Basal Area

AUS-TMS-AGR-BAS General Moderate confidence

Benchmark Value

No specific value — see range
Range: 8 to 12 m²/ha
Thresholds: Lower: 3, Upper: 20
Optimal Range: 8 to 12
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 16 benchmarks together — the OptimalRange form drives the primary score, while 15 guard(s) constrain the result.

Contributing Benchmarks

OptimalRange Primary OptimalRange Guard Point Guard MinimumOnly Guard MaximumOnly Guard OptimalRange Guard OptimalRange Guard MaximumOnly Guard MinimumOnly Guard OptimalRange Guard MinimumOnly Guard UpperThreshold Guard LowerThreshold Guard UpperThreshold Guard OptimalRange Guard UpperThreshold Guard

Evidence & Context

Based on this evidence, a target range of 8 to 12 m²/ha is proposed as the benchmark for best-on-offer condition.

Metric Definition:

Tree basal area within agricultural crop production systems in Australia's Tropical Monsoonal Savannas

Benchmark Definition:

A synthesized value representing a well-structured savanna woodland, balancing robust ecological function with the agronomic requirements of understory crop production.

Justification:

The benchmark is strongly grounded in established ecological theory and is quantitatively triangulated from robust empirical data from highly relevant analogous systems, including natural savanna woodlands and forests within the same biome.

Sources (1)

Preview of Synthesis of ecological thresholds in Australian tropical savanna ecosystems
Synthesis of ecological thresholds in Australian tropical savanna ecosystems Journal

Synthesis of ecological thresholds in Australian tropical savanna ecosystems

View Source

Supporting Sources (28)

Additional references from the underlying research that informed this benchmark.

Preview of (PDF) Ecological considerations in sustainable silvopasture design and management, accessed July 23, 2025
(PDF) Ecological considerations in sustainable silvopasture design and management, accessed July 23, 2025
Contextual Support GreyLiterature

(PDF) Ecological considerations in sustainable silvopasture design and management, accessed July 23, 2025

View Source
Preview of (PDF) Savanna tree density, herbivores, and the herbaceous community: Bottom-up vs. top-down effects - ResearchGate, accessed July 23, 2025
(PDF) Savanna tree density, herbivores, and the herbaceous community: Bottom-up vs. top-down effects - ResearchGate, accessed July 23, 2025
Contextual Support Journal

(PDF) Savanna tree density, herbivores, and the herbaceous community: Bottom-up vs. top-down effects - ResearchGate, accessed July 23, 2025

View Source
Preview of (PDF) Scattered trees: A complementary strategy for facilitating adaptive responses to climate change in modified landscapes? - ResearchGate, accessed July 23, 2025
(PDF) Scattered trees: A complementary strategy for facilitating adaptive responses to climate change in modified landscapes? - ResearchGate, accessed July 23, 2025
Contextual Support Journal

Soil, Production and Ecological Benefits of Trees on Farms - Soils For Life, accessed July 23, 2025

View Source
Preview of (PDF) Tree density, basal area and species diversity in a disturbed dry tropical forest of northern India: Implications for conservation - ResearchGate, accessed July 23, 2025
(PDF) Tree density, basal area and species diversity in a disturbed dry tropical forest of northern India: Implications for conservation - ResearchGate, accessed July 23, 2025
Contextual Support Journal

Influence of Tree Density on Vegetation Composition and Soil Chemical Properties in Savanna Rangeland of Eastern Cape, South Africa - Scientific Research Publishing, accessed July 23, 2025

View Source
Preview of (PDF) Tree growth rates in north Australian savanna habitats: seasonal patterns and correlations with leaf attributes - ResearchGate, accessed July 23, 2025
(PDF) Tree growth rates in north Australian savanna habitats: seasonal patterns and correlations with leaf attributes - ResearchGate, accessed July 23, 2025
Contextual Support Journal

(PDF) Tree growth rates in north Australian savanna habitats: seasonal patterns and correlations with leaf attributes - ResearchGate, accessed July 23, 2025

View Source
Preview of A scientific review of the impacts of land clearing on threatened species in Queensland 2016, accessed July 23, 2025
A scientific review of the impacts of land clearing on threatened species in Queensland 2016, accessed July 23, 2025
Regulatory Framework Government

A scientific review of the impacts of land clearing on threatened species in Queensland 2016, accessed July 23, 2025

