Microbial Biomass Carbon (MBC)

AUS-AIF-LVG-SMB General Moderate confidence

Benchmark Value

No specific value — see range

Range: 600 to 1600 mg/kg

Optimal Range: 600 to 1600

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 13 benchmarks together — the OptimalRange form drives the primary score, while 12 guard(s) constrain the result.

Contributing Benchmarks

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

Evidence & Context

The optimal condition is best described by a dynamic functional range of approximately 600 to 1600+ mg/kg.

Metric Definition:

Microbial Biomass Carbon (MBC) as the total carbon in living microbial cells in soil.

Benchmark Definition:

This benchmark represents the dynamic functional range of microbial biomass carbon indicating a healthy and resilient soil microbial community in the target biome under livestock grazing.

Justification:

Lower bound represents a healthy baseline during dry phases; upper bound reflects peak post-flood potential.

Sources (2)

Loss of Soil Carbon Associated with a Short-Duration Flood in a Semi-Arid Lowland River Floodplain Forest Journal

Loss of Soil Carbon Associated with a Short-Duration Flood in a ...

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Microbial biomass and microbial biodiversity in some soils from New South Wales, Australia | Request PDF - ResearchGate Journal

Microbial biomass and microbial biodiversity in some soils from New South Wales, Australia | Request PDF - ResearchGate

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Supporting Sources (1)

Additional references from the underlying research that informed this benchmark.

Preview of grazing impacts on the spatial distribution of soil microbial biomass around tussock grasses in a tropical grassland - Publication : USDA ARS

grazing impacts on the spatial distribution of soil microbial biomass around tussock grasses in a tropical grassland - Publication : USDA ARS

Direct Evidence Journal

grazing impacts on the spatial distribution of soil microbial biomass around tussock grasses in a tropical grassland - Publication : USDA ARS

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Context

Region Australia
Biome Arid Inland Floodplains & Ephemeral River Systems
Land Use Livestock Grazing & Pasture
Assessment Not Stated
Evidence Type HealthyOperationalRange

Lifecycle

Status Active
Version 1
Effective From 3 Jun 2026

Notes

A system operating within this range demonstrates both stability and responsiveness, indicating resilience and high functional capacity. No upper detrimental threshold — higher values are always better up to natural saturation. AssessmentContext defaulted to 'Not Stated' because the source document did not state one.

Related Benchmarks

Other benchmarks in the AUS-AIF-LVG-SMB family.