You are here

Invasive Species

Forested Wetlands

Cottonwood floodplain forest, Sand Island, Multnomah County

Cottonwood floodplain forest, Sand Island, Multnomah County
(John A. Christy, PSU Oregon Biodiversity Information Center)

Forested wetlands (see also Fens and Serpentine fens) and riparian forest occur on seasonally or perennially wet flats or slopes, depressions, or stream terraces. Forested wetlands, sometimes called swamps, may be hydrated from groundwater discharge or inflowing streams, and sometimes occur within riparian zones. Forested wetlands differ from riparian forest in their higher water tables, longer duration of soil moisture, finer-textured soils, and are typically flooded for several weeks during the growing season (seasonal flooding). In contrast, riparian forest usually has surface water for only a few days during a flood (temporary flooding), coarse sediment or cobbled soils that may desiccate by the end of the growing season, and disturbance to both vegetation and stream channels from flooding.

Forested Wetlands Map

Forested Wetlands Map

Habitat: Edges of rivers, streams, lakes and ponds, edges and interiors of peatlands, or larger expanses in basins and flats
Water regime: Perennial, seasonal, or temporary flooding
Water chemistry: Brackish or fresh

Ecoregion*: BM = Blue Mountains, BR = Northern Basin and Range, CB = Columbia Basin, CR = Coast Range, EC = East Cascades, KM = Klamath Mountains, WC = West Cascades, WV = Willamette Valley
Scientific & Common Name Global & State Rank Ecoregion*
wetland type image Abies amabilis / Oplopanax horridus Swamp Forest
Pacific silver fir / devil's club (NS)
G5S4 CR, WC
wetland type image Abies amabilis / Vaccinium ovalifolium Riparian Forest [Provisional]
Pacific silver fir / early blueberry (Murray 2000: 40; McCain 2004: 176)
G3S2 WC
wetland type image Abies grandis / Acer glabrum Riparian Forest
Grand fir/ mountain maple (Crowe et al. 2004: 304; Wells 2006: 54; NS)
G3S2 BM
wetland type image Abies grandis / Athyrium filix-femina Riparian Forest
Grand fir / lady fern (Crowe et al. 2004: 363, 423; NS)
G3S3 BM
wetland type image Abies grandis / Crataegus douglasii / Carex leptopoda Riparian Forest [Provisional]
Grand fir / Douglas hawthorn / slender-foot sedge (Wells 2006: 51)
G1S1 BM
wetland type image Abies grandis / Gymnocarpium disjunctum Riparian Forest [Provisional]
Grand fir / western oak fern (Crowe et al. 2004: 366)
G2S2 BM
wetland type image Abies grandis / Senecio triangularis Riparian Forest
Grand fir / arrowleaf groundsel (NS)
G3S3 BM, EC
wetland type image Abies grandis / Symphoricarpos albus Riparian Forest
Grand fir / common snowberry (Crowe et al. 2004: 307; NS)
G3S2 BM
wetland type image Abies grandis / Taxus brevifolia Riparian Forest
Grand fir / Pacific yew (Wells 2006: 49; NS)
G2S1 BM
wetland type image Abies grandis / Trautvetteria caroliniensis Forest
Grand fir / false bugbane (Murray 2000: 27, 28; Crowe et al. 2004: 320, 369; NS)
G3S3 BM
wetland type image Abies lasiocarpa / Athyrium filix-femina Riparian Forest [Provisional]
Grand fir / lady fern (Crowe et al. 2004: 416)
G2S2 BM
wetland type image Abies lasiocarpa / Carex aquatilis var. aquatilis Swamp Forest
Subalpine fir / aquatic sedge (NS)
G4S4 BM
wetland type image Abies lasiocarpa / Rhododendron columbianum Swamp Forest
Subalpine fir / western Labrador tea (Crowe et al. 2004: 408, 412, 414; NS)
G4S2 BM
wetland type image Abies lasiocarpa / Trautvetteria caroliniensis Swamp Forest
Subalpine fir / false bugbane (NS)
G3S3 BM
wetland type image Abies lasiocarpa - Picea engelmannii / Calamagrostis canadensis Swamp Forest
Subalpine fir - Engelmann spruce / bluejoint reedgrass (Crowe et al. 2004: 421; NS)
G5S4 BM, EC
wetland type image Abies lasiocarpa / Senecio triangularis / Micranthes odontoloma Forest [Provisional]
Subalpine fir / arrowleaf groundsel
G4S3 BM, EC
wetland type image Abies lasiocarpa - Picea engelmannii / Menziesia ferruginea - Vaccinium scoparium Riparian Forest
Subalpine fir - Engelmann spruce / fool's huckleberry - grouseberry (Wells 2006: 40; NS)
G3S1 BM
wetland type image Abies lasiocarpa / Vaccinium membranaceum / Valeriana sitchensis Riparian Forest
Subalpine fir / thin-leaved huckleberry / Sitka valerian (McCain 2004: 168; Wells 2006: 42; NS)
G3S1 BM, WC
wetland type image Acer macrophyllum / Acer circinatum Riparian Forest [Provisional]
Bigleaf maple / vine maple (McCain 2004: 119, 137)
G3S3 WC
wetland type image Acer macrophyllum / Acer circinatum - Corylus cornuta Riparian Forest [Provisional]
Bigleaf maple / vine maple - California hazelnut (McCain 2004: 139, 141, 143, 146)
G3S3 WC
wetland type image Acer macrophyllum / Corylus cornuta - Rubus spectabilis Riparian Forest [Provisional]
Bigleaf maple / California hazelnut - salmonberry (McCain 2004: 242)
G3S3 CR
wetland type image Acer macrophyllum / Symphoricarpos albus / Urtica dioica ssp. gracilis Riparian Forest
Bigleaf maple / common snowberry / northwest nettle (McCain 2004: 254, 261, 263, 279; NS)
G3S3 WV
wetland type image Alnus rhombifolia alluvial bar Riparian Forest [Provisional]
White alder (Crowe et al. 2004: 351)
G3S3 BM, BR, CB
wetland type image Alnus rhombifolia / Acer circinatum Riparian Forest [Provisional]
White alder / vine maple (Crowe et al. 2004: 361)
G1S1 EC
wetland type image Alnus rhombifolia / Betula occidentalis Riparian Forest
White alder / water birch (Crowe et al. 2004: 359; NS)
G1S1 BM, BR, CB
wetland type image Alnus rhombifolia / Carex nudata Riparian Forest [Provisional]
White alder / torrent sedge (Crowe et al. 2004: 353)
G1S1 BM, CB
wetland type image Alnus rhombifolia / Celtis reticulata Riparian Forest [Provisional]
White alder / netleaf hackberry (Crowe et al. 2004: 356; NS)
G1S1 BM, CB
wetland type image Alnus rhombifolia / Cornus sericea Riparian Forest
White alder / red-osier dogwood (Crowe et al. 2004: 357, 360; Wells 2006: 72, 74)
G2S2 BM, BR, CB, EC
wetland type image Alnus rhombifolia / Philadelphus lewisii Riparian Forest
White alder / Lewis' mockorange (Crowe et al. 2004: 354; Wells 2006: 72, 74; NS)
G1S1 BM, BR, CB
wetland type image Alnus rubra / Athyrium filix-femina - Asarum caudatum Swamp Forest
Red Alder / lady fern - wild ginger (Crowe et al. 2004: 377; NS)
G1S1 BM
wetland type image Alnus rubra / Athyrium filix-femina - Lysichiton americanus Swamp Forest
Red alder / lady fern - yellow skunk cabbage (Murray 2000: 41; Christy 2004: 21; NS)
G3S3 CR, WC, WV
wetland type image Alnus rubra / Cornus sericea Riparian Forest [Provisional]
Red alder / red-osier dogwood (Crowe et al. 2004: 381)
G2S2 BM, EC, WC
wetland type image Alnus rubra / Elymus glaucus Riparian Forest
Red alder / blue wildrye (McCain 2004: 74; NS)
G4S3 WC
wetland type image Alnus rubra / Oplopanax horridus - Rubus spectabilis Riparian Forest
Red alder / devil's club - salmonberry (Murray 2000: 43; McCain 2004: 161; NS)
G4S3 WC
wetland type image Alnus rubra / Oxalis (oregana, trilliifolia) Riparian Forest
Red alder / (Oregon oxalis, trillium-leaved oxalis) (McCain 2004: 105, 123, 126, 129, 131; NS)
G4S4 CR, WC, WV
wetland type image Alnus rubra / Petasites frigidus var. palmatus Riparian Forest
Red alder / sweet coltsfoot (Crowe et al. 2004: 379; NS)
G4S3 BM, EC, WC
wetland type image Alnus rubra / Physocarpus capitatus - Philadelphus lewisii Riparian Forest
Red alder / Pacific ninebark - Lewis' mockorange (Crowe et al. 2004: 375; NS)
G1S1 BM, EC, WC
wetland type image Alnus rubra / Rubus spectabilis Riparian Forest
Red alder / salmonberry (NS)
G4S4 CR, WC, WV
wetland type image

