Fungal:Bacterial Ratio

AUS-AIF-LVG-SFB General Moderate confidence

Benchmark Value

No specific value — see range
Range: 0.8 to 1.2 index
Thresholds: Lower: 0.3, Upper: 2
Optimal Range: 0.8 to 1.2
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. The scoring engine uses 14 benchmarks together — the OptimalRange form drives the primary score, while 13 guard(s) constrain the result.

Contributing Benchmarks

OptimalRange Primary Point Guard LowerThreshold Guard UpperThreshold Guard OptimalRange Guard LowerThreshold Guard Point Guard LowerThreshold Guard OptimalRange Guard Point Guard LowerThreshold Guard OptimalRange Guard UpperThreshold Guard Point Guard

Evidence & Context

The derived benchmark, representing the best available condition, is presented below, along with a summary of its functional range.

Metric Definition:

The ratio of fungal to bacterial biomass (F:B) in soil, reflecting the balance between fungal and bacterial microbial decomposer groups.

Benchmark Definition:

This benchmark represents the optimal fungal to bacterial biomass ratio in soil for the Arid Inland Floodplains & Ephemeral River Systems biome under Livestock Grazing & Pasture land use, indicating a balanced and healthy soil microbial community.

Justification:

The benchmark is derived by synthesizing findings from the most relevant study in Australian semi-arid grasslands (Wong et al., 2015), which showed higher F:B ratios in native pastures, with general pasture values from other literature.

Sources (1)

Preview of The incorporation of fungal to bacterial ratios and plant ecosystem effect traits into a state-and-transition model of land-use change in semi-arid grasslands - Research @ Flinders, accessed August 3, 2025
The incorporation of fungal to bacterial ratios and plant ecosystem effect traits into a state-and-transition model of land-use change in semi-arid grasslands - Research @ Flinders, accessed August 3, 2025 Journal

The incorporation of fungal to bacterial ratios and plant ecosystem effect traits into a state-and-transition model of land-use change in semi-arid grasslands - Research @ Flinders

View Source

Supporting Sources (8)

Additional references from the underlying research that informed this benchmark.

Preview of Do regenerative grazing management practices improve vegetation and soil health in grazed rangelands? Preliminary insights from a space-for-time study in the Great Barrier Reef catchments, Australia - CSIRO Publishing, accessed August 5, 2025,
Do regenerative grazing management practices improve vegetation and soil health in grazed rangelands? Preliminary insights from a space-for-time study in the Great Barrier Reef catchments, Australia - CSIRO Publishing, accessed August 5, 2025,
Contextual Support

Ludwig, J.A., Bastin, G.N., Chewings, V.H., Eager, R.W., and Liedloff, A.C. (2005). Clearing savannas for use as rangelands in Queensland: Altered landscapes and water-erosion processes. Rangeland Journal, 27(2), 135-149.

View Source
Preview of Fungal/bacterial ratios in grassland with contrasting nitrogen management - Wageningen University & Research, accessed July 28, 2025
Fungal/bacterial ratios in grassland with contrasting nitrogen management - Wageningen University & Research, accessed July 28, 2025
Contextual Support Journal

Fungal/bacterial ratios in grassland with contrasting nitrogen management - Wageningen University & Research, accessed July 30, 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 Grazing intensity influence soil microbial communities and their ..., accessed July 19, 2025
Grazing intensity influence soil microbial communities and their ..., accessed July 19, 2025
Contextual Support Journal

Grazing intensity influence soil microbial communities and their ..., accessed July 19, 2025

View Source
Preview of Soil and Landscape Grid of Australia - CSIRO, accessed July 30, 2025,
Soil and Landscape Grid of Australia - CSIRO, accessed July 30, 2025,
Contextual Support

Soil and Landscape Grid of Australia - CSIRO, accessed August 1, 2025

View Source
Preview of Soil Fungal:Bacterial Ratios Are Linked to Altered Carbon Cycling - PMC - PubMed Central, accessed July 19, 2025
Soil Fungal:Bacterial Ratios Are Linked to Altered Carbon Cycling - PMC - PubMed Central, accessed July 19, 2025
Contextual Support Journal

Soil Fungal:Bacterial Ratios Are Linked to Altered Carbon Cycling - PMC - PubMed Central, accessed July 19, 2025

View Source
Preview of The fungal-bacterial ratio for soil health - Farmer's Weekly, accessed July 28, 2025
The fungal-bacterial ratio for soil health - Farmer's Weekly, accessed July 28, 2025
Contextual Support GreyLiterature

Mechanisms and implications of bacterial–fungal competition for soil resources - PMC, accessed July 30, 2025,

View Source
Preview of The incorporation of fungal to bacterial ratios and plant ecosystem effect traits into a state-and-transition model of land-use change in semi-arid grasslands - Research @ Flinders, accessed July 19, 2025
The incorporation of fungal to bacterial ratios and plant ecosystem effect traits into a state-and-transition model of land-use change in semi-arid grasslands - Research @ Flinders, accessed July 19, 2025
Contextual Support Journal

The incorporation of fungal to bacterial ratios and plant ecosystem effect traits into a state-and-transition model of land-use change in semi-arid grasslands - Research @ Flinders, accessed July 19, 2025

View Source

Context

  • Region Australia
  • Biome Arid Inland Floodplains & Ephemeral River Systems
  • Land Use Livestock Grazing & Pasture
  • Assessment Pristine Reference
  • Evidence Type ReferenceCondition

Lifecycle

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

Notes

Lower Critical Threshold: 0.3 index. Upper Detrimental Threshold: 2 index. A ratio approaching or exceeding 1.0 indicates a shift to a balanced or fungal-leaning system, characteristic of regenerative management. Values below 0.3 indicate a degraded, bacterially-dominated system. Values above 1.5 to 2.0 indicate a successional shift toward woody vegetation, undesirable for pasture productivity.