Basal Area — Benchmark Detail - Nature Index

Benchmark Value

3 m²/ha

Thresholds: Lower: 3, 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 19 benchmarks together — the OptimalRange form drives the primary score, while 18 guard(s) constrain the result.

Contributing Benchmarks

OptimalRange Primary Point Guard MaximumOnly Guard MinimumOnly Guard OptimalRange Guard OptimalRange Guard MaximumOnly Guard MaximumOnly Guard MinimumOnly Guard MaximumOnly Guard OptimalRange Guard MinimumOnly Guard MaximumOnly Guard OptimalRange Guard MinimumOnly Guard Point Guard MinimumOnly Guard MaximumOnly Guard OptimalRange Guard

Evidence & Context

An Upper Detrimental Threshold is identified at >3-4 m²/ha, where intense resource competition from trees severely suppresses the productive understory, shifting the system from a functional agro-ecosystem to a closed woodland.

Metric Definition:

Basal area threshold above which competition from trees suppresses understory production and shifts ecosystem state.

Benchmark Definition:

Critical upper basal area threshold above which understory productivity is severely suppressed.

Justification:

Competition for water and light at basal areas above this level leads to a shift from open agro-ecosystem to closed woodland.

Sources (1)

Preview of Protect and restore paddock trees – ANU Sustainable Farms, accessed July 6, 2025,

Protect and restore paddock trees – ANU Sustainable Farms, accessed July 6, 2025, GreyLiterature

The role of trees in livestock grazing systems. - Kandanga Farm Store

Supporting Sources (33)

Additional references from the underlying research that informed this benchmark.

Preview of (PDF) Carbon sequestration and biodiversity restoration potential of semi-arid mulga lands of Australia interpreted from long-term grazing exclosures - ResearchGate, accessed July 6, 2025,

(PDF) Carbon sequestration and biodiversity restoration potential of semi-arid mulga lands of Australia interpreted from long-term grazing exclosures - ResearchGate, accessed July 6, 2025,

Contextual Support

(PDF) Carbon sequestration and biodiversity restoration potential of semi-arid mulga lands of Australia interpreted from long-term grazing exclosures - ResearchGate, accessed July 6, 2025,

Preview of (PDF) Scattered trees are keystone structures – Implications for conservation, accessed July 6, 2025,

(PDF) Scattered trees are keystone structures – Implications for conservation, accessed July 6, 2025,

Contextual Support Journal

(PDF) Scattered trees are keystone structures – Implications for conservation, accessed July 6, 2025,

Preview of (PDF) The Gibson, Great Sandy, and Little Sandy Deserts of Australia - ResearchGate, accessed July 6, 2025,

(PDF) The Gibson, Great Sandy, and Little Sandy Deserts of Australia - ResearchGate, accessed July 6, 2025,

Contextual Support GreyLiterature

(PDF) The Gibson, Great Sandy, and Little Sandy Deserts of Australia - ResearchGate, accessed July 6, 2025,

Preview of 1301.0 - Year Book Australia, 2006 - Australian Bureau of Statistics, accessed July 6, 2025,

1301.0 - Year Book Australia, 2006 - Australian Bureau of Statistics, accessed July 6, 2025,

Contextual Support Government

Vegetation Changes in Mediterranean Australia Since European Settlement1 - Forest Service, accessed July 23, 2025

Preview of a note on the significance of eucalyptus populnea for buffel grass production in infertile semi-arid rangelands, accessed July 6, 2025,

a note on the significance of eucalyptus populnea for buffel grass production in infertile semi-arid rangelands, accessed July 6, 2025,

Contextual Support Journal

a note on the significance of eucalyptus populnea for buffel grass production in infertile semi-arid rangelands, accessed July 6, 2025,

Acacia aneura - Agroforestree Species profile, accessed July 6, 2025,

Contextual Support GreyLiterature

Acacia aneura - Agroforestree Species profile, accessed July 6, 2025,

Preview of Agricultural production system in arid and semi-arid regions, accessed July 12, 2025,

Agricultural production system in arid and semi-arid regions, accessed July 12, 2025,

Contextual Support Journal

Opportunities for Integrated Ecological Analysis across Inland ...

