Microbial Respiration

AUS-TSR-FOR-SMR General Moderate confidence

Benchmark Value

50 mg/kg/day

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 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

The derived reference value for a high-functioning production forest is 50 mg CO2-C/kg/day.

Metric Definition:

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

Benchmark Definition:

A derived benchmark representing a high-functioning, stable production forest ecosystem.

Justification:

Due to a lack of direct Australian data, this value is based on the total soil respiration rate of an analogous old-growth tropical forest in carbon equilibrium (12.7 Mg C ha−1year−1), which serves as an aspirational target for a sustainably managed system.

Sources (2)

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

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

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Supporting Sources (1)

Additional references from the underlying research that informed this benchmark.

Soil Respiration - Natural Resources Conservation Service

Contextual Support Journal

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

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Context

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

Lifecycle

Status Active
Version 1
Effective From 20 Mar 2026

Notes

The conversion to mass-based units assumes a soil depth of 0-10 cm and a bulk density of 0.7 g/cm³, a value representative of North Queensland rainforest soils. Confidence is 'Moderate' as it relies on a robust proxy from a comparable biome but is not a direct measurement from the target land use in Australia.

Related Benchmarks

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