (EC)

AUS-AIF-FOR-SEC General Moderate confidence

Benchmark Value

20 dS/m

Direction: Lower 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 12 benchmarks together — the OptimalRange form drives the primary score, while 11 guard(s) constrain the result.

Contributing Benchmarks

OptimalRange Primary UpperThreshold Guard MaximumOnly Guard MinimumOnly Guard OptimalRange Guard MinimumOnly Guard MaximumOnly Guard MaximumOnly Guard OptimalRange Guard MinimumOnly Guard OptimalRange Guard MaximumOnly Guard

Evidence & Context

Therefore, an ECe of > 20 dS/m is proposed as the upper detrimental threshold. At this level, the system is considered to be in a degraded state, characterized by widespread tree stress, mortality, and loss of ecological function.

Metric Definition:

Soil Electrical Conductivity (ECe) measured as saturated paste extract, representing soil salinity affecting plant health.

Benchmark Definition:

This benchmark defines the upper detrimental soil salinity threshold above which significant ecosystem degradation occurs in Australian arid inland floodplains.

Justification:

Based on evidence of widespread dieback and classification of sodic clays with ECe > 13 dS/m as saline, significant ecosystem damage begins well before the physiological limit of 40 dS/m.

Sources (2)

Preview of Common soil types | Environment, land and water - Queensland Government, accessed August 9, 2025

Common soil types | Environment, land and water - Queensland Government, accessed August 9, 2025 Government

Sodic & Alkaline Soil - Soil Quality Knowledge Base

View Source

Preview of Modelling vegetation health from the interaction of saline groundwater and flooding on the Chowilla floodplain, South Australia - CSIRO Publishing, accessed July 21, 2025,

Modelling vegetation health from the interaction of saline groundwater and flooding on the Chowilla floodplain, South Australia - CSIRO Publishing, accessed July 21, 2025, Journal

Modelling vegetation health from the interaction ... - CSIRO Publishing

View Source

Supporting Sources (2)

Additional references from the underlying research that informed this benchmark.

Salinity and sodicity - Queensland Government publications

Direct Evidence Journal

Salinity and sodicity - Queensland Government publications

View Source

Slavich et al. (1999) via Bioregional Assessments

Direct Evidence

Slavich et al. (1999) via Bioregional Assessments

View Source

Context

Region Australia
Biome Arid Inland Floodplains & Ephemeral River Systems
Land Use Production Forestry
Assessment Not Stated
Evidence Type DegradationThreshold

Lifecycle

Status Active
Version 2
Effective From 3 Jun 2026

Notes

This threshold marks the onset of a degraded state with widespread tree stress and mortality. AssessmentContext defaulted to 'Not Stated' because the source document did not state one.

Related Benchmarks

Other benchmarks in the AUS-AIF-FOR-SEC family.