Pacific Island Ecosystems at Risk (PIER)

Amaranthus dubius


Note:  Risk assessment prepared for Australia

Information on Risk Assessments

      Amaranthus dubius
A.     southern pigweed
1 1.01 Is the species highly domesticated? Y
  1.02 Has the species become naturalised where grown? Y
  1.03 Does the species have weedy races?  
2 2.01 Species suited to Australian climates (0-low; 1-intermediate; 2-high) 2
  2.02 Quality of climate match data (0-low; 1-intermediate; 2-high) 1
  2.03 Broad climate suitability (environmental versatility) N
  2.04 Native or naturalised in regions with extended dry periods N
  2.05 Does the species have a history of repeated introductions outside its natural range? Y
3 3.01 Naturalised beyond native range Y
  3.02 Garden/amenity/disturbance weed Y
  3.03 Weed of agriculture Y
  3.04 Environmental weed  
  3.05 Congeneric weed Y
4 4.01 Produces spines, thorns or burrs N
  4.02 Allelopathic Y
  4.03 Parasitic N
  4.04 Unpalatable to grazing animals N
  4.05 Toxic to animals  
  4.06 Host for recognised pests and pathogens Y
  4.07 Causes allergies or is otherwise toxic to humans  
  4.08 Creates a fire hazard in natural ecosystems  
  4.09 Is a shade tolerant plant at some stage of its life cycle  
  4.10 Grows on infertile soils  
  4.11 Climbing or smothering growth habit N
  4.12 Forms dense thickets N
5 5.01 Aquatic N
  5.02 Grass N
  5.03 Nitrogen fixing woody plant N
  5.04 Geophyte N
6 6.01 Evidence of substantial reproductive failure in native habitat N
  6.02 Produces viable seed. Y
  6.03 Hybridises naturally Y
  6.04 Self-compatible or apomictic  
  6.05 Requires specialist pollinators N
  6.06 Reproduction by vegetative fragmentation N
  6.07 Minimum generative time (years) 1
7 7.01 Propagules likely to be dispersed unintentionally (plants growing in areas with much vehicle movement) Y
  7.02 Propagules dispersed intentionally by people Y
  7.03 Propagules likely to disperse as a produce contaminant Y
  7.04 Propagules adapted to wind dispersal N
  7.05 Propagules water dispersed  
  7.06 Propagules bird dispersed  
  7.07 Propagules dispersed by other animals (externally) Y
  7.08 Propagules survive passage through the gut  
8 8.01 Prolific seed production (>2000/m2) Y
  8.02 Evidence that a persistent propagule bank is formed (>1 yr) N
  8.03 Well controlled by herbicides  
  8.04 Tolerates, or benefits from, mutilation or cultivation N
  8.05 Effective natural enemies present in Australia N
    Outcome: Reject
    Score: 14
    Biogeography 8
    Score partition:                       Undesirable attributes 1
    Biology/ecology 5
    Biogeography 8
    Questions answered:                       Undesirable attributes 7
    Biology/ecology 19
    Total 34
    Agricultural 12
    Sector affected:                                   Environmental 8
    Nusiance 2
 A= agricultural, E = environmental, N = nuisance, C=combined  

Risk assessment prepared by Rod Randall

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This page new 12 June 2003.