Microbial Respiration

AUS-TMS-CON-SMR General Moderate confidence

Benchmark Value

6 mg/kg/day

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 5 benchmarks together — the OptimalRange form drives the primary score, while 4 guard(s) constrain the result.

Contributing Benchmarks

OptimalRange Primary Point Guard Point Guard Point Guard Point Guard

Evidence & Context

This derived value of 6.0 mg CO2-C/kg/day is proposed as the reference benchmark.

Metric Definition:

Microbial respiration is a fundamental ecological process reflecting the metabolic activity of soil microorganisms... involving the decomposition of soil organic matter (SOM) by bacteria, fungi, and other microbes, which results in the release of carbon dioxide (CO2).

Benchmark Definition:

This benchmark represents the basal microbial respiration rate in the topsoil of tropical monsoonal savanna woodlands under conservation management in Australia, reflecting healthy soil microbial activity during the wet season.

Justification:

The selected reference value of 6.0 mg CO2-C/kg/day is derived from Manzoni et al. (2016). This value represents basal soil respiration from the topsoil (0-10 cm) of a savanna woodland located near Darwin, NT... based on laboratory measurements conducted under "unheated" (ambient temperature) and "wet" (20% Gravimetric Water Content) conditions.

Sources (1)

Preview of Carbon and nitrogen stores in a savanna landscape in the Berrimah Agricultural Research Centre, northern Australia. CSIRO.

Carbon and nitrogen stores in a savanna landscape in the Berrimah Agricultural Research Centre, northern Australia. CSIRO. Journal

Davies, J. (2017). Carbon and water exchange in Australian tropical savannas. PhD Thesis, James Cook University.

View Source

Supporting Sources (13)

Additional references from the underlying research that informed this benchmark.

A review on effective soil health bio-indicators for ... - Frontiers

Contextual Support Journal

A review on effective soil health bio-indicators for ... - Frontiers

View Source

A review on effective soil health bio-indicators for ecosystem restoration and sustainability, accessed August 5, 2025,

Contextual Support Journal

Microorganisms as Indicators of Soil Health, accessed August 10, 2025

View Source

A review on effective soil health bio-indicators for ecosystem restoration and sustainability, accessed on June 7, 2025

Contextual Support Journal

A review on effective soil health bio-indicators for ecosystem restoration and sustainability, accessed on June 7, 2025

View Source

Can moisture affect temperature dependences of microbial growth and respiration? | Request PDF - ResearchGate

Contextual Support Direct Evidence Methodology Source GreyLiterature

Determinants of soil respiration in a semi-arid savanna ecosystem, Kruger National Park, South Africa

View Source

Carbon | Australia state of the environment 2021, accessed on June 7, 2025,

Contextual Support Government

CO₂ sink to source: Arid Australia's climate and rainfall driven tipping points

View Source

Carbon balance of a tropical savanna of northern Australia - CiteSeerX, accessed July 24, 2025,

Contextual Support GreyLiterature

Submission to the ERAC review of the ACCU scheme's 2021 measurement and modelled soil carbon method

View Source

Preview of Community Composition and Abundance of Bacterial, Archaeal and Nitrifying Populations in Savanna Soils on Contrasting Bedrock Material in Kruger National Park, South Africa - Frontiers, accessed on June 7, 2025

Community Composition and Abundance of Bacterial, Archaeal and Nitrifying Populations in Savanna Soils on Contrasting Bedrock Material in Kruger National Park, South Africa - Frontiers, accessed on June 7, 2025

Contextual Support Cross Reference Direct Evidence Journal

Community Composition and Abundance of Bacterial, Archaeal and Nitrifying Populations in Savanna Soils on Contrasting Bedrock Material in Kruger National Park, South Africa - Frontiers

View Source

Determinants of soil respiration in a semi-arid savanna ecosystem, Kruger National Park, South Africa, accessed July 30, 2025,

Contextual Support Journal

Touching on Practices for Grazing Management in Tropical and Subtropical Pastures

View Source

Preview of Fire regime impacts on soil microbes, soil organic carbon and ground cover in an Australian tropical savanna - CSIRO Publishing, accessed May 16, 2025,

Fire regime impacts on soil microbes, soil organic carbon and ground cover in an Australian tropical savanna - CSIRO Publishing, accessed May 16, 2025,

Contextual Support Direct Evidence Journal

Plant community characteristics of the CSIRO Car- digan research site, Queensland, Australia. - ResearchGate

View Source

Preview of Role of Soil Microbiota Enzymes in Soil Health and Activity Changes Depending on Climate Change and the Type of Soil Ecosystem, accessed on June 7, 2025

Role of Soil Microbiota Enzymes in Soil Health and Activity Changes Depending on Climate Change and the Type of Soil Ecosystem, accessed on June 7, 2025

Contextual Support Journal

Role of Soil Microbiota Enzymes in Soil Health and Activity Changes Depending on Climate Change and the Type of Soil Ecosystem, accessed on June 7, 2025

View Source

Soil Respiration - Natural Resources Conservation Service, accessed July 30, 2025,

Contextual Support Cross Reference Journal

Temperate Grasslands - Greening Australia, accessed August 12, 2025,

View Source

Soil Respiration - Natural Resources Conservation Service, accessed on June 7, 2025

Contextual Support Methodology Source Journal

Soil Respiration - Natural Resources Conservation Service

View Source

Preview of The Effect of Microbial Diversity and Biomass on Microbial Respiration in Two Soils along the Soil Chronosequence - PMC - PubMed Central, accessed on June 7, 2025

The Effect of Microbial Diversity and Biomass on Microbial Respiration in Two Soils along the Soil Chronosequence - PMC - PubMed Central, accessed on June 7, 2025

Contextual Support Journal

The Effect of Microbial Diversity and Biomass on Microbial Respiration in Two Soils along the Soil Chronosequence - PMC - PubMed Central

View Source

Context

Region Australia
Biome Tropical Monsoonal Savannas
Land Use Conservation / Protected Natural Areas
Assessment Pristine Reference
Vegetation Woodland
Season wet season
Evidence Type ReferenceCondition

Lifecycle

Status Active
Version 1
Effective From 26 May 2026

Notes

The reference value is derived from laboratory measurements of basal soil respiration in topsoil (0-10 cm) from a savanna woodland near Darwin, NT, Australia, under ambient temperature and non-limiting moisture (20% GWC).

Related Benchmarks

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