Fungal:Bacterial Ratio

AUS-TSR-CON-SFB General Moderate confidence

Benchmark Value

0.4 index
Thresholds: Lower: 0.4, Upper: —
Direction: Higher is desirable ↑
Form: LowerThreshold

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

A persistent F:B ratio below ~0.4 indicates a functional shift to a degraded, bacterially-dominated state, associated with losses of soil carbon and overall microbial biomass.

Metric Definition:

Ratio of Fungal PLFA to Bacterial PLFA in soil microbial communities

Benchmark Definition:

This benchmark defines the critical lower threshold of the fungal to bacterial PLFA ratio below which soil ecosystem function is impaired, indicating degradation.

Justification:

This threshold is based on empirical evidence from adjacent intensive agriculture sites showing a shift to bacterial dominance and associated ecosystem degradation.

Sources (1)

Preview of (PDF) Relative to rainforests and grasslands, banana and ..., accessed July 23, 2025
(PDF) Relative to rainforests and grasslands, banana and ..., accessed July 23, 2025 Journal

(PDF) Relative to rainforests and grasslands, banana and ..., accessed July 23, 2025

View Source

Supporting Sources (21)

Additional references from the underlying research that informed this benchmark.

Preview of (PDF) Managing a World Heritage Site in the Face of Climate Change: A Case Study of the Wet Tropics in Northern Queensland - ResearchGate, accessed July 23, 2025
(PDF) Managing a World Heritage Site in the Face of Climate Change: A Case Study of the Wet Tropics in Northern Queensland - ResearchGate, accessed July 23, 2025
Contextual Support Journal

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

View Source
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 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 23, 2025
Are Fungal to Bacterial Ratios (F:B Ratio) Important for Plant Growth? - Garden Myths, accessed July 23, 2025
Contextual Support GreyLiterature

Succession and Soil Productivity - GroundGrocer, accessed July 23, 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 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 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 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 Converting tropical rainforest to native rubber plantations alters soil bacterial and fungal communities - Maximum Academic Press, accessed July 23, 2025
Converting tropical rainforest to native rubber plantations alters soil bacterial and fungal communities - Maximum Academic Press, accessed July 23, 2025
Contextual Support Journal

Converting tropical rainforest to native rubber plantations alters soil bacterial and fungal communities - Maximum Academic Press, accessed July 23, 2025

View Source
Preview of Criteria and Indicators for Sustainable Forest Management in Victoria, accessed July 19, 2025
Criteria and Indicators for Sustainable Forest Management in Victoria, accessed July 19, 2025
Contextual Support Journal

Soil health: the foundation of sustainable agriculture - 2001 ...

View Source
Preview of Ecology of streams in a biogeographic isolate—the Queensland Wet Tropics, Australia - ResearchOnline@JCU, accessed July 23, 2025
Ecology of streams in a biogeographic isolate—the Queensland Wet Tropics, Australia - ResearchOnline@JCU, accessed July 23, 2025
Contextual Support Journal

Ecology of streams in a biogeographic isolate—the Queensland Wet Tropics, Australia - ResearchOnline@JCU, accessed July 23, 2025

View Source
Preview of Impact of drought on soil microbial biomass and extracellular enzyme activity - Frontiers, accessed July 23, 2025
Impact of drought on soil microbial biomass and extracellular enzyme activity - Frontiers, accessed July 23, 2025
Contextual Support Journal

Relative to rainforests and grasslands, banana and sugarcane soils ..., accessed July 23, 2025

View Source
Preview of Looking for suitable indicators. What should be considered to assess the effects of use and management on soil health? - ResearchGate, accessed July 19, 2025,
Looking for suitable indicators. What should be considered to assess the effects of use and management on soil health? - ResearchGate, accessed July 19, 2025,
Contextual Support Journal

(PDF) The measurement of soil fungal:bacterial biomass ratios as an indicator of ecosystem self-regulation in temperate meadow grasslands - ResearchGate, accessed July 23, 2025

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 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
Direct Evidence Journal

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

View Source
Preview of Modified fungal diversity in dense clay subsoils after deep-banding organic substrate - CSIRO Publishing, accessed July 23, 2025
Modified fungal diversity in dense clay subsoils after deep-banding organic substrate - CSIRO Publishing, accessed July 23, 2025
Contextual Support Journal

Modified fungal diversity in dense clay subsoils after deep-banding organic substrate - CSIRO Publishing, accessed July 23, 2025

View Source
Preview of Soil | Australia state of the environment 2021, accessed August 3, 2025,
Soil | Australia state of the environment 2021, accessed August 3, 2025,
Contextual Support

The effects of clipping frequency and nitrogen fertilisation on greenhouse gas emissions and net ecosystem exchange in an Australian temperate grassland - CSIRO PUBLISHING | The Rangeland Journal

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
Preview of Tropical Rainforest Restoration Plantations Are Slow to Restore the Soil Biological and Organic Carbon Characteristics of Old Growth Rainforest - PMC, accessed July 23, 2025
Tropical Rainforest Restoration Plantations Are Slow to Restore the Soil Biological and Organic Carbon Characteristics of Old Growth Rainforest - PMC, accessed July 23, 2025
Contextual Support

Tropical Rainforest Restoration Plantations Are Slow to Restore the Soil Biological and Organic Carbon Characteristics of Old Growth Rainforest - PMC, accessed July 23, 2025

View Source
Preview of Unravelling the effects of tropical land use conversion on the soil microbiome, accessed July 23, 2025
Unravelling the effects of tropical land use conversion on the soil microbiome, accessed July 23, 2025
Contextual Support Journal

Unravelling the effects of tropical land use conversion on the soil microbiome, accessed July 23, 2025

View Source
Preview of Wet Tropics of Queensland - UNESCO World Heritage Centre, accessed July 22, 2025,
Wet Tropics of Queensland - UNESCO World Heritage Centre, accessed July 22, 2025,
Contextual Support GreyLiterature

Wet Tropics of Queensland - UNESCO World Heritage Centre, accessed July 23, 2025

View Source

Context

  • Region Australia
  • Biome Tropical & Subtropical Rainforests
  • Land Use Conservation / Protected Natural Areas
  • Assessment Pristine Reference
  • Vegetation Forest
  • Evidence Type DegradationThreshold

Lifecycle

  • Status Active
  • Version 1
  • Effective From 24 Mar 2026

Notes

Crossing below this threshold indicates loss of fungal-mediated functions including nutrient cycling and carbon storage. No upper detrimental threshold — higher values are always better up to natural saturation.

Related Benchmarks

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

0.6 index High
Conservation / Protected Natural Areas · Pristine Reference · Forest
Point Active v1