Microbial Respiration

AUS-TMI-LVG-SMR General Moderate confidence

Benchmark Value

200 ppm

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 15 benchmarks together — the OptimalRange form drives the primary score, while 14 guard(s) constrain the result.

Contributing Benchmarks

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

Evidence & Context

Proposed Benchmark: > 200 ppm CO2-C (Measured via standardized 24-hour laboratory incubation, to be interpreted with contextual data)

Metric Definition:

Soil Microbial Respiration (SMR) is the flux of carbon dioxide (CO2) released from the soil surface as a direct result of the metabolic activity of soil microorganisms, including bacteria, fungi, and archaea.

Benchmark Definition:

A critical warning flag suggesting a potential decoupling of the carbon and nutrient cycles, where the soil's carbon capital is being consumed at an unsustainable rate.

Justification:

A value above 200 ppm CO2-C, which is considered very high for most agricultural soils, should trigger further investigation into the underlying cause... such as disturbance-induced loss or substrate imbalance.

Sources (1)

Preview of Microbial carbon dynamics in tropical forests: linking soil processes to atmospheric impacts under climate stress - PubMed, accessed July 30, 2025,

Microbial carbon dynamics in tropical forests: linking soil processes to atmospheric impacts under climate stress - PubMed, accessed July 30, 2025, Journal

Haney Test Interpretation Guide v1.0 - Ward Laboratories, Inc.

Supporting Sources (53)

Additional references from the underlying research that informed this benchmark.

Preview of (PDF) Soil respiration rate and its sensitivity to temperature in ..., accessed July 30, 2025,

(PDF) Soil respiration rate and its sensitivity to temperature in ..., accessed July 30, 2025,

Contextual Support Direct Evidence Journal

(PDF) Soil respiration rate and its sensitivity to temperature in ..., accessed July 30, 2025,

Preview of (PDF) The effects of grazing and fire on vegetation and the vertebrate assemblage in tropical savanna woodland in north-eastern Australia - ResearchGate, accessed July 30, 2025,

(PDF) The effects of grazing and fire on vegetation and the vertebrate assemblage in tropical savanna woodland in north-eastern Australia - ResearchGate, accessed July 30, 2025,

Contextual Support Journal

Overgrazing & Reducing Grazing Pressure | Bush Heritage Australia

Preview of A Global Meta-Analysis of Grazing Impacts on Soil Health Indicators - PubMed, accessed July 30, 2025,

A Global Meta-Analysis of Grazing Impacts on Soil Health Indicators - PubMed, accessed July 30, 2025,

Contextual Support Direct Evidence MetaAnalysis

Response of Grazing Land Soil Health to Management Strategies: A Summary Review

Preview of A Global Meta-Analysis of Grazing Impacts on Soil Health Indicators - ResearchGate, accessed July 30, 2025,

A Global Meta-Analysis of Grazing Impacts on Soil Health Indicators - ResearchGate, accessed July 30, 2025,

Contextual Support Direct Evidence Journal

Sward lifting in compacted grassland: effects on soil structure, grass rooting and productivity. - CABI Digital Library

Preview of A guide to managing livestock on small properties - Queensland Government publications, accessed July 30, 2025,

A guide to managing livestock on small properties - Queensland Government publications, accessed July 30, 2025,

Contextual Support Journal

Resting Subtropical Grasslands from Grazing in the Wet Season Boosts Biocrust Hotspots to Improve Soil Health

Preview of A Machine Learning Approach to Predict Short-Term Soil CO2 Emissions from Climate-Smart Fields - MDPI, accessed July 30, 2025,

A Machine Learning Approach to Predict Short-Term Soil CO2 Emissions from Climate-Smart Fields - MDPI, accessed July 30, 2025,

Contextual Support

A Machine Learning Approach to Predict Short-Term Soil CO2 Emissions from Climate-Smart Fields - MDPI

Preview of Australian National Soil Archive - CSIRO, accessed July 30, 2025,

Australian National Soil Archive - CSIRO, accessed July 30, 2025,

Contextual Support Government

Microbial Biogeochemical Cycling of Nitrogen in Arid Ecosystems - PMC - PubMed Central, accessed July 30, 2025,

