Western redcedar (Cw) - Thuja plicata
Other external information on Western redcedar
BC Distribution of Western redcedar (Cw)
Western redcedar is one of the most valuable tree species of B.C., considering its ecological, silvical, timber, and cultural values. This picture shows and extraordinary western redcedar tree in the coastal rain forest.
Western redcedar is a medium- to large-sized (rarely >60 m tall), evergreen, scale-leaved conifer, at maturity often with a forked (candelabra-like) top, a tapered fluted base, drooping branches, and thin, fibrous, brown bark. It is one of the most valuable conifers owing to the unique colour, texture, and durability of its wood; it is also the provincial tree of B.C.
Western North American/mainly Pacific and less Cordilleran
Distribution in Western North America:
(north), central, and (south) in the Pacific region; central in the Cordilleran region
(subalpine boreal) - cool temperate - cool mesothermal
submontane - montane - (subalpine)
Occurrence in biogeoclimatic zones:
(lower MH), (lower ESSF), (SBS), (MS), (PP), IDF, ICH, CDF, CWH
Range of soil moisture regimes:
(very dry) - moderately dry - slightly dry - fresh - moist - very moist - wet
Range of soil nutrient regimes:
very poor - poor - medium - rich - very rich
On the basis of sand culture experiments and field observations, Krajina (1969) and Krajina et al. (1973) concluded that western redcedar requires nitrate-N for its growth and cannot tolerate the complete replacement of nitrates by ammonium compounds. In this respect redcedar differs greatly from western hemlock, which tolerates the ammonium source of nitrogen.
Western redcedar was killed by ammonium, with the exception of one seedling (out of ten) which survived but showed evident N-deficiency. In contrast, all western hemlock seedlings treated with ammonium for two years were growing well, however those treated with complete Hoagland solution were growing better. In sand cultures, with a solution of only nitrates, all redcedars grew only slightly slower than those treated with complete Hoagland solution.
Western redcedar is able to survive and grow, though less vigorously, in soils with a low moisture and nutrient content. In fact, this species occurs on such soils over much of its natural range. However, common douglas tolerates poor soils somewhat better than redcedar.
|Root System Characteristics||In freely drained soils western redcedar develops a dense, profuse root system, with non-existent or poorly defined taproots. Fine roots form a very dense mat in the surface organic layer. Roots are mycorrhizal of the vesicular-arbuscular type.|
|Associated tree species and successional role||In British Columbia, western redcedar grows in uneven-aged, mixed-species stands, less frequently in pure, even-aged stands. It is present in early, mid-, and late stages of secondary succession; a major component in old-growth stands in the IDF, ICH, CDF, and CWH zones.|
Genetics and Notes
|Genetics||Western redcedar seems to vary less than many other tree species; however, some differences in the chemical properties were recently detected between coastal and interior populations.|
Minore, D. 1990. Thuja plicata. Pp. 590-600 in R.M. Burns and B.H. Honkala (technical coordinators) Silvics of North America, Vol. 1. Agri. Handbook 654, USDA For. Serv., Washington, D.C.
Minore, D. 1983. Western redcedar: a literature review. GTR-PNW-150, USDA For. Serv., Pacific Northwest Forest and Range Exp. Station, Portland, Oregon. 70 pp.
Smith, N.J. (editor) 1988. Western red cedar — does it have a future? Faculty of Forestry, University of British Columbia, Vancouver, B.C. 177 pp.
Similar to Alaska yellow-cedar, western redcedar is one of the most valuable tree species of British Columbia when considering its ecological, silvical, and timber values. It could be also considered a nurse species as its foliage improves decomposition of forest floor materials. More detailed silvics information is given by: