The Alaska Vegetation Classification - Alaska Geobotany Center ...

ll.D.2.d. Mountain-Heath Dwarf Shrub TundraDescrlptlon-Mountain-heath dwarf shrub tundra communities are dominated byPhyllodoce aleutica (P. aleutica ssp. glanduliflora in southeastern Alaska). Associated(sometimes codominant) dwarf shrubs include Cassiope mertensiana, C. stelleriana,Luetkea pectinata, Vaccinium uliginosum, and V. caespitosum. Several herbs, includingLupinus nootkatensis, Valeriana sitchensis, and Sedum rosea, may be minorcomponents of the vegetation. Mosses and lichens probably are common, but speciesnames have not been reported. Trees are absent or provide less than 10 percentcover. Shlubs taller than 20 centimeters (8 in) are absent or provide less than 25 percentcover. Plant cover ranges from open to complete but usually is fairly high.Distribution and slte characterlstlcs-Mountain-heath dwarf shrub tundra communitiesare common on alpine slopes and snowbed margins in south-central andsoutheastern Alaska. Most are well protected by snow in winter. Soils usually arerelatively thin and often are stony.Successional status-Successional relations are unknown. These communitiesappear to be stable.Closely related types-Mountain-heath dwarf shrub tundra can be similar to crowberrytundra and some stands of cassiope tundra but has a greater proportion ofPhyllodoce spp. Some stands also may be similar to ericaceous shrub bogs buthave little or no sphagnum or other peat formers and much more mountain-heath.Primary references-Klein 1965, Racine and Young 1978, Streveler and others1973.Communities-Phyllodoce aleutica-Cassiope stelleriana (Heusser 1960). Phyllodocealeutica-Cassiope spp.-Vaccinium spp. (Klein 1965). Phyllodoce aleutica-Cassiopemertensiana (Jaques 1973). Leutkea pectinata-Phyllodoce spp.-Cassiope spp.(Racine and Young 1978, Streveler and others 1973).ll.D.2.e. Cassiope Dwarf Shrub TundraDescription-Cassiope dwarf shrub tundra communities are dominated by Cassiopetetragona in the northern two-thirds of the State and by Cassiope mertensiana insnow beds in the mountains bordering the Pacific Coast (fig. 57). Common associateddwarf shrubs (sometimes codominant) include Vaccinium vitis-idaea,V. uliginosum, Empetrum nigrum, Salix reticulata. S. arctica, and Dryas spp. withCassiope tetragona; and Cassiope stelleriana. Phyllodoce aleutica ssp. glanduliflora,Vaccinium uliginosum, V. caespitosum, and Empetrum nigrum with Cassiopemeffensiana. Herbs, including Luzula spp., Pyrola spp., Saxifraga spp., and Carexbigelowii, are minor components of these communities. Mosses, including Distichiumcapillaceurn, Tomenthypnum nitens. Drepanocladus revolvens. Aulacomniumpalustre, and Hylocomium splendens, are abundant in Cassiope tetragona stands.Mosses associated with C. meffensiana are unknown. Lichens, such as Cetrariarichardsonii and C. cucullata, are common in Cassiope tetragona stands but providelittle cover. Trees are absent, and shrubs over 20 centimeters (8 in) tall (includingshrub birch of any height) are absent or provide less than 25 percent cover. Plantcover is usually complete or nearly so.155