Invasiveness Ranking System for Non-Native Plants of Alaska

Aquatic, wetland or riparian species (0–3) 3Foxtail barley can be found on roadsides and waste areas. It iscommon also on tidal flats, terraces, and riverbanks (Hultén1968, Tesky 1992, Welsh 1974).Total for Biological Characteristics and Dispersal 16/23Ecological Amplitude and Distribution ScoreHighly domesticated or a weed of agriculture (0–4) 4Foxtail barley is a common weed in cultivated fields (MAFRI2004, Robson et al. 2004). It also is considered a pasture weedbecause of the damage to animals (Tesky 1992).Known level of impact in natural areas (0–6) 3Foxtail barley is known to grow in grasslands throughout theWest. It reaches its greatest abundance on the edges of sloughsand salt marshes, grassy slopes, and flatlands of the prairies. Italso is abundant in sagebrush margins and irrigated meadows(Tesky 1992).Role of anthropogenic and natural disturbance inestablishment (0–5)This species has been observed invading areas with naturaldisturbances such as flooding and river erosion (J. Conn pers.obs.). Some types of disturbance, such as overgrazing, mowing,burning, increasing soil salinity, and soil contamination increasesthe density of foxtail barley (Badger and Ungar 1990, Robson etal. 2004, Tesky 1992).Current global distribution (0–5) 5Foxtail barley is native to western North America and hasbecome naturalized in eastern North America, Europe, andAsia, including arctic and subarctic regions. It also is recordedfrom Mexico and Great Britain (Hultén 1968, ITIS 2002, USDA2002).3Extent of the species U.S. range and/or occurrence of5formal state or provincial listing (0–5)The current range of Hordeum jubatum includes most of theUnited States except for the southeastern states (ITIS 2002,USDA 2002). Foxtail barley is declared a noxious weed inManitoba and Quebec (Invaders Database System 2003, USDA2002).Total for Ecological Amplitude and Distribution 20/25Feasibility of ControlScoreSeed banks (0–3) 3Test in Alaska indicated that up to 67% of seeds remained viableduring first year in the soil. Germinability decreased with burialand time. Less than 1% of buried seeds remain viable for up to 7years (Conn and Deck 1995, Badger and Ungar 1994).Vegetative regeneration (0–3) 2Foxtail barley reproduces by seed (MAFRI 2004, Whitson etal. 2000). Reproduction vegetatively by tilling has also beenreported (Tesky 1992). Foxtail barley has the ability to resproutafter mowing or cutting (J. Conn pers. com.).Level of effort required (0–4) 4Once established foxtail barley is hard to eradicate. Revegetatingdisturbed areas with desirable plants and controlling water levelsis effective in reducing the amount of foxtail barley (Tesky 1992).This species can be control with herbicides (MAFRI 2004).Total for Feasibility of Control 9/10Total score for 4 sections 63/100§Hordeum murinum ssp. leporinum(Link) Arcang.Ranking SummaryEcoregion known or expected to occur inSouth CoastalInterior BorealArctic AlpineNoYesNoPotential Max. ScoreEcological Impact 40 18Biological Characteristics and Dispersal 25 17Amplitude and Distribution 25 17Feasibility of Control 10 8Relative Maximum 60Climatic ComparisonCollected inAlaska regions?CLIMEXsimilarity?South Coastal No NoInterior Boreal Yes –Arctic Alpine No NoHordeum murinum ssp. leporinum has been collected in theMatanuska and Susitna Valleys in Alaska (AKEPIC 2004). Theclimatic similarity between Juneau and Fairbanks and areaswhere this species occurs is low (CLIMEX 1999, USDA 2002).This low similarity suggests that establishment of Hordeummurinum ssp. leporinum in south coastal and arctic alpineecogeographic regions is unlikely.common names: leporinum barley,lepor barley, rabbit barley, hare barleyEcological ImpactScoreImpact on Ecosystem Processes (0–10) 3Leporinum barley likely reduces soil moisture and nutrients(I. Lapina pers. obs.). This species can form high densities inAlaska where it certainly uses substantial soil moisture andnutrients (I. Lapina pers. obs.). It is not known if these resourcesare limiting to other species in these sites.Impact on Natural Community Structure (0–10) 3A high density of leporinum barley has been observed in anexisting layer of vegetation in south-central Alaska (I. Lapinapers. obs.). It becomes the dominant component of mixed croppastures in Australia and New Zealand (Cocks and Donald 1973,Govey et al. 2003, Popay 1981).Impact on Natural Community Composition (0–10) 5Leporinum barley can reduce the number of native individuals inforb and grass communities (Cocks and Donald 1973, Govey etal. 2003).Impact on Higher Trophic Levels (0–10) 7Awns of mature plants can cause serious injury to the eyes, nose,and throat of grazing animals (Klott 1981, Warr 19981, Whitsonet al. 2000). This plant also hosts several diseases (Klott 1981).Total for Ecological Impact 18/30B-51