Fungal:Bacterial Ratio

AUS-TDG-CON-SFB General Low confidence

Benchmark Value

0.5 index
Thresholds: Lower: 0.5, Upper: —
Direction: Lower 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.

Evidence & Context

Literature from broader contexts suggests that F:B ratios persistently below 0.3 to 0.5 are indicative of highly disturbed, bacterially-dominated systems.

Metric Definition:

Fungal:Bacterial Ratio indicating the lower critical threshold below which ecological health is compromised.

Benchmark Definition:

Lower critical threshold of Fungal:Bacterial Ratio below which ecosystem health is significantly compromised in temperate dry woodlands and native grasslands under conservation.

Justification:

Persistently low F:B ratios below 0.5 indicate disturbed, bacterially-dominated systems with compromised ecological health.

Sources (2)

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

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

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

The fungal-bacterial ratio for soil health - Farmer's Weekly, accessed June 7, 2025,

View Source

Supporting Sources (3)

Additional references from the underlying research that informed this benchmark.

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
Direct Evidence 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 Fungus and bacteria OH MY!! F:B Ratios explained - Mass Hydroponics
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
Preview of Response of soil microbial functionality and soil properties to ...
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

Context

  • Region Australia
  • Biome Temperate Dry Woodlands & Native Grasslands
  • Land Use Conservation / Protected Natural Areas
  • Assessment Pristine Reference
  • Evidence Type DegradationThreshold

Lifecycle

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

Notes

Low ratios commonly found in tilled agricultural soils or systems with high nitrogen inputs; fungi are more sensitive to disturbances than bacteria. No upper detrimental threshold — higher values are always better up to natural saturation.

Related Benchmarks

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