Fungal:Bacterial Ratio

AUS-TMS-AGR-SFB General Low confidence

Benchmark Value

0.5 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 4 benchmarks together — the OptimalRange form drives the primary score, while 3 guard(s) constrain the result.

Contributing Benchmarks

OptimalRange Primary OptimalRange Guard MinimumOnly Guard MinimumOnly Guard

Evidence & Context

A lower critical threshold, below which soil ecological function may be compromised, is suggested at <0.5.

Metric Definition:

Fungal:Bacterial ratio threshold below which soil ecological function is compromised.

Benchmark Definition:

This benchmark defines the lower critical threshold of fungal to bacterial biomass ratio in soil below which soil ecological function may be compromised in agricultural cropping systems of the Tropical Monsoonal Savannas biome.

Justification:

Suggested based on ecological principles and evidence from related systems indicating low F:B ratios are associated with degraded soil function.

Sources (1)

Preview of Responses of communities of soil organisms and plants to soil aging at two contrasting long-term chronosequences | Request PDF - ResearchGate, accessed July 19, 2025,

Responses of communities of soil organisms and plants to soil aging at two contrasting long-term chronosequences | Request PDF - ResearchGate, accessed July 19, 2025, Journal

Temporal and seasonal change in microbial community structure of ...

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Supporting Sources (12)

Additional references from the underlying research that informed this benchmark.

Preview of Dynamics of microbial biomass nitrogen in relation to plant nitrogen uptake during the crop growth period in a dry tropical cropland in Tanzania - Taylor & Francis Online

Dynamics of microbial biomass nitrogen in relation to plant nitrogen uptake during the crop growth period in a dry tropical cropland in Tanzania - Taylor & Francis Online

Contextual Support Journal

Dynamics of microbial biomass nitrogen in relation to plant nitrogen uptake during the crop growth period in a dry tropical cropland in Tanzania - Taylor & Francis Online

View Source

Dynamics of Sudanian Savanna-Woodland Ecosystem in Response to Disturbances - - Administrative page for SLU library

Contextual Support Journal

Dynamics of Sudanian Savanna-Woodland Ecosystem in Response to Disturbances - - Administrative page for SLU library

View Source

Effect of strategic tillage in soil microbial communities in Vertisols from Queensland, Australia - UQ eSpace, accessed July 17, 2025

Contextual Support Journal

Effect of strategic tillage in soil microbial communities in Vertisols from Queensland, Australia - UQ eSpace, accessed July 21, 2025

View Source

Preview of EFFECTS OF PRESCRIBED FIRE ON SOIL BIOGEOCHEMISTRY IN A MIXED GRASS PRAIRIE A Dissertation Submitted to the College of Graduate - HARVEST (uSask)

EFFECTS OF PRESCRIBED FIRE ON SOIL BIOGEOCHEMISTRY IN A MIXED GRASS PRAIRIE A Dissertation Submitted to the College of Graduate - HARVEST (uSask)

Contextual Support

Effects of fire on the soil microbial metabolic quotient: A global meta-analysis | Request PDF

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Final report - MLA

Contextual Support Journal

Final report - MLA

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Microbial Regulation of - Soil Structural Dynamics - CABI Digital Library

Contextual Support Journal

Microbial Regulation of - Soil Structural Dynamics - CABI Digital Library

View Source

Preview of Montealegre CM, van Kessel C, Russelle MP, Sadowsky MJ.. Changes in microbial activity and composition in a pasture ecosystem exposed to elevated atmospheric carbon dioxide. Plant Soil 243: 197-207 - ResearchGate

Montealegre CM, van Kessel C, Russelle MP, Sadowsky MJ.. Changes in microbial activity and composition in a pasture ecosystem exposed to elevated atmospheric carbon dioxide. Plant Soil 243: 197-207 - ResearchGate

Contextual Support Journal

View Source

Responses of communities of soil organisms and plants to soil aging at two contrasting long-term chronosequences | Request PDF - ResearchGate

Contextual Support Journal

Afforestation alters community structure of soil fungi | Request PDF - ResearchGate

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Seasonal dynamics of soil respiration and nitrification in three ...

Methodology Source Government

Seasonal dynamics of soil respiration and nitrification in three subtropical plantations in southern China - iForest - Biogeosciences and Forestry

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Soil Quality and Its Management in Humid Subtropical and Tropical Environments - UKnowledge, accessed May 15, 2025,

Contextual Support

Soil Quality and Its Management in Humid Subtropical and Tropical Environments - UKnowledge

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The Importance of Termites to the CH4 Balance of a Tropical Savanna Woodland of Northern Australia - ResearchGate

Contextual Support Journal

The Importance of Termites to the CH4 Balance of a Tropical Savanna Woodland of Northern Australia - ResearchGate

View Source

The legacy of intensive agricultural history on the soil health of (sub)tropical landscapes, accessed July 16, 2025,

Contextual Support

The legacy of intensive agricultural history on the soil health of (sub)tropical landscapes, accessed July 16, 2025,

View Source

Context

Region Australia
Biome Tropical Monsoonal Savannas
Land Use Agricultural Crop Production
Assessment Agricultural Biodiversity Target
Evidence Type DegradationThreshold

Lifecycle

Status Active
Version 1
Effective From 31 May 2026

Notes

Persistent F:B ratio below 0.5 should be a cause for concern and trigger investigation into soil management practices. No upper detrimental threshold applies.

Related Benchmarks

Other benchmarks in the AUS-TMS-AGR-SFB family.