Invasiveness Ranking System for Non-Native Plants of Alaska

Senecio vulgaris L.Ranking SummaryEcoregion known or expected to occur inSouth CoastalInterior BorealArctic AlpineYesYesYesPotential Max. ScoreEcological Impact 40 4Biological Characteristics and Dispersal 25 12Amplitude and Distribution 25 15Feasibility of Control 10 5Relative Maximum 46Climatic ComparisonCollected inAlaska regions?CLIMEXsimilarity?South Coastal Yes –Interior Boreal Yes –Arctic Alpine Yes –Senecio vulgaris is documented in all ecogeographic regions inAlaska (Hultén 1968, AKEPIC 2005, UAM 2004).Ecological ImpactScoreImpact on Ecosystem Processes (0–10) 0Common groundsel has been documented only on disturbedareas in Alaska (Hultén 1968, Welsh 1974, Weeds of AlaskaDatabase 2006). It is unlikely that measurable impacts toecosystem processes occur due to its presence.Impact on Natural Community Structure (0–10) 1Common groundsel establishes in a sparsely vegetatedherbaceous layer in disturbed areas, increasing the density of thelayer (I. Lapina pers obs.). No significant impact on the naturalcommunity structure has been documented or observed.Impact on Natural Community Composition (0–10) 0Common groundsel has been documented in undisturbedareas in Alaska (AKEPIC 2006); no perceived impact on nativepopulations is known.Impact on Higher Trophic Levels (0–10) 3Common groundsel is poisonous to livestock (Royer andDickinson 1999) and may be poisonous to wild animals. Also, it isan alternate host for a number of viruses, nematodes, and aphids(Townshend and Davidson 1962, Heathcote and Byford 1975,Royer and Dickinson 1999).Total for Ecological Impact 4/40Biological Characteristics and Dispersal ScoreMode of Reproduction (0–3) 3Common groundsel is an annual and reproduces only by seed(Alex and Switzer 1976). Each common groundsel plant iscapable of producing an average of 830 seeds (Kadereit 1984)and over 1,700 seeds per plant are possible (Royer and Dickinson1999).Long-distance dispersal (0–3) 2The seeds have a pappus of hairs and can be dispersed by wind forshort distances (Bergelson et al. 1993). Additionally, its seeds aresticky when wet and can attached to fur (Royer and Dickinson1999).Spread by humans (0–3) 3The seeds of common groundsel contaminate commercial seedsand horticultural stock. Wet seeds can attach to vehicles andclothing (Hodkinson and Thompson 1997, USDA, ARS 2006).common names: common groundsel,old-man-in-the-springAllelopathic (0–2) 0Common groundsel is not allelopathic (Qasem and Hill 1989,USDA, NRCS 2006). Possible allelopathic effects of commongroundsel were studied in a greenhouse experiment, but did notshow a significant effect on the growth of other plants (Qasemand Hill 1989).Competitive Ability (0–3) 1Common groundsel competes with cultivated crops (MAFRI2001).Thicket-forming/Smothering growth form (0–2) 0Common groundsel can form stands up to 18 inches tall (Alexand Switzer 1976, Douglas et al. 1998, Whitson et al. 2000). InAlaska it usually does not form dense stands and does not shadeother species (I. Lapina pers. obs.).Germination requirements (0–3) 0Common groundsel requires open soil and no vegetation forgermination and successful establishment (Popay and Roberts1970, Bergelson et al. 1993).Other invasive species in the genus (0–3) 3Senecio jacobaea L., S. madagascariensis Poir., and S. squalidus L.are listed as noxious weed in several American states (USDA,NRCS 2006).Aquatic, wetland or riparian species (0–3) 0Common groundsel inhabits open disturbed sites such as fields,gardens, lawns, roadsides, and waste places (Douglas et al. 1998).Total for Biological Characteristics and Dispersal 12/25Ecological Amplitude and Distribution ScoreHighly domesticated or a weed of agriculture (0–4) 4Common groundsel is a weed of agricultural fields and gardens(Royer and Dickinson 1999).Known level of impact in natural areas (0–6) 0Common groundsel is not known to cause any impacts in naturalareas.Role of anthropogenic and natural disturbance inestablishment (0–5)Common groundsel is distributed mainly in anthropogenichabitats, such as ruderal and agricultural lands (Douglas et al.1998). In its native range, common groundsel can be found onnaturally disturbed habitats such as sand dunes (Ashton andAbbott 1992, Hoffmann 2001).Current global distribution (0–5) 5Common groundsel is native to Europe and North Africa. It hasbeen introduced into South Africa, North and South America,Hawaii, Australia, and New Zealand (Hultén 1968). It now has anearly worldwide distribution, with introductions into arctic andsubarctic regions in Europe (Lid and Lid 1994).Extent of the species U.S. range and/or occurrence offormal state or provincial listing (0–5)Common groundsel is found throughout the United States andCanada (Royer and Dickinson 1999, USDA, NRCS 2006).Senecio vulgaris is declared a weed in Washington, Tennessee, andManitoba (Royer and Dickinson 1999, Rice 2006).Total for Ecological Amplitude and Distribution 15/2515B-117