Preview of Agroforestry - Wikipedia, accessed July 6, 2025,

Agroforestry - Wikipedia, accessed July 6, 2025,

Contextual Support GreyLiterature

Agroforestry - Wikipedia, accessed July 6, 2025,

Preview of Australian agriculture | EBSCO Research Starters, accessed July 8, 2025

Australian agriculture | EBSCO Research Starters, accessed July 8, 2025

Contextual Support GreyLiterature

Australian agriculture | EBSCO Research Starters

Preview of ch03, accessed July 6, 2025,

ch03, accessed July 6, 2025,

Contextual Support Government

ch03, accessed July 6, 2025,

Preview of collation and review of stem density data and thinning prescriptions ..., accessed July 10, 2025,

collation and review of stem density data and thinning prescriptions ..., accessed July 10, 2025,

Contextual Support

collation and review of stem density data and thinning prescriptions for the vegetation communities of new south - Environment and Heritage

Preview of Dryland cropping zones in Australia between the 300 and 600mm rainfall... - ResearchGate, accessed July 6, 2025,

Dryland cropping zones in Australia between the 300 and 600mm rainfall... - ResearchGate, accessed July 6, 2025,

Contextual Support GreyLiterature

Environment Monitoring Systems & Data for Ecosystem Studies ..., accessed July 27, 2025,

Preview of Farming carbon | Environment, land and water | Queensland Government, accessed July 6, 2025,

Farming carbon | Environment, land and water | Queensland Government, accessed July 6, 2025,

Contextual Support Government

Farming carbon | Environment, land and water | Queensland Government, accessed July 6, 2025,

Preview of Function Attribute Benchmarks for the Biodiversity Assessment Method: Data audit, compilation and analysis - Environment and Heritage, accessed July 10, 2025,

Function Attribute Benchmarks for the Biodiversity Assessment Method: Data audit, compilation and analysis - Environment and Heritage, accessed July 10, 2025,

Contextual Support

Victorian State of the Environment report

Preview of Great Sandy Desert - DBCA Library, accessed July 6, 2025,

Great Sandy Desert - DBCA Library, accessed July 6, 2025,

Contextual Support Journal

Great Sandy Desert - DBCA Library, accessed July 6, 2025,

Preview of Great Sandy Desert bioregion - DCCEEW, accessed July 6, 2025,

Great Sandy Desert bioregion - DCCEEW, accessed July 6, 2025,

Contextual Support Journal

Great Sandy Desert bioregion - DCCEEW, accessed July 6, 2025,

Preview of Hans Lambers Editor - On the Ecology of Australia's Arid Zone - eScholarship, accessed July 6, 2025,

Hans Lambers Editor - On the Ecology of Australia's Arid Zone - eScholarship, accessed July 6, 2025,

Contextual Support Journal

Hans Lambers Editor - On the Ecology of Australia's Arid Zone - eScholarship.org

Preview of IGC Proceedings (1989-2023): Grazing Pressure by Sheep: Consequences for Pasture Stability in an Australian Mulga Woodland - UKnowledge, accessed July 6, 2025,

IGC Proceedings (1989-2023): Grazing Pressure by Sheep: Consequences for Pasture Stability in an Australian Mulga Woodland - UKnowledge, accessed July 6, 2025,

Contextual Support GreyLiterature

Mulga woodlands | FutureBeef, accessed July 6, 2025,

Preview of Life in the “dead heart” of Australia: The geohistory of the Australian deserts and its impact on genetic diversity of arid zone lizards - ResearchGate, accessed July 6, 2025,

Life in the “dead heart” of Australia: The geohistory of the Australian deserts and its impact on genetic diversity of arid zone lizards - ResearchGate, accessed July 6, 2025,

Contextual Support

Life in the “dead heart” of Australia: The geohistory of the Australian deserts and its impact on genetic diversity of arid zone lizards - ResearchGate, accessed July 6, 2025,

