Invasive Species Presence
Benchmark Value
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 2 benchmarks together — the MaximumOnly form drives the primary score, while 1 guard(s) constrain the result.
Contributing Benchmarks
Evidence & Context
A pivotal study examining the abundance-impact relationship of an invasive herbaceous groundcover (Tradescantia fluminensis) in a temperate forest provides compelling ecological evidence for such a threshold. The research found that key metrics of ecosystem health—native species richness, abundance, and diversity—remained relatively stable as invasive cover increased from zero. However, once the invasive species cover reached a critical threshold of between 20% and 30%, all of these native biodiversity metrics began to decline sharply and linearly.
Percentage cover of exotic (invasive) plant species in the vegetation.
This benchmark marks the upper detrimental threshold for invasive species cover in Australian Temperate Grassy Woodlands & Plains conservation areas, beyond which ecosystem health declines rapidly.
Ecological evidence and regulatory practice both point to this threshold as a tipping point for ecosystem collapse.
Sources (1)
short-term review
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Additional references from the underlying research that informed this benchmark.
The assessment of ecological condition in South-East Queensland
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