Soil Moisture

AUS-TSR-CON-SMO General Moderate confidence

Benchmark Value

50 %
Thresholds: Lower: 50, Upper: —
Direction: Higher is desirable ↑
Form: LowerThreshold

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 3 benchmarks together — the OptimalRange form drives the primary score, while 2 guard(s) constrain the result.

Contributing Benchmarks

OptimalRange Primary LowerThreshold Guard MinimumOnly Guard

Evidence & Context

Ecosystem integrity is severely compromised below 50% of Relative Extractable Water (REW), a threshold associated with the onset of high tree mortality in tropical rainforests.

Metric Definition:

Relative Extractable Water (REW) is the fraction of plant-available water remaining in the soil, calculated as (³b8max²21³b8min)(³b8²21³b8min).

Benchmark Definition:

This benchmark represents the critical lower threshold of soil moisture, measured as Relative Extractable Water, below which tropical rainforest ecosystem integrity is severely compromised, leading to high tree mortality.

Justification:

This threshold is based on synthesis of large-scale tropical forest rainfall exclusion experiments showing a consistent mortality threshold.

Sources (1)

Preview of Threshold Responses to Soil Moisture Deficit by Trees and Soil in Tropical Rain Forests: Insights from Field Experiments - The Australian National University
Threshold Responses to Soil Moisture Deficit by Trees and Soil in Tropical Rain Forests: Insights from Field Experiments - The Australian National University GreyLiterature

Threshold Responses to Soil Moisture Deficit by Trees and Soil in Tropical Rain Forests: Insights from Field Experiments - The Australian National University

View Source

Supporting Sources (21)

Additional references from the underlying research that informed this benchmark.

Preview of accessed July 22
accessed July 22
Contextual Support GreyLiterature

accessed July 22

View Source
Preview of DENITRIFICATION FACT SHEET - Grains Research and Development Corporation (GRDC)
DENITRIFICATION FACT SHEET - Grains Research and Development Corporation (GRDC)
Contextual Support

DENITRIFICATION FACT SHEET - Grains Research and Development Corporation (GRDC)

View Source
Preview of Emission of CO2 from tropical riparian forest soil is controlled by soil temperature
Emission of CO2 from tropical riparian forest soil is controlled by soil temperature
Contextual Support Journal

Emission of CO2 from tropical riparian forest soil is controlled by soil temperature

View Source
Preview of ENV509 | Module 3: Australian rainforests - an overview - Learnline, accessed July 22, 2025,
ENV509 | Module 3: Australian rainforests - an overview - Learnline, accessed July 22, 2025,
Contextual Support GreyLiterature

NUTRIENT CYCLING IN MOIST TROPICAL ... - Annual Reviews

View Source
Preview of Nitrogen removal by tropical floodplain wetlands through denitrification - CSIRO Publishing
Nitrogen removal by tropical floodplain wetlands through denitrification - CSIRO Publishing
Contextual Support Journal

Nitrogen removal by tropical floodplain wetlands through denitrification - CSIRO Publishing

View Source
Preview of Nitrogen removal by tropical floodplain wetlands through denitrification - ResearchGate
Nitrogen removal by tropical floodplain wetlands through denitrification - ResearchGate
Contextual Support Journal

Water Balance of an Australian Subtropical Rainforest at Altitude: the Ecological and Physiological Significance of Intercepted Cloud and Fog - ResearchGate

View Source
Preview of Paleobotany reframes the fiery debate on Australia's rainforest edges - PMC
Paleobotany reframes the fiery debate on Australia's rainforest edges - PMC
Contextual Support Journal

Paleobotany reframes the fiery debate on Australia's rainforest edges - PMC

View Source
Preview of Rainforest - WetlandInfo - Department of the Environment, Tourism, Science and Innovation, accessed July 18, 2025,
Rainforest - WetlandInfo - Department of the Environment, Tourism, Science and Innovation, accessed July 18, 2025,
Contextual Support Government

Nutrient distribution and cycling in a subtropical rainforest in New South Wales, accessed July 19, 2025,

View Source
Preview of Robson Creek Flux Data Collection - TERN Data Discovery Portal
Robson Creek Flux Data Collection - TERN Data Discovery Portal
Contextual Support Government

