Basal Area — Benchmark Detail

Benchmark Value

No specific value — see range

Range: 28.6 to 63.3 m²/ha

Thresholds: Lower: 28.6, Upper: —

Optimal Range: 28.6 to 63.3

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 5 benchmarks together — the OptimalRange form drives the primary score, while 4 guard(s) constrain the result.

Contributing Benchmarks

OptimalRange Primary MaximumOnly Guard OptimalRange Guard MinimumOnly Guard MaximumOnly Guard

Evidence & Context

The data from these plots for trees with a DBH ²610 cm reveal that at the time of establishment, the stand basal area across these 20 high-integrity sites ranged from 28.6 to 63.3 mb2/ha.

Metric Definition:

Stand basal area is the sum of the cross-sectional area of all living tree stems, measured at 1.3 meters above the ground (DBH), within a given unit of land area.

Benchmark Definition:

Stand basal area measures the density and structure of forests in protected Australian tropical rainforests, representing the natural range of healthy, high-integrity ecosystems.

Justification:

This range captures the natural variability of high-integrity ecosystems across diverse environmental gradients, making it a robust indicator of the 'best available condition'.

Sources (1)

Preview of CSIRO Permanent Rainforest Plots of North Queensland, accessed July 20, 2025,

CSIRO Permanent Rainforest Plots of North Queensland, accessed July 20, 2025, Government

Estimating the relative magnitude of expected increases in soil ..., accessed July 18, 2025

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Supporting Sources (4)

Additional references from the underlying research that informed this benchmark.

Lowland Rainforest of Subtropical Australia ecological community - conservation advice

Contextual Support Government

Lowland Rainforest of Subtropical Australia ecological community - conservation advice

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Lowland Rainforest of Subtropical Australia ecological community - listing advice

Contextual Support Journal

Lowland Rainforest of Subtropical Australia ecological community - listing advice

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Patterns of basal area increment, mortality and recruitment were ..., accessed July 20, 2025,

Direct Evidence Journal

Patterns of basal area increment, mortality and recruitment were related to logging intensity in subtropical rainforest in Australia over 35 years | Request PDF - ResearchGate

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Stand basal area, accessed July 12, 2025,

Contextual Support

Vegetation and floristics of a lowland tropical rainforest in northeast ...

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Context

Region Australia
Biome Tropical & Subtropical Rainforests
Land Use Conservation / Protected Natural Areas
Assessment Pristine Reference
Evidence Type ReferenceCondition

Lifecycle

Status Active
Version 1
Effective From 22 Mar 2026

Notes

Lower Critical Threshold: 28.6 m²/ha. No upper detrimental threshold ²14 higher values are always better up to natural saturation. The benchmark represents the observed range of stand basal area (stems ²610 cm DBH) across 20 long-term (1971-2013) permanent plots in protected, old-growth Australian tropical rainforests.

Related Benchmarks

Other benchmarks in the AUS-TSR-CON-BAS family.