Salt marshes and brackish marshes occur in the intertidal zone of coastal estuaries. They are dominated by salt-tolerant herbaceous plants and are usually intermixed with intertidal mudflats that are rich with invertebrates and seaweeds. Farther inland in an estuary, salinity becomes diluted by fresh water from rivers and streams, and a gradual transition to freshwater plants and animals occurs, and woody vegetation becomes more evident. The Cowardin Classification identifies the transition from Estuarine to Riverine and Palustrine systems at points where salinity drops to less than 0.5 parts per thousand (ppt). This transition zone is a moving target in upper estuaries, and is influenced by seasonal or episodic river flows and fluctuations in daily tidal cycles. With the anticipated rise in sea level associated with global climate change, many salt and brackish marshes may become permanently inundated, and their landward edges will advance into what are currently freshwater marshes, shrub swamps, and uplands. The estuarine-freshwater transition zone will also migrate upriver with rising sea level.
Habitat: Edges of estuaries, tidal rivers, and tidal streams
Water regime: Subtidal, tidal, regularly to irregularly flooded
Water chemistry: Saline to brackish
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* | ||
Bolboschoenus maritimus Salt Marsh [Provisional] Seacoast bulrush (Eilers 1975: 225) |
G3S2 | CR | ||
Carex lyngbyei Salt Marsh Lyngby sedge (NS) |
G4S3 | CR | ||
Carex lyngbyei - Potentilla anserina ssp. pacifica Salt Marsh Lyngby sedge - Pacific silverweed (NS) |
G4S2 | CR | ||
Carex lyngbyei - (Distichlis spicata, Triglochin maritima) Salt Marsh Lyngby sedge - (saltgrass, arrow grass) (NS) |
G4S2 | CR | ||
Carex obnupta - Potentilla anserina ssp. pacifica Brackish Marsh Slough sedge - Pacific silverweed (Christy et al. 1998: 108; NS) |
G4S4 | CR | ||
Deschampsia cespitosa - Potentilla anserina ssp. pacifica Salt Marsh Tufted hairgrass - Pacific silverweed (NS) |
G3S2 | CR | ||
Deschampsia caespitosa - Juncus balticus Brackish Marsh [Provisional] Tufted hairgrass - Baltic rush (Taylor 1980: 71) |
G4S2 | CR | ||
Distichlis spicata - Potentilla anserina ssp. pacifica Salt Marsh [Provisional] Saltgrass - Pacific silverweed (Christy et al. 1998: 124) |
G3S2 | CR | ||
Distichlis spicata - (Sarcocornia perennis) Salt Marsh Saltgrass - (pickleweed) (NS) |
G4S2 | CR | ||
Juncus balticus - Carex obnupta Brackish Marsh [Provisional] Baltic rush - slough sedge (Taylor 1980: 57; Kunze 1994: 22) |
G4S4 | CR | ||
Juncus falcatus - Trifolium wormskjoldii Wet Meadow Sickle-leaved rush - springbank clover (NS) |
G4S3 | CR | ||
Lonicera involucrata / Potentilla anserina Brackish Shrub Swamp [Provisional] Black twinberry / Pacific silverweed (Brophy 2007) |
G3S2 | CR | ||
Picea sitchensis / Lonicera involucrata - Malus fusca Wet Brackish Swamp Forest [Provisional] Sitka spruce / black twinberry - western crabapple (Brophy et al. 2011) |
G3S2 | CR | ||
Potentilla anserina ssp. pacifica - Juncus balticus Salt Marsh Pacific silverweed - Baltic rush (NS) |
G3S2 | CR | ||
Potentilla anserina ssp. pacifica - Symphyotrichum subspicatum Brackish Marsh Pacific silverweed - Douglas aster (NS) |
G3S2 | CR | ||
Ruppia maritima Aquatic Vegetation Beaked ditch-grass (NS) |
G2S2 | CR | ||
Salix hookeriana / Potentilla anserina ssp. pacifica - Carex obnupta Wet Shrubland [Provisional] Hooker willow / Pacific silverweed - slough sedge (Christy et al. 1998: 76) |
G4S4 | CR | ||
Sarcocornia perennis - Distichlis spicata - Triglochin maritima (Jaumea carnosa) Salt Marsh Pickleweed - saltgrass - arrow grass (fleshy jaumea) (NS) |
G3S2 | CR | ||
Schoenoplectus acutus Marsh Hardstem bulrush (Christy 2004: 141; Crowe et al. 2004: 70; NS) |
G5S5 | CR | ||
Schoenoplectus pungens (estuarine) Salt Marsh [Provisional] Common three-square (Christy et al. 1998: 128, as S. americanus) |
G3S2 | CR | ||
Triglochin maritima - (Sarcocornia perennis) Salt Marsh Arrow grass - (pickleweed) (NS) |
G4S2 | CR | ||
Zostera marina Pacific Aquatic Vegetation Eelgrass (NVC) |
G5S3 | CR |