Fungal:Bacterial Ratio

AUS-AKW-LVG-SFB General Moderate confidence

Benchmark Value

0.1 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.

Evidence & Context

Synthesizing these points, an F:B ratio falling below 0.10 is proposed as the lower critical threshold for this biome and land use.

Metric Definition:

Fungal:Bacterial ratio measured by PLFA analysis representing the relative biomass of fungi to bacteria in soil.

Benchmark Definition:

The lower critical threshold of the Fungal:Bacterial ratio below which soil ecosystem function is impaired due to loss of fungal biomass in Australian arid karstic woodlands and shrublands under livestock grazing.

Justification:

Below this level, the soil system has likely lost the critical mass of its fungal component required to maintain resilience and carbon-storage functions.

Sources (2)

Preview of Biochemical properties of highly mineralised and infertile soil modified by acacia and spinifex plants in northwest Queensland, Australia | Request PDF - ResearchGate
Biochemical properties of highly mineralised and infertile soil modified by acacia and spinifex plants in northwest Queensland, Australia | Request PDF - ResearchGate Journal

Biochemical properties of highly mineralised and infertile soil modified by acacia and spinifex plants in northwest Queensland, Australia | Request PDF - ResearchGate

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Preview of Soil microbial biomass in semi-arid communal sandy rangelands in the western Bophirima District, South Africa - ResearchGate
Soil microbial biomass in semi-arid communal sandy rangelands in the western Bophirima District, South Africa - ResearchGate GreyLiterature

Soil microbial biomass in semi-arid communal sandy rangelands in the western Bophirima District, South Africa - ResearchGate

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Supporting Sources (1)

Additional references from the underlying research that informed this benchmark.

Preview of How Biodiversity-Friendly Is Regenerative Grazing? - Frontiers, accessed July 29, 2025
How Biodiversity-Friendly Is Regenerative Grazing? - Frontiers, accessed July 29, 2025
Direct Evidence Journal

Adaptive multi-paddock grazing increases soil nutrient availability and bacteria to fungi ratio in grassland soils | Request PDF - ResearchGate

View Source

Context

  • Region Australia
  • Biome Arid Karstic Woodlands & Shrublands
  • Land Use Livestock Grazing & Pasture
  • Assessment Conservation Target
  • Evidence Type DegradationThreshold

Lifecycle

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

Notes

Indicates a degraded, bacterially-dominated system with compromised carbon storage capacity and ecological resilience. No upper detrimental threshold — higher values are always better up to natural saturation.