Soil Nitrogen

AUS-TMS-CON-SON General Moderate confidence

Benchmark Value

No specific value — see range
Range: 800 to 1200 mg/kg
Thresholds: Lower: 300, Upper: 2000
Optimal Range: 800 to 1200
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.

Contributing Benchmarks

OptimalRange Primary OptimalRange Guard Point Guard

Evidence & Context

Soil Nitrogen 800 - 1200 (target 1000) mg/kg ... Represents the upper range of observed total N in less disturbed savanna sites (0-20 cm depth). The T1P1 site (1000 mg/kg) with >6 years fire exclusion and higher tree cover is indicative of good N retention.

Metric Definition:

Total soil nitrogen concentration in the topsoil (0-10 cm or 0-20 cm) representing high environmental health within conservation/protected natural areas.

Benchmark Definition:

Total soil nitrogen concentration in the topsoil representing a benchmark for high environmental health in conservation areas.

Justification:

Based on field measurements from less disturbed savanna sites, particularly the T1P1 site with >6 years fire exclusion and higher tree cover, indicating good nitrogen retention and ecosystem function.

Sources (1)

Preview of Butterbach-Bahl, K., Kiese, R., Liu, C., & Werner, C. (2014). Nitrogen and greenhouse gas dynamics in managed and natural savanna and pasture ecosystems in northern Australia. Biogeosciences, 11(21), 6047-6062.
Butterbach-Bahl, K., Kiese, R., Liu, C., & Werner, C. (2014). Nitrogen and greenhouse gas dynamics in managed and natural savanna and pasture ecosystems in northern Australia. Biogeosciences, 11(21), 6047-6062. Journal

N$_2$O, NO, N$_2$ and CO$_2$ emissions from tropical savanna and grassland of northern Australia: an incubation experiment with intact soil cores

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Supporting Sources (1)

Additional references from the underlying research that informed this benchmark.

Preview of Landscape Monitoring for Landscape Research | Landscape ..., accessed July 22, 2025,
Landscape Monitoring for Landscape Research | Landscape ..., accessed July 22, 2025,
Contextual Support

TERN Landscapes - Terrestrial Ecosystem Research Network, accessed May 15, 2025

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Context

  • Region Australia
  • Biome Tropical Monsoonal Savannas
  • Land Use Conservation / Protected Natural Areas
  • Assessment Conservation Target
  • Evidence Type ReferenceCondition

Lifecycle

  • Status Active
  • Version 1
  • Effective From 24 Mar 2026

Notes

Lower Critical Threshold: <300-400 mg/kg indicates significant loss of nutrient-conserving structures and functions. Optimal Range supports characteristic biodiversity and ecosystem processes. Upper Detrimental Threshold: >1500-2000 mg/kg or levels causing negative ecological shifts such as loss of N-fixing legumes and altered native community composition. [Migration] Original wider evidence range: 500 – 1200 (retained OptimalRange: 800 – 1200)