Microbial Respiration

AUS-AMR-CON-SMR General Moderate confidence

Benchmark Value

4.1 mg/kg/day

Direction: Higher is desirable ↑

Form: MinimumOnly

Scoring Curve

This curve shows how a field measurement for this indicator would score across all available benchmark forms in this context.

Evidence & Context

A critically low state is characterized by respiration rates below approximately 4.1 mg CO₂-C/kg/day.

Metric Definition:

Basal Microbial Respiration (BMR) rate below which soil biological function is significantly compromised.

Benchmark Definition:

Lower critical boundary for basal microbial respiration indicating a significantly compromised soil biological function.

Justification:

This threshold is based on observed respiration rates in low-resource patches under Triodia spinifex, representing degraded or resource-poor conditions within the landscape.

Sources (1)

Preview of Biochemical properties of highly mineralised and infertile soil modified by acacia and spinifex plants in northwest Queensland, Australia

Biochemical properties of highly mineralised and infertile soil modified by acacia and spinifex plants in northwest Queensland, Australia Journal

Biogeographical patterns of the soil fungal:bacterial ratio across France - PubMed Central

View Source

Supporting Sources (20)

Additional references from the underlying research that informed this benchmark.

Aridity thresholds of soil microbial metabolic indices along a 3,200 ..., accessed August 3, 2025

Contextual Support Journal

Aridity thresholds of soil microbial metabolic indices along a 3,200 ...

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Australia - Soils, Climate, Erosion | Britannica

Contextual Support GreyLiterature

SOIL TESTING

View Source

Preview of Australian dryland soils are acidic and nutrient-depleted, and have unique microbial communities compared with other drylands - PMC, accessed August 5, 2025,

Australian dryland soils are acidic and nutrient-depleted, and have unique microbial communities compared with other drylands - PMC, accessed August 5, 2025,

Contextual Support Journal

How should we manage our soils to increase soil carbon?, accessed May 10, 2026

View Source

Preview of Australian dryland soils are acidic and nutrient‐depleted, and have unique microbial communities compared with other drylands - Arid Ecology Lab, accessed August 3, 2025

Australian dryland soils are acidic and nutrient‐depleted, and have unique microbial communities compared with other drylands - Arid Ecology Lab, accessed August 3, 2025

Contextual Support Government

Soil Inorganic Carbon, the Other and Equally Important Soil Carbon Pool: Distribution, Controlling Factors, and the Impact of C

View Source

Preview of Basal and specific microbial respiration in semiarid agricultural soils: Organic amendment and irrigation management effects - Taylor & Francis Online, accessed August 3, 2025

Basal and specific microbial respiration in semiarid agricultural soils: Organic amendment and irrigation management effects - Taylor & Francis Online, accessed August 3, 2025

Contextual Support Journal

Basal and specific microbial respiration in semiarid agricultural soils: Organic amendment and irrigation management effects - Taylor & Francis Online

View Source

Carbon Pool Dynamic and Soil Microbial Respiration Affected by ...

Contextual Support Journal

Carbon Pool Dynamic and Soil Microbial Respiration Affected by Land Use Alteration: A Case Study in Humid Subtropical Area - MDPI

View Source

Preview of Contribution of microbial activity and vegetation cover to the spatial distribution of soil respiration in mountains - Frontiers, accessed August 28, 2025,

Contribution of microbial activity and vegetation cover to the spatial distribution of soil respiration in mountains - Frontiers, accessed August 28, 2025,

Contextual Support Journal

Contribution of microbial activity and vegetation cover to the spatial distribution of soil respiration in mountains - Frontiers

View Source

Preview of Final Technical Report - Quantifying the effectiveness of cover crops to increase water infiltration and reduce evaporation in the northern region, accessed July 9, 2025

Final Technical Report - Quantifying the effectiveness of cover crops to increase water infiltration and reduce evaporation in the northern region, accessed July 9, 2025

Contextual Support Journal

Fire and land use impact soil properties in a Mediterranean dry sclerophyll woodland

