Invasiveness Ranking System for Non-Native Plants of Alaska

Role of anthropogenic and natural disturbance in3establishment (0–5)Common mullein is an initial colonist in newly disturbed sites(Gross and Werner 1978, Pitcairn 2000). Seedling growth rateswere faster, producing more biomass within the same time periodon bare soils relative to vegetated soils (Gross 1984). Seedlingsdid not establish in small experimentally created openings, butthey did colonize larger openings such as those created by animaldigging. Only in the open plots did plants survive and produceseeds (Gross 1980).Current global distribution (0–5) 3Common mullein occurs throughout Europe to 64°N in Norway,east into Russia, and south to the Caucasus Mountains and tothe western Himalayas. It also is occurs in Asia Minor and China(Lid and Lid 1994, Gross and Werner 1978, Gubanov et al. 1995).Extent of the species U.S. range and/or occurrence of5formal state or provincial listing (0–5)Common mullein occurs in nearly all of the United States(USDA 2002). In Canada it occurs mainly in Ontario, Quebec,the eastern provinces, and British Columbia (Gross and Werner1978). Verbascum tapsus is a noxious weed in Colorado, Hawaii,and Manitoba (Royer and Dickinson 1999, USDA 2002).Total for Ecological Amplitude and Distribution 16/25Feasibility of ControlScoreSeed banks (0–3) 3The seeds may remain viable for over 100 years (Kivilaan andBandurski 1981), and viable seeds have been found in soil samplesarchaeologically dated from A.D. 1300 (Ødum 1965, cited inGross and Werner 1978).Vegetative regeneration (0–3) 1Plants will not die if cut above the root crown. This will causeincreased growth of lateral branches, which will produce flowerslater (Gross and Werner 1978).Level of effort required (0–4) 3Common mullein is difficult to control because of the largenumber of seed and long lived seed bank. Hairs on the leavesprevent herbicides from penetrating the leaf surface. Mechanical,chemical and biological control methods can be used for commonmullein. Sowing sites with native grasses and forbs may decreaseseed germination and the chance of successful establishment.A weevil specific to common mullein was introduced to NorthAmerica from Europe. The larvae destroy up to 50% of theseeds (Gross and Werner 1978, Hoshovsky 1986, Pitcairn 2000,Rutledge and McLendon 1996).Total for Feasibility of Control 7/10Total score for 4 sections 52/100§Vicia cracca L.Ranking SummaryEcoregion known or expected to occur inSouth CoastalInterior BorealArctic AlpineYesYesYesPotential Max. ScoreEcological Impact 40 27Biological Characteristics and Dispersal 25 16Amplitude and Distribution 25 21Feasibility of Control 10 9Relative Maximum 73Climatic ComparisonCollected inAlaska regions?CLIMEXsimilarity?South Coastal Yes –Interior Boreal Yes –Arctic Alpine No YesVicia cracca has been collected in the south coastal [Seward,Ketchikan, and Unalaska] (UAM 2004) and interior boreal[Anchorage, Wasilla, Fairbanks, Rampart, and Minto] (AKNHP2003, Hultén 1968, UAM 2004), ecogeographic regions ofAlaska. The climatic similarity between Nome and areas wherethe species is documented has a moderate match (CLIMEX1999). There is a 77% similarity between Nome and cityChirka-Kem’, Russia, where the species occurs (Hultén 1968).Additionally, the range of bird vetch includes Røros, Norway andArkhangel’sk, Russia (Hultén 1968), which have 76% of climaticmatches with Nome respectively. This suggests that establishmentof bird vetch in arctic and alpine regions of Alaska may bepossible.common names: bird vetch, cow vetchB-138Ecological ImpactScoreImpact on Ecosystem Processes (0–10) 7Bird vetch alters edaphic conditions due to fixation of atmosphericnitrogen (USDA 2002).Impact on Natural Community Structure (0–10) 7Vicia cracca can form dense stands in Alaska. It can overgrowherbaceous vegetation and climb over shrubs, such as alder,willow, and spruce up to 2 m in height, forming a new herbaceouslayer (Lapina pers. obs.).Impact on Natural Community Composition (0–10) 8Bird vetch quickly overtops herbaceous and low-woody species atboreal forest edges in Alaska. No data is present, but native plantspecies certainly suffer from its presence (M.L. Carlson pers obs.)Impact on Higher Trophic Levels (0–10) 5Bird vetch is highly palatable to grazing and browsing animals(USDA 2002). The seeds of bird vetch are toxic (CornelUniversity: PPID). Flowers are visited by native bees and mayalter pollination ecology of the surrounding area (Aarssen et al.1986, Klebesadel 1980, M.L. Carlson pers. obs.).Total for Ecological Impact 27/40Biological Characteristics and Dispersal ScoreMode of Reproduction (0–3) 2Bird vetch reproduces by seeds and also spreads vegetatively bygrowth of rhizomes (Aarssen et al. 1986, Klebesadel 1980, Nolen2002).Long-distance dispersal (0–3) 2The seeds of bird vetch are large and not easily dispersed. Thepods explosively split open when it dries. Plant can spread whentendrils and vine branches with seed pods cling to vectors, arebroken off the plant, and carried to a new location (Densmore etal. 2001).