Preview of Australian National Soil Information System, accessed July 30, 2025,

Australian National Soil Information System, accessed July 30, 2025,

Contextual Support Government

Australian National Soil Information System, accessed July 30, 2025,

Preview of Australian Soils and Landscapes | Monitoring & Data | TERN - esoil.io, accessed July 30, 2025,

Australian Soils and Landscapes | Monitoring & Data | TERN - esoil.io, accessed July 30, 2025,

Contextual Support Methodology Source Government

Australian Soils and Landscapes | Monitoring & Data | TERN - esoil.io

Preview of Comparison of temperature effects on soil respiration and bacterial and fungal growth rates | FEMS Microbiology Ecology | Oxford Academic, accessed July 30, 2025,

Comparison of temperature effects on soil respiration and bacterial and fungal growth rates | FEMS Microbiology Ecology | Oxford Academic, accessed July 30, 2025,

Contextual Support Direct Evidence Journal

Soil Moisture Affects the Rapid Response of Microbes to Labile Organic C Addition

Preview of CSU Research Output accessed July 30, 2025,

CSU Research Output accessed July 30, 2025,

Contextual Support Irrelevant null

CSU Research Output accessed July 30, 2025,

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

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

Direct Evidence Methodology Source Journal

Touching on Practices for Grazing Management in Tropical and Subtropical Pastures

Preview of Differences in soil respiration between different tropical ecosystems - CiteSeerX, accessed July 30, 2025,

Differences in soil respiration between different tropical ecosystems - CiteSeerX, accessed July 30, 2025,

Contextual Support Direct Evidence

Seasonal Influence of Biodiversity on Soil Respiration in a Temperate Forest - PMC, accessed August 1, 2025

Preview of Do regenerative grazing management practices improve vegetation and soil health in grazed rangelands? Preliminary insights from, accessed August 5, 2025,

Do regenerative grazing management practices improve vegetation and soil health in grazed rangelands? Preliminary insights from, accessed August 5, 2025,

Contextual Support

The effect of climate change on pastoralism in the Australian arid and semi-arid rangelands - Nuffield Farming Scholarships, accessed July 29, 2025,

Preview of Environment Monitoring Systems & Data for Ecosystem Studies ..., accessed July 30, 2025,

Environment Monitoring Systems & Data for Ecosystem Studies ..., accessed July 30, 2025,

Methodology Source Government

(PDF) Evaluation of genetic markers for the metabarcoding of ...

Preview of Gerry's Guide to greener tropical and subtropical pastures - DLF Seeds Australia, accessed July 30, 2025,

Gerry's Guide to greener tropical and subtropical pastures - DLF Seeds Australia, accessed July 30, 2025,

Contextual Support GreyLiterature

Tropical perennial grasses – pasture quality and livestock production - NSW Department of Primary Industries

Preview of Haney Test Interpretation Guide v1.0 - Ward Laboratories, Inc., accessed July 30, 2025,

Haney Test Interpretation Guide v1.0 - Ward Laboratories, Inc., accessed July 30, 2025,

Contextual Support Direct Evidence Journal

Ohio State University Soil Fertility Lab Protocol (2019)

Preview of HCAS 3.0 (1988-2022) base model ... - CSIRO Data Access Portal, accessed July 30, 2025,

HCAS 3.0 (1988-2022) base model ... - CSIRO Data Access Portal, accessed July 30, 2025,

Contextual Support Methodology Source Government

HCAS 3.0 (1988-2022) base model ... - CSIRO Data Access Portal

Preview of Heterotrophic soil respiration and carbon cycling in geochemically distinct African tropical forest soils, accessed July 30, 2025,

Heterotrophic soil respiration and carbon cycling in geochemically distinct African tropical forest soils, accessed July 30, 2025,

Contextual Support Direct Evidence Journal

Microbial carbon dynamics in tropical forests: linking soil processes to atmospheric impacts under climate stress - PubMed

