Environmental weed risk assessments

Page last updated: Friday, 17 August 2018 - 2:34pm

Introducing new plants to an area can have positive and negative effects on the environment, economy and community. To minimise the negative environmental impact of introducing new species, we use a risk assessment procedure based on widely accepted scientific standards and a system for recording and reporting the risks.

We encourage land managers wanting to introduce new species to use this information before making a decision.

Environmental risk assessment is only one of the criteria used to make decisions on introducing new species to an area.

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

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).

Map showing the regions used in assessing weed risk
Figure 1 Weed risk climatic regions
Table 1 Future Farm Industries CRC weed risk score, risk rating and interpretation
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

Table 2 Environmental weed risk ratings for species assessed under the FFI Process, for the 4 Western Australian climate regions. WA species are marked with an asterisk (*), and are no risk within their native ranges. Note: the species name hyperlink opens a PDF of the species weed risk assessment. Blank cells means that an assessment has not been done.
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
Back to top        
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
Back to top        
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  
Back to top        
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
Back to top        
Species name Kimberley
risk
Pilbara
risk
Gascoyne
risk
South-west
risk

Dactylis glomerata

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
Back to top        
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)
Back to top        
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
Back to top        
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 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
Back to top        
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
Back to top        
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  
Back to top        
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
Back to top        
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
Back to top        
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 good source of species references is the Global compendium of weeds (note this is a very large PDF download).

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

Contact information

Rod Randall
+61 (0)8 9363 4065