Alnus rubra / Rubus spectabilis / Carex obnupta - Lysichiton americanus Riparian Forest
Red alder / salmonberry / slough sedge-yellow skunk cabbage (Christy 2004: 22; NS)

G3S3 CR, WC, WV
wetland type image Alnus rubra / Symphoricarpos albus Riparian Forest [Provisional]
Red alder / common snowberry (Crowe et al. 2004: 382; Wells 2006: 69)
G2S1 BM
wetland type image (Alnus rubra - Abies amabilis) / Rubus spectabilis - Vaccinium ovalifolium / Lysichiton americanus Riparian Forest [Provisional]
(Red alder - silver fir) / salmonberry - early blueberry / skunk cabbage (McCain 2004: 170)
G2S2 WC
wetland type image Alnus rubra - Acer macrophyllum / Rubus spectabilis Riparian Forest
Red alder - bigleaf maple / salmonberry (Murray 2000: 42; McCain 2004: 78, 80, 90)
G4S3 WC
wetland type image (Alnus rubra - Populus trichocarpa) / Rubus spectabilis / Hydrophyllum tenuipes Riparian Forest [Provisional]
(Red alder - black cottonwood) / salmonberry / Pacific waterleaf (McCain 2004: 269)
G2S2 WV
wetland type image Callitropsis nootkatensis / Oplopanax horridus Forest
Alaska yellow cedar / devils club swamp (NS)
G3S2 WC
wetland type image Fraxinus latifolia / Carex leptopoda - Urtica dioica ssp. gracilis Riparian Forest
Oregon ash / slender-foot sedge - northwest nettle (Christy 2004: 24; NS)
G1S1 WV
wetland type image Fraxinus latifolia / Carex aquatilis var. aquatilis Riparian Forest [Provisional]
Oregon ash / water sedge (Christy 2004: 23)
G1S1 WV
wetland type image Fraxinus latifolia / Carex obnupta Riparian Forest
Oregon ash / slough sedge (Murray 2000: 44; Christy 2004: 25; NS)
G4S4 WV
wetland type image Fraxinus latifolia / Juncus patens Riparian Forest
Oregon ash / spreading rush (NS)
G2S2 KM, WV
wetland type image Fraxinus latifolia / Spiraea douglasii Riparian Forest
Oregon ash / Douglas spiraea (Christy 2004: 26; NS)
G3S3 WV
wetland type image Fraxinus latifolia / Symphoricarpos albus Riparian Forest
Oregon ash / common snowberry (Christy 2004: 27; NS)
G4S4 WV
wetland type image Fraxinus latifolia - Populus trichocarpa / Acer circinatum Riparian Forest
Oregon ash - black cottonwood / vine maple (McCain 2004: 267; NS)
G3S3 WV
wetland type image Fraxinus latifolia - Populus trichocarpa / Corylus cornuta - Physocarpus capitatus Riparian Forest
(Oregon ash - black cottonwood) / California hazelnut / Pacific ninebark (McCain 2004: 257; NS)
G2S2 WV
wetland type image Fraxinus latifolia - (Populus trichocarpa) / Cornus sericea Riparian Forest
Oregon ash (black cottonwood) / creek dogwood (NS)
G4S4 CR, WV
wetland type image Fraxinus latifolia - Populus trichocarpa / Rubus spectabilis Riparian Forest
Oregon ash-black cottonwood / salmonberry (McCain 2004: 271; NS)
G2S2 WV
wetland type image Fraxinus latifolia - Populus trichocarpa / Symphoricarpos albus Riparian Forest
(Oregon ash - black cottonwood) / common snowberry (McCain 2004: 281; NS)
G2S2 WV
wetland type image Picea engelmannii / Bromus vulgaris Riparian Forest [Provisional]
Engelmann spruce / Columbia brome (Crowe et al. 2004: 436)
G2S2 BM
wetland type image Picea engelmannii / Carex angustata Swamp Forest
Engelmann spruce / widefruit sedge (Crowe et al. 2004: 433, 442; NS)
G3S3 EC
