UPLAND 



Spring or Storm Tide 

 Daily Higli Tide 



switchgrass 

 high-tide bush 



black grass 



salt hay cordgrass 



spikegrass 



salt marsh aster smooth cordgrass 



glasswort (ta" 'o'"'") 



smooth cordgrass 

 (short form) 



V 



IRREGULARLY FLOODED MARSH 



Fig. 6. Cross-sectional diagram of a Northeastern salt marsh. 



REGULARLY 



FLOODED 



MARSH 



V 



INTERTIDAL 

 FLAT 



ESTUARINE 



OPEN WATER 



(BAY) 



salinity areas. Tidal flats appear at low tide largely as 

 unvegetated expanses of mud or sand, although micro- 

 scopic plants like diatoms, bluegreen algae and dinofla- 

 gellates may be extremely abundant (Figure 7). On 

 occasion, macroscopic algae like sea lettuce may locally 

 dominate these flats. These wetlands are particularly ex- 

 tensive in areas with high tidal ranges such as Alaska and 

 Maine. 



Estuarine Scrub-Shrub Wetlands 



Estuarine scrub-shrub wetlands are characterized by 

 salt-tolerant woody vegetation less than 20 feet in height. 

 Common estuarine shrubs along the Atlantic and Gulf 

 coasts are high-tide bush and sea myrtle. Estuarine shrub 

 wetlands are perhaps best represented by mangrove 

 swamps, which have a limited distribution in the U.S. 





,^-. 



Cowardin et al 





Cowardin et al 



Fig. 7. Examples of estuarine intertida! flats, (a) Alaska and (b) Virginia. 



