Microbial Biomass Carbon (MBC)

AUS-AIF-LVG-SMB General Moderate confidence

Benchmark Value

1600 mg/kg
Direction: Higher is desirable ↑
Form: Point

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.

Evidence & Context

This post-recession value of 1600 mg/kg represents a system operating at its peak functional capacity.

Metric Definition:

Microbial Biomass Carbon (MBC) is a measure of the total carbon held within the living cells of microorganisms, primarily bacteria and fungi, in a given mass of soil.

Benchmark Definition:

This benchmark represents the peak functional capacity of microbial biomass carbon in soils under best-practice livestock grazing in Australia's Arid Inland Floodplains & Ephemeral River Systems.

Justification:

The value is chosen because it is the highest field-measured MBC value found in the literature directly situated within the target biome, representing the peak functional state during the natural flood pulse.

Sources (1)

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

View Source

Supporting Sources (2)

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

View Source
Preview of Microbial biomass and microbial biodiversity in some soils from New South Wales, Australia | Request PDF - ResearchGate
Microbial biomass and microbial biodiversity in some soils from New South Wales, Australia | Request PDF - ResearchGate
Contextual Support Journal

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

View Source

Context

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

Lifecycle

  • Status Active
  • Version 1
  • Effective From 3 Jun 2026

Notes

The benchmark represents the best available condition, observed after a managed flood recession, capturing the peak functional state of the ecosystem when the hydrological pulse is active. 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.