NatureServe Explorer logo.An Online Encyclopedia of Life
Search
 
Ecological System Comprehensive Report: Record 1 of 1 selected. View Glossary
<< Previous | Next >>

Classification
Scientific Name: North Pacific Mountain Hemlock Forest
Unique Identifier: CES204.838
Classification Confidence: 1 - Strong

Search for Images on Google
Summary: This forested ecological system occurs throughout the mountains of the North Pacific, from the southern Cascades of Oregon north to southwestern British Columbia. It is the predominant forest of subalpine elevations in the coastal mountains of British Columbia, western Washington and western Oregon. It also occurs on mountain slopes on the outer coastal islands of British Columbia. It lies between the Western Hemlock, Pacific Silver Fir, or Shasta Red Fir zones and the Subalpine Parkland or Alpine Tundra Zone, at elevations ranging from 300 to 2300 m (1000-7500 feet). The lower and upper elevational limits decrease from south to north and from east to west. The climate is generally characterized by short, cool summers, rainy autumns and long, cool, wet winters with heavy snow cover for 5-9 months. The heavy snowpack is ubiquitous, but at least in southern Oregon and perhaps the eastern Cascades, summer drought is more significant. Fire is very rare or absent across the majority of the range of the system. Tsuga mertensiana is one of the dominant tree species throughout, and Abies amabilis becomes an important associated species in the southern portion of the range (British Columbia, Washington, and northwestern Oregon). Tsuga heterophylla often occurs at lower elevations in this system but is much less abundant than Tsuga mertensiana. Callitropsis nootkatensis occurs in the more coastal portions, while Abies lasiocarpa is found inland and becomes increasingly common near the transition to the Subalpine Fir-Engelmann Spruce Zone in the Cascades and British Columbia. On the leeward side of the Cascades, this is usually a dense canopy composed of Abies lasiocarpa and Tsuga mertensiana, with some Picea engelmannii or Abies amabilis. In the Cascades of central to southern Oregon, Abies magnifica var. shastensis is typically present and often codominant. Picea sitchensis and Thuja plicata are occasionally present. Deciduous trees are rare. Common understory species include Vaccinium ovalifolium, Menziesia ferruginea, Elliottia pyroliflora, and Blechnum spicant. Parklands (open woodlands or sparse trees with dwarf-shrub or herbaceous vegetation) are not part of this system but of North Pacific Maritime Mesic Subalpine Parkland (CES204.837) or Alaskan Pacific Maritime Subalpine Mountain Hemlock Woodland (CES204.143).

Classification Approach: International Terrestrial Ecological Systems Classification (ITESC)

Classification Comments: Farther inland, Tsuga mertensiana becomes limited to the coldest and wettest pockets of the more continental subalpine fir forests, described from the eastern Cascades and northern Rocky Mountains. In the northern Rocky Mountains of northern Idaho and Montana, Tsuga mertensiana occurs as patches within the matrix of Rocky Mountain Subalpine Mesic-Wet Spruce-Fir Forest and Woodland (CES306.830) only in the most maritime of environments and is included in the spruce-fir system. In the northern Rocky Mountains, this forest system is codominated by Abies lasiocarpa and/or Picea engelmannii. Mountain hemlock forests in Alaska are placed into Alaskan Pacific Maritime Mountain Hemlock Forest (CES204.142) or Alaskan Pacific Maritime Subalpine Mountain Hemlock Woodland (CES204.143).

