The Alaska Vegetation Classification - Alaska Geobotany Center ...

(Crow 1977b, Ritchie and others 1981). Poa eminens-Festuca rubra-Potentilla egedii(Vince and Snow 1984). Poa eminens-Deschampsia beringensis-Festuca rubra(Shacklette and others 1969). Agropyronpauciflorum-fpilobium angustifolium(Hanson 1951). Carex macrochaefa-Fesfuca rubra (Byrd 1984). Agropyronpauciflorum-Fesfuca rubra-Achillea borealis-Lafhyrus palusfris (Hanson 1951). Poaglauca-Carex macrochaefa-Calamagrosfis canadensis-Angelica lucida (Hanson1951). Carex macrochaefa-Deschampsia beringensis (Friedman 1982). Potentillaegedii-Festuca rubra (del Moral and Watson 1978). Hedysarum alpinurn-Deschampsiaberingensis (Crow 1968).III.A.1.e. Hair-GrassDescription-These communities are dominated by hair-grasses (Deschampsiaspp.), usually D. beringensis. Broad-leaved herbs may be common but not codominant.Mosses may be common or absent. Woody plants and lichens generally arerare. The canopy may be open or closed, and the hair-grass usually grows 40 to80 centimeters (16 to 32 in) tall.These are often rather diverse stands, with small numbers of a great many species.Sometimes the hair-grass is only weakly dominant over the other species in thestand. Common associated species (not all are likely to be present at any one site)include Potentilla egedii, Calamagrostis canadensis, Poa eminens, Achillea borealis,Fesfuca rubra, and Hedysarum alpinum.Distribution and site characteristics-Hair-grass communities are found insouthern Alaska (including the Aleutian Islands) in coastal or near-coastal settingssuch as channel levees, fringes of coastal marshes, cliff tops, and cliff bases. Soilsare generally well drained and mesic to dry. Textures range from clays to sands, andpH generally is circumneutral to slightly acid, with the few reported values hoveringaround 6.7 to 6.8. Some hair-grass communities are flooded irregularly by brackishwater during storm surges, but this seems to have no appreciable effect on soilsalinity. Permafrost is absent.Successional status-Hair-grass communities may be near the middle of severalsuccessional sequences. Communities on coastal channel levees probably developfrom halophytic herb communities via midgrass-herb communities. Hair-grass communitiesat the upper fringes of coastal marshes may develop from halophytic sedge(especially Carex lyngbyael) stands if drainage is adequate and the marsh isprograding.Some hair-grass communities may be invaded by Calamagrostis canadensis(Hanson 1951) and eventually replaced by it. Other stands may be replacedeventually by willows or alders.Closely related types-Hair-grass communities are most similar to midgrass-herbcommunities but lack a dominant broad-leaved herb (forb) component. Forbs may becommon or scarce but not codominant. Some hair-grass communities have a substantialcover of Calamagrosfis canadensis and are similar to bluejoint meadows orbluejoint-herb meadows but have less bluejoint (Calamagrostis canadensis) andmore hair-grass.165