Common (Translated Scientific) Name: Douglas-fir - Ponderosa Pine / Moss Western North American Cliff, Scree & Rock Vegetation Macrogroup
Colloquial Name: Western North American Cliff, Scree & Rock Vegetation
Hierarchy Level: Macrogroup
Type Concept: This type is found throughout temperate and boreal western North America and consists of sparsely vegetated rock outcrops and cliff faces found on the Alaska peninsula, Aleutian Islands, Alaskan boreal region, Coast Mountains of British Columbia, the Rocky Mountain Cordillera, Cascades, Sierra Nevada and other ranges tall enough to have a temperate or boreal climate. The vegetation is highly variable and is typically sparse cover of vascular species with sparse to dense cover of lichens, mosses or other nonvascular organisms. Characteristic species include trees from the surrounding landscape, such as Abies concolor, Abies lasiocarpa, Abies magnifica, Pinus albicaulis, Pinus contorta, Pinus flexilis, Pinus monticola, Pinus ponderosa, Pseudotsuga menziesii (not in Alaska), Populus tremuloides, Tsuga mertensiana, or Pinus edulis, Pinus monophylla, Juniperus spp., and Cercocarpus ledifolius at lower elevations. Common shrubs species may include Amelanchier alnifolia, Arctostaphylos nevadensis, Holodiscus spp., Jamesia americana, Juniperus communis, Ledum glandulosum, Mahonia repens, Physocarpus spp., Ribes spp., Rosa woodsii, or Rhus trilobata. Potential herbaceous species are numerous and may include sparse cover of Aspidotis densa, Festuca viridula, Poa curtifolia, and Pseudoroegneria spicata. Characteristic nonvascular species information is not available. Stands occur on moderate to steep slopes, cliff faces, narrow canyons, and rock outcrops. In general these are the dry, sparsely vegetated sites. Substrates are often unstable scree and talus that typically occur below cliff faces.
Diagnostic Characteristics: Greater than 10% dense covering of mosses and/or nonvascular plants and sparse cover of herbaceous and woody vascular plants on exposed bedrock or talus.
Rationale for Nominal Species or Physiognomic Features:
Classification Comments: More work is required to delineate a more accurate geographic distribution between lithomorphic macrogroups, which may be better defined by nonvascular species. However, insufficient information is available regarding moss and other nonvascular species information to validate this possibility. Moss and other nonvascular species information is needed. Inclusion of the boreal cliff and rock vegetation here is tentative.
Similar NVC Types:
Physiognomy and Structure: The vegetation is highly variable and is typically sparse cover of vascular species from the surrounding landscape with sparse to dense cover of lichens, mosses or other nonvascular organisms.
Floristics: The vegetation is highly variable and is typically sparse cover of vascular species from the surrounding landscape with sparse to dense cover of lichens, mosses or other nonvascular organisms. Characteristic trees in Rocky Mountain stands include species from the surrounding landscape, such as Abies concolor, Abies lasiocarpa, Pinus flexilis, Pinus ponderosa, Populus tremuloides, Pseudotsuga menziesii, or Pinus edulis and Juniperus spp. at lower elevations. There may be scattered shrubs present, such as species of Amelanchier, Holodiscus, Juniperus, Physocarpus, Rhus, Ribes, Rosa, and Jamesia americana, or Mahonia repens. Characteristic species at low-elevation sites in the Cascades also include Pseudotsuga menziesii and Pinus ponderosa, as well as Pinus monticola trees with sparse ground cover of Aspidotis densa, Arctostaphylos nevadensis, and Pseudoroegneria spicata. Higher elevations have Pinus contorta var. latifolia, Pinus albicaulis, Abies lasiocarpa, and Tsuga mertensiana with Juniperus communis, Ledum glandulosum, Vaccinium scoparium, Poa curtifolia, and Festuca viridula. Vegetation in the Sierra Nevada and Klamath Mountains may include Abies magnifica, Pinus contorta var. murrayana, Pinus jeffreyi, Pinus ponderosa, Pseudotsuga menziesii, Populus tremuloides, or Pinus monophylla, Juniperus osteosperma, and Cercocarpus ledifolius at lower elevations. There may be shrubs, including species of Arctostaphylos or Ceanothus. Herbaceous cover is limited. In the northern Cascades to Alaska, scattered stunted trees include Abies spp., Callitropsis nootkatensis (= Chamaecyparis nootkatensis) (not southern range), Pinus contorta, Pseudotsuga menziesii (not in Alaska), Thuja plicata, or Tsuga spp., and the broadleaf tree species Arbutus menziesii and Quercus garryana. There may be scattered shrubs as well, such as Acer circinatum, Alnus viridis, Arctostaphylos columbiana, Arctostaphylos uva-ursi, Holodiscus discolor, Ribes spp., and Rosa gymnocarpa. Herbaceous cover is limited and may include species such as Selaginella wallacei, Polypodium glycyrrhiza, Cryptogramma acrostichoides, and graminoids such as Danthonia spp., Festuca idahoensis ssp. roemeri (= Festuca roemeri), Koeleria macrantha, and forbs such as Collinsia parviflora, Eriophyllum lanatum, Heuchera glabra, Heuchera micrantha, Phlox diffusa, Saxifraga ferruginea, Saxifraga rufidula, and Sedum spathulifolium. Mosses or lichens may be very dense, well-developed and display cover well over 10%. Amphidium lapponicum, Cladonia portentosa (= Cladina portentosa), Cystocoleus ebeneus, Dicranum scoparium, Polytrichum juniperinum, and Racomitrium spp. are characteristic mosses and lichens in the Georgia Basin. Characteristic moss and nonvascular species information is not available for most of the range of the type. Floristic information was compiled from Hess and Wasser (1982), Kruckeberg (1984), Andrews and Righter (1992), Ecosystems Working Group (1998), Larson et al. (2000a, b), Barbour et al. (2007a), and Sawyer et al. (2009). Boreal composition needs to be described.
