Home/Ecosystems/ Pacific Northwest Mountain Shrubland

Pacific Northwest Mountain Shrubland

EVT 7084North Pacific Montane Shrubland

CES204.087GNRShrubShrubland

Summary

This system occurs as small to large patches scattered throughout the North Pacific region, but it is largely absent from the windward sides of the coastal mountains where fires are rare due to very wet climates. It is defined as long-lived seral shrublands that persist for several decades or more after major wildfires, or smaller patches of shrubland on dry sites that are marginal for tree growth and that have typically also experienced fire. This system occurs on ridgetops and upper to middle mountain slopes and is more common on sunny southern aspects. It occurs from about 152 m (500 feet) elevation up to the lower limits of subalpine parkland. Vegetation is mostly deciduous broadleaf shrubs, sometimes mixed with shrub-statured trees or sparse evergreen needleleaf trees. It can also be dominated by evergreen shrubs, especially Xerophyllum tenax (usually considered a forb). Species composition is highly variable; some of most common species include Acer circinatum, Arctostaphylos nevadensis, Acer glabrum, Vaccinium membranaceum, Ceanothus velutinus, Holodiscus discolor, Shepherdia canadensis, Sorbus spp., and Rubus parviflorus. On the west side of the Cascades, Gaultheria shallon is an important dominant.

Source: NatureServe Explorer

Vegetation

Vegetation is mostly deciduous broadleaf shrubs, sometimes mixed with shrub-statured trees or sparse evergreen needleleaf trees. It can also be dominated by evergreen shrubs, especially Xerophyllum tenax (usually considered a forb). Species composition is highly variable; some of most common species include Acer circinatum, Arctostaphylos nevadensis, Acer glabrum, Vaccinium membranaceum, Ceanothus velutinus, Holodiscus discolor, Shepherdia canadensis, Sorbus spp., and Rubus parviflorus. On the west side of the Cascades, Gaultheria shallon is an important dominant.

Source: NatureServe Explorer

Environment

Source: NatureServe Explorer

Distribution

This system occurs as small to large patches scattered throughout mountainous regions of the Pacific Northwest, from the southern Cascade and Coast ranges north to southern British Columbia. Its northernmost distribution is not clear, but it does not appear to occur in Alaska.

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)

Acer circinatum, Acer glabrum, Arctostaphylos nevadensis, Ceanothus velutinus, Holodiscus discolor, Rubus parviflorus, Shepherdia canadensis, Sorbus scopulina, Sorbus sitchensis, Vaccinium membranaceum

Short shrub/sapling

Gaultheria shallon

Herb (field)

Xerophyllum tenax

Nonvascular

Phaeocollybia californica

Source: NatureServe Ecological System assessment

Ecologically Associated Animals (6)

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 Name	Scientific Name	G-Rank
Cascade Golden-mantled Ground Squirrel	Callospermophilus saturatus	G5
Snowshoe Hare	Lepus americanus	G5
Long-tailed Vole	Microtus longicaudus	G5
American Ermine	Mustela richardsonii	G5
Yellow-pine Chipmunk	Neotamias amoenus	G5

Amphibians (1)

Common Name	Scientific Name	G-Rank
Crater Lake Newt	Taricha granulosa mazamae	G5T1Q

Source: NatureServe Ecological System assessment

At-Risk Species Associated with this Ecosystem (2)

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 Name	Scientific Name	G-Rank	ESA Status
a fungus	Phaeocollybia californica	G3	--
Crater Lake Newt	Taricha granulosa mazamae	G5T1Q	Under Review

Source: NatureServe Ecological System assessment

Component Associations (4)

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.

Name	G-Rank
Acer circinatum / Athyrium filix-femina - Tolmiea menziesii Shrub Swamp	G5	NatureServe
Rubus parviflorus / Chamerion angustifolium - Heracleum maximum Shrubland	G4	NatureServe
Vaccinium membranaceum / Xerophyllum tenax Shrubland	G3	NatureServe
Xerophyllum tenax - Sanguisorba officinalis Meadow	G1	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.

