Invasiveness Ranking System for Non-Native Plants of Alaska

Long-distance dispersal (0–3) 3Seeds spread by wind because of their light weight and smallwings (Gubanov et al. 2004).Spread by humans (0–3) 3Creeping bellflower was introduced to North America as anornamental plant (Royer and Dickinson 1999). It frequentlyescapes from gardens (Whitson et al. 2000). This plant alsodisperses with nursery stock (Alfnes 1975).Allelopathic (0–2)UUnknownCompetitive Ability (0–3) 3Creeping bellflower is a serious competitor for soil moisture andnutrients. It thrives under the canopy or in sun (Whitson et al.2000, Royer and Dickinson 1999). This species appears to be asuccessful competitor with lawn grasses and native raspberries(M. Rasy pers. obs.).Thicket-forming/Smothering growth form (0–2) 1Creeping bellflower is able to form dense thickets and quicklycolonize areas (Gubanov et al. 2004); however, it does notgenerally overtop surrounding vegetation.Germination requirements (0–3)UUnknownOther invasive species in the genus (0–3) 3Campanula glomerata is an introduced cultivated species knownto be invasive in gardens (J. Riley pers. com.); however, it doesnot have legal weed status (USDA 2002).Aquatic, wetland or riparian species (0–3) 0Creeping bellflower is a weed of gardens, horticultural fields, andforest plantations. It is a serious weed in lawns. In its native rangecreeping bellflower grows in open woodlands, forest edges, andmeadows (Gubanov et al. 2004, Royer and Dickinson 1999).Total for Biological Characteristics and Dispersal 16/20Ecological Amplitude and Distribution ScoreHighly domesticated or a weed of agriculture (0–4) 4Creeping bellflower is used as an ornamental plant in Europe andNorth America (USDA, ARS 2005, Whitson et al. 2000). It is aserious weed in the nursery industry (Alfnes 1975). In Europeancountries it is cultivated in vegetable gardens (Plants For AFuture 2004).Known level of impact in natural areas (0–6) 3Creeping bellflower is known to invade mixed birch–spruceforest in Anchorage (M. Rasy pers. obs.).Role of anthropogenic and natural disturbance in3establishment (0–5)It is readily establish along trails, but is capable of moving intoadjacent undisturbed areas (M. Rasy pers. obs.).Current global distribution (0–5) 5Creeping bellflower is native to Europe and Western Asia,including arctic and subarctic regions of Norway and Sweden(Lid and Lid 1995). It has naturalized in North America andhas been occasionally recorded in Siberia (USDA, ARS 2005,Gubanov et al. 2004).Extent of the species U.S. range and/or occurrence offormal state or provincial listing (0–5)Creeping bellflower is found in most American states andCanadian provinces (USDA 2002, Royer and Dickinson 1999).This species is listed as a weed in Alberta and Manitoba (InvadersDatabase System 2003, Royer and Dickinson 1999).Total for Ecological Amplitude and Distribution 20/25Feasibility of ControlScoreSeed banks (0–3)UUnknownVegetative regeneration (0–3) 2Creeping bellflower sprouts readily from roots fragments(I. Lapina pers. obs., Plants For A Future 2004).Level of effort required (0–4) 3Creeping bellflower infestation is extremely difficult to eradicate(Gubanov et al. 2004). It is practically impossible to controlthis species mechanically, and it is problematic to control itby chemical methods. Some of the selective herbicides can beeffective (Alfnes 1975).Total for Feasibility of Control 5/7Total score for 4 sections 59/92§5B-11