Preview of How does livestock graze management affect woodland soil health? - Frontiers, accessed July 30, 2025,

How does livestock graze management affect woodland soil health? - Frontiers, accessed July 30, 2025,

Direct Evidence Irrelevant

How does livestock graze management affect woodland soil health? - Frontiers, accessed July 30, 2025,

$Preview of How many soil samples are enough for study on spatial distribution of soil organic matter fractions and microbial features in afforestation? | ResearchGate, accessed July 30, 2025,$

How many soil samples are enough for study on spatial distribution of soil organic matter fractions and microbial features in afforestation? | ResearchGate, accessed July 30, 2025,

Contextual Support GreyLiterature

How does livestock graze management affect woodland soil health? - Frontiers

Preview of How To Measure Soil Health With The Haney Test - Noble Research Institute, accessed July 30, 2025,

How To Measure Soil Health With The Haney Test - Noble Research Institute, accessed July 30, 2025,

Direct Evidence Methodology Source GreyLiterature

Soil Respiration | South Dakota Soil Health Coalition

Preview of Impacts of rehabilitating degraded lands on soil health, pastures, runoff, erosion, nutrient and sediment movement. Part II - FutureBeef, accessed July 30, 2025,

Impacts of rehabilitating degraded lands on soil health, pastures, runoff, erosion, nutrient and sediment movement. Part II - FutureBeef, accessed July 30, 2025,

Contextual Support Direct Evidence Journal

The relative importance of cattle grazing in subtropical grasslands: does it reduce or enhance plant biodiversity? - The Australian National University

Preview of Inherent Factors Affecting Soil Respiration - USDA, accessed July 30, 2025,

Inherent Factors Affecting Soil Respiration - USDA, accessed July 30, 2025,

Contextual Support Direct Evidence Journal

Inherent Factors Affecting Soil Respiration - USDA

Preview of Island Bound: Cross-cultural Considerations of Island Field Containment in the Torres Strait - CSIRO Research Publications Repository, accessed July 30, 2025,

Island Bound: Cross-cultural Considerations of Island Field Containment in the Torres Strait - CSIRO Research Publications Repository, accessed July 30, 2025,

Contextual Support Journal

Soil - CSIRO

Preview of Landscape rehydration and regenerative agriculture improves soil health, accessed July 30, 2025,

Landscape rehydration and regenerative agriculture improves soil health, accessed July 30, 2025,

Contextual Support Direct Evidence GreyLiterature

Soil Health and Regenerative Agriculture - Southern Queensland Landscapes, accessed July 27, 2025,

Preview of Managing Grazing to Restore Soil Health, Ecosystem Function, and Ecosystem Services - Frontiers, accessed July 30, 2025,

Managing Grazing to Restore Soil Health, Ecosystem Function, and Ecosystem Services - Frontiers, accessed July 30, 2025,

Contextual Support Direct Evidence Journal

Do regenerative grazing management practices improve vegetation and soil health in grazed rangelands? Preliminary insights from a space-for-time study in the Great Barrier Reef catchments, Australia - CSIRO Publishing, accessed July 10, 2025,

Preview of Overgrazing & Reducing Grazing Pressure | Bush Heritage Australia, accessed July 30, 2025,

Overgrazing & Reducing Grazing Pressure | Bush Heritage Australia, accessed July 30, 2025,

Contextual Support

Soil PhD Research | Bush Heritage Australia, accessed July 28, 2025

Preview of P.PSH.1050 – Phosphorus management and requirements of tropical legume pasture swards - MLA, accessed July 30, 2025,

P.PSH.1050 – Phosphorus management and requirements of tropical legume pasture swards - MLA, accessed July 30, 2025,

Contextual Support Journal

Pacific Islands Soil Project

Preview of Pacific Islands Soil Project, accessed July 30, 2025,

Pacific Islands Soil Project, accessed July 30, 2025,

Contextual Support Irrelevant

Pacific Islands Soil Project, accessed July 30, 2025,

Preview of Pasture-fed Livestock Association, accessed July 30, 2025,

Pasture-fed Livestock Association, accessed July 30, 2025,

Contextual Support

Soil temperature, microbial biomass and enzyme activity are the critical factors affecting soil respiration in different soil layers in Ziwuling Mountains, China - Frontiers

