Invasiveness Ranking System for Non-Native Plants of Alaska

Competitive Ability (0–3) 1Silene species can rapidly colonize disturbed sites and competewith other vegetation (Royer and Dickinson 1999). However;cultivated field experiments demonstrated that bladdercampion did not compete well with alfalfa and barley (Wall andMorrison 1990). Bladder campion and red catchfly tolerate highconcentrations of copper, nickel, zinc, lead, and air pollution;and are highly adapted to water and nutrient deficient conditions(Brooks and Crooks 1980, Leopold et al. 1999, Wierzbicka andPaufnik 1998).Thicket-forming/Smothering growth form (0–2) 0Silene species can grow up to 3 feet tall, but are not characterizedby a climbing or smothering growth habit (Douglas andMacKinnon 1998, Royer and Dickinson 1999, Whitson et al.2000).Germination requirements (0–3) 0Buried seeds germinate readily after soil disturbance (Guide toWeeds in British Columbia 2002). Some populations may requirelight for germination.Other invasive species in the genus (0–3) 3The genus Silene consists of a number of serious agriculturalweeds (Royer and Dickinson 1999, Whitson et al. 2000).Aquatic, wetland or riparian species (0–3) 0These plants are important weeds of pastures, grain fields, andgardens. They are also found along highways, railroad tracks, andin waste places (Gubanov et al. 2003, McNeill 1980, Royer andDickinson 1999).Total for Biological Characteristics and Dispersal 9/25Ecological Amplitude and Distribution ScoreHighly domesticated or a weed of agriculture (0–4) 3Silene species are found in most agricultural areas of United Statesand Canada, they are important weeds particularly of grain andleguminous crops (Royer and Dickinson 1999, McNeill 1980,Whitson et al. 2000).Known level of impact in natural areas (0–6) 0Silene species are known as agricultural weeds, but have not beenreported to impact natural habitats (Royer and Dickinson 1999,Whitson et al. 2000).Role of anthropogenic and natural disturbance in0establishment (0–5)Silene species can colonize open ground. Buried seeds remainviable and germinate and establish easily after soil disturbance(Guide to Weeds in British Columbia 2002, Matlack and Harper1986).Current global distribution (0–5) 5The native range of Silene species extends across Europe andSouthwest Asia. They are now found throughout Canada and theUnited States with the exception of Alabama, Arkansas, Hawaii,Nevada, Arizona, South Carolina, Tennessee, and Texas (USDA2002). Silene noctiflora has been recorded from Australia andGreenland (McNeill 1980). Silene noctiflora and S. dioica havebeen recorded from arctic Norway and Finland (Lid and Lid1994, Thompson 1975).Extent of the species U.S. range and/or occurrence of5formal state or provincial listing (0–5)Night-flowering catchfly, white cockle, and bladder campionare declared federal noxious weeds in Canada. These species arealso listed as weeds in Connecticut, Wisconsin, and Washington(Royer and Dickinson 1999).Total for Ecological Amplitude and Distribution 13/25Feasibility of ControlScoreSeed banks (0–3) 3The seeds of night-flowering catchfly and bladder campion canremain viable in the soil for at least 5 years (Chepil 1946). Seedsof red catchfly older than 2 years normally do not germinate(Carlsson-Graner et al. 1998).Vegetative regeneration (0–3) 1White campion and bladder campion can resprout from root andstem fragments (Whitson et al. 2000).Level of effort required (0–4) 3Mowing or burning is unlikely to control Silene species because ofits large seed bank. Cultivation usually increases the infestationby facilitating the spread of Silene. Herbicides provide limitedcontrol, as these species are resistant or somewhat resistant tomany common herbicides. No biological control agent is available(Guide to weeds in British Columbia 2002, McNeill 1980).Total for Feasibility of Control 7/10Total score for 4 sections 42/100§B-119