Basal Area

AUS-AMR-LVG-BAS General Moderate confidence

Benchmark Value

15 m²/ha
Direction: Higher is desirable ↑
Form: MaximumOnly

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

An upper detrimental threshold, where woody encroachment severely limits pasture productivity, is identified at approximately 15 m²/ha.

Metric Definition:

Basal area representing the upper detrimental threshold beyond which ecosystem function is impaired.

Benchmark Definition:

The upper detrimental threshold for basal area indicating significant woody encroachment and loss of pasture productivity in arid grazing landscapes.

Justification:

This value is supported by a simulation study by MacLeod et al. (2010) and represents the point at which management intervention is necessary.

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 DegradationThreshold

Lifecycle

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

Notes

Significant woody encroachment. Severe suppression of the herbaceous layer, leading to a dramatic reduction in livestock carrying capacity. Altered hydrology and loss of ground-layer biodiversity. Requires intervention to restore function. AssessmentContext defaulted to 'Not Stated' because the source document did not state one.