Fungal:Bacterial Ratio

AUS-AIF-CON-SFB General Moderate confidence

Benchmark Value

0.15 index
Thresholds: Lower: 0.15, Upper: —
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. The scoring engine uses 8 benchmarks together — the OptimalRange form drives the primary score, while 7 guard(s) constrain the result.

Contributing Benchmarks

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

Evidence & Context

An F:B ratio of < 0.15 should be viewed as a management trigger, prompting investigation into potential stressors and indicating that the system's capacity for nutrient retention and long-term stability may be compromised.

Metric Definition:

Ratio of fungal to bacterial biomass in soil as measured by PLFA analysis.

Benchmark Definition:

This benchmark defines the critical lower threshold of the fungal to bacterial biomass ratio, below which ecosystem degradation and loss of fungal-mediated services are indicated in arid inland floodplains.

Justification:

The F:B ratio of 0.14 measured under the stable native Spinifex community represents a baseline for a resilient but lower-functioning native state; values below ~0.15 indicate significant functional loss.

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

Biochemical properties of highly mineralised and infertile soil modified by acacia and spinifex plants in northwest Queensland, Australia - CSIRO Publishing, accessed June 7, 2025,

View Source

Supporting Sources (25)

Additional references from the underlying research that informed this benchmark.

Preview of (PDF) The measurement of soil fungal:bacterial biomass ratios as an ..., accessed July 19, 2025,
(PDF) The measurement of soil fungal:bacterial biomass ratios as an ..., accessed July 19, 2025,
Contextual Support Journal

Soil microbial community composition under Eucalyptus plantations of different age in subtropical China - ResearchGate, accessed July 23, 2025

View Source
Preview of (PDF) The pH of Australian soils: field results from a national survey - ResearchGate, accessed July 25, 2025,
(PDF) The pH of Australian soils: field results from a national survey - ResearchGate, accessed July 25, 2025,
Contextual Support Journal

Soil pH | Environment, land and water - Queensland Government, accessed August 28, 2025,

View Source
Preview of ALLOCHTHONOUS CARBON LOADS AND POTENTIAL ... - La Trobe, accessed July 22, 2025,
ALLOCHTHONOUS CARBON LOADS AND POTENTIAL ... - La Trobe, accessed July 22, 2025,
Contextual Support Journal

Australian dryland soils are acidic and nutrient-depleted, and have unique microbial communities compared with other drylands - PMC, accessed July 22, 2025

View Source
Preview of Analyzing your Fungal to Bacterial Ratio Results - MicroBiometer, accessed July 18, 2025
Analyzing your Fungal to Bacterial Ratio Results - MicroBiometer, accessed July 18, 2025
Contextual Support GreyLiterature

Analyzing your Fungal to Bacterial Ratio Results - microBIOMETER, accessed June 7, 2025,

View Source
Preview of Are Fungal to Bacterial Ratios (F:B Ratio) Important for Plant Growth? - Garden Myths, accessed July 28, 2025
Are Fungal to Bacterial Ratios (F:B Ratio) Important for Plant Growth? - Garden Myths, accessed July 28, 2025
Contextual Support GreyLiterature

Fungal/bacterial ratios in grasslands with contrasting nitrogen management, accessed July 23, 2025

View Source
Preview of ausplotsR: TERN AusPlots Australian Ecosystem Monitoring Data - The Comprehensive R Archive Network, accessed July 15, 2025
ausplotsR: TERN AusPlots Australian Ecosystem Monitoring Data - The Comprehensive R Archive Network, accessed July 15, 2025
Contextual Support Journal

ausplotsR: TERN AusPlots Australian Ecosystem Monitoring Data - CRAN - R Project, accessed May 19, 2025

View Source
Preview of ausplotsR: TERN AusPlots Australian Ecosystem Monitoring Data - The Comprehensive R Archive Network, accessed July 22, 2025
ausplotsR: TERN AusPlots Australian Ecosystem Monitoring Data - The Comprehensive R Archive Network, accessed July 22, 2025
Contextual Support Government

ausplotsR: TERN AusPlots Australian Ecosystem Monitoring Data - The Comprehensive R Archive Network, accessed July 22, 2025