State	S-Rank
OR	SNR
WA	SNR

Roadless Areas (105)

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.

California (9)

Area	Forest	Coverage	Hectares
Knox Mtn.	Modoc National Forest	14.9%	359.82
Big Canyon	Modoc National Forest	9.1%	244.71
Sears Flat	Modoc National Forest	8.1%	422.91
Dry	Modoc National Forest	5.8%	181.62
Callahan Flow	Klamath National Forest	3.2%	42.48
Mt. Bidwell	Modoc National Forest	2.1%	99.09
Bear Camp Flat	Modoc National Forest	2.0%	19.62
Steele Swamp	Modoc National Forest	1.8%	138.6
Hat Mtn.	Modoc National Forest	1.7%	66.96

Oregon (44)

Area	Forest	Coverage	Hectares
Bull Of The Woods	Willamette National Forest	61.9%	12.87
Elkhorn	Willamette National Forest	30.0%	1,140.12
Medicine Creek Appendage	Umpqua National Forest	26.9%	81.09
Bearwallows	Deschutes National Forest	22.0%	650.97
Three Sisters	Deschutes National Forest	20.0%	623.7
Opal Creek	Willamette National Forest	19.9%	436.77
Hanan Trail	Fremont National Forest	19.7%	647.82
Last	Umpqua National Forest	12.4%	384.75
Williams Creek	Umpqua National Forest	10.5%	248.76
Mt. Hagen	Willamette National Forest	10.2%	264.96
Antler	Fremont National Forest	10.0%	221.67
Brattain Butte	Fremont National Forest	7.3%	175.68
Buck Creek	Fremont National Forest	6.5%	260.01
Yamsay Mt.	Winema National Forest	6.5%	175.95
Deadhorse Rim	Fremont National Forest	6.2%	341.1
South Paulina	Deschutes National Forest	4.3%	158.94
Rolling Grounds Appendage	Umpqua National Forest	4.0%	32.4
Bend Watershed	Deschutes National Forest	3.9%	236.61
Mt. Bidwell	Fremont National Forest	3.9%	70.29
West - South Bachelor	Deschutes National Forest	3.8%	401.4
Lonesome Meadow Appendage	Umpqua National Forest	3.1%	11.61
Limpy Rock	Umpqua National Forest	3.0%	81.81
Bull Of The Woods	Mt. Hood National Forest	2.7%	96.3
Cornpatch	Willamette National Forest	2.7%	79.38
Skimmerhorn Appendage	Umpqua National Forest	2.6%	19.08
North Paulina	Deschutes National Forest	2.3%	186.93
Mt. Jefferson	Deschutes National Forest	2.3%	21.6
Metolius Breaks	Deschutes National Forest	2.3%	104.49
Eagle	Mt. Hood National Forest	2.2%	151.74
Sherwood	Rogue River National Forests	2.2%	61.65
Rogue - Umpqua Divide	Rogue River National Forests	2.0%	55.44
Cougar Bluff	Umpqua National Forest	1.9%	44.01
Mt. Hood Additions	Mt. Hood National Forest	1.9%	100.08
Mt. Bailey	Umpqua National Forest	1.8%	133.38
Larch	Mt. Hood National Forest	1.7%	87.57
Castle Rock Appendage	Umpqua National Forest	1.6%	30.87
Charlton	Deschutes National Forest	1.6%	45.81
Charlton Butte	Willamette National Forest	1.6%	19.44
Crane Mountain	Fremont National Forest	1.5%	142.02
Olallie	Mt. Hood National Forest	1.4%	41.76
Jackson Creek Appendage	Umpqua National Forest	1.3%	25.29
Canton Creek	Umpqua National Forest	1.3%	35.55
Calf - Copeland Creek	Umpqua National Forest	1.1%	71.82
Roaring River	Mt. Hood National Forest	1.1%	121.68

Washington (52)

