Ground Cover - Tree Canopy

AUS-TMS-CON-TCC General Moderate confidence

Benchmark Value

40 %

Thresholds: Lower: —, Upper: 40

Direction: Higher is desirable ↑

Form: UpperThreshold

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 12 benchmarks together — the OptimalRange form drives the primary score, while 11 guard(s) constrain the result.

Contributing Benchmarks

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

Evidence & Context

An upper detrimental threshold for savanna character is identified when TCC exceeds approximately 40-50% at a landscape scale.

Metric Definition:

Tree Canopy Cover (TCC) as the percentage of ground area covered by tree canopy.

Benchmark Definition:

The maximum tree canopy cover beyond which fire suppression and loss of savanna characteristics occur, leading to transition to closed woodland.

Justification:

Based on fire-suppression thresholds and ecological studies indicating transition to closed woodland above this level.

Sources (1)

Preview of Hoffmann, W. A., Geiger, E. L., Gotsch, S. G., Rossatto, D. R., Silva, L. C. R., Lau, O. L., Haridasan, M., & Franco, A. C. (2012). Ecological thresholds at the savanna-forest boundary: How plant traits, resources and fire govern the distribution of tropical biomes. Ecology Letters, 15(1), 759-768.

Hoffmann, W. A., Geiger, E. L., Gotsch, S. G., Rossatto, D. R., Silva, L. C. R., Lau, O. L., Haridasan, M., & Franco, A. C. (2012). Ecological thresholds at the savanna-forest boundary: How plant traits, resources and fire govern the distribution of tropical biomes. Ecology Letters, 15(1), 759-768. Journal

Ecological thresholds at the savanna-forest boundary: How plant traits, resources and fire govern the distribution of tropical biomes

View Source

Supporting Sources (8)

Additional references from the underlying research that informed this benchmark.

Australia's forests – overview - DAFF

Contextual Support

Australia's forests – overview - DAFF

Australia's forests – overview - DAFF

Contextual Support

Australia's forests – overview - DAFF

Australia's forests – overview - DAFF, accessed August 5, 2025,

Contextual Support Government

Eastern Australian Temperate Forests | One Earth, accessed April 29, 2025,

View Source

Australia's tropical savannas: vast, ancient and rich landscapes - CSIRO Research Publications Repository, accessed May 11, 2025,

Contextual Support GreyLiterature

Williams RJ, Duff GA, Bowman DMJS, Cook GD. Australia's tropical savannas: vast, ancient and rich landscapes. In: David Keith, editor/s. Australian vegetation. Cambridge, UK: Cambridge University Press; 2017. 368-388.

View Source

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 Martin, T. G., Kutt, A. S., & Woinarski, J. C. Z. (2004). The forest fauna of the Northern Territory: an overview. In J. C. Z. Woinarski, T. G. Martin, & A. S. Kutt (Eds.), Conserving Australia's Forest Fauna (pp. 29-50). Royal Zoological Society of New South Wales.

Martin, T. G., Kutt, A. S., & Woinarski, J. C. Z. (2004). The forest fauna of the Northern Territory: an overview. In J. C. Z. Woinarski, T. G. Martin, & A. S. Kutt (Eds.), Conserving Australia's Forest Fauna (pp. 29-50). Royal Zoological Society of New South Wales.

Contextual Support Journal

The forest fauna of the Northern Territory: knowledge, conservation and management, accessed May 20, 2025

View Source

Preview of Price, J. N., & Morgan, J. W. (2008). Woody plant encroachment reduces species richness of herb-rich woodlands in southern Australia. Austral Ecology, 33(3), 278-289.

Price, J. N., & Morgan, J. W. (2008). Woody plant encroachment reduces species richness of herb-rich woodlands in southern Australia. Austral Ecology, 33(3), 278-289.

Contextual Support Journal

SoE2016 Biodiversity - Australia state of the environment 2021

View Source

Preview of Rossiter-Rachor, N. A., Setterfield, S. A., Douglas, M. M., Hutley, L. B., Cook, G. D., & Schmidt, S. (2009). Effects of Canopy Cover and Ground Disturbance on Establishment of an Invasive Grass in an Australia Savanna. Weed Science, 57(3), 320-325.

Rossiter-Rachor, N. A., Setterfield, S. A., Douglas, M. M., Hutley, L. B., Cook, G. D., & Schmidt, S. (2009). Effects of Canopy Cover and Ground Disturbance on Establishment of an Invasive Grass in an Australia Savanna. Weed Science, 57(3), 320-325.

Contextual Support Journal

Effects of Canopy Cover and Ground Disturbance on Establishment of an Invasive Grass in an Australia Savanna1 - ResearchGate, accessed May 20, 2025

View Source

Context

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

Lifecycle

Status Active
Version 1
Effective From 1 Jun 2026

Notes

Above 40-50% TCC, fire spread is inhibited, leading to loss of savanna biodiversity and function.

Related Benchmarks

Other benchmarks in the AUS-TMS-CON-TCC family.