Invasiveness Ranking System for Non-Native Plants of Alaska

Competitive Ability (0–3) 2Timothy has intermediate competitive abilities. It can suppressthe growth of other grasses and dominate (Gasser 1968).Timothy has excellent cold tolerance and winter hardiness. Itwill tolerate high shade and thrives in partial shade (Esser 1993).It will tolerate flooding and high soil salinity levels (ForageInformation System 2004).Thicket-forming/Smothering growth form (0–2) 1This large grass can occur at high densities and shade out forbsand other grasses (I. Lapina pers. obs.).Germination requirements (0–3) 1Open soil facilitates germination and establishment of timothy.Competition from other species may prevent seedlingsestablishment (Forages 2004).Other invasive species in the genus (0–3) 0Few introduced species of Phleum are recorded in NorthAmerica, but they are not listed as invasive (USDA 2004).Aquatic, wetland or riparian species (0–3) 1Timothy can be found on roadsides, along waterways, and in dryto wet meadows (Gubanov et al. 1995, Rutledge and McLendon1996).Total for Biological Characteristics and Dispersal 14/25Ecological Amplitude and Distribution ScoreHighly domesticated or a weed of agriculture (0–4) 4Timothy was introduced to North America for use as hay andcontinues to be widely used today (Rutledge and McLendon1996, USDA 2002).Known level of impact in natural areas (0–6) 3It is the most widely distributed non-native in Glacier NationalPark (Montana), reducing graminoid species in native fescuegrasslands and moist subalpine forests. It has become establishedat medium to high elevations grasslands and aspen and coniferforests (Esser 1993). It can be found in aspen–spruce–fircommunities, occasionally in oak–sagebrush, pinyon juniper,and mountain brush communities in Colorado (Rutledge andMcLendon 1996).Role of anthropogenic and natural disturbance in2establishment (0–5)Timothy readily establishes in disturbed areas and may extendto adjacent undisturbed areas. Natural and human induced firesstimulate tilling (Esser 1993).Current global distribution (0–5) 5Timothy is a native of Europe. It is now widespread in Northand South America, South Africa, New Zealand, and Australia,including subarctic regions (Hultén 1968).Extent of the species U.S. range and/or occurrence of5formal state or provincial listing (0–5)It is found in all 50 states and throughout Canada (Esser 1993).It is a restricted weed seed in New Jersey and Virginia (InvaderDatabase System 2004).Total for Ecological Amplitude and Distribution 19/25Feasibility of ControlScoreSeed banks (0–3) 2The seeds remain viable for 4–5 years in dry, cool places (Esser1993).Vegetative regeneration (0–3) 2Vegetative reproduction occurs through tilling. When plantsare cut or plowed, rooting stems may develop new plants (Esser1993).Level of effort required (0–4) 3Hand pulling can be used for timothy control, and frequentcutting or mowing can weaken overall plant health (Rutledgeand McLendon 1996). Timothy stands also become weak undercontinuous grazing (USDA 2002).Total for Feasibility of Control 7/10Total score for 4 sections 54/100§B-93