Preview of Little Sandy Desert bioregion - DCCEEW, accessed July 6, 2025,

Little Sandy Desert bioregion - DCCEEW, accessed July 6, 2025,

Contextual Support Journal

Little Sandy Desert bioregion - DCCEEW, accessed July 6, 2025,

Preview of Mulga woodlands | FutureBeef

Mulga woodlands | FutureBeef

Direct Evidence Journal

Mulga woodlands | FutureBeef

Preview of Mulga, a major tropical dry open forest of Australia - ResearchOnline ..., accessed July 6, 2025,

Mulga, a major tropical dry open forest of Australia - ResearchOnline ..., accessed July 6, 2025,

Contextual Support Journal

Mulga, a major tropical dry open forest of Australia - ResearchOnline ..., accessed July 6, 2025,

Preview of Reducing Wind Erosion through Agroforestry: A Case Study Using Large Eddy Simulations, accessed July 6, 2025,

Reducing Wind Erosion through Agroforestry: A Case Study Using Large Eddy Simulations, accessed July 6, 2025,

Contextual Support Journal

(PDF) Scattered trees are keystone structures – Implications for conservation

Preview of Regenerative Agriculture - Landscape SA, accessed July 6, 2025,

Regenerative Agriculture - Landscape SA, accessed July 6, 2025,

Contextual Support Government

Regenerative Agriculture Program - Landscape SA

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

Regenerative agriculture is key to dry season preparation - Soils For Life, accessed July 23, 2025

Preview of Revitalize Dry Land with Regenerative Agriculture Practices, accessed July 6, 2025,

Revitalize Dry Land with Regenerative Agriculture Practices, accessed July 6, 2025,

Contextual Support GreyLiterature

Pasture cropping: A regenerative solution from Down Under | Opinions | Al Jazeera, accessed July 22, 2025,

Preview of Scattered paddock trees | Sustainable Farms, accessed July 6, 2025,

Scattered paddock trees | Sustainable Farms, accessed July 6, 2025,

Contextual Support Journal

Scattered paddock trees | Sustainable Farms, accessed July 6, 2025,

Preview of Scattered Trees are Keystone Structures, accessed July 6, 2025,

Scattered Trees are Keystone Structures, accessed July 6, 2025,

Contextual Support Journal

Scattered Trees are Keystone Structures, accessed July 6, 2025,

Preview of Shelterbelts for control of wind erosion | Erosion | Soil | Farm management, accessed July 6, 2025,

Shelterbelts for control of wind erosion | Erosion | Soil | Farm management, accessed July 6, 2025,

Contextual Support Government

Shelterbelts for control of wind erosion | Erosion | Soil | Farm management, accessed July 6, 2025,

Preview of Snapshot of Australian Agriculture 2025 - DAFF, accessed July 8, 2025

Snapshot of Australian Agriculture 2025 - DAFF, accessed July 8, 2025

Contextual Support Government

Snapshot of Australian Agriculture 2025 - DAFF, accessed July 27, 2025,

Preview of The continental dunefield of Australia, accessed July 6, 2025,

The continental dunefield of Australia, accessed July 6, 2025,

Contextual Support GreyLiterature

The continental dunefield of Australia, accessed July 6, 2025,

Preview of The Rangeland Journal - CSIRO PUBLISHING, accessed July 6, 2025,

The Rangeland Journal - CSIRO PUBLISHING, accessed July 6, 2025,

Contextual Support Journal

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

Preview of Untitled, accessed July 6, 2025,

Untitled, accessed July 6, 2025,

Contextual Support Journal

Untitled, accessed July 6, 2025,

Context

Region Australia
Biome Arid Interior Dunefields & Sandy Deserts
Land Use Agricultural Crop Production
Assessment Not Stated
Evidence Type DegradationThreshold

Lifecycle

Status Active
Version 1
Effective From 2 Jun 2026

Notes

Represents the point where negative impacts of tree density outweigh ecological benefits. AssessmentContext defaulted to 'Not Stated' because the source document did not state one.

Related Benchmarks

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