Trial of Tree Species and Initial Spacing on West Coast Vancouver Island (EP 571)


E.P. 571 was initiated by J.C. Hetherington of the B.C. Forest Service to obtain information on the silvics and silviculture of 4 species: Douglas-fir, Sitka spruce, western hemlock and western redcedar, planted on a variety of sites at three initial spacings.  The study areas, located within the CWHb1 variant, initially supported old-growth stand of western hemlock western redcedar and amabilis fir, and occasional Douglas-fir and Sitka spruce. The areas were logged between 1958 and 1960 and slashburned to various extents in 1961. The experimental sites have been used for a number of studies examining the effects of tree species on soils.


  1. To study seedling survival and early growth prior to canopy closure of four species: Douglas-fir, Sitka spruce, western hemlock and western redcedar.
  2. To provide information about the effects of initial espacement and site conditions on growth and yield of these species.
  3. To determine changes to site and soil conditions which may occur under the different single-species plantations. 


The experiment was established in 1962 on south-western Vancouver Island at Port Renfrew, Sarita (Franklin) River and Mooyah Bay.  Four factors were investigated: spacing (2.7m x 2.7m, 3.7m x 3.7m, and 4.6m x 4.6m); species (Douglas fir, Sitka spruce, western hemlock, and western red cedar); location (Renfrew, Franklin, and Mooyah); and aspect-within-location (north, south, valley bottom high elevation, valley bottom low elevation).  Each treatment combination was replicated twice with some treatment combinations missing. The sites have been used for a number of studies examining the effects of tree species on soils.


Sarita plots remain active;  Mooyah Bay plots were last measured and released in 2005. Renfrew plots were last measured and released in 2014.


  • Kranabetter, J.M. 2019. Increasing soil carbon content with declining soil manganese in temperate rainforests: Is there a link to fungal Mn? Soil Biol. Biochem. 128:179–181.
  • Kranabetter, J.M., R. Harman-Denhoed, and B.J. Hawkins. 2018. Saprotrophic and ectomycorrhizal fungal sporocarp stoichiometry (C:N:P) across temperate rainforests as evidence of shared nutrient constraints among symbionts. New Phytologist 221(1):482–492. DOI: 10.1111/nph.15380.
  • Ubhi, R. 2017. Nitrogen form uptake capacities by arbuscular mycorrhizae and ectomycorrhizae. MSc thesis. Univ. Victoria, Victoria, B.C.
  • Wang, X.L., K. Klinka, H.Y.H. Chen, and L. de Montigny. 2002. Root structure of western hemlock and western redcedar in single- and mixed-species stands. Can. J. For. Res. 32:997–1004.
  • Berch, S.M., B.H. Baumbrough, J.P. Battigelli, P. Kroeger, N. Strub, and L.E. de Montigny. 2001. Preliminary assessment of selected communities of soil organisms under different conifer species. B.C. Min. For., Res. Br., Victoria, B.C. Res. Rep. 20.
  • Collins, D.B., K. Klinka, M.C. Feller, and L. de Montigny. 2001. Forest floor properties in single- and mixed-species stands of western hemlock and western redcedar. N.W. Sci. 75(4):406–416.
  • Prescott, C.E., L. Vesterdal, J. Pratt, K. Venner, S.M. Berch, and L. de Montigny. 2000. Nutrient availability in forest floors of single species conifer plantations in coastal British Columbia. Can. J. For. Res. 30:1341–1352. 
  • Klinka, K., H.Y.H. Chen, Q. Wang, and L. de Montigny. 1996. Forest canopies and their influence on understory vegetation in early-seral stands on west Vancouver Island. N.W. Sci. 70(3):193–200.
  • Omule, S.A.Y. and G.J. Krumlik. 1987. Juvenile height growth of four species on four sites in the CWHb1 variant. Can. For. Serv. and B.C. Min. For. Lands, Victoria, B.C. FRDA Rep. 007