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BC Conservation Data Centre: Ecological Community Summary

Pseudotsuga menziesii / Melica subulata
Douglas-fir / Alaska oniongrass

 
Scientific Name: Pseudotsuga menziesii / Melica subulata
English Name: Douglas-fir / Alaska oniongrass
Scientific Name - Concept Reference: Meidinger, D. 1992. Vegetation classification hierarchy: DBASE September 1992. B.C. Minist. For. Res. Branch, Victoria.
Ecosystem Group: Terrestrial Realm - Forest: Coniferous - dry
   
Conservation Status / Legal Designation
Global Status: G1
Provincial Status: S1 (Feb 2018)
BC List: Red
Provincial FRPA list: Y (Jun 2006)  
Notable Species:
 
Ecology & Dynamics
Environmental Summary: This ecological community occurs on dry sites, from 0 to 150 m elevation, which typically have a southerly aspect. These sites are rapidly- to well-drained and are often composed of inactive colluvial and sometimes morainal parent materials. They occur on middle to upper slopes on all aspects. Slopes are gentle to steep, and are often adjacent to rock outcrops. The soils are classified as Sombric or Dystric Brunisols and are often shallow to bedrock (<1 metre), mostly with a sandy loam texture with moderate coarse fragment content. The soil nutrient regime is rich to very rich and the soil moisture is rated as very dry (Roemer 1972, Flynn and Cadrin 2004, Reid and Cadrin 2012, NatureServe 2005).
Vegetation Summary: This mixed coniferous and deciduous ecosystem occurs on southeastern Vancouver Island and the southern Gulf Islands. It is characterized by a moderately open canopy of Pseudotsuga menziesii (Douglasfir) with some interspersed Quercus garryana (Garry oak), especially in canopy gaps. Arbutus menziesii (Arbutus) is occasionally present, but other conifer species are absent. The shrub layer is sparse to absent, and consists of Lonicera hispidula (hairy honeysuckle), Symphoricarpos albus (common snowberry) and Mahonia aquifolium (tall Oregon-grape). Other shrubs that are occasionally present may include Amelanchier alnifolia (Saskatoon), Gaultheria shallon (salal), Holodiscus discolor (oceanspray) and Rosa gymnocarpa (baldhip rose). The diverse and well-developed herb layer is often dominated by Melica subulata (Alaska oniongrass) and may also include Carex inops (long-stoloned sedge) and Sanicula crassicaulis (Pacific sanicle) and usually with Satureja douglasii (yerba buena). Other herbs usually present in small amounts include Elymus glaucus (blue wildrye), Festuca occidentalis (western fescue), Moehringia macrophylla (big-leaved sandwort), Dodecatheon hendersonii (broad-leaved shootingstar) and Galium aparine (cleavers). The moss layer is characterized by Rhytidiadelphus triquetrus (electrified cats-tail moss) with a minor component of Eurhynchium oreganum (Oregon beaked moss) (Roemer 1972, Green and Klinka 1994, Reid and Cadrin 2012, NatureServe 2005).
Dynamic Processes Summary: This is a late-successional (mature and climax) climatic forest ecosystem. The natural disturbance regime is described as infrequent stand-initiating events, through medium to high-intensity crown fires every 150 to 200 years and covering 5 to 50 ha (Biodiversity Guidebook 1995). Occasionally windthrow was the stand-initiating event, with regeneration occurring in the resulting canopy gaps. Stand-maintaining surface fires helped maintain an open forest canopy by killing understory regeneration. Death of individual or small groups of trees may be caused by root rot, drought, defoliating insects and windthrow. Succession rates are very slow, and it takes a long time to develop large, old trees, snags and coarse woody debris (Pojar 2004, NatureServe 2005).
Spatial Pattern: Small patch
 
Distribution
Endemic: Y
   
Authors / Contributors
Author: de Groot, A., Cadrin, C.M., H.K. Yearsley, I. Ronalds and D.S. McLennan
Last updated: Feb 22, 2012
   