View Source

Great Western Woodlands Flux Data Release 2022_v2

Contextual Support

Soil | Australia state of the environment 2021

View Source

Land | State of the Environment Report 2011

Contextual Support Journal

Australian dryland soils are acidic and nutrient-depleted, and have unique microbial communities compared with other drylands - PMC, accessed August 28, 2025

View Source

Preview of Microbial community composition and activity in paired irrigated and non-irrigated pastures in New Zealand - CSIRO Publishing, accessed August 3, 2025

Microbial community composition and activity in paired irrigated and non-irrigated pastures in New Zealand - CSIRO Publishing, accessed August 3, 2025

Contextual Support Journal

Microbial community composition and activity in paired irrigated and non-irrigated pastures in New Zealand - CSIRO Publishing, accessed July 29, 2025

View Source

National Soil Monitoring Program - CSIRO, accessed August 4, 2025,

Contextual Support GreyLiterature

National Soil Monitoring Program - CSIRO, accessed July 8, 2025

View Source

Preview of Productivity and Seasonality Drive Total Soil Respiration in Semi-Arid Juniper Woodlands (Juniperus thurifera L., Southern Spain) - MDPI, accessed August 3, 2025

Productivity and Seasonality Drive Total Soil Respiration in Semi-Arid Juniper Woodlands (Juniperus thurifera L., Southern Spain) - MDPI, accessed August 3, 2025

Contextual Support Journal

Productivity and Seasonality Drive Total Soil Respiration in Semi-Arid Juniper Woodlands (Juniperus thurifera L., Southern Spain) - MDPI

View Source

Soil the driver of carbon dioxide variability over Australia | TERN Australia, accessed August 28, 2025,

Contextual Support Government

Soil respiration–driven CO2 pulses dominate Australia's flux variability

View Source

Soil Constraints in an Arid Environment—Challenges, Prospects, and Implications - MDPI, accessed July 6, 2025,

Contextual Support Journal

Soil Constraints in an Arid Environment—Challenges, Prospects, and Implications - MDPI

View Source

Soil Microbial Activity in Conventional and Organic Agricultural ..., accessed July 28, 2025

Contextual Support GreyLiterature

Soil respiration dynamics in fire affected semi-arid ecosystems: Effects of vegetation type and environmental factors | Request PDF - ResearchGate

View Source

Soil Research - CSIRO PUBLISHING, accessed August 5, 2025,

Contextual Support Journal

Soil Research - CSIRO PUBLISHING

View Source

Summary of the collections of arid soils from Australia. - ResearchGate

Contextual Support GreyLiterature

Summary of the collections of arid soils from Australia. - ResearchGate

View Source

Preview of The Biogeography of Soil Bacteria in Australia Exhibits Greater Resistance to Climate Change Than Fungi - PubMed Central, accessed July 28, 2025

The Biogeography of Soil Bacteria in Australia Exhibits Greater Resistance to Climate Change Than Fungi - PubMed Central, accessed July 28, 2025

Contextual Support Journal

Soil and Landscape Grid National Soil Attribute Maps - Soil Bacteria and Fungi Beta Diversity (3" resolution) - Release 1 - Research Data Australia

View Source

Preview of Twenty years of progress, challenges, and opportunities in measuring and understanding soil respiration - Forest Service, accessed August 3, 2025

Twenty years of progress, challenges, and opportunities in measuring and understanding soil respiration - Forest Service, accessed August 3, 2025

Contextual Support

Twenty years of progress, challenges, and opportunities in measuring and understanding soil respiration - Forest Service

View Source

Context

Region Australia
Biome Arid Mountain Ranges & Uplands
Land Use Conservation / Protected Natural Areas
Assessment Pristine Reference
Evidence Type DegradationThreshold

Lifecycle

Status Active
Version 1
Effective From 5 Jun 2026

Notes

No upper detrimental threshold — higher values are always better up to natural saturation. Rates below this value suggest a low-functioning state characteristic of degraded areas or patches with severe water and nutrient limitation.

Related Benchmarks

Other benchmarks in the AUS-AMR-CON-SMR family.