Microbial Respiration

AUS-TDG-LVG-SMR General Moderate confidence

Benchmark Value

No specific value — see range

Range: 35 to 60 mg/kg/day

Thresholds: Lower: 20, Upper: —

Optimal Range: 35 to 60

Direction: Higher is desirable ↑

Form: OptimalRange

Scoring Curve

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

Evidence & Context

Based on this derivation, a central benchmark value of approximately 40 mg CO2-C/kg/day is proposed.

Metric Definition:

Basal microbial respiration rate measured as mg CO2-C/kg/day under standardized laboratory conditions reflecting microbial metabolic activity.

Benchmark Definition:

Basal microbial respiration rate as a measure of microbial metabolic activity in soil, expressed in mg CO2-C/kg/day, indicating soil health under conservation grazing management in temperate dry woodlands and native grasslands.

Justification:

This benchmark is a derived estimate based on the highest labile carbon value (19.74 mg C/g soil) from a best-practice grazing system, applying a conservative daily respiration rate of approximately 0.2% of the labile carbon pool.

Sources (1)

Grazing management for soil carbon in Australia: A review, accessed August 5, 2025, Journal

Grazing management for soil carbon in Australia: A review

View Source

Supporting Sources (18)

Additional references from the underlying research that informed this benchmark.

Climate change impacts and adaptation on Australian farms - DAFF, accessed August 9, 2025

Contextual Support

Tool 6.7 Soil health benchmarks and guidelines for managing problem soils

View Source

Preview of Comparison of grazed and cleared temperate grassy woodlands in eastern Australia: patterns in space and inferences in time - ResearchGate, accessed July 10, 2025,

Comparison of grazed and cleared temperate grassy woodlands in eastern Australia: patterns in space and inferences in time - ResearchGate, accessed July 10, 2025,

Contextual Support Journal

Comparison of grazed and cleared temperate grassy woodlands in eastern Australia: patterns in space and inferences in time - ResearchGate

View Source

Preview of Composition and production from native pastures in response to fertiliser and rotational grazing | EverGraze More livestock from perennials

Composition and production from native pastures in response to fertiliser and rotational grazing | EverGraze More livestock from perennials

Contextual Support GreyLiterature

Composition and production from native pastures in response to fertiliser and rotational grazing | EverGraze More livestock from perennials

View Source

Crop and Pasture Science - CSIRO PUBLISHING

Direct Evidence Journal

Temperature response of soil respiration largely unaltered with experimental warming

View Source

Evaluation of microorganisms response to soil physical conditions under different agriculture use systems - SciELO Colombia

Contextual Support

Evaluation of microorganisms response to soil physical conditions under different agriculture use systems - SciELO Colombia

View Source

Grazing intensity influence soil microbial communities and their implications for soil respiration | Request PDF - ResearchGate

Contextual Support GreyLiterature

Effects of grazing on soil respiration in global grassland ecosystems - ResearchGate

View Source

Preview of Grazing intensity influence soil microbial communities and their implications for soil respiration | Request PDF - ResearchGate, accessed July 19, 2025,

Grazing intensity influence soil microbial communities and their implications for soil respiration | Request PDF - ResearchGate, accessed July 19, 2025,

Contextual Support Journal

Grazing intensity influence soil microbial communities and their implications for soil respiration | Request PDF - ResearchGate, accessed July 11, 2025,

View Source

Grazing management for soil carbon in Australia: A review - ResearchGate, accessed August 5, 2025,

Direct Evidence Journal

Managing grazing to increase ground cover in rangelands: using remote sensing to detect change | Request PDF - ResearchGate

View Source

Grazing Regulates Changes in Soil Microbial Communities in Plant-Soil Systems - MDPI

Contextual Support Journal

Managing Pastures for Soil Health FACT SHEET 12 - Local Land Services, accessed July 11, 2025,

View Source

Impacts of Rotational Grazing on Soil Carbon in Native Grass-Based ..., accessed August 5, 2025,

Contextual Support Journal

Impacts of Rotational Grazing on Soil Carbon in Native Grass-Based Pastures in Southern Australia | PLOS One - Research journals

View Source

Preview of Impacts of Rotational Grazing on Soil Carbon in Native Grass-Based Pastures in Southern Australia - ResearchGate, accessed August 5, 2025,

Impacts of Rotational Grazing on Soil Carbon in Native Grass-Based Pastures in Southern Australia - ResearchGate, accessed August 5, 2025,

Contextual Support Journal

Grazing management for soil carbon in Australia: A review - ResearchGate

View Source

Inherent Factors Affecting Soil Respiration - Solvita, accessed August 5, 2025,

Contextual Support Journal

Inherent Factors Affecting Soil Respiration - Solvita

View Source

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

Contextual Support Journal

Twenty years of progress, challenges, and opportunities in measuring and understanding soil respiration, accessed August 13, 2025,

View Source

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

Contextual Support 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,

View Source

Removing Grazing Pressure from a Native Pasture Decreases Soil Organic Carbon in Southern New South Wales, Australia - ResearchGate

Contextual Support

Removing Grazing Pressure from a Native Pasture Decreases Soil Organic Carbon in Southern New South Wales, Australia - ResearchGate

View Source

Soil Biology in Pasture Systems - Making More From Sheep

Contextual Support Journal

Soil respiration and its autotrophic and heterotrophic components in response to nitrogen addition among different degraded temperate grasslands - ResearchGate

View Source

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

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

Contextual Support Journal

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

View Source

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

Contextual Support Journal

Temperature sensitivity of soil respiration rates enhanced by microbial community response - PubMed, accessed August 13, 2025,

View Source

Context

Region Australia
Biome Temperate Dry Woodlands & Native Grasslands
Land Use Livestock Grazing & Pasture
Assessment Conservation Target
Evidence Type TargetCondition

Lifecycle

Status Active
Version 1
Effective From 22 Mar 2026

Notes

Lower Critical Threshold: 30 mg/kg/day. No upper detrimental threshold — higher values are always better up to natural saturation. The benchmark must be interpreted within a functional spectrum including a lower critical threshold (~30 mg CO2-C/kg/day) indicating degradation, an optimal range (35–60 mg CO2-C/kg/day) reflecting high ecosystem health, and a conceptual upper boundary where rates above 80 mg CO2-C/kg/day may indicate system instability and net carbon loss. RangeFixup applied 2026-03-22 08:35 UTC: LowerThreshold: 30 → 20; LowerBound: 20 → 30 [Migration] Original wider evidence range: 30 – 60 (retained OptimalRange: 35 – 60)