Pacific Northwest Alpine Shrubland and Meadow

EVT 7068North Pacific Dry and Mesic Alpine Dwarf-Shrubland
CES204.862GNRShrubShrubland
Summary
This ecological system occurs above the environmental limit of trees, at the highest elevations of the mountain regions of the Pacific Northwest coast. It is confined to the coldest, wind-blown areas above treeline and above the subalpine parkland. This system is found at elevations above 2350 m (7200 feet) in the Klamath Mountains and Cascades north into the Cascade Range and Coast Mountains of British Columbia. It is commonly composed of a mosaic of plant communities with characteristic species including Cassiope mertensiana, Phyllodoce empetriformis, Phyllodoce glanduliflora, Luetkea pectinata, Saxifraga tolmiei, and Carex spp. It occurs on slopes and in depressions where snow lingers, the soil has become relatively stabilized, and the water supply is more or less constant. Vegetation in these areas is controlled by snow retention, wind desiccation, permafrost, and a short growing season. This system includes all vegetated areas in the alpine zone of the North Pacific. Typically it is a mosaic of dwarf-shrublands, fell-fields, tundra (sedge turfs), and sparsely vegetated snowbed communities. Small patches of krummholz (shrub-form trees) are also part of this system and occur at the lower elevations. Communities are dominated by graminoids, foliose lichens, dwarf-shrubs, and/or forbs. Vegetation cover ranges from about 5 or 10% (snowbeds) to nearly 100%. The alpine tundra of the northern Cascades has floristic affinities with many mountain regions in western North America. The strongest relationships are with the Arctic and Cordilleran regions to the north and east.
Source: NatureServe Explorer
Dynamics
Landfire VDDT models: #RALME includes this and Rocky Mountain alpine systems.
Source: NatureServe Explorer
Distribution
This system occurs above the environmental limit of trees, at the highest elevations of the mountain regions of the Pacific Northwest coast. Alpine systems in Alaska are placed into different types than this.
Source: NatureServe Explorer
Ecologically Associated Plant Species

Plant species that characterize this ecosystem type, organized by vegetation stratum. These are species ecologically associated with the ecosystem, not confirmed present in any specific area.

Shrub/sapling (tall & short)

Phyllodoce empetriformis

Short shrub/sapling

Cassiope mertensiana, Luetkea pectinata, Phyllodoce glanduliflora, Vaccinium deliciosum, Vaccinium scoparium

Herb (field)

Arabis olympica, Carex nigricans, Carex spectabilis, Micranthes tolmiei, Phlox diffusa ssp. longistylis, Synthyris lanuginosa
Source: NatureServe Ecological System assessment
Ecologically Associated Animals (7)

Animal species ecologically associated with this ecosystem type based on NatureServe assessment. These are species whose habitat requirements overlap with this ecosystem, not confirmed present in any specific roadless area.

Mammals (5)

Common NameScientific NameG-Rank
Snowshoe HareLepus americanusG5
Olympic MarmotMarmota olympusG2G3
Creeping VoleMicrotus oregoniG5
Yellow-pine ChipmunkNeotamias amoenusG5
American PikaOchotona princepsG5

Amphibians (1)

Common NameScientific NameG-Rank
Crater Lake NewtTaricha granulosa mazamaeG5T1Q

Insects (1)

Common NameScientific NameG-Rank
Olympic GrasshopperNisquallia olympicaG1G2
Source: NatureServe Ecological System assessment
At-Risk Species Associated with this Ecosystem (5)

Species with conservation concern that are ecologically associated with this ecosystem type. G-Rank indicates global conservation status: G1 (critically imperiled) through G5 (secure). ESA status indicates U.S. Endangered Species Act listing.

Common NameScientific NameG-RankESA Status
Olympic RockcressArabis olympicaG1--
Olympic MarmotMarmota olympusG2G3--
Olympic GrasshopperNisquallia olympicaG1G2--
Cutleaf SynthyrisSynthyris lanuginosaG2--
Crater Lake NewtTaricha granulosa mazamaeG5T1QUnder Review
Source: NatureServe Ecological System assessment
Component Associations (16)

Plant community associations that occur within this ecological system. Associations are the finest level of the U.S. National Vegetation Classification (USNVC) and describe specific, repeating assemblages of plant species. Each association represents a distinct community type that may be found where this ecosystem occurs.

