Soil Organic Carbon (SOC)

AUS-AIF-FOR-SOC General Moderate confidence

Benchmark Value

4.5 %

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 13 benchmarks together — the OptimalRange form drives the primary score, while 12 guard(s) constrain the result.

Contributing Benchmarks

OptimalRange Primary Point Guard Point Guard LowerThreshold Guard OptimalRange Guard Point Guard MinimumOnly Guard LowerThreshold Guard MaximumOnly Guard OptimalRange Guard Point Guard LowerThreshold Guard OptimalRange Guard

Evidence & Context

The key finding for this report is that these communities had "up to 4.5% C content in the surface (0–5 cm) soil".

Metric Definition:

Soil Organic Carbon (SOC) content in the surface soil layer (0–5 cm depth)

Benchmark Definition:

This benchmark represents the highest Soil Organic Carbon content measured in surface soils (0–5 cm) of mature River Red Gum forest communities in the Arid Inland Floodplains biome, indicating peak ecological function and carbon storage under favorable conditions.

Justification:

This value of ~4.5% is selected as the benchmark for the best available condition as it represents the highest level of ecological function and carbon storage achieved in the field under favorable conditions in mature River Red Gum forest communities on clay-rich floodplains.

Sources (1)

Preview of Carbon storage in temperate and semi-arid Australian plant communities containing cotton

Carbon storage in temperate and semi-arid Australian plant communities containing cotton Journal

Baseline map of organic carbon in Australian soil to support national carbon accounting and monitoring under climate change

Supporting Sources (20)

Additional references from the underlying research that informed this benchmark.

Preview of (PDF) Rivers in Australia - ResearchGate

(PDF) Rivers in Australia - ResearchGate

Contextual Support Journal

Fluvial Form Variability in Arid Central Australia - Smithsonian Institution

Preview of (PDF) Rivers in Australia - ResearchGate, accessed July 16, 2025,

(PDF) Rivers in Australia - ResearchGate, accessed July 16, 2025,

Contextual Support

Modelling the flow regime of an arid zone floodplain river, Diamantina River, Australia | Request PDF - ResearchGate

Preview of (PDF) Soil Organic Carbon for Enhancing Soil Health - ResearchGate

(PDF) Soil Organic Carbon for Enhancing Soil Health - ResearchGate

Contextual Support GreyLiterature

Soil Organic Carbon (SOC): Importance and Impacts on Soil Health, Plant Growth, Environment & More - Advance Pesticides

Preview of (PDF) Sources, sinks and transformations of organic carbon in ...

(PDF) Sources, sinks and transformations of organic carbon in ...

Contextual Support Journal

(PDF) Sources, sinks and transformations of organic carbon in ...

Preview of 4 reasons to measure Soil Organic Carbon | AgroCares

4 reasons to measure Soil Organic Carbon | AgroCares

Contextual Support GreyLiterature

4 reasons to measure Soil Organic Carbon | AgroCares

Preview of How Much Carbon Can Soil Store | Fact Sheets | soilquality.org.au

How Much Carbon Can Soil Store | Fact Sheets | soilquality.org.au

Contextual Support Government

How Much Carbon Can Soil Store | Fact Sheets | soilquality.org.au

Preview of Impacts of Soil Organic Carbon on Soil Physical Behavior - USDA ARS

Impacts of Soil Organic Carbon on Soil Physical Behavior - USDA ARS

Contextual Support Journal

Impacts of Soil Organic Carbon on Soil Physical Behavior - USDA ARS

Preview of Impacts of Soil Organic Carbon on Soil Physical Behavior | Health & Environmental Research Online (HERO) | US EPA

Impacts of Soil Organic Carbon on Soil Physical Behavior | Health & Environmental Research Online (HERO) | US EPA

Contextual Support Government

Impacts of Soil Organic Carbon on Soil Physical Behavior | Health & Environmental Research Online (HERO) | US EPA

Preview of Mean total organic carbon (TOC) distribution (AE1 s.e.m.) by vegetation... - ResearchGate