View Source
Preview of Agriculture | Australia's Northern Territory, accessed July 23, 2025
Agriculture | Australia's Northern Territory, accessed July 23, 2025
Contextual Support Government

Agriculture | Australia's Northern Territory, accessed July 23, 2025

View Source
Preview of Australian Savanna Biome, accessed May 17, 2025,
Australian Savanna Biome, accessed May 17, 2025,
Contextual Support GreyLiterature

The Tropical Savannas of Northern Australia - Charles Darwin University, accessed July 23, 2025

View Source
Preview of Australian tropical savanna factsheet - Cool.org, accessed July 23, 2025
Australian tropical savanna factsheet - Cool.org, accessed July 23, 2025
Contextual Support GreyLiterature

Australian tropical savanna factsheet - Cool.org, accessed July 23, 2025

View Source
Preview of Calculating basal area - YouTube
Calculating basal area - YouTube
Methodology Source GreyLiterature

Calculating basal area - YouTube, accessed July 23, 2025

View Source
Preview of Decadal dynamics of tree cover in an Australian tropical savanna - ResearchGate, accessed May 14, 2025,
Decadal dynamics of tree cover in an Australian tropical savanna - ResearchGate, accessed May 14, 2025,
Contextual Support

(PDF) Ecological thresholds at the savanna-forest boundary: How plant traits, resources and fire govern the distribution of tropical biomes - ResearchGate, accessed July 23, 2025

View Source
Preview of DOUGLAS DALY AGRICULTURAL ZONE ECONOMIC ANALYSIS Regional Development Australia NT Pr, accessed July 23, 2025
DOUGLAS DALY AGRICULTURAL ZONE ECONOMIC ANALYSIS Regional Development Australia NT Pr, accessed July 23, 2025
Contextual Support Journal

Tree effects on grass growth in savannas: competition, facilitation and the stress-gradient hypothesis - Jornada Experimental Range, accessed July 23, 2025

View Source
Preview of Environmental and allometric drivers of tree growth rates in a north Australian savanna, accessed July 23, 2025
Environmental and allometric drivers of tree growth rates in a north Australian savanna, accessed July 23, 2025
Contextual Support GreyLiterature

Grass, Trees, and Fire: Elements of a Savanna Lifecycle - SIAM.org, accessed July 23, 2025

View Source
Preview of Fire drives functional thresholds on the savanna-forest transition, accessed July 23, 2025
Fire drives functional thresholds on the savanna-forest transition, accessed July 23, 2025
Contextual Support Journal

Fire drives functional thresholds on the savanna-forest transition, accessed July 23, 2025

View Source
Preview of Fire in Australian savannas: from leaf to landscape - PMC - PubMed Central, accessed July 23, 2025
Fire in Australian savannas: from leaf to landscape - PMC - PubMed Central, accessed July 23, 2025
Contextual Support GreyLiterature

Australian Savanna Biome - Blue Planet Biomes, accessed July 23, 2025

View Source
Preview of Food, Climate & Regenerative Farming FAQ - The Nature Conservancy, accessed May 11, 2025,
Food, Climate & Regenerative Farming FAQ - The Nature Conservancy, accessed May 11, 2025,
Contextual Support

Food, Climate & Regenerative Farming FAQ - The Nature Conservancy

View Source
Preview of How Trees and Grasses Grow and Compete (Chapter 7) - Only in Africa, accessed July 23, 2025
How Trees and Grasses Grow and Compete (Chapter 7) - Only in Africa, accessed July 23, 2025
Contextual Support Government

How Trees and Grasses Grow and Compete (Chapter 7) - Only in Africa, accessed July 23, 2025

View Source
Preview of Intra-specific variation in leaf attributes of four savanna tree species across a rainfall gradient in tropical Australia - CSIRO PUBLISHING | Australian Journal of Botany, accessed July 23, 2025
Intra-specific variation in leaf attributes of four savanna tree species across a rainfall gradient in tropical Australia - CSIRO PUBLISHING | Australian Journal of Botany, accessed July 23, 2025
Contextual Support Journal

Tree water use and soil water dynamics in savannas of northern Australia, accessed July 23, 2025

View Source
Preview of Land clearing guidelines - Northern Territory Government, accessed July 23, 2025
Land clearing guidelines - Northern Territory Government, accessed July 23, 2025
Regulatory Framework Journal

