Soil Organic Carbon (SOC)

AUS-TSR-CON-SOC General Moderate confidence

Benchmark Value

3.2 %
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 3 benchmarks together — the OptimalRange form drives the primary score, while 2 guard(s) constrain the result.

Contributing Benchmarks

OptimalRange Primary Point Guard MinimumOnly Guard

Evidence & Context

Based on a synthesis of the available evidence, a benchmark value of 3.2% SOC is proposed for the 0–10 cm soil layer in Australian Tropical and Subtropical Rainforests under conservation management.

Metric Definition:

Soil Organic Carbon (SOC) concentration in the 0–10 cm soil layer, expressed as a percentage of soil mass.

Benchmark Definition:

SOC concentration in the top 0–10 cm of soil representing the best available condition in typical loamy soils of tropical and subtropical rainforests.

Justification:

This value is selected for several reasons: direct measurement in primary tropical forest, corroboration by other high-functioning systems, and representation of typical well-drained mature rainforest soils on common granitic or metamorphic parent materials.

Sources (1)

Preview of Soil carbon distribution and its temperature sensitivity in tropical forests with different forest types
Soil carbon distribution and its temperature sensitivity in tropical forests with different forest types Journal

Soil carbon distribution and its temperature sensitivity in tropical forests with different forest types

View Source

Supporting Sources (3)

Additional references from the underlying research that informed this benchmark.

Preview of Addressing the rundown of nitrogen and soil organic carbon - GRDC, accessed July 25, 2025,
Addressing the rundown of nitrogen and soil organic carbon - GRDC, accessed July 25, 2025,
Degradation Threshold Journal

Soil | Australia state of the environment 2021

View Source
Preview of Nutrient relationships of tree species in a New South Wales Subtropical rainforest
Nutrient relationships of tree species in a New South Wales Subtropical rainforest
Contextual Support Journal

Nutrient relationships of tree species in a New South Wales Subtropical rainforest

View Source
Preview of Soil Organic Carbon Distribution, Enzyme Activities, and the ... - MDPI
Soil Organic Carbon Distribution, Enzyme Activities, and the ... - MDPI
Contextual Support Journal

Soil Organic Carbon Distribution, Enzyme Activities, and the ... - MDPI

View Source

Context

  • Region Australia
  • Biome Tropical & Subtropical Rainforests
  • Land Use Conservation / Protected Natural Areas
  • Assessment Conservation Target
  • Evidence Type ReferenceCondition

Lifecycle

  • Status Active
  • Version 1
  • Effective From 6 Jun 2026

Notes

No upper detrimental threshold — higher values are always better up to natural saturation. The benchmark is based on direct measurements and corroborated by multiple studies. SOC potential is strongly controlled by soil texture and geology. A texture-differentiated approach is recommended for accurate assessment.

Related Benchmarks

Other benchmarks in the AUS-TSR-CON-SOC family.

6.6 % Moderate
Conservation / Protected Natural Areas · Conservation Target
Point Active v1
2 % Moderate
Conservation / Protected Natural Areas · Conservation Target
Point Active v1
2.2 % Moderate
Conservation / Protected Natural Areas · Conservation Target
MinimumOnly Active v1
4.6 % Moderate
Conservation / Protected Natural Areas · Conservation Target
MinimumOnly Active v1
1.4 % Moderate
Conservation / Protected Natural Areas · Conservation Target
MinimumOnly Active v1
— % Moderate
Conservation / Protected Natural Areas · Conservation Target
OptimalRange Active v1