Why assess environmental weed risk for introduced plants?
There is a well-documented history of introduced plants becoming environmental weeds.
"There are approximately 15 800 native plant species and close to 29 000 introduced exotic species in Australia (Diez et al. 2009). Of these introduced species, about 3300 species have naturalised (Gallagher et al. 2015) and approximately 500 of these species are now proclaimed as noxious weeds under state/territory legislation (Invasive Plants and Animals Committee 2015)." (DAWR 2018)
Western Australia has 10 252 published native species (FloraBase 2018) and 3583 of these are listed as 'threatened or priority flora' (DBCA 2018). Introduced species that have spread from their managed area are one of the significant threats to native flora.
It is no accident that many of the agricultural species in the south-west of Western Australia are also a high environmental weed risk – many of these plants have characteristics that mean they are highly productive and competitive.
How we assess environmental weed risk
Our environmental weed risk assessment of a species in WA is done for each of 4 regions (Figure 1). The risk score is based on climatic suitability for each species within each region and invasive and impacts criteria in the Future Farm Industries weed risk protocol, and multiplied across all 3 sections to produce the final score.
This information is of particular interest to pastoral lessees because non-indigenous species can only be introduced with approval from the Department of Planning, Lands and Heritage under the Land Administration Act 1997.
The assessment protocol results in every species having 4 regional risk scores, for the Kimberley, Pilbara, Gascoyne and south-west Western Australia (Table 2).
| Final FFI score | Risk rating | Interpretation |
|---|---|---|
| >236 | Very high | Use is not recommended: if used, requires a detailed management plan and there are significant environmental and management risks |
| 112–235 | High | Use is not normally recommended: use requires a risk management plan |
| 50–111 | Medium | Can be used: monitor, manage and report any offsite movement |
| 0–49 | Low to negligible | Can be used with minimal concern. This rating covers low, low to negligible, negligible to low, and negligible. |
More detail on the Future Farm Industries CRC system is in the Environmental Weed Risk Assessment Protocol, and the Guide to the Genetic Risk Assessment Protocol.
Plants are listed in alphabetical Genus order: A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z
| Species name | Kimberley risk | Pilbara risk | Gascoyne risk | South-west risk |
|---|---|---|---|---|
| Acacia saligna* | Negligible | Negligible | Low | Native |
| Acroceras macrum | Low | Low | Low | Low |
| Agrostis stolonifera | Low | Medium | Very high | Very high |
| Albizia lebbeck* | Native | Medium | Low | Negligible |
| Allium cepa | Low | Low | Low | Low |
| Alloteropsis semialata* | Native | |||
| Alysicarpus vaginalis | Medium | Low | Low | Low |
| Arachis glabrata | Low | Low | Low | Low |
| Arachis pintoi | Low | Low | Low | Low |
| Asparagus officinalis | Low | Low | Low | Low |
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| Species name | Kimberley risk | Pilbara risk | Gascoyne risk | South-west risk |
| Astrebla elymoides* | Native | Native | ||
| Astrebla lappacea* | Native? | Native | Native | |
| Atriplex amnicola* | Native | Native | Native | |
| Atriplex nummularia* | Native (southern) | Native | ||
| Atriplex semibaccata* | Native | |||
| Rytidosperma caespitosum* syn. Austrodanthonia caespitosa | Native (southern) | Native | ||
| Avena sativa | Low | Low | Low | Low |
| Beta vulgaris | Low | Low | Low | High |
| Bothriochloa insculpta | High | High | Medium | Low |
| Bothriochloa pertusa | Medium | Low | Low | Low |
| Brassica napus | Low | Low | Low | Low |
| Brassica rapa | Low | Low | Low | Low |
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| Species name | Kimberley risk | Pilbara risk | Gascoyne risk | South-west risk |