wetland type image Picea (engelmannii x glauca, engelmanii) / Carex disperma Swamp Forest
Engelmann spruce / softleaf sedge (Crowe et al. 2004: 431; NS)
G3S2 BM, EC
wetland type image Picea engelmannii / Cornus sericea Swamp Woodland
Engelmann spruce / creek dogwood (Crowe et al. 2004: 438; NS)
G3S3 BM
wetland type image Picea engelmannii / Equisetum arvense Swamp Forest
Engelmann spruce / field horsetail (Crowe et al. 2004: 428; NS)
G4S3 BM, EC
wetland type image Picea engelmannii / Senecio triangularis Swamp Forest
Engelmann spruce / arrowleaf groundsel (Crowe et al. 2004: 425; Wells 2006: 46; NS)
G3S3 BM, EC
wetland type image Picea engelmannii / Vaccinium uliginosum Swamp Forest
Engelmann spruce / bog bilberry (Crowe et al. 2004: 410, 440; Wells 2006: 38, 44; NS)
G3S3 BM, EC
wetland type image Picea sitchensis / Carex obnupta - Lysichiton americanus Swamp Forest
Sitka spruce / slough sedge - yellow skunk cabbage swamp (Christy 2004: 28; NS)
G2S1 CR
wetland type image Picea sitchensis / Cornus sericea / Lysichiton americanus Swamp Forest
Sitka spruce / creek dogwood - skunk cabbage (Christy 2004: 29; NS)
G2S1 CR
wetland type image Picea sitchensis / Oplopanax horridus Riparian Forest
Sitka spruce / devil's club (NS)
G4S3 CR
wetland type image Pinus contorta var. contorta / Carex obnupta Forest
Shore pine / slough sedge swamp (Christy 2004: 31; NS)
G2S2 CR
wetland type image Pinus contorta var. latifolia / Calamagrostis canadensis Swamp Forest
Lodgepole pine / bluejoint (Crowe et al. 2004: 462; NS)
G5S3 BM, EC
wetland type image Pinus contorta var. latifolia / Carex (aquatilis var. aquatilis, angustata) Swamp Woodland
Lodgepole pine / (aquatic sedge, widefruit sedge) (Crowe et al. 2004: 457, 459; NS)
G4S3 BM, EC
wetland type image Pinus contorta var. latifolia / Deschampsia caespitosa Swamp Forest
Lodgepole pine / tufted hairgrass (Crowe et al. 2004: 463; NS)
G3S3 BM, EC
wetland type image Pinus contorta var. latifolia / Spiraea douglasii Forest
Lodgpole pine / Douglas spiraea (Crowe et al. 2004: 451; NS)
G3S3 EC
wetland type image Pinus contorta var. latifolia / Vaccinium uliginosum Forest
Lodgepole pine / bog bilberry woodland (Crowe et al. 2004: 447, 449; NS)
G3S3 EC, WC
wetland type image Pinus contorta var. latifolia - Populus tremuloides / Spiraea douglasii Swamp Forest
Lodgpole pine - quaking aspen / Douglas spiraea (Crowe et al. 2004: 390, 392, 454; NS)
G3S3 EC
wetland type image Pinus monticola / Deschampsia cespitosa Riparian Forest
Western white pine / tufted hairgrass (Crowe et al. 2004: 372; NS)
G1S1 BM
wetland type image Pinus ponderosa / Crataegus douglasii Riparian Woodland
Ponderosa pine / Douglas hawthorn (Crowe et al. 2004: 324; Wells 2006: 60; NS)
G2S2 BM, CB, EC
wetland type image Pinus ponderosa / Symphoricarpos albus Riparian Woodland
Ponderosa pine / common snowberry (Crowe et al. 2004: 321, 373; NS)
G2S2 BM, EC
wetland type image Populus tremuloides / Alnus incana Riparian Forest
Quaking aspen / mountain alder (Crowe et al. 2004: 395; NS)
G3S2 BM, BR, CB, EC
wetland type image Populus tremuloides / Alnus incana - Betula glandulosa - Ribes spp. Riparian Forest
Quaking aspen / mountain alder - bog birch - currant (NS)
