Soil Nitrogen

AUS-TSW-FOR-SON General Moderate confidence

Benchmark Value

500 mg/kg
Thresholds: Lower: 500, Upper: —
Direction: Higher is desirable ↑
Form: MinimumOnly

Scoring Curve

Scoring curve unavailable

The scoring engine could not generate a curve for this benchmark context. The primary form is CompositeFramework, but the benchmark data may be missing required fields (e.g., optimal range bounds for an OptimalRange benchmark). This is typically a data quality issue in the benchmark pipeline.

Contributing Benchmarks

CompositeFramework Primary OptimalRange Guard LowerThreshold Guard UpperThreshold Guard Point Guard MinimumOnly Guard OptimalRange Guard MaximumOnly Guard Point Guard OptimalRange Guard Point Guard LowerThreshold Guard OptimalRange Guard UpperThreshold Guard Point Guard OptimalRange Guard MaximumOnly Guard Point Guard MinimumOnly Guard MaximumOnly Guard OptimalRange Guard OptimalRange Guard

Evidence & Context

Based on this, a lower critical threshold of approximately 500 mg/kg (0.05%) is proposed.

Metric Definition:

Total Soil Nitrogen (NTO) as a percentage of fine soil mass converted to mg/kg.

Benchmark Definition:

This threshold marks the lower critical soil nitrogen level below which woodland soil function and recovery capacity are likely to be severely impaired in temperate semi-arid shrublands under production forestry.

Justification:

Below this threshold, the soil's capacity to support resilient woodland functions and facilitate recovery from disturbances is likely to be critically compromised.

Sources (1)

Preview of Al-Beidh, S., & Al-Tawaha, A. R. M. (2023). Basic Properties and Mineralogy of Soils and Their Impact on the Growth of Jarrah Forest in Southwestern Australia. Land, 12(6), 1236.
Al-Beidh, S., & Al-Tawaha, A. R. M. (2023). Basic Properties and Mineralogy of Soils and Their Impact on the Growth of Jarrah Forest in Southwestern Australia. Land, 12(6), 1236. Journal

Soil Characteristics and Fertility of the Unique Jarrah Forest of Southwestern Australia, with Particular Consideration of Plant Nutrition and Land Rehabilitation - MDPI, accessed July 19, 2025,

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Supporting Sources (1)

Additional references from the underlying research that informed this benchmark.

Preview of Review of C:N Ratios in Vegetation, Litter and Soil Under Australian Native Forests and Plantations - DCCEEW
Review of C:N Ratios in Vegetation, Litter and Soil Under Australian Native Forests and Plantations - DCCEEW
Contextual Support Journal

Review of C:N Ratios in Vegetation, Litter and Soil ... - DCCEEW

View Source

Context

  • Region Australia
  • Biome Temperate Semi-Arid Shrublands & Open Woodlands
  • Land Use Production Forestry
  • Assessment Pristine Reference
  • Evidence Type DegradationThreshold

Lifecycle

  • Status Active
  • Version 1
  • Effective From 25 Mar 2026

Notes

Native vegetation is adapted to low N, but extreme depletion impairs function.

Related Benchmarks

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

1000 mg/kg Moderate
Production Forestry · Pristine Reference
Point Active v1
2000 mg/kg Moderate
Production Forestry · Pristine Reference
MaximumOnly Active v1
— mg/kg Moderate
Production Forestry · Pristine Reference
OptimalRange Active v1