Pacific Island Ecosystems at Risk (PIER)

Alternanthera pungens


Note:  Risk assessment prepared for Australia

Information on Risk Assessments

        Alternanthera pungens
A. Biogeography/ khaki weed
  historical P&C
1 Domestication/ 1.01 Is the species highly domesticated? N
  cultivation 1.02 Has the species become naturalised where grown? Y
  1.03 Does the species have weedy races? N
2 Climate and 2.01 Species suited to Australian climates (0-low; 1-intermediate; 2-high) 2
  Distribution 2.02 Quality of climate match data (0-low; 1-intermediate; 2-high) 2
  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 Weed 3.01 Naturalised beyond native range Y
  Elsewhere 3.02 Garden/amenity/disturbance weed Y
  (interacts with 2.01 3.03 Weed of agriculture  
  to give a weighted 3.04 Environmental weed Y
  score) 3.05 Congeneric weed Y
B. Biology/Ecology
4 Undesirable 4.01 Produces spines, thorns or burrs Y
  traits 4.02 Allelopathic
  4.03 Parasitic
  4.04 Unpalatable to grazing animals Y
  4.05 Toxic to animals
  4.06 Host for recognised pests and pathogens
  4.07 Causes allergies or is otherwise toxic to humans Y
  4.08 Creates a fire hazard in natural ecosystems
  4.09 Is a shade tolerant plant at some stage of its life cycle N
  4.10 Grows on infertile soils N
  4.11 Climbing or smothering growth habit
  4.12 Forms dense thickets N
5 Plant 5.01 Aquatic N
  type 5.02 Grass
  5.03 Nitrogen fixing woody plant
  5.04 Geophyte
6 Reproduction 6.01 Evidence of substantial reproductive failure in native habitat N
  6.02 Produces viable seed. Y
  6.03 Hybridises naturally
  6.04 Self-compatible or apomictic
  6.05 Requires specialist pollinators
  6.06 Reproduction by vegetative fragmentation Y
  6.07 Minimum generative time (years) 1
7 Dispersal mechanisms 7.01 Propagules likely to be dispersed unintentionally (plants growing in areas with much vehicle movement) Y
  7.02 Propagules dispersed intentionally by people
  7.03 Propagules likely to disperse as a produce contaminant
  7.04 Propagules adapted to wind dispersal
  7.05 Propagules water dispersed Y
  7.06 Propagules bird dispersed
  7.07 Propagules dispersed by other animals (externally) Y
  7.08 Propagules survive passage through the gut
8 Persistence 8.01 Prolific seed production (>2000/m2) N
  attributes 8.02 Evidence that a persistent propagule bank is formed (>1 yr)
  8.03 Well controlled by herbicides Y
  8.04 Tolerates, or benefits from, mutilation or cultivation Y
  8.05 Effective natural enemies present in Australia Y
  Outcome: Reject
  Score: 17
  Statistical summary   Biogeography 10
  of scoring Score partition:                       Undesirable attributes 3
  Biology/ecology 4
  Biogeography 7
  Questions answered:                       Undesirable attributes 6
  Biology/ecology 12
  Total 25
  Agricultural 9
  Sector affected:                                   Environmental 11
  Nusiance 3
   A= agricultural, E = environmental, N = nuisance, C=combined  

Risk assessment prepared by Rod Randall

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This page new 12 June 2003.