Fungal:Bacterial Ratio

AUS-TMI-CON-SFB General Moderate confidence

Benchmark Value

1 index
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 9 benchmarks together — the OptimalRange form drives the primary score, while 8 guard(s) constrain the result.

Contributing Benchmarks

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

Evidence & Context

The evidence strongly indicates that a critical functional threshold exists around an F:B ratio of 1.0. A ratio that falls below 1.0 signifies a fundamental shift from a fungal-influenced to a bacterially-dominated soil system.

Metric Definition:

Ratio of fungal to bacterial biomass in soil microbial communities.

Benchmark Definition:

This benchmark defines the minimum fungal to bacterial biomass ratio in soil microbial communities below which the soil system is considered degraded or disturbed in conservation areas of tropical and subtropical maritime islands in Australia.

Justification:

A ratio below 1.0 indicates a shift to a bacterially-dominated, disturbed state with impaired ecological function, consistent with ecological degradation or disturbance.

Sources (1)

Preview of Fungal/bacterial ratios in grasslands with contrasting nitrogen management, accessed July 19, 2025,
Fungal/bacterial ratios in grasslands with contrasting nitrogen management, accessed July 19, 2025, Journal

Mechanisms and implications of bacterial–fungal competition for soil resources - PMC

View Source

Supporting Sources (21)

Additional references from the underlying research that informed this benchmark.

Preview of A curated soil fungal dataset to advance fungal ecology and conservation research in Australia and Antarctica - PubMed Central
A curated soil fungal dataset to advance fungal ecology and conservation research in Australia and Antarctica - PubMed Central
Contextual Support Journal

A curated soil fungal dataset to advance fungal ecology and conservation research in Australia and Antarctica - PubMed Central

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 July 23, 2025

View Source
Preview of Arbuscular mycorrhizal fungi promote coexistence and niche divergence of sympatric palm species on a remote oceanic island - PubMed
Arbuscular mycorrhizal fungi promote coexistence and niche divergence of sympatric palm species on a remote oceanic island - PubMed
Contextual Support Journal

Norfolk Island Water Resource Assessment

View Source
Preview of Australian Microbiome - Bioplatforms Australia
Australian Microbiome - Bioplatforms Australia
Contextual Support GreyLiterature

Australian Microbiome - Bioplatforms Australia, accessed July 29, 2025

View Source
Preview of Australian Microbiome – Australian Microbiome
Australian Microbiome – Australian Microbiome
Contextual Support Government

Australian Microbiome – Australian Microbiome

View Source
Preview of Australian Microbiome Initiative – Environomics Future Science Platform - CSIRO Research
Australian Microbiome Initiative – Environomics Future Science Platform - CSIRO Research
Contextual Support Government

Terrestrial Ecosystem Research Network TERN Australia - Queensland science

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
Direct Evidence Journal

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

View Source
Preview of Contrasting Soil pH Effects on Fungal and Bacterial Growth Suggest Functional Redundancy in Carbon Mineralization | Applied and Environmental Microbiology - ASM Journals, accessed July 28, 2025
Contrasting Soil pH Effects on Fungal and Bacterial Growth Suggest Functional Redundancy in Carbon Mineralization | Applied and Environmental Microbiology - ASM Journals, accessed July 28, 2025
Contextual Support

Contrasting Soil pH Effects on Fungal and Bacterial Growth Suggest Functional Redundancy in Carbon Mineralization | Applied and Environmental Microbiology - ASM Journals, accessed July 23, 2025

View Source
Preview of CSIRO and UQ collaborate to boost Australia's ecosystem research, accessed July 25, 2025,
CSIRO and UQ collaborate to boost Australia's ecosystem research, accessed July 25, 2025,
Contextual Support Government

CSIRO and UQ collaborate to boost Australia's ecosystem research

View Source
Preview of Distribution of soil F:B ratio and its relationship to NrE and N min.... - ResearchGate, accessed on June 5, 2025
Distribution of soil F:B ratio and its relationship to NrE and N min.... - ResearchGate, accessed on June 5, 2025
Contextual Support Journal