Preview of Potential for soil carbon sequestration in Northern Australian grazing lands: A review of the evidence, accessed July 30, 2025,

Potential for soil carbon sequestration in Northern Australian grazing lands: A review of the evidence, accessed July 30, 2025,

Contextual Support Direct Evidence Journal

Keeping carbon – ensuring soil carbon gains through improved grazing management persist through drought in Australia's tropical and semi-arid grasslands - QUT

Preview of Requirements for graziers | Environment, land and water | Queensland Government, accessed July 30, 2025,

Requirements for graziers | Environment, land and water | Queensland Government, accessed July 30, 2025,

Contextual Support Regulatory Framework Government

Reef protection regulations Grazing guide Version 2 - Queensland Government, accessed July 18, 2025

Preview of Response of Grazing Land Soil Health to Management Strategies: A Summary Review, accessed August 5, 2025,

Response of Grazing Land Soil Health to Management Strategies: A Summary Review, accessed August 5, 2025,

Contextual Support Direct Evidence Journal

Rangeland Soil Quality: Infiltration - Natural Resources Conservation Service, accessed July 18, 2025

Preview of Rocks To Feed Tropical Crops - Mirage News, accessed July 30, 2025,

Rocks To Feed Tropical Crops - Mirage News, accessed July 30, 2025,

Contextual Support GreyLiterature

P.PSH.1050 – Phosphorus management and requirements of tropical legume pasture swards - MLA

Preview of Seasonal Soil Moisture Thresholds Inhibit Bacterial Activity and Decomposition during Drought in a Tallgrass Prairie - e-Publications@Marquette, accessed July 30, 2025,

Seasonal Soil Moisture Thresholds Inhibit Bacterial Activity and Decomposition during Drought in a Tallgrass Prairie - e-Publications@Marquette, accessed July 30, 2025,

Contextual Support Methodology Source Journal

Seasonal Soil Moisture Thresholds Inhibit Bacterial Activity and Decomposition during Drought in a Tallgrass Prairie - e-Publications@Marquette

Preview of Soil - CSIRO

Soil - CSIRO

Contextual Support

Soil - CSIRO

Preview of Soil - CSIRO

Soil - CSIRO

Contextual Support Government

Soil - CSIRO, accessed July 27, 2025

Preview of Soil microbial respiration responses to changing temperature and substrate availability in fertile grassland - CSIRO Publishing, accessed July 30, 2025,

Soil microbial respiration responses to changing temperature and substrate availability in fertile grassland - CSIRO Publishing, accessed July 30, 2025,

Contextual Support Direct Evidence

Soil microbial respiration responses to changing temperature and substrate availability in fertile grassland - CSIRO Publishing

Preview of Soil Moisture Affects the Rapid Response of Microbes to Labile Organic C Addition, accessed July 30, 2025,

Soil Moisture Affects the Rapid Response of Microbes to Labile Organic C Addition, accessed July 30, 2025,

Contextual Support Journal

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

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

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

Direct Evidence Journal

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

Preview of Soil respiration - Wikipedia, accessed July 30, 2025,

Soil respiration - Wikipedia, accessed July 30, 2025,

Direct Evidence Methodology Source

Soil respiration - Wikipedia

Preview of Soil Respiration | South Dakota Soil Health Coalition, accessed July 30, 2025,

Soil Respiration | South Dakota Soil Health Coalition, accessed July 30, 2025,

Direct Evidence Methodology Source GreyLiterature

Original Research Article QUANTIFICATION OF MICROBIAL BIOMASSCARBON AND NITROGENIN LEAF LITTER AMENDED SOIL IN NORTHERN NIGERIA - AWS

Preview of Soil Respiration in European Grasslands in Relation to Climate and Assimilate Supply - PMC - PubMed Central, accessed July 30, 2025,