NameG-Rank
Antennaria lanata Alpine MeadowG4 NatureServe
Arctostaphylos uva-ursi Alpine Dwarf-shrublandG3 NatureServe
Calamagrostis purpurascens Alpine MeadowG2 NatureServe
Carex breweri Alpine MeadowG3 NatureServe
Carex capitata Alpine MeadowG3 NatureServe
Carex nardina Scree Alpine MeadowGNR NatureServe
Carex pellita Wet MeadowG3 NatureServe
Carex proposita Alpine MeadowG3 NatureServe
Carex scirpoidea ssp. pseudoscirpoidea Alpine MeadowG3 NatureServe
Cassiope mertensiana - Phyllodoce empetriformis Alpine Dwarf-shrublandG5 NatureServe
Dryas octopetala Alpine Dwarf-shrub MeadowG3 NatureServe
Empetrum nigrum / Lupinus sellulus Alpine Dwarf-shrublandG3 NatureServe
Phyllodoce glanduliflora / Oreostemma alpigenum Alpine Dwarf-shrublandG3 NatureServe
Salix cascadensis / Festuca brachyphylla Alpine Dwarf-shrublandG3 NatureServe
Salix nivalis / Festuca brachyphylla Alpine Dwarf-shrublandG3 NatureServe
Saxifraga tolmiei - Luzula piperi Alpine SnowbedG4 NatureServe
State Conservation Ranks (2)

Subnational conservation status ranks (S-ranks) assigned by Natural Heritage Programs in each state where this ecosystem occurs. S1 indicates critically imperiled at the state level, S2 imperiled, S3 vulnerable, S4 apparently secure, and S5 secure. An ecosystem may be globally secure but imperiled in specific states at the edge of its range.

StateS-Rank
ORSNR
WASNR
Roadless Areas (14)

Inventoried Roadless Areas where this ecosystem is present, identified from LANDFIRE 2024 Existing Vegetation Type spatial analysis. Coverage indicates the proportion of each area occupied by this ecosystem type.

Oregon (2)

AreaForestCoverageHectares
Three SistersDeschutes National Forest1.0%29.7
Bend WatershedDeschutes National Forest0.7%42.84

Washington (12)

AreaForestCoverageHectares
Pasayten RimOkanogan National Forest5.8%400.68
Myrtle LakeWenatchee National Forest5.4%241.65
TiffanyOkanogan National Forest4.0%354.42
Liberty BellOkanogan National Forest2.9%1,274.49
Hidden LakeMt Baker-Snoqualmie National Forest1.9%50.49
SawtoothOkanogan National Forest1.8%876.69
ChelanWenatchee National Forest1.6%470.7
Long SwampOkanogan National Forest1.1%286.56
Mt. Baker MaMt Baker-Snoqualmie National Forest1.0%101.52
Alpine Lakes Adj.Wenatchee National Forest0.7%171.63
TeanawayWenatchee National Forest0.6%163.98
EntiatWenatchee National Forest0.4%105.3
Methodology and Data Sources

Ecosystem classification: Ecosystems are classified using the LANDFIRE 2024 Existing Vegetation Type (EVT) layer, mapped to NatureServe Terrestrial Ecological Systems via a curated crosswalk. Each EVT is linked to the USNVC (U.S. National Vegetation Classification) hierarchy through pixel-level co-occurrence analysis of LANDFIRE EVT and NatureServe IVC Group rasters across all roadless areas.

Vegetation coverage: Coverage percentages and hectares are derived from zonal statistics of the LANDFIRE 2024 EVT raster intersected with roadless area boundaries.

Ecosystem narratives and community species: Sourced from the NatureServe Explorer API, representing professional ecological assessments of vegetation composition, environmental setting, dynamics, threats, and characteristic species assemblages.

IVC hierarchy: The International Vegetation Classification hierarchy is sourced from the USNVC v3.0 Catalog, providing the full classification from Biome through Association levels.

Component associations: Plant community associations listed as components of each NatureServe Ecological System. Association data from the NatureServe Explorer API.

State ranks: Conservation status ranks assigned by NatureServe member programs in each state where the ecosystem occurs.