The Biogeography of Soil Bacteria in Australia Exhibits Greater Resistance to Climate Change Than Fungi - PubMed Central

View Source
Preview of Drivers and human impacts on topsoil bacterial and fungal community biogeography across Australia - CSIRO Research Publications Repository
Drivers and human impacts on topsoil bacterial and fungal community biogeography across Australia - CSIRO Research Publications Repository
Contextual Support Journal

Drivers and human impacts on topsoil bacterial and fungal community biogeography across Australia - CSIRO Research Publications Repository

View Source
Preview of Managing a World Heritage Site in the Face of Climate Change: A Case Study of the Wet Tropics in Northern Queensland - MDPI
Managing a World Heritage Site in the Face of Climate Change: A Case Study of the Wet Tropics in Northern Queensland - MDPI
Contextual Support Journal

Managing a World Heritage Site in the Face of Climate Change: A Case Study of the Wet Tropics in Northern Queensland - MDPI, accessed July 23, 2025

View Source
Preview of Mapping Australia's soil biodiversity - CSIRO, accessed August 5, 2025,
Mapping Australia's soil biodiversity - CSIRO, accessed August 5, 2025,
Contextual Support GreyLiterature

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

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 Norfolk Island Water Resource Assessment, accessed July 30, 2025,
Norfolk Island Water Resource Assessment, accessed July 30, 2025,
Contextual Support Journal

Climate-Affected Australian Tropical Montane Cloud Forest Plants: Metabolomic Profiles, Isolated Phytochemicals, and Bioactivities - PubMed Central

View Source
Preview of Restoration of soil microbes and organic matter ... - UQ eSpace
Restoration of soil microbes and organic matter ... - UQ eSpace
Direct Evidence Journal

Restoration of soil microbes and organic matter ... - UQ eSpace

View Source
Preview of Soil Fungal:Bacterial Ratios Are Linked to Altered Carbon Cycling - PMC - PubMed Central, accessed July 28, 2025
Soil Fungal:Bacterial Ratios Are Linked to Altered Carbon Cycling - PMC - PubMed Central, accessed July 28, 2025
Contextual Support Journal

The fungal-bacterial ratio for soil health - Farmer's Weekly, accessed July 21, 2025

View Source
Preview of Soil microbiome and biodiversity implications – are we ignoring cost-effective proxies of biodiversity measures? | TERN Australia, accessed on June 7, 2025,
Soil microbiome and biodiversity implications – are we ignoring cost-effective proxies of biodiversity measures? | TERN Australia, accessed on June 7, 2025,
Contextual Support GreyLiterature

Environment Monitoring Systems & Data for Ecosystem Studies ...

View Source
Preview of The biogeography of relative abundance of soil fungi versus bacteria in surface topsoil, accessed on June 5, 2025
The biogeography of relative abundance of soil fungi versus bacteria in surface topsoil, accessed on June 5, 2025
Direct Evidence Journal

Fungal/bacterial ratios in grasslands with contrasting nitrogen management, accessed July 31, 2025

View Source
Preview of Vegetation and floristics of a lowland tropical rainforest in northeast Australia - Biodiversity Data Journal
Vegetation and floristics of a lowland tropical rainforest in northeast Australia - Biodiversity Data Journal
Contextual Support Journal

Vegetation and floristics of a lowland tropical rainforest in northeast Australia - Biodiversity Data Journal

View Source

Context

  • Region Australia
  • Biome Tropical & Subtropical Maritime Islands
  • Land Use Conservation / Protected Natural Areas
  • Assessment Conservation Target
  • Evidence Type DegradationThreshold

Lifecycle

  • Status Active
  • Version 1
  • Effective From 8 Jun 2026

Notes

An F:B ratio below 1.0 is a critical warning sign that the soil system is no longer functioning as a healthy, mature, self-regulating ecosystem and may be losing resilience and critical ecosystem services.

Related Benchmarks

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

— index Low
Conservation / Protected Natural Areas · Conservation Target
OptimalRange Active v1