Basal Area — Benchmark Detail

Benchmark Value

No specific value — see range

Range: 21 to 26 m²/ha

Thresholds: Lower: 21, Upper: 26

Optimal Range: 21 to 26

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 9 benchmarks together — the OptimalRange form drives the primary score, while 8 guard(s) constrain the result.

Contributing Benchmarks

OptimalRange Primary OptimalRange Guard OptimalRange Guard OptimalRange Guard Point Guard OptimalRange Guard OptimalRange Guard Point Guard UpperThreshold Guard

Evidence & Context

A loss of 25-40% of this value (below ~21-26 m²/ha) likely indicates a critical threshold for biodiversity loss.

Metric Definition:

Basal area in m²/ha

Benchmark Definition:

A basal area below 21-26 m²/ha indicates a critical threshold where biodiversity loss and ecosystem degradation are likely in the tropical and subtropical maritime island biome under conservation land use.

Justification:

Based on evidence of non-linear collapse in key biodiversity and functional indicators with basal area loss exceeding 25-40%.

Sources (1)

(PDF) Thresholds of biodiversity and ecosystem function in a forest ... GreyLiterature

(PDF) Thresholds of biodiversity and ecosystem function in a forest ...

View Source

Supporting Sources (2)

Additional references from the underlying research that informed this benchmark.

Preview of Managing drought-sensitive forests under global change. Low competition enhances long-term growth and water uptake in Abies pinsapo | Request PDF - ResearchGate

Managing drought-sensitive forests under global change. Low competition enhances long-term growth and water uptake in Abies pinsapo | Request PDF - ResearchGate

Contextual Support Journal

Managing drought-sensitive forests under global change. Low competition enhances long-term growth and water uptake in Abies pinsapo | Request PDF - ResearchGate

View Source

Vegetation and floristics of a lowland tropical rainforest in northeast Australia - Biodiversity Data Journal

Direct Evidence Journal

Vegetation and floristics of a lowland tropical rainforest in northeast Australia - Biodiversity Data Journal

View Source

Context

Region Australia
Biome Tropical & Subtropical Maritime Islands
Land Use Conservation / Protected Natural Areas
Assessment Conservation Target
Evidence Type DegradationThreshold

Lifecycle

Status Superseded
Version 1
Effective From 22 Mar 2026
Effective To 22 Mar 2026

Notes

Below this range, loss of essential symbiotic groups and fundamental processes accelerates, signaling rapid biodiversity loss and functional impairment.

Related Benchmarks

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