Fungal:Bacterial Ratio

AUS-TMI-FOR-SFB General Low confidence

Benchmark Value

No specific value — see range

Range: 1.5 to 3.5 index

Optimal Range: 1.5 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. The scoring engine uses 6 benchmarks together — the OptimalRange form drives the primary score, while 5 guard(s) constrain the result.

Contributing Benchmarks

OptimalRange Primary MinimumOnly Guard OptimalRange Guard MinimumOnly Guard OptimalRange Guard MinimumOnly Guard

Evidence & Context

Based on this synthesis, the proposed reference value for the F:B ratio in a best-practice, sustainably managed production forest in this biome is an inferred range of 1.5 to 3.5.

Metric Definition:

Fungal to bacterial biomass ratio in soil

Benchmark Definition:

This benchmark represents the healthy balance of fungal to bacterial biomass in soil for sustainably managed production forests in the Tropical & Subtropical Maritime Islands biome, indicating a robust fungal community and improved ecosystem function compared to degraded states.

Justification:

Derived from synthesis of analogous systems due to lack of direct measurements; reflects best available condition for production forestry in this biome accounting for natural tropical ecosystem characteristics and production disturbances.

Sources (1)

Synthesis based on Burton et al. (2007), Paul et al. (2020), and global patterns from Shi et al. (2022)

Synthesis based on Burton et al. (2007), Paul et al. (2020), and global patterns from Shi et al. (2022)

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Supporting Sources (7)

Additional references from the underlying research that informed this benchmark.

Preview of Bailey VL, Smith JL, Bolton H Jr.. Fungal-to-bacterial ratios in soils investigated for enhanced C sequestration. Soil Bio Biochem 34: 997-1007 | Request PDF - ResearchGate, accessed on June 5, 2025

Bailey VL, Smith JL, Bolton H Jr.. Fungal-to-bacterial ratios in soils investigated for enhanced C sequestration. Soil Bio Biochem 34: 997-1007 | Request PDF - ResearchGate, accessed on June 5, 2025

Cross Reference Journal

Bailey VL, Smith JL, Bolton H Jr.. Fungal-to-bacterial ratios in soils investigated for enhanced C sequestration. Soil Bio Biochem 34: 997-1007 | Request PDF - ResearchGate

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Biogeographical patterns of the soil fungal:bacterial ratio across France - PubMed Central, accessed August 1, 2025

Cross Reference Journal

Biogeographical patterns of the soil fungal:bacterial ratio across France - PubMed Central, accessed August 1, 2025

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Fungi to bacteria ratio: Historical misinterpretations and potential implications | Request PDF, accessed July 18, 2025

Contextual Support Journal

Mechanisms and implications of bacterial–fungal competition for soil resources - PMC, accessed July 21, 2025

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Soil Fungal:Bacterial Ratios Are Linked to Altered Carbon ... - Frontiers, accessed July 18, 2025

Contextual Support Journal

How Biodiversity-Friendly Is Regenerative Grazing? - Frontiers

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Preview of Soil organic matter and geochemical characteristics shape microbial community composition and structure across different land uses in an Australian wet tropical catchment | Request PDF - ResearchGate, accessed August 1, 2025

Soil organic matter and geochemical characteristics shape microbial community composition and structure across different land uses in an Australian wet tropical catchment | Request PDF - ResearchGate, accessed August 1, 2025

Contextual Support Journal

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Preview of Srivastava, S. C., & Singh, J. S. (1989). Effect of cultivation on microbial biomass C and N of a dry tropical forest soil. Biology and Fertility of Soils, 8(4), 343-348.

Srivastava, S. C., & Singh, J. S. (1989). Effect of cultivation on microbial biomass C and N of a dry tropical forest soil. Biology and Fertility of Soils, 8(4), 343-348.

Direct Evidence GreyLiterature

Soil microbial biomass, activity and community composition in adjacent native and plantation forests of subtropical Australia | Request PDF - ResearchGate

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Preview of Urbanization and edge effects interact to drive mutualism breakdown and the rise of unstable pathogenic communities in forest soil | PNAS, accessed August 1, 2025

Urbanization and edge effects interact to drive mutualism breakdown and the rise of unstable pathogenic communities in forest soil | PNAS, accessed August 1, 2025

Contextual Support Journal

Urbanization and edge effects interact to drive mutualism breakdown and the rise of unstable pathogenic communities in forest soil | PNAS, accessed August 1, 2025

View Source

Context

Region Australia
Biome Tropical & Subtropical Maritime Islands
Land Use Production Forestry
Assessment Not Stated
Evidence Type ReferenceCondition

Lifecycle

Status Active
Version 1
Effective From 8 Jun 2026

Notes

Lower Critical Threshold: <1.0, indicating a highly disturbed, bacterially-dominated system with compromised ecological function. No upper detrimental threshold — higher values are always better up to natural saturation. Optimal Range: 1.5–3.5, reflecting a balance between production and key ecosystem services like carbon sequestration. AssessmentContext defaulted to 'Not Stated' because the source document did not state one.

Related Benchmarks

Other benchmarks in the AUS-TMI-FOR-SFB family.