G1S1 BM
wetland type image Populus tremuloides / Alnus incana - Salix spp. Riparian Forest
Quaking aspen / mountain alder - willow (NS)
G4S3 BM
wetland type image Populus tremuloides / Betula occidentalis Riparian Forest
Quaking aspen / water birch (Crowe et al. 2004: 398; NS)
G3S2 BM, BR, CB
wetland type image Populus tremuloides / Calamagrostis canadensis Riparian Forest
Quaking aspen / bluejoint reedgrass (Crowe et al. 2004: 388; NS)
G3S3 BM, EC
wetland type image Populus tremuloides / Carex aquatilis var. aquatilis Riparian Forest
Quaking aspen / aquatic sedge (Crowe et al. 2004: 384; NS)
G1S1 BM, CB
wetland type image Populus tremuloides / Carex obnupta Riparian Forest
Quaking aspen / slough sedge (Christy 2004: 33; NS)
G2S1 WV
wetland type image Populus tremuloides / Carex pellita Riparian Forest
Quaking aspen / woolly sedge (Crowe et al. 2004: 385; NS)
G2S2 BM, BR, EC
wetland type image Populus tremuloides / Cornus sericea Riparian Forest
Quaking aspen / creek dogwood (Crowe et al. 2004: 396; NS)
G4S3 BM, BR, CB, EC
wetland type image Populus tremuloides / Prunus virginiana Forest
Quaking aspen / western chokecherry (Crowe et al. 2004: 399; NS)
G3G4 BR
wetland type image Populus tremuloides / Symphoricarpos albus Forest
Quaking aspen / common snowberry (Crowe et al. 2004: 401; NS)
G3S2 BM, BR, EC
wetland type image Populus tremuloides / Symphoricarpos albus / Elymus glaucus Woodland
Quaking aspen / common snowberry / blue wildrye (Crowe et al. 2004: 404; NS)
G3S2 BM, BR, EC
wetland type image Populus tremuloides / tall forbs Forest
Quaking aspen / tall forbs (Crowe et al. 2004: 406; NS)
G5S3 BM, BR, CB, EC
wetland type image (Populus tremuloides) / Crataegus douglasii / Heracleum maximum Wet Shrubland
(Quaking aspen) / Douglas hawthorn / cow parsnip (NS)
G1S1 CB
wetland type image (Populus tremuloides) / Crataegus douglasii - Symphoricarpos albus Wet Shrubland
(Quaking aspen) / Douglas hawthorn - common snowberry (Crowe et al. 2004: 180; Wells 2006: 110, 112; NS)
G3S2 CB
wetland type image (Populus tremuloides) / Crataegus douglasii - Symphoricarpos albus Wet Shrubland
(Quaking aspen) / Douglas hawthorn - common snowberry (Crowe et al. 2004: 180; Wells 2006: 110, 112; NS)
G3S2 CB
wetland type image Populus trichocarpa / Acer glabrum Riparian Forest [Provisional]
Black cottonwood / mountain maple (Crowe et al. 2004: 343)
G2S2 BR
wetland type image Populus trichocarpa / Alnus incana Riparian Forest
Black cottonwood / mountain alder (Crowe et al. 2004: 339, 349, 350; Wells 2006:64; NS)
G3S2 BM, BR, EC
wetland type image Populus trichocarpa / Betula occidentalis Riparian Forest [Provisional]
Black cottonwood / water birch (Crowe et al. 2004: 335)
G2S2 CB, BM, BR
wetland type image Populus trichocarpa / Cornus sericea Riparian Forest
Black cottonwood / creek dogwood (NS)
G3S3 BM, BR, CB, EC
wetland type image Populus trichocarpa / Cornus sericea / Lysichiton americanus Riparian Forest
Black cottonwood / creek dogwood / yellow skunk cabbage (Christy 2004: 32; NS)
G3S3 CR, WV
wetland type image Populus trichocarpa / Crataegus douglasii Riparian Forest
Black cottonwood / Douglas spiraea (Crowe et al. 2004: 337; NS)
G1S1 BM, CB, EC