| Cajanus cajan | Low | Low | Low | Low |
| Cenchrus americanus | High | High | Low | Low |
| Cenchrus ciliaris | Very high | Very high | Very high | Very high |
| Cenchrus clandestinus | Low | Low | Low | High |
| Cenchrus purpureus | Medium | Low | Low | High |
| Cenchrus setiger | High | Very high | Very high | High |
| Centrosema brasilianum | Low | Low | Low | Low |
| Centrosema pascuorum | Medium | Low | Low | Medium |
| Chamaecrista rotundifolia | Low | Low | Low | Low |
| Chenopodium auricomum* | Native | Native | Native | |
| Chloris gayana | High | Low | Low | Medium |
| Chrysopogon fallax* | Native | Native | Native | |
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| Species name | Kimberley risk | Pilbara risk | Gascoyne risk | South-west risk |
| Cicer arietinum | Low | Low | Low | Low |
| Cichorium intybus | Low | Low | Low | Low |
| Citrullus lanatus | Low | Low | Low | Low |
| Citrus reticulata | Low | Low | Low | Low |
| Citrus x sinensis | Low | Low | Low | Medium |
| Citrus x limon | Low | Low | Low | Low |
| Citrus x paradisi | Low | Medium | Low | Low |
| Clitoria ternatea | Very high | High | Medium | Low |
| Cucumis melo | Medium | Medium | Low | Medium |
| Cucurbita argyrosperma | Low | Low | Low | Low |
| Cucurbita maxima | Low | Low | Low | Low |
| Cucurbita moschata | Low | Low | Low | Low |
| Cucurbita pepo | Low | Low | Low | Low |
| Cullen australasicum* | Native | Native | Native | Low |
| Cullen graveolens* | Native | Native | ||
| Cynodon dactylon | Very high | Very high | Very high | Very high |
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| Species name | Kimberley risk | Pilbara risk | Gascoyne risk | South-west risk |
| Low | Low | Low | High | |
| Daucus carota | Low | Low | Low | Low |
| Desmanthus virgatus | High | Medium | Medium | Low |
| Desmodium heterophyllum | Medium | Low | Low | Low |
| Desmodium intortum | Low | Low | Low | Low |
| Desmodium uncinatum | Low | Medium | Low | Low |
| Dichanthium annulatum | Low | Very high | Very high | Very high |
| Dichanthium aristatum | Low | Low | Low | Medium |
| Dichanthium fecundum* | Native | Native | ||
| Dichanthium sericeum* | Native | Native | Native | Native |
| Digitaria eriantha | Low | Medium | Low | Medium |
| Digitaria milanjiana | Medium | Low | Low | Low |
| Dimocarpus longan | Low | Low | Low | Low |
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| Species name | Kimberley risk | Pilbara risk | Gascoyne risk | South-west risk |
| Echinochloa esculenta | Low | Low | Low | Low |
| Echinochloa polystachya | Medium | Low | Low | Low |
| Ehrharta calycina | Low | Low | Medium | Very high |
| Eragrostis curvula | High | Very high | Very high | Very high |
| Eucalyptus angustissima* | Negligible to Low | Negligible to Low | Native | Native |
| Eucalyptus kochii * | Negligible to Low | Negligible to Low | Negligible to Low | Native |
| Eucalyptus loxophleba subsp. lissophloia* | Negligible to Low | Negligible to Low | Native (southern) | Native |
| Eucalyptus occidentalis* | Negligible to Low | Negligible to Low | Negligible to Low | Native |
| Eucalyptus polybractea | Low | Low | Low | Low |
| Eucalyptus rudis* | Negligible to Low | Negligible to Low | Negligible to Low | Native |
| Eulalia aurea* | Native | Native | Native | Native (northern) |
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| Species name | Kimberley risk | Pilbara risk | Gascoyne risk | South-west risk |
| Festuca arundinacea | Low | Low | Medium | High |
| Ficus carica | Low | Low | Low | High |
| Glycine max | Low | Low | Low | Low |
| Gossypium barbadense | Low | Low | Low | Low |
| Gossypium hirsutum | Low | Low | Low | Low |
| Helianthus annuus | Low | Medium | Medium | Medium |
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| Species name | Kimberley risk | Pilbara risk | Gascoyne risk | South-west risk |
| Hordeum vulgare | Low | Low | Low | Medium |
| Ipomoea batatas | Low | Low | Low | Low |
| Iseilema macratherum* | Native | Native | ||