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

Root Structure and Functioning for Efficient Acquisition of Phosphorus: Matching Morphological and Physiological Traits

View Source
Preview of ausveg - fact sheet: soil microbiology, accessed July 18, 2025
ausveg - fact sheet: soil microbiology, accessed July 18, 2025
Contextual Support Journal

ausveg - fact sheet: soil microbiology

View Source
Preview of Biogeographical patterns of the soil fungal:bacterial ratio across France - PubMed Central, accessed July 18, 2025
Biogeographical patterns of the soil fungal:bacterial ratio across France - PubMed Central, accessed July 18, 2025
Contextual Support Journal

Mechanisms and implications of bacterial–fungal competition for soil resources - PMC, accessed July 23, 2025

View Source
Preview of Considering fungal: Bacterial dominance in soils - Methods, controls, and ecosystem implications | Request PDF - ResearchGate, accessed July 22, 2025
Considering fungal: Bacterial dominance in soils - Methods, controls, and ecosystem implications | Request PDF - ResearchGate, accessed July 22, 2025
Contextual Support Journal

Mechanisms and implications of bacterial–fungal competition for soil resources - PMC, accessed August 3, 2025

View Source
Preview of Contrasting sensitivity of soil bacterial and fungal community composition to one year of water limitation in Scots pine mesocosms | FEMS Microbiology Ecology | Oxford Academic, accessed July 22, 2025
Contrasting sensitivity of soil bacterial and fungal community composition to one year of water limitation in Scots pine mesocosms | FEMS Microbiology Ecology | Oxford Academic, accessed July 22, 2025
Contextual Support Journal

Soil | Australia state of the environment 2021, accessed July 8, 2025

View Source
Preview of Ecosystem Processes – Environmental Data Collection Methods - TERN Australia
Ecosystem Processes – Environmental Data Collection Methods - TERN Australia
Methodology Source Government

TERN Surveillance monitoring program: Soil vis-NIR spectral library with accompanying soil measurement data for 367 specimens - CSIRO Data Access Portal, accessed July 17, 2025,

View Source
Preview of Fungal/bacterial ratios in grasslands with contrasting nitrogen management - ResearchGate, accessed July 18, 2025
Fungal/bacterial ratios in grasslands with contrasting nitrogen management - ResearchGate, accessed July 18, 2025
Contextual Support Journal

Adaptive multi-paddock grazing increases soil nutrient availability and bacteria to fungi ratio in grassland soils | Request PDF - ResearchGate, accessed August 9, 2025,

View Source
Preview of Maintaining groundcover to reduce erosion and sustain production, accessed July 27, 2025,
Maintaining groundcover to reduce erosion and sustain production, accessed July 27, 2025,
Contextual Support Journal

Final Report – Volume 2 - Estimating Pasture Total Standing Biomass (TSDM) from Landsat Fractional Cover., accessed April 29, 2025,

View Source
Preview of Marine and Freshwater Research - CSIRO PUBLISHING, accessed July 22, 2025
Marine and Freshwater Research - CSIRO PUBLISHING, accessed July 22, 2025
Contextual Support Journal

Impact of inundation on soil microbiology - CSIRO Publishing, accessed July 22, 2025

View Source
Preview of Mechanisms and implications of bacterial–fungal competition for soil resources - PMC, accessed July 18, 2025
Mechanisms and implications of bacterial–fungal competition for soil resources - PMC, accessed July 18, 2025
Contextual Support Journal

Soil Fungal:Bacterial Ratios Are Linked to Altered Carbon Cycling - Frontiers, accessed July 23, 2025

