Ecological integrity assessment: northern Rocky Mountain mesic montane mixed conifer forest. Version 2.16.2011

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The interior Pacific Northwest Northern Rocky Mountain Mesic Montane Mixed Conifer Forest ecological system is composed of the highly variable montane coniferous forests in the Rocky Mountains in southeastern British Columbia, eastern Washington, northern Idaho, western Montana, and northeastern Oregon. This system, locally referred to as cedar-hemlock, is associated with a submesic climate regime in areas influenced by incursions of mild, wet, Pacific maritime air masses producing an annual precipitation ranging from 30 to 60 in (75–150 cm), with a maximum in winter or late spring. Winter snowpacks typically melt off in early spring at lower elevations. Elevations range from 2500 to 6000 ft (759–1800 m). At the periphery of its distribution (such as northeastern Washington), this system is more confined to moist canyons and cooler, moister aspects. Forest canopies are typically closed although higher elevation or colder sites may be open. In the northeast and southeast corners of Washington, Tsuga heterophylla, Thuja plicata and /or Abies grandis commonly share the tree canopy with Pseudotsuga menziesii var. glauca although the former species can be sole canopy dominants. Picea engelmannii, Pinus monticola, Pinus contorta, Taxus brevifolia and Larix occidentalis are major canopy associates. Abies lasiocarpa may be present but only on the colder sites. Linnaea borealis, Paxistima myrsinites, Alnus incana, Acer glabrum, Spiraea betulifolia, Cornus canadensis, Rubus parviflorus, Menziesia ferruginea, and Vaccinium membranaceum are common shrub or sub-shrub species. The composition of the herbaceous layer reflects local climate and degree of canopy closure but is typically very diverse in all but closed-canopy conditions. Important mesic-site forbs and ferns include Actaea rubra, Adiantum pedatum, Anemone piperi, Aralia nudicaulis, Asarum caudatum, Clintonia uniflora, Gymnocarpium dryopteris, Polystichum munitum, Rubus pedatus, Thalictrum occidentale, Tiarella trifoliata, Trientalis borealis, Trillium ovatum, Viola glabella and Xerophyllum tenax.

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ELECTRONIC FILE - Ecology

SWAP (2/19/2016) citation:
Crawford R. 2011. Ecological integrity assessment: northern Rocky Mountain mesic montane mixed conifer forest. Version 2.16.2011. Olympia (WA): Washington State Department of Natural Resources, Natural Heritage Program. 12 p. [accessed 2015 Dec 04]. http://www1.dnr.wa.gov/nhp/refdesk/communities/pdf/eia/nrm_mesic_mix_con....

Additional info if needed: Sponsored by Washington Department of Fish and Wildlife.