Invasiveness Ranking System for Non-Native Plants of Alaska

Chenopodium album L.Ranking SummaryEcoregion known or expected to occur inSouth CoastalInterior BorealArctic AlpineYesYesYesPotential Max. ScoreEcological Impact 40 5Biological Characteristics and Dispersal 25 12Amplitude and Distribution 25 15Feasibility of Control 10 5Relative Maximum 37Climatic ComparisonCollected inAlaska regions?common names: lambsquarters, white goosefootCLIMEXsimilarity?South Coastal Yes –Interior Boreal Yes –Arctic Alpine Yes –Chenopodium album has been collected from all Alaskanecoregions: south coastal (Afognak, Kodiak, Middleton Island,and Skagway), interior boreal (Anchorage, Bettles, Big Delta,Circle, Fairbanks, Gulkana, and Ophir), and arctic alpine(Nulato) (Hultén 1968, Welsh 1974, Densmore et al. 2001, UAM2003).Ecological ImpactScoreImpact on Ecosystem Processes (0–10) 1Chenopodium album has not been observed in undisturbed areasin Alaska (Densmore et al. 2001, Hultén 1968, Welsh 1974). It isunlikely that measurable impacts to ecosystem processes occurdue to its presence.Impact on Natural Community Structure (0–10) 1Lambsquarters establishes in a sparsely vegetated herbaceouslayer, increasing the density of the layer in south-central Alaska(I. Lapina and M.L. Carlson pers obs.).Impact on Natural Community Composition (0–10) 0Lambsquarters has not been observed in undisturbed areas inAlaska, no perceived impact on native populations has beendocumented (Densmore et al. 2001).Impact on Higher Trophic Levels (0–10) 3Plants are reported to be poisonous to sheep and pigs, but no datais present regarding its toxicity to native herbivores (CU-PPID2004). It is an alternate host for a number of viral diseases ofbarley, beet, potato, turnip, and tobacco—some of these crops aregrown commercially in Alaska (Royer and Dickinson 1999). Allparts of the plants contain nitrate.Total for Ecological Impact 5/40Biological Characteristics and Dispersal ScoreMode of Reproduction (0–3) 3Lambsquarters reproduces entirely by seed. Each plant canproduce over 500,000 seeds (Royer and Dickinson 1999).Long-distance dispersal (0–3) 2Chenopodium album lacks any seed dispersal adaptations andmost seeds are deposited near the parental plant. Seeds may bewashed into ditches and can be moved long distances despitelacking buoyancy. Also, seeds remain viable after passing throughthe digestive tract of animals (Rutledge and McLendon 1996).Spread by humans (0–3) 2The seeds can be a contaminant in grass and cereal seed. It hasbeen reported to spread as a contaminant of the topsoil andhorticultural stock. It appears to spread along off-road vehicletrails and road edges in Alaska (M.L. Carlson pers. obs.)Allelopathic (0–2) 2Leachates from Chenopodium album significantly reducetomato shoot biomass and accumulation of N, P, K, Ca, and Mg(Qasem et al. 1989). The allelopathic effects were separated fromcompetitive effectsCompetitive Ability (0–3) 0Lambsquarters is moderately competitive for moisture andnutrient in cultivated fields. However, it competes poorly withnative species (Densmore et al. 2001, Royer and Dickinson 1999,Rutledge and McLendon 1996).Thicket-forming/Smothering growth form (0–2) 0Lambsquarters can grow up to 3.5 feet tall (Royer and Dickinson1999), but usually does not form dense stands in Alaska (I.Lapina pers. obs.).Germination requirements (0–3) 0Seeds must be in the top 3 cm of soil to germinate. Light has beenreported as necessary for germination. Germination is inhibitedin areas shaded by other plants (Densmore et al. 2001, Royer andDickinson 1999, Rutledge and McLendon 1996).Other invasive species in the genus (0–3) 3Chenopodium murale L. is considered invasive (USDA, NRCS2002).Aquatic, wetland or riparian species (0–3) 0Lambsquarters is found in cultivated fields, roadsides, and wasteareas (Densmore et al. 2001, Gubanov et al. 2003).Total for Biological Characteristics and Dispersal 12/25Ecological Amplitude and Distribution ScoreHighly domesticated or a weed of agriculture (0–4) 4Lambsquarters is a cosmopolitan weed of cultivated areas (Royerand Dickinson 1999).Known level of impact in natural areas (0–6) 1Chenopodium album is found in river bottoms and eroded areasassociated with overgrazing, burns, or logging in the desertor desert grassland, pinyon juniper, and yellow pine forests inArizona (Parker 1990).Role of anthropogenic and natural disturbance inestablishment (0–5)Lambsquarters is a short-lived colonizer of disturbed areas andwill be present for only 1–3 years unless the site is repeatedlydisturbed (Densmore et al. 2001, Royer and Dickinson 1999).Current global distribution (0–5) 5Introduced from Europe, its current distribution is worldwide,including Africa, North and South America, Australia, Hawaii,Greenland, and New Zealand (Hultén 1968).Extent of the species U.S. range and/or occurrence offormal state or provincial listing (0–5)Chenopodium album is listed as “noxious” in Minnesota and as a“weed” in Kentucky, Nebraska, Florida, Manitoba, and Quebec(Invaders Database System 2003, Royer and Dickinson 1999,USDA, NRCS 2002).Total for Ecological Amplitude and Distribution 15/2505B-21