Basal Area

AUS-TMS-FOR-BAS General Moderate confidence

Benchmark Value

4 m²/ha
Thresholds: Lower: 4, 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 12 benchmarks together — the OptimalRange form drives the primary score, while 11 guard(s) constrain the result.

Evidence & Context

A sustained Basal Area below approximately 4-5 m²/ha (for stems >20cm DBH) is likely to indicate compromised ecological health, diminished resilience, and impaired habitat functions.

Metric Definition:

Basal Area (BA) quantifies the cross-sectional area of tree stems at breast height per unit of ground area.

Benchmark Definition:

This benchmark defines a lower critical threshold basal area of 4 m²/ha below which the ecological health and sustainability of production forestry in Australian Tropical Monsoonal Savannas is significantly compromised.

Justification:

Based on the lower observed range in natural systems and implications for habitat and resilience.

Sources (1)

Preview of Karan, M. et al. (2016) The Australian SuperSite Network...
Karan, M. et al. (2016) The Australian SuperSite Network... Journal

Karan, M. et al. (2016) The Australian SuperSite Network...

View Source

Supporting Sources (4)

Additional references from the underlying research that informed this benchmark.

Preview of Fire exclusion and the changing landscape of Queensland's Wet Tropics Bioregion 1. The extent and pattern of transition - ResearchGate
Fire exclusion and the changing landscape of Queensland's Wet Tropics Bioregion 1. The extent and pattern of transition - ResearchGate
Contextual Support GreyLiterature

Fire exclusion and the changing landscape of Queensland's Wet Tropics Bioregion 1. The extent and pattern of transition - ResearchGate

View Source
Preview of Hutley, L. B., et al. (2011) Patterns and processes of carbon, water and energy cycles...
Hutley, L. B., et al. (2011) Patterns and processes of carbon, water and energy cycles...
Contextual Support Journal

Hutley, L. B., et al. (2011) Patterns and processes of carbon, water and energy cycles...

View Source
Preview of Ironwood Erythrophleum chlorostachys in the Northern Territory ...
Ironwood Erythrophleum chlorostachys in the Northern Territory ...
Contextual Support Journal

Ironwood Erythrophleum chlorostachys in the Northern Territory ...

View Source
Preview of The Science Behind Mining - Aluminium Stewardship Initiative, accessed May 16, 2025,
The Science Behind Mining - Aluminium Stewardship Initiative, accessed May 16, 2025,
Contextual Support Journal

aluminium-stewardship.org

View Source

Context

  • Region Australia
  • Biome Tropical Monsoonal Savannas
  • Land Use Production Forestry
  • Assessment Pristine Reference
  • Evidence Type DegradationThreshold

Lifecycle

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

Notes

Values below this threshold are associated with environmental stress and poor site conditions. No upper detrimental threshold — higher values are always better up to natural saturation.

Related Benchmarks

Other benchmarks in the AUS-TMS-FOR-BAS family.