Microbial Respiration

AUS-TSR-FOR-SMR General Moderate confidence

Benchmark Value

10 mg/kg/day
Thresholds: Lower: 10, Upper: —
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 4 benchmarks together — the Point form drives the primary score, while 3 guard(s) constrain the result.

Contributing Benchmarks

Point Primary Point Guard MinimumOnly Guard MaximumOnly Guard

Evidence & Context

A respiration rate that remains consistently below 10 mg C/kg/day in the growing season should be considered an indicator of a critically impaired ecosystem.

Metric Definition:

Soil microbial respiration rate measured as mg CO2-C per kg of soil per day.

Benchmark Definition:

Lower critical threshold below which soil microbial respiration indicates functional collapse.

Justification:

Reflects severe depletion of soil organic matter and microbial biomass, indicating a critically degraded state.

Sources (1)

Preview of Soil Respiration - Natural Resources Conservation Service
Soil Respiration - Natural Resources Conservation Service Journal

Reforestation, carbon sequestration and relationships between soil attributes in the Wet Tropics of Australia (Schmidt et al., 2014)

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Supporting Sources (2)

Additional references from the underlying research that informed this benchmark.

Preview of Maycock, Colin Rulzion (1998) Plant-soil nutrient relationships in ...
Maycock, Colin Rulzion (1998) Plant-soil nutrient relationships in ...
Direct Evidence Journal

Maycock, Colin Rulzion (1998) Plant-soil nutrient relationships in ...

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Preview of Soil Microbial Biomass, Basal Respiration and Enzyme Activity of Main Forest Types in the Qinling Mountains | PLOS One - Research journals, accessed August 5, 2025,
Soil Microbial Biomass, Basal Respiration and Enzyme Activity of Main Forest Types in the Qinling Mountains | PLOS One - Research journals, accessed August 5, 2025,
Direct Evidence

Major and persistent shifts in below‐ground ... - yadvinder malhi

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Context

  • Region Australia
  • Biome Tropical & Subtropical Rainforests
  • Land Use Production Forestry
  • Assessment Pristine Reference
  • Evidence Type DegradationThreshold

Lifecycle

  • Status Active
  • Version 1
  • Effective From 20 Mar 2026

Notes

This threshold applies under optimal temperature and moisture conditions.

Related Benchmarks

Other benchmarks in the AUS-TSR-FOR-SMR family.

50 mg/kg/day Moderate
Production Forestry · Pristine Reference
Point Active v1
60 mg/kg/day Moderate
Production Forestry · Pristine Reference
MaximumOnly Active v1