| Iseilema vaginiflorum* | Native | Native | Native | |
| Lablab purpureus | Low | Low | Low | Low |
| Leucaena collinsii (assessed for sterile leucaena breeding program) | Negligible to Low | Negligible to Low | Negligible to Low | Negligible to Low |
| Leucaena confertiflora (assessed for sterile leucaena breeding program) | Negligible to Low | Negligible to Low | Negligible to Low | Negligible to Low |
| Leucaena cuspidata | Negligible to Low | Negligible to Low | Negligible to Low | Negligible to Low |
| Leucaena esculenta | Negligible to Low | Negligible to Low | Negligible to Low | Negligible to Low |
| Leucaena diversifolia (assessed for sterile leucaena breeding program) | Medium | Negligible to Low | Negligible to Low | Negligible to Low |
| Leucaena greggii (assessed for sterile leucaena breeding program) | Negligible to Low | Negligible to Low | Negligible to Low | Negligible to Low |
| Leucaena lanceolata (assessed for sterile leucaena breeding program) | Very high | Very high | Medium | Negligible to Low |
| Leucaena leucocephala | Very high | Very high | Medium | Low |
| Leucaena macrophylla (assessed for sterile leucaena breeding program) | Medium | Negligible to Low | Negligible to Low | Negligible to Low |
| Leucaena pallida (assessed for sterile leucaena breeding program) | Negligible to Low | Negligible to Low | Negligible to Low | Negligible to Low |
| Leucaena pulverulenta (assessed for sterile leucaena breeding program) | Negligible to Low | Negligible to Low | Negligible to Low | Negligible to Low |
| Leucaena retusa (assessed for sterile leucaena breeding program) | Negligible to Low | Negligible to Low | Negligible to Low | Negligible to Low |
| Leucaena shannoni (assessed for sterile leucaena breeding program) | Negligible to Low | Negligible to Low | Negligible to Low | Negligible to Low |
| Leucaena trichandra (assessed for sterile leucaena breeding program) | Negligible to Low | Negligible to Low | Negligible to Low | Negligible to Low |
| Leucaena trichodes (assessed for sterile leucaena breeding program) | Negligible to Low | Negligible to Low | Negligible to Low | Negligible to Low |
| Lolium multiflorum | Low | Low | Medium | Very high |
| Lolium perenne | Low | Low | Low | Very high |
| Lolium rigidum | Low | Low | Low | Very high |
| Lotus corniculatus | Low | Low | Low | Low |
| Lotus uliginosus | Low | Low | Low | High |
| Lupinus angustifolius | Low | Low | Low | Medium |
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| Species name | Kimberley risk | Pilbara risk | Gascoyne risk | South-west risk |
| Macroptilium atropurpureum | Very high | High | High | Low |
| Macroptilium bracteatum | Low | Low | Low | Low |
| Mangifera indica | Medium | Medium | Low | Low |
| Medicago littoralis | Low | Low | Low | Low |
| Medicago orbicularis | Low | Low | Low | Medium |
| Medicago polymorpha | Low | Low | Medium | Very high |
| Medicago sativa | Low | Low | Low | Medium |
| Medicago scutellata | Low | Low | Low | Medium |
| Medicago truncatula | Low | Low | Low | High |
| Megathyrsus maximus | High | Very high | Low | Low |
| Moringa oleifera | High | Low | Low | Low |
| Neonotonia wightii | Very high | Very high | Very high | Medium |
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| Species name | Kimberley risk | Pilbara risk | Gascoyne risk | South-west risk |
| Ornithopus sativus | Low | Low | Low | Low |
| Oryza rufipogon* | Native | |||
| Panicum coloratum | Medium | High | Medium | Medium |
| Panicum decompositum* | Native | Native | Native | Native (northern) |
| Passiflora edulis | High | Low | Low | Low |
| Phalaris aquatica | Low | Low | Low | Medium |
| Phoenix dactylifera | Low | Medium | Medium | Very high |
| Plantago lanceolata | Low | Low | Low | High |
| Prunus persica | Low | Low | Low | Medium |
| Puccinellia ciliata | Low | Low | Low | Medium |
| Raphanus sativus | Low | Low | Medium | High |
| Rhagodia preissii* | Native (coastal) | Native (coastal) | Native | |
| Rhynchosia minima* | Native | Native | Native | |
