Basal Area

AUS-AMR-LVG-BAS General Moderate confidence

Benchmark Value

2.6 m²/ha
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 18 benchmarks together — the OptimalRange form drives the primary score, while 17 guard(s) constrain the result.

Evidence & Context

The mean value of 2.6 m²/ha for the grazed control plots in arid A. aneura woodlands is the most robust and relevant figure. It represents a long-term, stable condition under grazing in a dominant vegetation type of the Arid Mountain Ranges & Uplands biome.

Metric Definition:

Basal area, the cross-sectional area of tree stems at a standardized height (typically breast height), providing a measure of stand density and size of mature trees.

Benchmark Definition:

This benchmark represents the typical basal area of woody vegetation in sustainably managed grazing landscapes within the Arid Mountain Ranges & Uplands biome, reflecting a functional and stable ecosystem under grazing.

Justification:

This value is selected as it represents the "best-on-offer" real-world condition for a functional, sustainably managed grazing landscape, rather than an ungrazed wilderness state. Confidence is 'Moderate' as the source is a robust, large-scale CSIRO study, but the value is an average across multiple sites and not specific to the Arid Mountain Ranges & Uplands biome, which introduces some uncertainty.

Sources (1)

Preview of Long-term monitoring and modelling of pasture regeneration and water quality from a Bothriochloa pertusa site in the Great Barrier Reef catchments - CSIRO PUBLISHING | The Rangeland Journal, accessed July 15, 2025,
Long-term monitoring and modelling of pasture regeneration and water quality from a Bothriochloa pertusa site in the Great Barrier Reef catchments - CSIRO PUBLISHING | The Rangeland Journal, accessed July 15, 2025, Journal

Reducing the impacts of grazing on water quality - EPA Victoria, accessed July 10, 2025,

View Source

Supporting Sources (1)

Additional references from the underlying research that informed this benchmark.

Preview of Does grazing exclusion in Australia's rangelands affect biomass and debris carbon stocks?
Does grazing exclusion in Australia's rangelands affect biomass and debris carbon stocks?
Contextual Support Journal

Does grazing exclusion in Australia's rangelands affect biomass and debris carbon stocks?

View Source

Context

  • Region Australia
  • Biome Arid Mountain Ranges & Uplands
  • Land Use Livestock Grazing & Pasture
  • Assessment Not Stated
  • Evidence Type ReferenceCondition

Lifecycle

  • Status Active
  • Version 1
  • Effective From 7 Jun 2026

Notes

The benchmark sits within an optimal functional range of approximately 1.0–5.0 m²/ha. A lower critical threshold is qualitatively described as approaching zero, indicating severe degradation. An upper detrimental threshold is identified at approximately 15 m²/ha, beyond which woody encroachment severely limits pasture productivity. AssessmentContext defaulted to 'Not Stated' because the source document did not state one.