Basal Area

AUS-TMS-CON-BAS General Moderate confidence

Benchmark Value

2 m²/ha
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 17 benchmarks together — the OptimalRange form drives the primary score, while 16 guard(s) constrain the result.

Evidence & Context

Persistent basal area values falling below 2-3 m²/ha across significant areas may signify severe degradation.

Metric Definition:

Basal area (BA) as the sum of cross-sectional areas of tree stems per hectare.

Benchmark Definition:

A lower critical basal area threshold below which essential savanna woodland functions are lost, indicating severe degradation.

Justification:

Based on ecological principles and evidence of severe fire effects reducing basal area to near-zero levels.

Sources (1)

Preview of Meat & Livestock Australia. (Date of P.PSH.0823 publication, e.g., 2020). P.PSH.0823 – Development of Emissions Reduction Fund Carbon Sequestration methods for savanna fire management in North Australia. Final Report. Meat & Livestock Australia.
Meat & Livestock Australia. (Date of P.PSH.0823 publication, e.g., 2020). P.PSH.0823 – Development of Emissions Reduction Fund Carbon Sequestration methods for savanna fire management in North Australia. Final Report. Meat & Livestock Australia. Journal

Meat & Livestock Australia. (Date of P.PSH.0823 publication, e.g., 2020). P.PSH.0823 – Development of Emissions Reduction Fund Carbon Sequestration methods for savanna fire management in North Australia. Final Report. Meat & Livestock Australia.

View Source

Supporting Sources (4)

Additional references from the underlying research that informed this benchmark.

Preview of Additional peer-reviewed articles underpinning concepts of woody encroachment, fire ecology, and savanna dynamics as cited from search results like.1
Additional peer-reviewed articles underpinning concepts of woody encroachment, fire ecology, and savanna dynamics as cited from search results like.1
Contextual Support Direct Evidence Journal

Liddell, M. J., Preece, N. D., Krix, D., Edwards, A. C., & Hutley, L. B. (2024). Seasonal litter decomposition and accumulation in north Australian savanna. International Journal of Wildland Fire, WF24053.

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Preview of Liddell, M. J., Preece, N. D., Krix, D., Edwards, A. C., & Hutley, L. B. (2024). Seasonal litter decomposition and accumulation in north Australian savanna. International Journal of Wildland Fire, WF24053.
Liddell, M. J., Preece, N. D., Krix, D., Edwards, A. C., & Hutley, L. B. (2024). Seasonal litter decomposition and accumulation in north Australian savanna. International Journal of Wildland Fire, WF24053.
Direct Evidence

Liddell, M. J., Preece, N. D., Krix, D., Edwards, A. C., & Hutley, L. B. (2024). Seasonal litter decomposition and accumulation in north Australian savanna. International Journal of Wildland Fire, WF24053.

View Source
Preview of Murphy, B. P., Lehmann, C. E. R., Russell-Smith, J., & Lawes, M. J. (2015). Fire or Water: Which Limits Tree Biomass in Australian Savannas? In: Ecology of Australian Freshwater Plants (pp. 273-294). CSIRO Publishing.
Murphy, B. P., Lehmann, C. E. R., Russell-Smith, J., & Lawes, M. J. (2015). Fire or Water: Which Limits Tree Biomass in Australian Savannas? In: Ecology of Australian Freshwater Plants (pp. 273-294). CSIRO Publishing.
Contextual Support Journal

Murphy, B. P., Lehmann, C. E. R., Russell-Smith, J., & Lawes, M. J. (2015). Fire or Water: Which Limits Tree Biomass in Australian Savannas? In: Ecology of Australian Freshwater Plants (pp. 273-294). CSIRO Publishing.

View Source
Preview of Queensland Department of Environment and Science. (Various dates for BioCondition Manual and REDD).
Queensland Department of Environment and Science. (Various dates for BioCondition Manual and REDD).
Contextual Support Methodology Source Government

Queensland Department of Environment and Science. (Various dates for BioCondition Manual and REDD).

View Source

Context

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

Lifecycle

  • Status Superseded
  • Version 1
  • Effective From 1 Jun 2026
  • Effective To 1 Jun 2026

Notes

Below this threshold, the ecosystem may transition to a treeless grassland or highly impoverished state. No upper detrimental threshold — higher values are always better up to natural saturation.