Similar Ecological Systems
Unique Identifier Name
CES204.142 Alaskan Pacific Maritime Mountain Hemlock Forest
CES204.143 Alaskan Pacific Maritime Subalpine Mountain Hemlock Woodland
CES204.151 Alaskan Pacific Maritime Sitka Spruce Forest


Component Associations
Association Unique ID Association Name
CEGL000123 Tsuga mertensiana / Quercus sadleriana / Orthilia secunda Forest
CEGL000124 Tsuga mertensiana - Abies amabilis / Rhododendron macrophyllum Forest
CEGL000316 Abies lasiocarpa - (Pinus contorta) / Lupinus arcticus ssp. subalpinus Woodland
CEGL000500 Tsuga mertensiana - Abies amabilis / Xerophyllum tenax Forest
CEGL000501 Tsuga mertensiana - Abies amabilis / Caltha leptosepala ssp. howellii Woodland
CEGL000502 Tsuga mertensiana / Chimaphila umbellata Forest
CEGL000503 Tsuga mertensiana - Abies amabilis - (Callitropsis nootkatensis) / Elliottia pyroliflora - Vaccinium membranaceum Woodland
CEGL000507 Abies amabilis - Tsuga mertensiana / Oplopanax horridus Swamp Forest
CEGL000515 Tsuga mertensiana - Abies amabilis / Vaccinium membranaceum - Xerophyllum tenax Forest
CEGL002617 Tsuga mertensiana - Abies amabilis / Vaccinium ovalifolium / Maianthemum dilatatum Forest
CEGL002632 Tsuga mertensiana - Abies amabilis / Rhododendron albiflorum Forest
CEGL005519 Abies amabilis - Tsuga mertensiana / Streptopus lanceolatus var. curvipes Forest
CEGL005520 Abies amabilis - Tsuga mertensiana / Vaccinium membranaceum / Rubus lasiococcus Forest
CEGL005521 Abies amabilis - Tsuga mertensiana - (Abies magnifica var. shastensis) / Vaccinium membranaceum Forest
CEGL005522 Abies lasiocarpa - Tsuga mertensiana / Vaccinium scoparium Woodland
CEGL005580 Tsuga mertensiana - Abies amabilis / Vaccinium alaskaense / Rubus pedatus Forest
CEGL005581 Tsuga mertensiana - Abies amabilis / Vaccinium membranaceum / Valeriana sitchensis Woodland
CEGL005582 Tsuga mertensiana - (Abies amabilis) / Vaccinium scoparium Woodland
CEGL007381 Tsuga mertensiana - (Abies amabilis, Abies lasiocarpa) / Luzula glabrata var. hitchcockii Woodland
CEGL008685 Tsuga mertensiana / Sparse Understory Forest



Classifiers

Land Cover Class: Forest and Woodland
Spatial Pattern: Matrix
Natural/Seminatural: No
Vegetated ( > 10% vascular cover):
Upland: Yes
Wetland: No
Isolated Wetland: No

Diagnostic Classifiers
Primary Classifier Secondary Classifier
Forest and Woodland (Treed)  
Temperate Temperate Oceanic
Tsuga mertensiana  

Non-diagnostic Classifiers
Primary Classifier Secondary Classifier
Montane Upper Montane
Montane Montane

At-Risk Species Reported for this Ecological System
Scientific Name
  (Common Name)
NatureServe Global Status U.S. Endangered Species Act Status
Botrychium ascendens
  (Upward-lobed Moonwort)
G3  
Erigeron peregrinus var. thompsonii
  (Thompson's Wandering Daisy)
G5T3  
Hydnotrya inordinata
  (a fungus)
G2  
Pedicularis rainierensis
  (Mount Rainier Lousewort)
G2G3  
Penstemon eriantherus var. whitedii
  (Crested-tongue Beardtongue)
G4G5T2  
Pristiloma johnsoni
  (Broadwhorl Tightcoil Snail)
G3  
Rana pretiosa
  (Oregon Spotted Frog)
G2 LT: Listed threatened
Rhizopogon alexsmithii
  (a fungus)
G2  
Rhizopogon atroviolaceus
  (a fungus)
G2G3  
Sisyrinchium sarmentosum
  (Pale Blue-eyed-grass)
G2  
Taricha granulosa mazamae
  (Crater Lake Newt)
G5T1Q  
Viola lanceolata ssp. occidentalis
  (Western Bog Violet)
G5T2  

Vegetation Composition (incomplete)
Species Name Rounded Global Status Growth Form Stratum Char-
acter-
istic
Domi-nant Con-stant
Cover Class %
Con-
stancy
%
Abies amabilis G5 Needle-leaved tree Tree canopy    
 
