Main content area

Species composition of old-growth and riparian Sitka spruce-western hemlock forests in southeastern Alaska

Hanley, T.A., Hoel, T.
Canadian journal of forest research = 1996 v.26 no.9 pp. 1703-1708
riparian forests, botanical composition, Vaccinium, natural regeneration, Tsuga heterophylla, Picea sitchensis, understory, Alaska
We studied six 1.2-ha stands, two each of three types of forest: (1) old-growth, riparian floodplain forest, (2) old-growth, upland forest, and (3) 40-year-old, red alder (Alnus rubra Bong.) riparian forest originating after clear-cut logging of floodplain forest. Sitka spruce (Picea sitchensis (Bong.) Carriere) dominated the old-growth riparian stands and shared dominance with western hemlock (Tsuga heterophylla (Raf.) Sarg.) in the uplands. Regeneration was predominantly spruce in the alder riparian, spruce and hemlock in the old-growth riparian, and hemlock in the upland stands. Total understory biomass and ground cover did not differ significantly between forest types, but species-specific biomasses did differ (P < 0.05). Understory of the upland forest was dominated by early blueberry (Vaccinium ovalifolium Sm.) and Alaska blueberry (Vaccinium alaskensis How.), while that of both riparian types was dominated by devilsclub (Oplopanax horridum (Sm.) Miq.). Other species-specific differences occurred in forbs (three species) and mosses (three species). Contrary to typical stand age understory relations in upland conifer forests of the region, the understory of the 40-year-old red alder stands was very species rich and productive.