Microbial Biomass Carbon (MBC)

AUS-TMI-FOR-SMB General Low confidence

Benchmark Value

400 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 9 benchmarks together — the OptimalRange form drives the primary score, while 8 guard(s) constrain the result.

Contributing Benchmarks

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

Evidence & Context

Therefore, a benchmark of mg kg−1 is proposed.

Metric Definition:

Microbial Biomass Carbon (MBC) in the topsoil (0–10 cm) under sustainable production forestry

Benchmark Definition:

This benchmark represents a proxy value for the best available condition of microbial biomass carbon in the topsoil (0–10 cm) under sustainable production forestry in tropical & subtropical maritime islands.

Justification:

Due to a lack of direct data for this specific biome and land use, it was triangulated from global and regional data and best-practice understanding.

Sources (2)

A global analysis of soil microbial biomass carbon, nitrogen and phosphorus in terrestrial ecosystems Journal

A global analysis of soil microbial biomass carbon, nitrogen and phosphorus in terrestrial ecosystems

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Preview of Topsoil microbial biomass carbon pool and the microbial quotient under distinct land-use types across China

Topsoil microbial biomass carbon pool and the microbial quotient under distinct land-use types across China GreyLiterature

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

View Source

Supporting Sources (1)

Additional references from the underlying research that informed this benchmark.

Preview of Traditional Aboriginal and Torres Strait Islander Land Management Practices: Fire-Stick Farming and Beyond - Welcome To Country - Shop, accessed July 30, 2025

Traditional Aboriginal and Torres Strait Islander Land Management Practices: Fire-Stick Farming and Beyond - Welcome To Country - Shop, accessed July 30, 2025

Direct Evidence GreyLiterature

A meta-analysis of soil microbial biomass responses to forest disturbances - PMC

View Source

Context

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

Lifecycle

Status Active
Version 1
Effective From 5 Jun 2026

Notes

The benchmark is a proxy-based value due to the absence of direct measurements in the target biome and land use. There is no simple upper detrimental threshold; high MBC coupled with high metabolic quotient can indicate microbial stress. AssessmentContext defaulted to 'Not Stated' because the source document did not state one.

Related Benchmarks

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