The Alaska Vegetation Classification - Alaska Geobotany Center ...

Communities-Picea glauca/Alnus fenuifolia/Hylocomium splendens (Dyrnessand others 1988). Picea glauca/Alnus crispa-A. tenuifolia/Vaccinium vifis-idaea/Hylocomium splendens (Dyrness and others 1988, Viereck 1989). Picea glauca/Alnus fenuifolia/Calamagrosfis canadensis-Vaccinium vifis-idaea (Dyrness and others1988). Picea glauca/Betula glandulosa/Hylocomium splendens (Hettinger and Janz1974; Viereck 1970b, 1975, 1979; Williamson and Peyton 1962). Piceaglauca/Betulaglandulosa/Sphagnumspp. (Hettinger and Janz 1974; Viereck 1970b, 1975. 1979;Williamson and Peyton 1962). Picea glauca/Betula glandulosa/Cladonia spp. (Racineand Anderson 1979, Viereck 1979). Picea glauca/Salix bebbiana/Rosa acicularis/Equisefum spp.-Epilobium spp./lichens (Yarie 1983). Picea glauca/Salix spp./Shepherdia canadensis/Vaccinium vitis-idaea (Yarie 1983). Picea glauca/Salixspp./Ledum decumbens/Vaccinium vitis-idaea (Yarie 1983). Picea glauca/Alnuscrispa-Salix spp./€quisefum arvense (Craighead and others 1988). Picea glaucdVaccinium spp.-Salix spp./€quisefum arvense (Craighead and others 1988). Piceaglauca/Salix spp./€quisefum arvense (Craighead and others 1988). Picea glaucdSalix spp./feathermosses (Craighead and others 1988). Picea glaucalfeathermosses(Craighead and others 1988). Picea glauca/Alnus crispaAeathermosses (Craigheadand others 1988). Picea g/auca/Alnus crispa-Salix spp./Vaccinium uliginosunVfeathermosses (Craighead and others 1988). Picea glauca/Befula nana-Vacciniumuliginosu~feathermosses (Craighead and others 1988).1.A.2.f. Open Black Spruce ForestDescrlptlon4pen black spruce forest is generally dominated by small blackspruce trees 3 to 9 meters (9 to 30 ft) tall and 4 to 7 centimeters (1.5 to 3 in) d.b.h.growing at densities of 1200 to 3700 stems per hectare (480 to 1,500 stems peracre) (fig. 16). Stands over 100 years old occasionally are found; however, moststands are younger. In older stands the trees are larger (up to 18 centimeters [7 in]d.b.h. and 17 meters 156 ft] tall) and grow less densely. Black spruce seedlings andsaplings are common in some stands; in others, reproduction is primarily by layering.Other tree species that may be present in minor quantities include paper birch, whitespruce, and tamarack (Larix laricina).An open to nearly continuous cover of low shrubs 10 to 100 centimeters (4 to 39 in)tall is characteristic of these communities. Common shrubs include Vacciniumuliginosum, V. vitis-idaea, Ledumgroenlandicum, and sometimes Rosa acicularis,Potentilla fruticosa. €mpetrum nigrum and L. decumbens. The tall shrubs Ahuscrispa, Betula glandulosa, and Salix spp. also occur in some stands. Common herbsinclude Calamagrostis spp., Equisetum sylvaticum, Rubus chamaemorus, Eriophowmvaginatum, and Carex bigelowii. The ground layer generally is dominated by feathermosses(commonly Pleurozium schreberi and Hylocomium splendens), thoughPolyfrichum spp., Sphagnum spp., and fruticose and foliose lichens are usuallypresent and may be dominant in some stands.Distrlbutlon and site characteristics-Open black spruce forests are extremelycommon on vast areas of poorly drained, cold terrain in interior and south-centralAlaska. Soils are usually Histic Pergelic Cryaquepts and sometimes Cryochrepts.Permafrost usually is present at depths of 30 to 60 centimeters (12 to 24 in) butmay be absent in the southern part of the State and where the soil is shallow overbedrock. The forest floor layer is usually 5 to 20 centimeters (2 to 8 in) thick butsometimes is over 1 meter (3 it) thick.74