Fungal:Bacterial Ratio

AUS-TDG-CON-SFB General Moderate confidence

Benchmark Value

No specific value — see range

Range: 2.3 to 3.5 ratio

Optimal Range: 2.3 to 3.5

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

In molecular tests (such as PLFA analysis), it's more likely to be 2.3-3.5 (or higher) in pasture.

Metric Definition:

Phospholipid fatty acid (PLFA) analysis ratio of active fungal biomarkers to bacterial biomarkers in topsoil (0-10 cm).

Benchmark Definition:

Healthy fungal to bacterial ratio range based on PLFA molecular tests for perennial grass-dominated soils.

Justification:

This range represents the molecular-tested target for perennial grass-dominated soils in Australia, providing a robust, non-culture-dependent target for grasslands.

Sources (1)

Preview of Different responses of soil fungal and bacterial communities to nitrogen addition in a forest grassland ecotone - Frontiers

Different responses of soil fungal and bacterial communities to nitrogen addition in a forest grassland ecotone - Frontiers Journal

Soil microbiology factsheet

View Source

Supporting Sources (7)

Additional references from the underlying research that informed this benchmark.

Fungal/bacterial ratios in grasslands with contrasting nitrogen ...

Direct Evidence

Fungal/bacterial ratios in grasslands with contrasting nitrogen ...

View Source

Fungal/bacterial ratios in grasslands with contrasting nitrogen management - ResearchGate, accessed July 18, 2025

Direct Evidence GreyLiterature

Fungal/bacterial ratios in grasslands with contrasting nitrogen management - ResearchGate

View Source

Fungus and bacteria OH MY!! F:B Ratios explained - Mass Hydroponics

Contextual Support GreyLiterature

Soil Fungal:Bacterial Ratios Are Linked to Altered Carbon Cycling - PMC - PubMed Central, accessed July 21, 2025

View Source

Global biogeography of fungal and bacterial biomass carbon in topsoil

Irrelevant

Biogeographic patterns of soil bacterial and fungal biomass C and their ratios across major biomes

View Source

Response of soil microbial functionality and soil properties to ...

Contextual Support Journal

Pastures to woodlands: Changes in soil microbial communities and carbon following reforestation | Request PDF - ResearchGate

View Source

Role of Soil Fungus | Ohioline - The Ohio State University, accessed on June 5, 2025

Contextual Support GreyLiterature

Role of Soil Fungus | Ohioline - The Ohio State University, accessed on June 7, 2025,

View Source

Unlocking the power of microbes to enhance the soil

Contextual Support GreyLiterature

Unlocking the power of microbes to enhance the soil

View Source

Context

Region Australia
Biome Temperate Dry Woodlands & Native Grasslands
Land Use Conservation / Protected Natural Areas
Assessment Agricultural Biodiversity Target
Vegetation Grassland
Evidence Type HealthyOperationalRange

Lifecycle

Status Active
Version 1
Effective From 19 Jun 2026

Notes

PLFA ratios are higher than CFU ratios because they extract lipids from both culturable and non-culturable active microbial membranes.

Related Benchmarks

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