wetland type image Populus trichocarpa / Philadelphus lewisii Riparian Forest [Provisional]
Black cottonwood / Lewis' mockorange (Crowe et al. 2004: 333)
G3S3 BM, BR, CB, EC
wetland type image Populus trichocarpa / Salix exigua Riparian Forest
Black cottonwood / narrow-leaved willow (NS)
G1S1 BM, BR, CB
wetland type image Populus trichocarpa / Salix lasiolepis Riparian forest [Provisional]
Black cottonwood / arroyo willow (Crowe et al. 2004: 327)
G3S1 BR
wetland type image Populus trichocarpa / Salix lasiandra var. caudata Riparian Woodland
Black cottonwood / greenleaf willow (Crowe et al. 2004: 325, 328; NS)
G2S2 BM
wetland type image Populus trichocarpa / Salix spp. Riparian Woodland
Black cottonwood / willow (NS)
G4S2 BM, BR, CB
wetland type image Populus trichocarpa / Symphoricarpos (albus, oreophilus, occidentalis) Riparian Forest
Black cottonwood / snowberry (Murray 2000: 44; Crowe et al. 2004: 346; Wells 2006: 66; NS)
G2S2 BM, CB, EC, WC
wetland type image Populus trichocarpa - Acer macrophyllum / Equisetum hyemale Riparian Forest
Black cottonwood - bigleaf maple / scouring rush (McCain 2004: 256; NS)
G3S3 WV
wetland type image Populus trichocarpa - Alnus rhombifolia Riparian Forest
Black cottonwood - white alder (Crowe et al. 2004: 331; NS)
G1S1 BM, BR, CB, WV
wetland type image Pseudotsuga menziesii / Acer glabrum Riparian Forest
Douglas fir / mountain maple (Crowe et al. 2004: 309; Wells 2006: 56; NS)
G4S2 BM, EC
wetland type image Pseudotsuga menziesii / Betula occidentalis Riparian Woodland
Douglas fir / water birch (Crowe et al. 2004: 313; NS)
G3S2 BM, CB, EC
wetland type image Pseudotsuga menziesii / Symphoricarpos albus Forest
Douglas fir / common snowberry (Crowe et al. 2004: 315, 317; Wells 2006: 58; NS)
G5S3 BM, CB, EC, WC
wetland type image Quercus garryana - (Fraxinus latifolia) / Symphoricarpos albus Forest
Oregon white oak - (Oregon ash) / common snowberry (McCain 2004: 274, 283; Buechling et al. 2008: 9; NS)
G2S2 WC
wetland type image Thuja plicata / Athyrium filix-femina Forest
Western red cedar / common lady fern (NS)
G3S2 WC
wetland type image Thuja plicata - Acer macrophyllum - Abies grandis / (Oemleria cerasiformis) / Polystichum munitum Forest
Western red cedar - bigleaf maple - grand fir / osoberry / sword fern (McCain 2004: 285; NS)
G1S1 WV
wetland type image Thuja plicata - Tsuga heterophylla / Lysichiton americanus Swamp Forest
Western red cedar - western hemlock / skunk cabbage (Murray 2000: 45; McCain 2004: 173; Christy 2004: 34; NS)
G3S1 CR, WC, WV
wetland type image Thuja plicata - Tsuga heterophylla / Oplopanax horridus Rocky Mountain Swamp Forest
Western red cedar - western red cedar / devils club (NS)
G3S1 BM
wetland type image Tsuga heterophylla / Acer circinatum / Lysichiton americanus Swamp Forest
Western hemlock / vine maple / skunk cabbage swamp (NS)
G4S4 CR, EC, WC
wetland type image Tsuga heterophylla - (Thuja plicata) / Oplopanax horridus / Polystichum munitum Forest
Western hemlock - (western red cedar) / devils club / sword fern (McCain 2004: 156, 158, 161, 165)
G4S4 WC

Authored by John A. Christy, Wetlands Ecologist, (ORBIC) Oregon Biodiversity Information Center (2012 rev. 2017)

randomness