Robson Creek Flux Data Collection - TERN Data Discovery Portal

View Source
Preview of Robson Creek Rainforest SuperSite | Atherton Tablelands | QLD - TERN Australia
Robson Creek Rainforest SuperSite | Atherton Tablelands | QLD - TERN Australia
Contextual Support Government

Robson Creek Rainforest SuperSite | Atherton Tablelands | QLD - TERN Australia

View Source
Preview of Robson Creek Rainforest SuperSite | Atherton Tablelands | QLD - TERN Australia, accessed July 22, 2025,
Robson Creek Rainforest SuperSite | Atherton Tablelands | QLD - TERN Australia, accessed July 22, 2025,
Contextual Support GreyLiterature

ASC - DERMOSOLS - Soil Science Australia

View Source
Preview of Soil Research - CSIRO PUBLISHING, accessed July 20, 2025,
Soil Research - CSIRO PUBLISHING, accessed July 20, 2025,
Contextual Support Journal

Consider the Anoxic Microsite: Acknowledging and Appreciating Spatiotemporal Redox Heterogeneity in Soils and Sediments | ACS Earth and Space Chemistry

View Source
Preview of Soils of the Babinda - Cairns Area - Queensland Government publications
Soils of the Babinda - Cairns Area - Queensland Government publications
Contextual Support Journal

Science and Innovation

View Source
Preview of Struggle in the flood: tree responses to flooding stress in four tropical floodplain systems - PMC - PubMed Central
Struggle in the flood: tree responses to flooding stress in four tropical floodplain systems - PMC - PubMed Central
Contextual Support GreyLiterature

Struggle in the flood: tree responses to flooding stress in four tropical floodplain systems - PMC - PubMed Central

View Source
Preview of Tour TERN's rainforest monitoring SuperSite | TERN Australia, accessed July 22, 2025
Tour TERN's rainforest monitoring SuperSite | TERN Australia, accessed July 22, 2025
Contextual Support Government

Robson Creek Flux Data Release 2022_v2 - TERN Data Discovery Portal

View Source
Preview of Understanding Water Movement Throughout Different Soil Profiles ..., accessed July 6, 2025,
Understanding Water Movement Throughout Different Soil Profiles ..., accessed July 6, 2025,
Contextual Support Journal

A closer look at rainforests - Forestry Corporation

View Source
Preview of Understanding Water Movement Throughout Different Soil Profiles Across the Upper North
Understanding Water Movement Throughout Different Soil Profiles Across the Upper North
Contextual Support Government

Understanding Water Movement Throughout Different Soil Profiles Across the Upper North

View Source
Preview of Waterlogged yard (forum) - Daleys Fruit Tree Nursery
Waterlogged yard (forum) - Daleys Fruit Tree Nursery
Contextual Support Journal

Waterlogged yard (forum) - Daleys Fruit Tree Nursery

View Source
Preview of Waterlogging : how it reduces plant growth and how plants can overcome its effects
Waterlogging : how it reduces plant growth and how plants can overcome its effects
Contextual Support Journal

Waterlogging : how it reduces plant growth and how plants can overcome its effects

View Source
Preview of Waterlogging | Fact Sheets | soilquality.org.au, accessed July 19, 2025,
Waterlogging | Fact Sheets | soilquality.org.au, accessed July 19, 2025,
Contextual Support Government

Waterlogging | Fact Sheets | soilquality.org.au

View Source
Preview of Waterlogging in Australian agricultural landscapes: a review of plant responses and crop models - ResearchGate, accessed July 7, 2025,
Waterlogging in Australian agricultural landscapes: a review of plant responses and crop models - ResearchGate, accessed July 7, 2025,
Contextual Support Journal

Manage wet soils – North East Victoria, Southern NSW and South West Victoria (Upper)

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Context

  • Region Australia
  • Biome Tropical & Subtropical Rainforests
  • Land Use Conservation / Protected Natural Areas
  • Assessment Pristine Reference
  • Vegetation Forest
  • Evidence Type DegradationThreshold

Lifecycle

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

Notes

Lower Critical Threshold: 50 %. No upper detrimental threshold — higher values are always better up to natural saturation. Represents the point where adaptive mechanisms to drought are overwhelmed.

Related Benchmarks

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

— % Moderate
Conservation / Protected Natural Areas · Pristine Reference · Forest
OptimalRange Active v1
80 % Moderate
Conservation / Protected Natural Areas · Pristine Reference · Forest
MinimumOnly Active v1