 
Abies x shastensis GNA Needle-leaved tree Tree canopy    
 
 
Tsuga mertensiana G5 Needle-leaved tree Tree canopy    
 
 
Vaccinium membranaceum G5 Broad-leaved deciduous shrub Shrub/sapling (tall & short)    
 
 
Erigeron peregrinus var. thompsonii T3 Flowering forb Herb (field)      
 
 
Pedicularis rainierensis G2 Flowering forb Herb (field)      
 
 
Penstemon eriantherus var. whitedii T2 Flowering forb Herb (field)      
 
 
Sisyrinchium sarmentosum G2 Flowering forb Herb (field)      
 
 
Viola lanceolata ssp. occidentalis T2 Flowering forb Herb (field)      
 
 
Botrychium ascendens G3 Fern (Spore-bearing forb) Herb (field)      
 
 
Bryoria pikei G5 Lichen Nonvascular      
 
 
Hydnotrya inordinata G2 Non-plant Nonvascular      
 
 
Rhizopogon alexsmithii G2 Non-plant Nonvascular      
 
 
Rhizopogon atroviolaceus G2 Non-plant Nonvascular      
 
 


Animal Species Reported for this Ecological System
Scientific Name
  (Common Name)
Global Status U.S. Endangered Species Act Status Charact-
eristic
Exotic
Callospermophilus saturatus
  (Cascade Golden-mantled Ground Squirrel)
G5      
Lepus americanus
  (Snowshoe Hare)
G5      
Myodes gapperi
  (Southern Red-backed Vole)
G5      
Neotamias amoenus
  (Yellow-pine Chipmunk)
G5      
Peromyscus keeni
  (Northwestern Deermouse)
G5      
Pristiloma johnsoni
  (Broadwhorl Tightcoil Snail)
G3      
Rana pretiosa
  (Oregon Spotted Frog)
G2 LT: Listed threatened    
Sorex cinereus
  (Cinereus Shrew)
G5      
Sorex monticolus
  (Dusky Shrew)
G5      
Sorex vagrans
  (Vagrant Shrew)
G5      
Tamiasciurus douglasii
  (Douglas' Squirrel)
G5      
Taricha granulosa mazamae
  (Crater Lake Newt)
G5T1Q      


Distribution
Color legend for Distribution Map
Nation: United States
United States Distribution: OR, WA
Nation: Canada
Canadian Province Distribution: BC
Global Range: This system occurs from coastal British Columbia to the southern Cascades of Oregon.

Biogeographic Divisions
Division Code and Name Primary Occurrence Status
204-North American Pacific Maritime C: Confident or certain
306-Rocky Mountain C: Confident or certain

The Nature Conservancy's Conservation Ecoregions
Code Name Occurrence Status
1 Pacific Northwest Coast Confident or certain
3 North Cascades Confident or certain
69 S.E. Alaska - B.C. Coastal Forest and Mountains Confident or certain
81 West Cascades Confident or certain

MRLC 2000 Mapzones
Code Name Occurrence Status
1 Northern Cascades Confident or certain
2 Oregon Coastal Range Confident or certain
3 Northern California Coastal Range Possible
6 Sierra Nevada Mountain Range Confident or certain
7 Cascade Mountain Range Confident or certain
9 Blue Mountain Region Never was there
77 Prince William Never was there
78 Southeast Alaska Never was there

National Mapping
ESLF Code (Ecological System Lifeform): 4228
ESP Code (Environmental Site Potential): 1041
EVT Code (Existing Vegetation Type): 2041

West Landfire Legend: Yes
East Landfire Legend: No

Authors/Contributors
Element Description Edition Date: 08Dec2008
Element Description Author(s): G. Kittel, C. Chappell and M.S. Reid

Ecological data developed by NatureServe and its network of natural heritage programs (see Local Programs) and other contributors and cooperators (see Sources).


