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Home/Ecosystems/ Rocky Mountain Subalpine Streamside Woodland

Rocky Mountain Subalpine Streamside Woodland

EVT 9022Rocky Mountain Subalpine-Montane Riparian Woodland
CES306.833GNRTreeRiparian
View on NatureServe Explorer
Summary
This riparian woodland system comprises seasonally flooded forests and woodlands found at montane to subalpine elevations of the Rocky Mountain cordillera, from southern New Mexico north into Montana, and west into the Intermountain West region and the Colorado Plateau. It occurs throughout the interior of British Columbia and the eastern slopes of the Cascade Range. This system contains the conifer and aspen woodlands that line montane streams. These are communities tolerant of periodic flooding and high water tables. Snowmelt moisture in this system may create shallow water tables or seeps for a portion of the growing season. Stands typically occur at elevations between 1500 and 3300 m (4920-10,830 feet), farther north elevation ranges between 900 and 2000 m. This is confined to specific riparian environments occurring on floodplains or terraces of rivers and streams, in V-shaped, narrow valleys and canyons (where there is cold-air drainage). Less frequently, occurrences are found in moderate-wide valley bottoms on large floodplains along broad, meandering rivers, and on pond or lake margins. Dominant tree species vary across the latitudinal range, although it usually includes Abies lasiocarpa and/or Picea engelmannii; other important species include Pseudotsuga menziesii, Picea pungens, Picea engelmannii x glauca, Populus tremuloides, and Juniperus scopulorum. Other trees possibly present but not usually dominant include Alnus incana, Abies concolor, Abies grandis, Pinus contorta, Populus angustifolia, Populus balsamifera ssp. trichocarpa, and Juniperus osteosperma.
Source: NatureServe Explorer
Distribution
This system is found at montane to subalpine elevations of the Rocky Mountain cordillera, from southern New Mexico north into Montana, Alberta and British Columbia, and west into the Intermountain region and the Colorado Plateau.
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.

Tree canopy

Abies concolor var. concolor, Abies grandis, Abies lasiocarpa, Juniperus osteosperma, Juniperus scopulorum, Picea engelmannii, Picea pungens, Picea x 1, Pinus contorta, Populus angustifolia, Populus balsamifera ssp. trichocarpa, Populus tremuloides, Pseudotsuga menziesii

Shrub/sapling (tall & short)

Alnus incana

Herb (field)

Botrychium ascendens, Botrychium paradoxum, Sidalcea oregana var. calva
Source: NatureServe Ecological System assessment
Ecologically Associated Animals (4)

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 (2)

Common NameScientific NameG-Rank
American BeaverCastor canadensisG5
a dusky shrewSorex obscurusG5

Amphibians (1)

Common NameScientific NameG-Rank
Oregon Spotted FrogRana pretiosaG2

Other (1)

Common NameScientific NameG-Rank
Western Jumping MouseZapus princepsG5
Source: NatureServe Ecological System assessment
At-Risk Species Associated with this Ecosystem (3)

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
Peculiar MoonwortBotrychium paradoxumG3G4--
Oregon Spotted FrogRana pretiosaG2Threatened
Wanatchee Mountains Checker-mallowSidalcea oregana var. calvaG5T1Endangered
Source: NatureServe Ecological System assessment
Component Associations (51)

