Pacific Island Ecosystems at Risk (PIER)


Sphagneticola trilobata


RISK ASSESSMENT RESULTS: Reject, Score: 6

Note:  Risk assessment prepared for Australia

Information on Risk Assessments


        Wedelia trilobata
A. Biogeography/     wedelia
  historical   Leguminosae P&R
1 Domestication/ 1.01 Is the species highly domesticated?  
  cultivation 1.02 Has the species become naturalised where grown?  
    1.03 Does the species have weedy races?  
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) 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 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  
  score) 3.05 Congeneric weed Y
B. Biology/Ecology    
4 Undesirable 4.01 Produces spines, thorns or burrs N
  traits 4.02 Allelopathic  
    4.03 Parasitic N
    4.04 Unpalatable to grazing animals N
    4.05 Toxic to animals  
    4.06 Host for recognised pests and pathogens  
    4.07 Causes allergies or is otherwise toxic to humans N
    4.08 Creates a fire hazard in natural ecosystems N
    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 Plant 5.01 Aquatic N
  type 5.02 Grass N
    5.03 Nitrogen fixing woody plant N
    5.04 Geophyte N
6 Reproduction 6.01 Evidence of substantial reproductive failure in native habitat  
    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) N
    7.02 Propagules dispersed intentionally by people Y
    7.03 Propagules likely to disperse as a produce contaminant N
    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)  
    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  
    8.04 Tolerates, or benefits from, mutilation or cultivation Y
    8.05 Effective natural enemies present in Australia  
      Outcome: Reject
      Score: 6
  Statistical summary   Biogeography 6
  of scoring   Score partition:                       Undesirable attributes -1
      Biology/ecology 1
      Biogeography 5
      Questions answered:                       Undesirable attributes 7
      Biology/ecology 13
      Total 25
      Agricultural 4
      Sector affected:                                   Environmental 5
      Nusiance 2
   A= agricultural, E = environmental, N = nuisance, C=combined  

Risk assessment prepared by Paul Pheloung and Rod Randall


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This page new 26 January 2001.