References
  • Banner, A., W. MacKenzie, S. Haeussler, S. Thomson, J. Pojar, and R. Trowbridge. 1993. A field guide to site identification and interpretation for the Prince Rupert Forest Region. Ministry of Forests Research Program. Victoria, BC. Parts 1 and 2. Land Management Handbook Number 26.

  • Comer, P., D. Faber-Langendoen, R. Evans, S. Gawler, C. Josse, G. Kittel, S. Menard, C. Nordman, M. Pyne, M. Reid, M. Russo, K. Schulz, K. Snow, J. Teague, and R. White. 2003-present. Ecological systems of the United States: A working classification of U.S. terrestrial systems. NatureServe, Arlington, VA.

  • Ecosystems Working Group. 1998. Standards for broad terrestrial ecosystem classification and mapping for British Columbia. Prepared by the Ecosystems Working Group, Terrestrial Ecosystem Task Force, Resources Inventory Committee, for the Province of British Columbia. 174 pp. plus appendices. [http://srmwww.gov.bc.ca/risc/pubs/teecolo/tem/indextem.htm]

  • Eyre, F. H., editor. 1980. Forest cover types of the United States and Canada. Society of American Foresters, Washington, DC. 148 pp.

  • Franklin, J. F. 1988. Pacific Northwest forests. Pages 104-130 in: M. G. Barbour and W. D. Billings, editors. North American terrestrial vegetation. Cambridge University Press, New York.

  • Kertis, Jane. Personal communication. Ecologist, Siuslaw National Forest, U.S. Forest Service, Corvallis, OR.

  • Klinka, K., and C. Chourmouzis. 2002. The mountain hemlock zone of British Columbia. Forest Sciences Department, University of British Columbia. [http://www.for.gov.bc.ca/research/becweb/zone~MH/02_authos.htm]

  • Kopper, Karen. Personal communication. Fire Ecologist, North Cascades National Park, National Park Service, Marblemount, WA.

  • Steen, O. A., and R. A. Coupé. 1997. A field guide to forest site identification and interpretation for the Cariboo Forest Region. Land Management Handbook No. 39. Parts 1 and 2. British Columbia Ministry of Forests Research Program, Victoria, BC.

  • WNHP [Washington Natural Heritage Program]. 2018. Unpublished data files. Washington Natural Heritage Program, Department of Natural Resources, Olympia, WA.


Use Guidelines and Citation

The Small Print: Trademark, Copyright, Citation Guidelines, Restrictions on Use, and Information Disclaimer.

Note: All species and ecological community data presented in NatureServe Explorer at http://explorer.natureserve.org were updated to be current with NatureServe's central databases as of March 2019.
Note: This report was printed on

Trademark Notice: "NatureServe", NatureServe Explorer, The NatureServe logo, and all other names of NatureServe programs referenced herein are trademarks of NatureServe. Any other product or company names mentioned herein are the trademarks of their respective owners.

Copyright Notice: Copyright © 2019 NatureServe, 2511 Richmond (Jefferson Davis) Highway, Suite 930, Arlington, VA 22202, U.S.A. All Rights Reserved. Each document delivered from this server or web site may contain other proprietary notices and copyright information relating to that document. The following citation should be used in any published materials which reference the web site.

Citation for data on website including State Distribution, Watershed, and Reptile Range maps:
NatureServe. 2019. NatureServe Explorer: An online encyclopedia of life [web application]. Version 7.1. NatureServe, Arlington, Virginia. Available http://explorer.natureserve.org. (Accessed:

Citation for Bird Range Maps of North America:
Ridgely, R.S., T.F. Allnutt, T. Brooks, D.K. McNicol, D.W. Mehlman, B.E. Young, and J.R. Zook. 2003. Digital Distribution Maps of the Birds of the Western Hemisphere, version 1.0. NatureServe, Arlington, Virginia, USA.

Acknowledgement Statement for Bird Range Maps of North America:
"Data provided by NatureServe in collaboration with Robert Ridgely, James Zook, The Nature Conservancy - Migratory Bird Program, Conservation International - CABS, World Wildlife Fund - US, and Environment Canada - WILDSPACE."