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
Abies concolor - Acer negundo / Alnus incana ssp. tenuifolia Riparian Forest NatureServe
Abies concolor - Picea pungens - Populus angustifolia / Acer glabrum Forest NatureServe
Abies lasiocarpa / Carex aquatilis Swamp NatureServe
Abies lasiocarpa - Picea engelmannii / Alnus incana Riparian Forest NatureServe
Abies lasiocarpa - Picea engelmannii / Alnus viridis ssp. sinuata Riparian Forest NatureServe
Abies lasiocarpa - Picea engelmannii / Mertensia ciliata Riparian Forest NatureServe
Abies lasiocarpa - Picea engelmannii / Oplopanax horridus SwampG3 NatureServe
Abies lasiocarpa - Picea engelmannii / Salix drummondiana Riparian Forest NatureServe
Abies lasiocarpa - Picea engelmannii / Streptopus amplexifolius Riparian ForestG4 NatureServe
Abies lasiocarpa / Trautvetteria caroliniensis Riparian Forest NatureServe
Picea engelmannii / Caltha leptosepala SwampG3 NatureServe
Picea engelmannii / Carex angustata Swamp NatureServe
Picea engelmannii / Carex scopulorum var. prionophylla Swamp Woodland NatureServe
Picea engelmannii / Cornus sericea Riparian Woodland NatureServe
Picea engelmannii / Eleocharis quinqueflora Swamp Woodland NatureServe
Picea engelmannii - Populus angustifolia / Heracleum maximum Riparian Forest NatureServe
Picea engelmannii / Salix drummondiana Riparian Woodland NatureServe
Picea engelmannii / Senecio triangularis Riparian Forest NatureServe
Picea glauca Alluvial Black Hills ForestG2 NatureServe
Picea pungens / Alnus incana Riparian Woodland NatureServe
Picea pungens / Betula occidentalis Riparian Woodland NatureServe
Picea pungens / Cornus sericea Riparian Woodland NatureServe
Picea pungens / Dasiphora fruticosa Riparian Woodland NatureServe
Picea pungens / Equisetum arvense Riparian Woodland NatureServe
Pinus contorta / Calamagrostis canadensis Swamp NatureServe
Pinus contorta / Carex (aquatilis, angustata) Swamp Woodland NatureServe
Pinus contorta / Cornus sericea Swamp Woodland NatureServe
Pinus contorta / Deschampsia cespitosa Swamp NatureServe
Populus balsamifera ssp. trichocarpa - Picea engelmannii / Equisetum arvense Riparian Forest NatureServe
Populus balsamifera ssp. trichocarpa - Populus tremuloides - Conifer / Calamagrostis canadensis Riparian Forest NatureServe
Populus balsamifera ssp. trichocarpa - Populus tremuloides - Conifer / Cornus sericea Riparian Forest NatureServe
Populus balsamifera ssp. trichocarpa - Populus tremuloides - Conifer / Heracleum maximum Riparian Forest NatureServe
Populus tremuloides - Abies lasiocarpa - Picea engelmannii / Streptopus amplexifolius Forest NatureServe
Populus tremuloides / Alnus incana / Betula nana - Ribes spp. Riparian Forest NatureServe
Populus tremuloides / Alnus incana Riparian Forest NatureServe
Populus tremuloides / Alnus incana - Salix spp. Riparian Forest NatureServe
Populus tremuloides / Betula occidentalis Riparian Forest NatureServe
Populus tremuloides / Calamagrostis canadensis Swamp NatureServe
Populus tremuloides Canyon Formation Riparian Forest NatureServe
Populus tremuloides / Carex aquatilis var. aquatilis Swamp NatureServe
Populus tremuloides / Carex obnupta Swamp NatureServe
Populus tremuloides / Carex pellita SwampG2 NatureServe
Populus tremuloides / Cornus sericea Riparian ForestG4 NatureServe
Populus tremuloides / Corylus cornuta ForestG3 NatureServe
Populus tremuloides / Equisetum arvense Riparian Forest NatureServe
Populus tremuloides / Quercus gambelii / Symphoricarpos oreophilus ForestGNR NatureServe
Populus tremuloides / Ranunculus alismifolius Riparian Forest NatureServe
Populus tremuloides / Ribes montigenum Riparian ForestG2 NatureServe
Populus tremuloides / Salix drummondiana Riparian Forest NatureServe
Populus tremuloides / Senecio bigelovii var. bigelovii Riparian Forest NatureServe
Populus tremuloides / Veratrum californicum Riparian Forest NatureServe
State Conservation Ranks (11)

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
AZSNR
COSNR
IDSNR
MTSNR
NMSNR
NVSNR
ORSNR
SDSNR
UTSNR
WASNR
WYSNR
Roadless Areas (117)

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 (3)

AreaForestCoverageHectares
Hoover - Emma LakeHumboldt-Toiyabe National Forest2.8%11.61
Sweetwater (CA)Humboldt-Toiyabe National Forest0.6%44.37
Boundary Peak (CA)Inyo National Forest0.2%158.04

Montana (29)