Area	Forest	Coverage	Hectares
Gotchen Creek	Gifford Pinchot National Forest	21.4%	650.7
Naneum	Wenatchee National Forest	17.2%	313.02
Chelan	Wenatchee National Forest	16.5%	4,994.91
Slide Ridge	Wenatchee National Forest	16.5%	762.66
Teanaway	Wenatchee National Forest	16.2%	4,781.97
Stormy Mtn.	Wenatchee National Forest	14.1%	1,866.6
Black Canyon	Wenatchee National Forest	14.0%	9.99
Pasayten Rim	Okanogan National Forest	11.9%	820.17
Entiat	Wenatchee National Forest	10.1%	2,964.69
Norse Peak	Wenatchee National Forest	8.1%	333.45
Myrtle Lake	Wenatchee National Forest	7.9%	355.68
Black Canyon	Okanogan National Forest	7.4%	291.6
Alpine Lakes Adj.	Wenatchee National Forest	7.0%	1,622.07
Quartz	Wenatchee National Forest	6.6%	229.05
Hungry Ridge	Okanogan National Forest	6.2%	218.97
Manastash	Wenatchee National Forest	6.0%	269.82
Lion Rock	Wenatchee National Forest	5.7%	108.63
Sawtooth	Okanogan National Forest	5.7%	2,824.65
Devils Gulch	Wenatchee National Forest	5.6%	549.9
Long Swamp	Okanogan National Forest	5.5%	1,478.61
Liberty Bell	Okanogan National Forest	5.1%	2,242.89
Twin Lakes	Wenatchee National Forest	4.8%	434.07
Blue Slide	Wenatchee National Forest	4.8%	336.69
Thorp Mtn.	Wenatchee National Forest	4.7%	433.8
Granite Mountain	Okanogan National Forest	4.4%	490.77
Canyon Creek	Wenatchee National Forest	4.3%	139.68
Norse Peak	Mt Baker-Snoqualmie National Forest	4.2%	156.42
Jefferson Ridge	Olympic National Forest	3.7%	98.46
Wodouglas Adj.	Wenatchee National Forest	3.6%	260.73
Glacier Peak K	Mt Baker-Snoqualmie National Forest	3.3%	638.28
Eagle Rock	Mt Baker-Snoqualmie National Forest	3.3%	459
Taneum	Wenatchee National Forest	3.3%	348.21
South Ridge	Okanogan National Forest	2.6%	65.16
Glacier Peak L	Mt Baker-Snoqualmie National Forest	2.6%	145.89
Nason Ridge	Wenatchee National Forest	2.1%	163.17
Mt. Baker West	Mt Baker-Snoqualmie National Forest	2.0%	209.52
Tiffany	Okanogan National Forest	1.9%	172.44
Boulder River	Mt Baker-Snoqualmie National Forest	1.8%	232.47
Hidden Lake	Mt Baker-Snoqualmie National Forest	1.6%	42.66
Silver Star	Gifford Pinchot National Forest	1.6%	50.67
Rock Creek	Wenatchee National Forest	1.5%	198.63
Heather Lake	Wenatchee National Forest	1.5%	63.18
Goat Rocks Adj	Wenatchee National Forest	1.4%	35.46
Siouxon	Gifford Pinchot National Forest	1.4%	73.35
White Chuck Mountain	Mt Baker-Snoqualmie National Forest	1.0%	24.57
Glacier Peak H	Mt Baker-Snoqualmie National Forest	0.9%	38.25
Mt. Baker North	Mt Baker-Snoqualmie National Forest	0.9%	60.57
Glacier Peak B	Mt Baker-Snoqualmie National Forest	0.8%	66.33
Quilcene	Olympic National Forest	0.7%	56.52
Mt. Baker Ma	Mt Baker-Snoqualmie National Forest	0.7%	71.82
Higgins Mountain	Mt Baker-Snoqualmie National Forest	0.7%	36.63
Mt. Baker Noisy - Diobsud	Mt Baker-Snoqualmie National Forest	0.6%	130.41

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.