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| Species name | Kimberley risk | Pilbara risk | Gascoyne risk | South-west risk |
| Salvia hispanica | Low | Low | Low | Low |
| Santalum album | Low | Low | Low | Low |
| Santalum spicatum* | Low | Native | Native | Native |
| Secale strictum | Low | Low | Low | Low |
| Sesamum indicum | Low | Low | Low | Low |
| Solanum tuberosum | Low | Low | Low | Low |
| Sorghum bicolor | Low | Low | Low | Low |
| Sorghum bicolor ‘Forage Hybrids’ | Low | Low | Low | Low |
| Sorghum laxiflorum* | Native | |||
| Sorghum x almum | Low | Low | Low | Low |
| Sorghum x drummondii | Low | Low | Low | Medium |
| Stylosanthes guianensis | High | Medium | Medium | Low |
| Stylosanthes hamata | Medium | Low | Low | Low |
| Stylosanthes scabra | Medium | Low | Low | Low |
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| Species name | Kimberley risk | Pilbara risk | Gascoyne risk | South-west risk |
| Tamarindus indica | Low | Low | Low | Low |
| Themeda avenacea* | Native | Native | Native | Native (northern) |
| Themeda triandra* | Native | Native | Native | Native |
| Thinopyrum ponticum | Low | Low | Low | High |
| Trifolium alexandrinum | Low | Low | Low | Low |
| Trifolium michelianum | Low | Low | Low | Low |
| Trifolium pratense | Low | Low | Low | Very high |
| Trifolium repens | Low | Low | Low | High |
| Trifolium resupinatum | Low | Low | Low | Low |
| Trifolium subterraneum | Low | Low | Low | High |
| Trifolium vesiculosum | Low | Low | Low | Low |
| Triodia pungens* | Native | Native | Native | |
| Triticum aestivum | Low | Low | Low | Medium |
| Urochloa decumbens | Medium | Low | Low | Low |
| Urochloa humidicola | Medium | Low | Low | Low |
| Urochloa mosambicensis | Very high | Very high | Medium | Low |
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| Species name | Kimberley risk | Pilbara risk | Gascoyne risk | South-west risk |
| Vaccinium corymbosum | Low | Low | Low | Low |
| Vaccinium corymbosum L. x Vaccinium ashei x Vaccinium darrowi | Low | Low | Low | Low |
| Vicia faba | Low | Low | Low | Low |
| Vicia sativa | Low | Low | Low | High |
| Vicia villosa | Low | Low | Low | Very high |
| Vigna radiata | Low | Low | Low | Low |
| Vigna unguiculata | Medium | Low | Low | Medium |
| Vitis vinifera | Low | Low | Medium | Very high |
| Zea mays | Low | Low | Low | Low |
For more information
There are many sources of information on weeds and species that may potentially be weeds: we recommend that you investigate online and contact professional weed scientists for any proposed plant introduction (new to the area being considered).
A highly recommended source of species references is:
Randall, RP 2017, A Global Compendium of Weeds, 3rd Edition, Perth, Western Australia, viewed 21 March 2019, https://www.cabi.org/isc/FullTextPDF/2017/20173071957.pdf, viewed 21 March 2019. Note: this is a very large PDF download.
DBCA How does Parks and Wildlife manage weeds? This includes a download of the weed prioritisation process, and regional species-led ecological impact and invasiveness ratings.
References
Department of Agriculture and Water Resources 2018, Reasons for the weed risk assessment system, viewed 9 January 2018, www.agriculture.gov.au/biosecurity/risk-analysis/weeds/reasons_for_the_wra_system
Department of Biodiversity, Conservation and Attractions 2018, Threatened and priority flora list, viewed 9 January 2018, www.dpaw.wa.gov.au/plants-and-animals/threatened-species-and-communities/threatened-plants?view=categories&id=108
FloraBase 2018, Western Australian Flora Statistics – 2017 Vascular Flora Statistics, viewed 9 January 2018, https://florabase.dpaw.wa.gov.au/statistics/
Randall, RP 2007, The introduced flora of Australia and its weed status, CRC for Australian Weed Management, Glen Osmond, South Australia, www.cabdirect.org/cabdirect/FullTextPDF/2009/20093033838.pdf
Randall, RP 2017, A Global Compendium of Weeds, 3rd Edition, Perth, Western Australia, viewed 21 March 2019, https://www.cabi.org/isc/FullTextPDF/2017/20173071957.pdf