Citation for Mammal Range Maps of North America:
Patterson, B.D., G. Ceballos, W. Sechrest, M.F. Tognelli, T. Brooks, L. Luna, P. Ortega, I. Salazar, and B.E. Young. 2003. Digital Distribution Maps of the Mammals of the Western Hemisphere, version 1.0. NatureServe, Arlington, Virginia, USA.

Acknowledgement Statement for Mammal Range Maps of North America:
"Data provided by NatureServe in collaboration with Bruce Patterson, Wes Sechrest, Marcelo Tognelli, Gerardo Ceballos, The Nature Conservancy-Migratory Bird Program, Conservation International-CABS, World Wildlife Fund-US, and Environment Canada-WILDSPACE."

Citation for Amphibian Range Maps of the Western Hemisphere:
IUCN, Conservation International, and NatureServe. 2004. Global Amphibian Assessment. IUCN, Conservation International, and NatureServe, Washington, DC and Arlington, Virginia, USA.

Acknowledgement Statement for Amphibian Range Maps of the Western Hemisphere:
"Data developed as part of the Global Amphibian Assessment and provided by IUCN-World Conservation Union, Conservation International and NatureServe."

NOTE: Full metadata for the Bird Range Maps of North America is available at:
http://www.natureserve.org/library/birdDistributionmapsmetadatav1.pdf.

Full metadata for the Mammal Range Maps of North America is available at:
http://www.natureserve.org/library/mammalsDistributionmetadatav1.pdf.

Restrictions on Use: Permission to use, copy and distribute documents delivered from this server is hereby granted under the following conditions:
  1. The above copyright notice must appear in all copies;
  2. Any use of the documents available from this server must be for informational purposes only and in no instance for commercial purposes;
  3. Some data may be downloaded to files and altered in format for analytical purposes, however the data should still be referenced using the citation above;
  4. No graphics available from this server can be used, copied or distributed separate from the accompanying text. Any rights not expressly granted herein are reserved by NatureServe. Nothing contained herein shall be construed as conferring by implication, estoppel, or otherwise any license or right under any trademark of NatureServe. No trademark owned by NatureServe may be used in advertising or promotion pertaining to the distribution of documents delivered from this server without specific advance permission from NatureServe. Except as expressly provided above, nothing contained herein shall be construed as conferring any license or right under any NatureServe copyright.
Information Warranty Disclaimer: All documents and related graphics provided by this server and any other documents which are referenced by or linked to this server are provided "as is" without warranty as to the currentness, completeness, or accuracy of any specific data. NatureServe hereby disclaims all warranties and conditions with regard to any documents provided by this server or any other documents which are referenced by or linked to this server, including but not limited to all implied warranties and conditions of merchantibility, fitness for a particular purpose, and non-infringement. NatureServe makes no representations about the suitability of the information delivered from this server or any other documents that are referenced to or linked to this server. In no event shall NatureServe be liable for any special, indirect, incidental, consequential damages, or for damages of any kind arising out of or in connection with the use or performance of information contained in any documents provided by this server or in any other documents which are referenced by or linked to this server, under any theory of liability used. NatureServe may update or make changes to the documents provided by this server at any time without notice; however, NatureServe makes no commitment to update the information contained herein. Since the data in the central databases are continually being updated, it is advisable to refresh data retrieved at least once a year after its receipt. The data provided is for planning, assessment, and informational purposes. Site specific projects or activities should be reviewed for potential environmental impacts with appropriate regulatory agencies. If ground-disturbing activities are proposed on a site, the appropriate state natural heritage program(s) or conservation data center can be contacted for a site-specific review of the project area (see Visit Local Programs).

Feedback Request: NatureServe encourages users to let us know of any errors or significant omissions that you find in the data through (see Contact Us). Your comments will be very valuable in improving the overall quality of our databases for the benefit of all users.

Copyright 2019
NatureServe
Version 7.1 (2 February 2009)
Data last updated: March 2019