Soil Respiration in European Grasslands in Relation to Climate and Assimilate Supply - PMC - PubMed Central, accessed July 30, 2025,

Contextual Support Direct Evidence Journal

Pasture-fed Livestock Association

Preview of Soil respiration rate and its sensitivity to temperature in pasture systems of dry-tropics - Taylor & Francis Online, accessed July 30, 2025,

Soil respiration rate and its sensitivity to temperature in pasture systems of dry-tropics - Taylor & Francis Online, accessed July 30, 2025,

Contextual Support Direct Evidence Journal

Soil respiration rate and its sensitivity to temperature in pasture systems of dry-tropics - Taylor & Francis Online

Preview of Soil temperature, microbial biomass and enzyme activity are the critical factors affecting soil respiration in different soil layers in Ziwuling Mountains, China - Frontiers, accessed July 30, 2025,

Soil temperature, microbial biomass and enzyme activity are the critical factors affecting soil respiration in different soil layers in Ziwuling Mountains, China - Frontiers, accessed July 30, 2025,

Direct Evidence Irrelevant Journal

The optimum temperature of soil microbial respiration

Preview of Temperature sensitivity of soil respiration rates enhanced by microbial community response - PubMed, accessed July 30, 2025,

Temperature sensitivity of soil respiration rates enhanced by microbial community response - PubMed, accessed July 30, 2025,

Contextual Support Direct Evidence Journal

Soil Respiration in Semiarid Temperate Grasslands under Various Land Management - PMC - PubMed Central

Preview of TERN - Australia's Terrestrial Ecosystem Research Network, accessed July 30, 2025,

TERN - Australia's Terrestrial Ecosystem Research Network, accessed July 30, 2025,

Contextual Support Government

Australia's State of the Forests Report 2018 - DAFF, accessed July 31, 2025,

Preview of Terrestrial Ecosystem Research Network TERN Australia - Queensland science, accessed July 30, 2025,

Terrestrial Ecosystem Research Network TERN Australia - Queensland science, accessed July 30, 2025,

Contextual Support Government

Australian National Soil Information System

Preview of The optimum temperature of soil microbial respiration, accessed July 30, 2025,

The optimum temperature of soil microbial respiration, accessed July 30, 2025,

Contextual Support Direct Evidence Journal

The optimum temperature of soil microbial respiration, accessed July 30, 2025,

Preview of The relative importance of cattle grazing in subtropical grasslands: does it reduce or enhance plant biodiversity? - The Australian National University, accessed July 30, 2025,

The relative importance of cattle grazing in subtropical grasslands: does it reduce or enhance plant biodiversity? - The Australian National University, accessed July 30, 2025,

Contextual Support Journal

Do regenerative grazing management practices improve vegetation ...

Preview of Touching on Practices for Grazing Management in Tropical and Subtropical Pastures, accessed July 30, 2025,

Touching on Practices for Grazing Management in Tropical and Subtropical Pastures, accessed July 30, 2025,

Contextual Support

Gerry's Guide to greener tropical and subtropical pastures - DLF Seeds Australia

Preview of Tropical perennial grasses – pasture quality and livestock production - NSW Department of Primary Industries, accessed July 30, 2025,

Tropical perennial grasses – pasture quality and livestock production - NSW Department of Primary Industries, accessed July 30, 2025,

Contextual Support Government

Managing Grazing to Restore Soil Health, Ecosystem Function, and Ecosystem Services - Frontiers

Context

Region Australia
Biome Tropical & Subtropical Maritime Islands
Land Use Livestock Grazing & Pasture
Assessment Not Stated
Evidence Type DegradationThreshold

Lifecycle

Status Active
Version 1
Effective From 30 May 2026

Notes

A reading above 200 ppm must be interpreted in context. If it is accompanied by a documented decline in the total SOC percentage over time... it strongly indicates that the system is out of balance. AssessmentContext defaulted to 'Not Stated' because the source document did not state one.

Related Benchmarks

Other benchmarks in the AUS-TMI-LVG-SMR family.