Fungal:Bacterial Ratio

AUS-TSW-CON-SFB General Moderate confidence

Benchmark Value

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 7 benchmarks together — the OptimalRange form drives the primary score, while 6 guard(s) constrain the result.

Evidence & Context

Proposed Reference Value (PLFA-based): A PLFA-based F:B ratio of >3.0 is proposed as the benchmark representing a high-health state for conservation areas in Australia's Temperate Semi-Arid Shrublands & Open Woodlands.

Metric Definition:

Fungal to bacterial biomass ratio in soil as measured by Phospholipid Fatty Acid (PLFA) analysis.

Benchmark Definition:

This benchmark represents the fungal to bacterial biomass ratio in soil indicating a high-health conservation state in Australia's Temperate Semi-Arid Shrublands & Open Woodlands, where a ratio above 3.0 reflects a healthy ecosystem.

Justification:

The confidence in this benchmark is rated as Moderate because it is derived by extrapolation from a functionally similar proxy system (well-managed pasture) rather than direct measurement from conservation areas in the target biome. The directional evidence from the primary source is strong and aligned with the biome and land use context.

Sources (2)

Preview of ausveg - fact sheet: soil microbiology, accessed July 18, 2025
ausveg - fact sheet: soil microbiology, accessed July 18, 2025 Journal

ausveg - fact sheet: soil microbiology

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 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

Context

  • Region Australia
  • Biome Temperate Semi-Arid Shrublands & Open Woodlands
  • Land Use Conservation / Protected Natural Areas
  • Assessment Conservation Target
  • Evidence Type ReferenceCondition

Lifecycle

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

Notes

No upper detrimental threshold — higher values are always better up to natural saturation. ConsistencyResolver applied 2026-03-24 20:10 UTC: BenchmarkValue 3 → 1 (check: MinAboveMax, rationale: Swapping the MinimumOnly benchmark's value to 1 aligns it as the lower floor threshold consistent with its role and Notes.) [Migration] Observed upper spread: 5 index