Invasiveness Ranking System for Non-Native Plants of Alaska

Competitive Ability (0–3) 3Due to its extensive root system, field bindweed is extremelycompetitive (Elmore and Cudney 2003, Rutledge and McLendon1996) and is able to outcompete native grasses for moisture andnutrients (Lyons 1982). Field bindweed is tolerant of a variety ofenvironmental conditions allowing it to effectively compete forresources (Rutledge and McLendon 1996, Whitson et al. 2000).Thicket-forming/Smothering growth form (0–2) 2Field bindweed can twine, climb ,and form dense, tangled matsover other forbs and shrubs (Gubanov et al. 2004, Zouhar 2004,Weaver and Riley 1982).Germination requirements (0–3) 0Field bindweed establishes and germinates better on bare groundthan on sites with vegetation or litter (Zouhar 2004).Other invasive species in the genus (0–3) 0No other weedy Convolvulus species are known (USDA 2002).Aquatic, wetland or riparian species (0–3) 0Field bindweed is especially common in cereal crops, orchards,and vineyards. It can also be found on ditch banks, alongroadsides, streambanks, and lakeshores (Lyons 1998, SAFRR2005). It is found on dry or moderately moist soils and it is notnormally a weed of wetlands (Weaver and Riley 1982).Total for Biological Characteristics and Dispersal 14/25Ecological Amplitude and Distribution ScoreHighly domesticated or a weed of agriculture (0–4) 4Field bindweed has had a reputation as a weed in Europeangardens since the 17th century. In the late 19th century this pestbecame a problem in North America (Austin 2000) and nowit is considered to be the worst agricultural weed in many areas(Hitchcock et al. 1959). It is particularly troublesome in whitebean, cereal, and corn crops and is abundant in vineyards andorchards and in sugar beet and vegetable crops. Field bindweedcan reduce crop yields by 50% (Royer and Dickinson 1999).This species has not been recorded in agricultural field of Alaskahowever, (J. Conn pers. com).Known level of impact in natural areas (0–6) 2Field bindweed occurs in open annual grassland and oaksavanna sites in California where it threatens endangered nativegrasses and forbs. In Idaho field bindweed outcompetes nativegrasses and threatens bunchgrass and forb-dominated habitats.Field bindweed dominates the understory in tree and shrubcommunities in Wyoming and has invaded remote, undisturbedaspen stands, riparian areas, and mountain shrublands andgrasslands in Colorado (Lyons 1982, Zouhar 2004). It occurs inthe understory in cottonwood stands along the Missouri Riverin southeastern South Dakota (Wilson 1970). Field bindweed isa dominant species in some disturbed riverbank areas in Quebec(Morin et al. 1989).Role of anthropogenic and natural disturbance in0establishment (0–5)Field bindweed is an early successional species that establisheswell on bare ground or in disturbed natural communities.Germination is better on bare ground than on sites with litter orvegetation (Zouhar 2004).Current global distribution (0–5) 5Field bindweed is native to Europe and Asia, but is nowcosmopolitan between 60°N and 45°S latitudes, growing intemperate, tropical, and Mediterranean climates (Gubanov et al.2004, Weaver and Riley 1982).Extent of the species U.S. range and/or occurrence of5formal state or provincial listing (0–5)Field bindweed is common in the United States, except inthe extreme Southeast, New Mexico, and Arizona. It is foundin agricultural regions of all Canadian provinces, exceptNewfoundland and Prince Edward Island (Weaver and Riley1982). Field bindweed is a noxious weed in 35 American statesand 5 Canadian provinces (Invaders Database System 2003,USDA 2002) and is a prohibited noxious weed in Alaska (AlaskaAdministrative Code 1987).Total for Ecological Amplitude and Distribution 16/25Feasibility of ControlScoreSeed banks (0–3) 3The seed bank of field bindweed is extremely persistent. Seedsmay lie dormant in the soil more than 50 years (Elmore andCudney 2003, Lyons 1998, Timmons 1949, Whitson et al. 2000).Vegetative regeneration (0–3) 2Field bindweed resprouts repeatedly following removal ofaboveground growth. Root fragments 2.5 inches or more inlength are able to produce new shoots under conditions ofsufficient moisture (Lyons 1998, Sherwood 1945, Swan andChancellor 1976). Roots and rhizomes of field bindweed storecarbohydrates and proteins that provide the resources necessaryfor resprouting (Lyons 1998).Level of effort required (0–4) 3Herbicides are generally the most effective control of fieldbindweed. Mechanical control is not a likely option becauseplants are able to reproduce from roots. Currently, no biologicalcontrol agents are available (Elmore and Cudney 2003, Whitsonet al. 2000, Rutledge and McLendon 1996).Total for Feasibility of Control 8/10Total score for 4 sections 56/100§B-26