Invasiveness Ranking System for Non-Native Plants of Alaska

Prunus padus L.Ranking SummaryEcoregion known or expected to occur inSouth CoastalInterior BorealArctic AlpineYesYesNoPotential Max. ScoreEcological Impact 40 31Biological Characteristics and Dispersal 25 21Amplitude and Distribution 25 17Feasibility of Control 10 5Relative Maximum 74Climatic ComparisonCollected inAlaska regions?CLIMEXsimilarity?South Coastal Yes –Interior Boreal Yes –Arctic Alpine No NoPrunus padus is documented from Fairbanks, Salcha River,(interior boreal ecoregion), and Baranof Island (south coastalecoregion) (UAM 2003). It is widely planted as ornamental inAnchorage (I. Lapina pers. obs., M. Shephard pers. obs.). Therange of the species includes Ust’Tsil’ma and Chirka-Kem’ inRussia, and Røros, Norway (USDA, ARS 2004), which haverelatively high climatic match with Nome (78%, 77%, and 76%respectively). However, it appears to reach its physiologicallimit around Fairbanks and Anchorage as it withstands wintertemperatures to -33 °F and requires 110 frost-free days (USDA,NRCS 2006). Nome typically has 110 frost-free days, but wintertemperatures reach -54 °F (WRCC 2001). It is unlikely toestablish in the arctic alpine ecoregion of Alaska.Ecological ImpactScoreImpact on Ecosystem Processes (0–10) 7European bird cherry likely reduces light, soil moisture, andnutrient availability for other species since becoming thedominant woody species in riparian habitats in Anchorage(J. Conn pers. com.). Very little is known about this species’impact on ecosystem processes.Impact on Natural Community Structure (0–10) 7European bird cherry can create a tall shrub–small tree layereliminating native willow–alder layers and all layers below(M. Shephard pers. obs.).Impact on Natural Community Composition (0–10) 10European bird cherry replaces willows and other shrubs inriparian communities. It may also delay germination andgrowth of shade intolerant trees (M. Carlson, M. Shephard, andP. Spencer pers. obs.).Impact on Higher Trophic Levels (0–10) 7European bird cherry can cause reduction of high qualitywillow-dominated foraging sites for moose (M. Carlson,M. Shephard pers. obs.). Six species of insect visit flowers ofbird cherry (Leather 1996). Fruits are desirable to birds (Snowand Snow 1988, M. Carlson pers. obs.). Twenty-three speciesof phytophagous insect were found on European bird cherry inBritain (Leather 1985).Total for Ecological Impact 31/40Biological Characteristics and Dispersal ScoreMode of Reproduction (0–3) 3European bird cherry reproduces by seeds and bare roots. Alsoit is propagated by cuttings. This plant has very extensive seedproduction (USDA, NRCS 2006).common names: European bird cherryB-107Long-distance dispersal (0–3) 3Fruits of European bird cherry are dispersed by birds (Snowand Snow 1988). Seeds also falls beneath the trees and may bedispersed by small mammals (Leather 1996).Spread by humans (0–3) 3European bird cherry is widely planted as an ornamental insouthern Alaska (Welsh 1974). Cultivars have been developed(USDA. NRCS 2006).Allelopathic (0–2) 0European bird cherry is not listed as allelopathic (USDA, NRCS2006).Competitive Ability (0–3) 3In Anchorage, European bird cherry appears to be successfullycompeting in largely intact native habitats, with numerousseedlings being recruited (M. Shephard pers. obs.). Adult trees aredrought and frost tolerant (Malyugin 1980).Thicket-forming/Smothering growth form (0–2) 1This shrub or tree does not form dense thickets, but grows tallerthan most surrounding species (Welsh 1974).Germination requirements (0–3) 3European bird cherry is found germinating well in mixed foreststhat were disturbed several decades ago (M. Shephard pers. com).Other invasive species in the genus (0–3) 3Prunus virginiana L. and P. serotina Ehrh. are considered invasivein the Northeast (Rice 2006, USDA, NRCS 2006).Aquatic, wetland or riparian species (0–3) 2In its native range European bird cherry inhabits wet woodland,meadows, riverbanks, and forest clearcuts (British Trees 2004,Gubanov et al. 1995). It is common along riparian areas ofAnchorage.Total for Biological Characteristics and Dispersal 21/25Ecological Amplitude and Distribution ScoreHighly domesticated or a weed of agriculture (0–4) 4European bird cherry has been grown for food and as anornamental plant (USDA, ARS 2004, Welsh 1974).Known level of impact in natural areas (0–6) 3There are observed impacts in riparian communities in Alaskathat have been invaded by European bird cherry (M. Shephardpers. obs.). No information was found relating to impacts inhabitats outside of Alaska.Role of anthropogenic and natural disturbance inestablishment (0–5)In south-central Alaska European bird cherry has established onsites that were disturbed in the last 50 years (M. Shephard pers.obs.). Grazing favors young saplings establishment (Leather1996).Current global distribution (0–5) 3European bird cherry is native to Europe, temperate Asia, andnorthern Africa. It is naturalized in North America (USDA, ARS2004).Extent of the species U.S. range and/or occurrence offormal state or provincial listing (0–5)European bird cherry occurs in Alaska, Illinois, New York, NewJersey, Pennsylvania, and Delaware (USDA, NRCS 2006). It isnot considered a noxious weed in North America (Rice 2006).Total for Ecological Amplitude and Distribution 17/2552