Name:
Picea sitchensis / Bryophyte Forest
Reference:
Shephard, M. E. 1995. Plant comm...
Description:
From Boggs (2000): This association is a minor, yet widespread, type on terraces of floodplains and outwash plains of the Copper River Delta, Alaska (except the Copper River outwash where it does not occur), on the higher positions of stabilized dunes of beaches and spits and on moraines. On outwash plains and floodplains, the sites are well-drained, although during high riverflows, they may be inundated. The surface topography differs from level to pitted with hummocks. On coastal dunes, the sites are well-drained and have an undulating surface topography. Site shape is usually linear. Vegetation zones, moving from dunes of increasing stability, elevation, and distance from the ocean, typically change from <i>Elymus arenarius</i> types to various herbaceous types to forested types. The soils are variable, classified as either Spodic Cryopsamments, Typic Cryumbrepts, or Typic Cryorthents. In general, they are characterized by a litter layer 5 to 10 cm (2-4 inches) thick over sand. The pH of the litter layer ranges from 4.5 to 5.4, and the mineral layer pH ranges from 5.4 to 6.5. Horizon development in the soil profiles was uncommon. Gleying was not found, and mottling was noted in one profile. Salinity was low in all stands. Stands are composed of moderately dense mature <i>Picea sitchensis</i> and a scattering of <i>Populus trichocarpa</i> (black cottonwood) trees. Other shrub, forb (except <i>Equisetum arvense</i>), graminoid, and fern species have consistently low cover values. Tree height of an average-sized tree ranges from 10.7 to 27.5 m (35-90 feet), and their age ranges from 37 to 125 years. The stands are typically a single cohort. Dead <i>Alnus crispa ssp. sinuata</i> (Sitka alder) occurs as a major component in most stands. <i>Equisetum arvense</i> occasionally dominates the herbaceous understory. In all stands, bryophytes form a carpet consisting of <i>Hylocomium splendens, Rhytidiadelphus loreus, Rhytidiadelphus squarrosus</i>, and other moss species. This is a mid-successional type that follows <i>Picea sitchensis / Alnus crispa</i> community type [~<i>Picea sitchensis / Alnus viridis ssp. sinuata</i> Woodland (CEGL003254)$$] or <i>Populus trichocarpa</i> / young community type (Boggs 2000). On all landscapes, this community is seral to other <i>Picea sitchensis</i> types and, eventually, <i>Tsuga heterophylla</i> communities.
Accession Code:
VB.CC.37163.CEGL003268
Plot-observations of this Community Concept:
0
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