Land clearing guidelines - Northern Territory Government, accessed July 23, 2025

View Source
Preview of Land clearing guidelines and management plans, accessed July 23, 2025
Land clearing guidelines and management plans, accessed July 23, 2025
Regulatory Framework Journal

Land clearing guidelines and management plans, accessed July 23, 2025

View Source
Preview of Regenerative Agriculture - Project Regeneration, accessed July 25, 2025,
Regenerative Agriculture - Project Regeneration, accessed July 25, 2025,
Contextual Support GreyLiterature

Regenerative agriculture in Australia: the changing face of farming - Frontiers, accessed July 23, 2025

View Source
Preview of Regenerative agriculture in Australia: the changing face of farming - Frontiers, accessed August 4, 2025
Regenerative agriculture in Australia: the changing face of farming - Frontiers, accessed August 4, 2025
Contextual Support Journal

NCC: Regenerative Agriculture and Soil Health - Wet Tropics Plan, accessed July 27, 2025,

View Source
Preview of Savanna fire ecology in northern Australia | Department of Biodiversity, Conservation and Attractions, accessed July 23, 2025
Savanna fire ecology in northern Australia | Department of Biodiversity, Conservation and Attractions, accessed July 23, 2025
Contextual Support Journal

Savanna fire ecology in northern Australia | Department of Biodiversity, Conservation and Attractions, accessed July 23, 2025

View Source
Preview of Scattered trees are keystone structures – Implications for conservation, accessed July 23, 2025
Scattered trees are keystone structures – Implications for conservation, accessed July 23, 2025
Contextual Support Journal

Scattered trees are keystone structures – Implications for conservation, accessed July 23, 2025

View Source
Preview of Structure, Function and Behaviour of Savannas - OPUS at UTS, accessed July 24, 2025,
Structure, Function and Behaviour of Savannas - OPUS at UTS, accessed July 24, 2025,
Contextual Support Journal

The biodiversity cost of carbon sequestration in tropical savanna - PMC - PubMed Central, accessed July 23, 2025

View Source
Preview of The effects of a moratorium on land-clearing in the Douglas-Daly region, Northern Territory, Australia - CSIRO PUBLISHING | The Rangeland Journal, accessed July 23, 2025
The effects of a moratorium on land-clearing in the Douglas-Daly region, Northern Territory, Australia - CSIRO PUBLISHING | The Rangeland Journal, accessed July 23, 2025
Contextual Support Journal

The effects of a moratorium on land-clearing in the Douglas-Daly region, Northern Territory, Australia - CSIRO PUBLISHING | The Rangeland Journal, accessed July 23, 2025

View Source
Preview of The effects of a moratorium on land-clearing in the Douglas-Daly region, Northern Territory, Australia - ResearchOnline@JCU, accessed July 23, 2025
The effects of a moratorium on land-clearing in the Douglas-Daly region, Northern Territory, Australia - ResearchOnline@JCU, accessed July 23, 2025
Contextual Support Journal

The effects of a moratorium on land-clearing in the Douglas-Daly region, Northern Territory, Australia - ResearchOnline@JCU, accessed July 23, 2025

View Source
Preview of The importance of scattered trees for biodiversity conservation: A global meta-analysis, accessed July 23, 2025
The importance of scattered trees for biodiversity conservation: A global meta-analysis, accessed July 23, 2025
Contextual Support GreyLiterature

The importance of scattered trees for biodiversity conservation: A global meta-analysis, accessed July 23, 2025

View Source

Context

  • Region Australia
  • Biome Tropical Monsoonal Savannas
  • Land Use Agricultural Crop Production
  • Assessment Pristine Reference
  • Evidence Type TargetCondition

Lifecycle

  • Status Active
  • Version 1
  • Effective From 22 Mar 2026

Notes

Lower Critical Threshold: 3 m²/ha. Upper Detrimental Threshold: 20 m²/ha. A basal area below approximately 3 m²/ha is considered critically low, representing a simplified system that has lost key ecological functions. A basal area approaching 20 m²/ha is considered detrimental, leading to excessive crop competition and an undesirable ecological state shift from savanna to closed forest, with associated loss of savanna-specialist biodiversity.

Related Benchmarks

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

21.5 m²/ha Moderate
Agricultural Crop Production · Pristine Reference
UpperThreshold Active v1