View Source
Preview of Mechanisms and implications of bacterial–fungal competition for soil resources | The ISME Journal | Oxford Academic, accessed July 18, 2025
Mechanisms and implications of bacterial–fungal competition for soil resources | The ISME Journal | Oxford Academic, accessed July 18, 2025
Contextual Support Journal

ratio of fungi to bacteria | The Prairie Ecologist, accessed June 7, 2025,

View Source
Preview of Microbial Communities in an Ephemeral Stream System and the Implications of Saline Mine Discharge - UQ eSpace - The University of Queensland, accessed July 22, 2025
Microbial Communities in an Ephemeral Stream System and the Implications of Saline Mine Discharge - UQ eSpace - The University of Queensland, accessed July 22, 2025
Contextual Support Journal

Climate dictates microbial community composition and diversity in Australian biological soil crusts (biocrusts) - PMC - PubMed Central, accessed July 22, 2025

View Source
Preview of Microbial communities in floodplain ecosystems in relation to altered flow regimes and experimental flooding | Request PDF - ResearchGate, accessed July 22, 2025
Microbial communities in floodplain ecosystems in relation to altered flow regimes and experimental flooding | Request PDF - ResearchGate, accessed July 22, 2025
Contextual Support Journal

Microbial communities in floodplain ecosystems in relation to altered flow regimes and experimental flooding | Request PDF - ResearchGate, accessed July 22, 2025

View Source
Preview of Soil condition | NSW State of the Environment, accessed July 22, 2025
Soil condition | NSW State of the Environment, accessed July 22, 2025
Contextual Support Journal

Soil condition | NSW State of the Environment, accessed July 22, 2025

View Source
Preview of Soil microbes - farming with your underground livestock for healthy soil - Landscape SA, accessed July 22, 2025
Soil microbes - farming with your underground livestock for healthy soil - Landscape SA, accessed July 22, 2025
Contextual Support Government

Soil microbes - farming with your underground livestock for healthy soil - Landscape SA, accessed July 22, 2025

View Source
Preview of The Biota of Intermittent Rivers and Ephemeral Streams: Prokaryotes, Fungi, and Protozoans | Request PDF - ResearchGate, accessed July 22, 2025
The Biota of Intermittent Rivers and Ephemeral Streams: Prokaryotes, Fungi, and Protozoans | Request PDF - ResearchGate, accessed July 22, 2025
Contextual Support

The Biota of Intermittent Rivers and Ephemeral Streams: Prokaryotes, Fungi, and Protozoans | Request PDF - ResearchGate, accessed July 22, 2025

View Source
Preview of The fungal to bacterial ratio in soil food webs, and its measurement - ResearchGate, accessed July 22, 2025
The fungal to bacterial ratio in soil food webs, and its measurement - ResearchGate, accessed July 22, 2025
Methodology Source Journal

The fungal to bacterial ratio in soil food webs, and its measurement - ResearchGate, accessed July 22, 2025

View Source
Preview of Things you need to know about the Fungal to Bacterial Ratio (F:B) - MicroBiometer, accessed July 28, 2025
Things you need to know about the Fungal to Bacterial Ratio (F:B) - MicroBiometer, accessed July 28, 2025
Contextual Support GreyLiterature

Australian dryland soils are acidic and nutrient-depleted, and have unique microbial communities compared with other drylands - PMC, accessed July 23, 2025

View Source

Context

  • Region Australia
  • Biome Arid Inland Floodplains & Ephemeral River Systems
  • Land Use Conservation / Protected Natural Areas
  • Assessment Pristine Reference
  • Evidence Type DegradationThreshold

Lifecycle

  • Status Active
  • Version 1
  • Effective From 23 Mar 2026

Notes

A ratio below 0.15 signals a shift away from fungal-mediated processes towards bacterial dominance, indicating degradation. No upper detrimental threshold — higher values are always better up to natural saturation.

Related Benchmarks

Other benchmarks in the AUS-AIF-CON-SFB family.

0.25 index Moderate
Conservation / Protected Natural Areas · Pristine Reference
Point Active v1
— index Moderate
Conservation / Protected Natural Areas · Pristine Reference
OptimalRange Active v1