AreaForestCoverageHectares
Saginaw CreekBeaverhead-Deerlodge National Forest2.6%82.62
West Big HoleBeaverhead-Deerlodge National Forest2.5%1,367.64
BeartoothGallatin National Forest2.3%48.87
North Big HoleBeaverhead-Deerlodge National Forest2.0%425.34
SapphiresBeaverhead-Deerlodge National Forest1.9%521.82
Anderson MountainBeaverhead-Deerlodge National Forest1.9%237.42
Marshall PeakLolo National Forest1.7%62.55
Beaver LakeBeaverhead-Deerlodge National Forest1.6%74.43
Whitetail / HaystackBeaverhead-Deerlodge National Forest1.5%473.94
West PioneerBeaverhead-Deerlodge National Forest1.5%1,512.99
O'Neil CreekBeaverhead-Deerlodge National Forest1.3%33.3
EmerineBeaverhead-Deerlodge National Forest0.7%40.14
Northwest PeaksKootenai National Forest0.7%41.94
Bear - Marshall - Scapegoat - SwanLewis and Clark National Forest0.7%927.27
East PioneerBeaverhead-Deerlodge National Forest0.6%378.45
Flint Range / Dolus LakesBeaverhead-Deerlodge National Forest0.6%152.46
Cabin Creek Wildlife Management Area OcdGallatin National Forest0.6%84.06
Blue Joint (mwsa) (01941)Bitterroot National Forest0.5%133.83
Electric PeakHelena National Forest0.5%55.89
Tash PeakBeaverhead-Deerlodge National Forest0.5%118.08
FleecerBeaverhead-Deerlodge National Forest0.5%58.77
Crazy MountainGallatin National Forest0.4%139.23
MadisonGallatin National Forest0.4%181.35
Italian PeakBeaverhead-Deerlodge National Forest0.3%118.98
Middle Mtn. / Tobacco RootsBeaverhead-Deerlodge National Forest0.3%120.69
ElkhornHelena National Forest0.3%92.79
Hyalite - Porcupine - Buffalo Horn Wilderness Study AreaGallatin National Forest0.3%174.24
HoodooLolo National Forest0.3%122.76
Bmss Ra 1485Flathead National Forest0.2%306.45

Nevada (6)

AreaForestCoverageHectares
Elk MountainHumboldt-Toiyabe National Forest1.3%44.28
Boulder BasinHumboldt-Toiyabe National Forest1.1%30.15
Ruby - Lamoille CynHumboldt-Toiyabe National Forest0.9%114.39
Ruby - SegundaHumboldt-Toiyabe National Forest0.8%43.02
Copper Mtns.Humboldt-Toiyabe National Forest0.5%63.45
Toiyabe RangeHumboldt-Toiyabe National Forest0.3%117.81

New Mexico (2)

AreaForestCoverageHectares
Canjilon Mtn.Carson National Forest1.8%58.68
Pecos WS RiverSanta Fe National Forest1.1%24.57

Oregon (11)

AreaForestCoverageHectares
Castle RidgeWallowa-Whitman National Forest3.1%105.84
Little CreekWallowa-Whitman National Forest2.9%33.12
Upper Grande RondeWallowa-Whitman National Forest2.6%124.47
Lake ForkWallowa-Whitman National Forest2.2%195.66
Jumpoff JoeUmatilla National Forest2.1%47.25
ReservoirWallowa-Whitman National Forest1.5%80.64
Greenhorn Mtn.Umatilla National Forest1.4%62.01
Beaver CreekWallowa-Whitman National Forest1.3%66.15
Upper Catherine CreekWallowa-Whitman National Forest1.3%32.76
Jaussaud CorralUmatilla National Forest1.1%24.93
Twin MountainWallowa-Whitman National Forest1.1%253.71

Utah (11)

AreaForestCoverageHectares
Little West Fork BlacksWasatch-Cache National Forest2.7%90.99
High Uintas (UT)Wasatch-Cache National Forest1.9%789.48
418042Uinta National Forest1.4%40.95
Boulder Mtn. / Boulder Top / Deer LakeDixie National Forest1.3%594.81
Mt. Um Plateau - Mt TerrillFishlake National Forest1.0%68.31
Widdop MountainWasatch-Cache National Forest0.9%30.69
418004Uinta National Forest0.9%63.18
0419020Ashley National Forest0.9%1,344.96
Fishlake MountainFishlake National Forest0.7%74.7
0401005Ashley National Forest0.7%107.37
LakesWasatch-Cache National Forest0.5%241.83