Mean total organic carbon (TOC) distribution (AE1 s.e.m.) by vegetation... - ResearchGate

Contextual Support GreyLiterature

Mean total organic carbon (TOC) distribution (AE1 s.e.m.) by vegetation... - ResearchGate

Preview of ORGANIC CARBON IN FORESTED SANDY SOILS: PROPERTIES, PROCESSES, AND THE IMPACT OF FOREST MANAGEMENT - Scion

ORGANIC CARBON IN FORESTED SANDY SOILS: PROPERTIES, PROCESSES, AND THE IMPACT OF FOREST MANAGEMENT - Scion

Contextual Support Journal

FOREST CARBON MARKETS - Forestry Australia, accessed July 21, 2025

Preview of pmc.ncbi.nlm.nih.gov

pmc.ncbi.nlm.nih.gov

Contextual Support Journal

pmc.ncbi.nlm.nih.gov

Preview of Rivers, wetlands and floodplains | Murray–Darling Basin Authority

Rivers, wetlands and floodplains | Murray–Darling Basin Authority

Contextual Support Journal

Rivers, wetlands and floodplains | Murray–Darling Basin Authority

Preview of Soil carbon saturation: Linking concept and measurable carbon pools

Soil carbon saturation: Linking concept and measurable carbon pools

Contextual Support Journal

The six rights of how and when to test for soil C saturation - Copernicus.org

Preview of Soil Carbon Saturation: Linking Concept and Measurable Carbon Pools - ResearchGate

Soil Carbon Saturation: Linking Concept and Measurable Carbon Pools - ResearchGate

Contextual Support Journal

Soil Carbon Saturation: Linking Concept and Measurable Carbon Pools - ResearchGate

Preview of Soil Carbon Saturation: What Do We Really Know? (Journal Article) | OSTI.GOV, accessed August 3, 2025,

Soil Carbon Saturation: What Do We Really Know? (Journal Article) | OSTI.GOV, accessed August 3, 2025,

Contextual Support Journal

(PDF) Mapping soil organic carbon fractions for Australia, their stocks, and uncertainty

Preview of Soils and carbon for reduced emissions - Agriculture Victoria, accessed July 6, 2025,

Soils and carbon for reduced emissions - Agriculture Victoria, accessed July 6, 2025,

Contextual Support Government

Soils and carbon for reduced emissions - Agriculture Victoria, accessed July 21, 2025,

Preview of The relationships between land management practices and soil condition and the quality of ecosystem services delivered from agri - DAFF, accessed July 22, 2025,

The relationships between land management practices and soil condition and the quality of ecosystem services delivered from agri - DAFF, accessed July 22, 2025,

Direct Evidence Journal

Maintaining groundcover to reduce erosion and sustain production - NSW Department of Primary Industries

Preview of Too Much Organic Matter - Maine Organic Farmers and Gardeners Association

Too Much Organic Matter - Maine Organic Farmers and Gardeners Association

Contextual Support GreyLiterature

Too Much Organic Matter - Maine Organic Farmers and Gardeners Association

Preview of Western Australia - Arid, Semi-arid, Mediterranean | Britannica, accessed July 13, 2025

Western Australia - Arid, Semi-arid, Mediterranean | Britannica, accessed July 13, 2025

Contextual Support GreyLiterature

Climate of South Australia - Britannica, accessed July 13, 2025

Preview of What Kind of Harm Can Come From Soil Organic Matter?

What Kind of Harm Can Come From Soil Organic Matter?

Contextual Support GreyLiterature

What Kind of Harm Can Come From Soil Organic Matter?

Context

Region Australia
Biome Arid Inland Floodplains & Ephemeral River Systems
Land Use Production Forestry
Assessment Pristine Reference
Evidence Type ReferenceCondition

Lifecycle

Status Active
Version 1
Effective From 18 Mar 2026

Notes

The benchmark is derived from direct measurements in high-health, mature River Red Gum forests on clay-rich floodplains, representing a high-functioning forest ecosystem likely at or near its natural carbon saturation capacity.

Related Benchmarks

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