Dynamics: Poor soil development, high levels of exposure and steep sites impede the establishment of species from surrounding communities and maintain occurrences of this macrogroup.
Environmental Description: This type is located throughout temperate and boreal western North America from the Alaska peninsula and Aleutian Islands south to the Coast Mountains of British Columbia, the Rocky Mountain Cordillera, Cascades, Blue Mountains, Sierra Nevada and other ranges tall enough to have a temperate climate. Sites range from moderate to steep slopes, cliff faces, narrow canyons, and rock outcrops. In general these are the dry, sparsely vegetated sites.
Soil/substrate/hydrology: Parent material includes outcrops of various igneous (intrusives), sedimentary, and metamorphic bedrock types. In Cascades and Klamath Mountains thin rocky, ultramafic (peridotite, serpentinite) soils are also common. Also included are unstable scree and talus slopes that typically occur below cliff faces. In general these are the dry, sparsely vegetated places. Soil development is limited. Environmental information compiled from Hess and Wasser (1982), Andrews and Righter (1992), Ecosystems Working Group (1998), Larson et al. (2000a, b), Barbour et al. (2007a), and Sawyer et al. (2009).
Geographic Range: This macrogroup is located throughout temperate and boreal western North America on rock outcrops and cliff faces found on the Alaska peninsula, Aleutian Islands and Alaskan boreal, Coast Mountains of British Columbia, the Rocky Mountain Cordillera, Cascades, Sierra Nevada and other ranges tall enough to have a temperate climate.
Nations: CA, MX, US
States/Provinces: AK, BC, CA, OR, WA
|US Forest Service Ecoregions (2007)|
Southwest Plateau and Plains Dry Steppe and Shrub Province
Confident or certain
Yellowstone Highlands Section
Confident or certain
Confidence Level: Moderate
Confidence Level Comments:
Concept Author(s): M. Reid, in Faber-Langendoen et al. (2014)
Author of Description: K.A. Schulz and G. Kittel
Version Date: 29Mar2017
- Andrews, R. R., and R. R. Righter. 1992. Colorado birds. Denver Museum of Natural History, Denver.
- Barbour, M. G., T. Keeler-Wolf, and A. A. Schoenherr, editors. 2007a. Terrestrial vegetation of California, third edition. University of California Press, Berkeley.
- 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]
- Faber-Langendoen, D., J. Drake, S. Gawler, M. Hall, C. Josse, G. Kittel, S. Menard, C. Nordman, M. Pyne, M. Reid, L. Sneddon, K. Schulz, J. Teague, M. Russo, K. Snow, and P. Comer, editors. 2010-2019a. Divisions, Macrogroups and Groups for the Revised U.S. National Vegetation Classification. NatureServe, Arlington, VA. plus appendices. [in preparation]
- Hess, K., and C. H. Wasser. 1982. Grassland, shrubland, and forest habitat types of the White River-Arapaho National Forest. Unpublished final report 53-82 FT-1-19. USDA Forest Service, Rocky Mountain Forest and Range Experiment Station, Fort Collins, CO. 335 pp.
- Kruckeberg, A. R. 1984. California serpentines: Flora, vegetation, geology, soils, and management problems. University of California Press, Berkeley.
- Larson, D. W., U. Matthes, and P. E. Kelly. 2000b. Cliff ecology: Patterns and processes in cliff ecosystems. Cambridge University Press, Cambridge, MA.
- Larson, D. W., U. Matthes, J. A. Gerrath, N. W. K. Larson, J. M. Gerrath, C. Nekola, G. L. Walker, S. Porembski, and A. Charlton. 2000a. Evidence for the widespread occurrence of ancient forest on cliffs. Journal of Biogeography 27(2):319-331.
- Sawyer, J. O., T. Keeler-Wolf, and J. Evens. 2009. A manual of California vegetation. Second edition. California Native Plant Society, Sacramento CA. 1300 pp.