References and Related Literature
B.C. Ministry of Forests and Range. 2006. Biogeoclimatic Subzone/Variant Map [computer file]. 6th edition. Ministry of Forests and Range, Research Branch. Victoria, BC
Biodiversity Guidebook. 1995. Forest Practices Code of British Columbia. B.C. Minist. For. and B.C. Minist. Environ., Victoria B.C. ix + 99p.
British Columbia Ministry of Forests Research Branch. 2002. Vegetation classification hierarchy: BECMaster September 2002. B.C. Min. For., Victoria.
Brown, K.J. and R.J. Hebda. 1999. Long-term fire incidence in coastal forests of British Columbia. Northwest Sci. 73:41-43.
Erickson, W. 1993. Garry Oak Ecosystems. B.C. Minist. Environ., Lands and Parks, Wildl. Branch. Victoria, B.C. 6 pp.
Flynn, S. 1999. Coastal Douglas-fir Ecosystems. B.C. Minist. Environ., Lands and Parks, Wildl. Branch. Victoria, B.C. 6 pp.
Green, R.N., and K. Klinka. 1994. A field guide to site identification and interpretation for the Vancouver Forest Region. B.C. Minist. For., Res. Branch, Victoria, B.C. Land Manage. Handb. No. 28.
McPhee, M., P. Ward, J. Kirkby, L. Wolfe, N. Page, K. Dunster, N.K. Dawe, and I. Nykwist. 2000. Sensitive Ecosystems Inventory: East Vancouver Island and Gulf Islands, 1993 - 1997. Volume 2: Conservation Manual. Tech. Rep. Ser. No. 345, Can. Wildl. Serv., Pac. and Yukon Reg., BC.
NatureServe. 2005n. Global Comprehensive Report for Pseudotsuga menziesii - Quercus garryana / Melica subulata Forest. Online. Available: http://natureserve.org/explorer/servlet/NatureServe?searchCommunityUid=ELEMENT_GLOBAL.2.686311.
Reid, H. and C. Cadrin. 2012. Field guides to the Douglas-fir / dull Oregon-grape and the Douglas-fir / Alaska oniongrass Ecological Communities. Version 2. Madrone Consultants and Conservation Data Centre, Ministry of Environment, Victoria, B.C.
Roemer, H.L. 1972. Forest vegetation and environments on the Saanich Peninsula, Vancouver Island. Ph.D. Thesis., Univ. Victoria, Victoria, BC.
Sensitive Ecosystems Inventory [SEI] of East Vancouver Island and Gulf Islands: Sensitive Ecosystems Mapping, Disturbance Mapping and Re-evaluation of Major Riparian Corridors. 2004. Prepared by Axys Environ. Consulting Ltd. for Environ. Can., Can. Wildl. Serv., B.C. Minist. Sustainable Resour. Manage., and B.C. Minist. Water, Land and Air Prot., and the Habitat Conserv. Trust Fund. 66 mapsheets, 1:20 000 scale.
Sensitive Ecosystems Inventory [SEI] of the Sunshine Coast and Adjacent Islands. 2005. Cadrin, C., C. Erwin, B. Fuller, C. Schaefer and J. Stacey. 1:20 000 spatial data.
Terrestrial Ecosystem Mapping [TEM] of Helliwell Provincial Park. 2001. Prepared for BC Parks, Strathcona District Office, B.C., by K. Dunster and J. Booth. 1:5000 spatial data.
Terrestrial Ecosystem Mapping [TEM] of the Coastal Douglas-fir Biogeoclimatic Zone. 2008. Prepared for B. Zinovich, Integrated Land Management Bureau, B.C. Minist. of Agric. and Lands, Nanaimo B.C. by Madrone Environmental Services, Duncan B.C. 1:20,000 spatial data.
University of British Columbia Department of Forest Sciences. 1991. Vegetation and Site Classification for Coastal British Columbia. Vegetation and Environment Summaries. Univ. B.C., Vancouver, BC.
Ward, P., G. Radcliffe, J. Kirkby, J. Illingworth, and C. Cadrin. 1998. Sensitive Ecosystems Inventory: East Vancouver Island and Gulf Islands 1993-1997. Volume 1: Methodology, Ecological Descriptions and Results. Tech. Rep. Ser. No. 320, Can. Wildl. Serv., Pac. and Yukon Reg., BC.
 

Please visit the website Conservation Status Ranks for definitions of the data fields used in this summary report.

Suggested Citation:

B.C. Conservation Data Centre. 2012. Ecological Community Summary: Pseudotsuga menziesii / Melica subulata. B.C. Minist. of Environment. Available: https://a100.gov.bc.ca/pub/eswp/ (accessed Jun 5, 2026).