Invasiveness Ranking System for Non-Native Plants of Alaska

Germination requirements (0–3) 0Buttercup populations in established grasslands and woodlandsare more likely to increase by vegetative spread than bygermination and establishment of seedlings (Lovett-Douts 1981,Lovett-Doust et al. 1990).Other invasive species in the genus (0–3) 3Ranunculus abortivus L., R. arvensis L., R. bulbosus L., andR. sardous Crantz are invasive in other areas of the United States(USDA 2002).Aquatic, wetland or riparian species (0–3) 2Buttercups occur on disturbed soils including gardens andcroplands, grasslands, woodlands, and semiaquatic communities,such as swamps, margins of ponds, rivers, and ditches. The plantsare able to tolerate some salinity, therefore, are found on beaches,in salt marshes, and on the margins of tidal estuaries (Harper1957, Lovett-Doust et al. 1990). In southeast Alaska it is a weed ofwet, but not flooded sites along the road (T. Heutte pers. obs.).Total for Biological Characteristics and Dispersal 13/23Ecological Amplitude and Distribution ScoreHighly domesticated or a weed of agriculture (0–4) 4Creeping buttercup is a serious agricultural weed, especially instrawberry cultivation (Harper 1957, Lovett-Doust et al. 1990). Itis considered a weed in 40 countries (NAPPO 2003).Known level of impact in natural areas (0–6) 1Creeping and tall buttercup have become widespread in marshes,meadows, and woodlands of Montana, Ohio, and Minnesota(Ohio perennial and biennial weed guide 2005).Role of anthropogenic and natural disturbance inestablishment (0–5)Seedlings establish readily in open ground and rapidly colonizebare areas in the year following germination (Harper 1957). It isfavored by regular mowing and thrives on lawn (T. Heutte pers.com.).Current global distribution (0–5) 5Creeping buttercup originates in Europe and extends northwardto 72°N in Norway. It is now naturalized in many temperateregions of the globe including North, Central, and SouthAmerica, Asia, Africa, Australia, and New Zealand (Harper1975, Hultén 1968, NAPPO 2003). Tall buttercup is generallydistributed over Europe with its natural northern limit at 71°N inNorway. It has established in North America, South Africa, Asia,and New Zealand (Harper 1957, Hultén 1968).0Extent of the species U.S. range and/or occurrence of5formal state or provincial listing (0–5)Ranunculus repens and R. acris are very common throughout theUnited States (USDA 2002). Both species are considered weedsin the western United States (Whitson et al. 2000). Ranunculusacris is also designated as a weed in Manitoba and Quebec (Royerand Dickinson 1999).Total for Ecological Amplitude and Distribution 15/25Feasibility of ControlScoreSeed banks (0–3) 3Harper (1957) reports that creeping buttercup seeds remainviable for at least 3 years. Lewis (1973) documents a 16 year seedviability period. Viable seeds of creeping buttercup were alsoextracted from 68-year old soil samples (Chippindale and Milton1934). A depression of germination rate was not observed for tallbuttercup seeds stored for 4 years under laboratory conditions(Harper 1957).Vegetative regeneration (0–3) 3Buttercups are able to regrow after cutting or heavy grazing(Harper 1957). Creeping buttercup readily regenerates from rootfragments (Lovett-Doust et al. 1990).Level of effort required (0–4) 3Herbicides are generally recommended to control buttercups.Plants may be weakened by cultivation, but parts of stolon mayregenerate and cause population increase. Plowing providesideal conditions for germination of seed, therefore, it is notrecommended as an eradication technique (Harper 1957, Lovett-Doust et al. 1990). Experience of control of creeping buttercupin southeast Alaska shown that this weed is very resistant toherbicides (T. Heutte pers. com.).Total for Feasibility of Control 9/10Total score for 4 sections 53/98§B-109