Washington (9)

AreaForestCoverageHectares
Harvey CreekColville National Forest2.0%81.36
Long DrawOkanogan National Forest1.8%28.53
TiffanyOkanogan National Forest1.2%105.21
EntiatWenatchee National Forest1.1%317.7
Stormy Mtn.Wenatchee National Forest0.9%122.4
Myrtle LakeWenatchee National Forest0.8%36.18
Long SwampOkanogan National Forest0.6%168.48
SawtoothOkanogan National Forest0.4%219.87
Liberty BellOkanogan National Forest0.3%145.26

Wyoming (46)

AreaForestCoverageHectares
Campbell LakeMedicine Bow-Routt National Forest7.0%200.97
Libby FlatsMedicine Bow-Routt National Forest7.0%313.47
Snowy RangeMedicine Bow-Routt National Forest6.5%780.03
Nugent Park - Hams Fork RidgeBridger-Teton National Forest4.6%391.68
Pass CreekShoshone National Forest4.2%104.13
French CreekMedicine Bow-Routt National Forest3.8%91.44
Hideout CreekBighorn National Forest3.4%140.94
West Slope WindsBridger-Teton National Forest3.4%1,987.65
Sibley LakeBighorn National Forest3.4%141.03
Middle ForkShoshone National Forest2.4%511.11
Canyon CreekShoshone National Forest2.4%73.8
Carson LakeShoshone National Forest2.3%40.14
East Fork EncampmentMedicine Bow-Routt National Forest2.3%68.13
Middle ForkMedicine Bow-Routt National Forest2.2%120.15
Platte River AdditionMedicine Bow-Routt National Forest2.0%66.06
Illinois CreekMedicine Bow-Routt National Forest2.0%54.72
Togwotee PassShoshone National Forest2.0%58.14
Bruce MountainBighorn National Forest1.9%41.58
Riley RidgeBridger-Teton National Forest1.8%35.64
Warm Spring CreekShoshone National Forest1.8%45.72
Mosquito Lake - Seven LakesBridger-Teton National Forest1.7%358.56
Beartooth Proposed WildernessShoshone National Forest1.7%115.74
Spread Creek - Gros Ventre RiverBridger-Teton National Forest1.6%1,105.65
Doyle CreekBighorn National Forest1.6%41.4
Cloud Peak ContiguousBighorn National Forest1.5%689.22
Huston Park AdditionMedicine Bow-Routt National Forest1.3%45.9
Sheridan PassShoshone National Forest1.3%44.82
Encampment River AdditionMedicine Bow-Routt National Forest1.3%26.55
North MountainBridger-Teton National Forest1.3%50.67
Lake Alice - Commissary RidgeBridger-Teton National Forest1.3%843.48
Gros Ventre MountainsBridger-Teton National Forest1.2%514.71
Piney CreekBighorn National Forest1.1%98.46
Pacific Creek - Blackrock CreekBridger-Teton National Forest1.1%108.81
Hazelton PeaksBighorn National Forest1.1%43.74
Strawberry CreekMedicine Bow-Routt National Forest1.1%25.56
Little Sheep MountainBridger-Teton National Forest1.1%60.93
South Beartooth HighwayShoshone National Forest0.9%400.86
Dunoir Special Management UnitShoshone National Forest0.8%101.52
South Wyoming RangeBridger-Teton National Forest0.8%284.76
Rock CreekMedicine Bow-Routt National Forest0.8%62.37
Salt River RangeBridger-Teton National Forest0.7%659.34
Walker PrairieBighorn National Forest0.6%150.66
Bear RocksBighorn National Forest0.6%56.79
Grayback RidgeBridger-Teton National Forest0.5%649.53
Devils CanyonBighorn National Forest0.5%76.68
Gannett Hills - Spring CreekBridger-Teton National Forest0.5%88.38
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.