Microbial Biomass Carbon (MBC)

AUS-TSW-FOR-SMB General Moderate confidence

Benchmark Value

No specific value — see range
Range: 200 to 400 mg/kg
Optimal Range: 200 to 400
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 3 benchmarks together — the OptimalRange form drives the primary score, while 2 guard(s) constrain the result.

Evidence & Context

The optimal range for a functioning, sustainable system is considered to be 200–400 mg/kg.

Metric Definition:

Optimal functional range for Microbial Biomass Carbon (MBC) indicating a healthy, sustainably managed system.

Benchmark Definition:

This benchmark defines the optimal range of Microbial Biomass Carbon that indicates a healthy and sustainably managed soil system in temperate semi-arid woodlands under production forestry.

Justification:

Spans the zone from a minimally acceptable state to the 'attainable microbial biomass' for a healthy, well-managed system under the given climatic and land-use constraints.

Sources (1)

Preview of Green Carbon in the Great Western Woodlands: A global opportunity for conservation, climate change and sustainable futures
Green Carbon in the Great Western Woodlands: A global opportunity for conservation, climate change and sustainable futures Journal

Green Carbon in the Great Western Woodlands: A global opportunity for conservation, climate change and sustainable futures

View Source

Supporting Sources (2)

Additional references from the underlying research that informed this benchmark.

Preview of Interpreting Microbial Biomass Carbon | Fact Sheets | soilquality.org.au, accessed August 28, 2025,
Interpreting Microbial Biomass Carbon | Fact Sheets | soilquality.org.au, accessed August 28, 2025,
Contextual Support GreyLiterature

Interpreting Microbial Biomass Carbon | Fact Sheets | soilquality.org.au

View Source
Preview of The Effect of Harvest on Forest Soil Carbon: A Meta-Analysis - MDPI, accessed August 5, 2025
The Effect of Harvest on Forest Soil Carbon: A Meta-Analysis - MDPI, accessed August 5, 2025
Contextual Support Journal

Refining benchmarks for soil organic carbon in Australia's temperate ...

View Source

Context

  • Region Australia
  • Biome Temperate Semi-Arid Shrublands & Open Woodlands
  • Land Use Production Forestry
  • Assessment Conservation Target
  • Vegetation Woodland
  • Evidence Type HealthyOperationalRange

Lifecycle

  • Status Active
  • Version 1
  • Effective From 5 Jun 2026

Notes

A production forestry system that consistently maintains its soil MBC within this range can be considered healthy and sustainably managed.

Related Benchmarks

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