marshes is more diverse than that on other coasts of the United States and 

 elevation zones are less discrete. There is no single species such as Pacific 

 cordgrass colonizing and dominating the lowermost, regularly flooded zone of 

 this region. The regularly flooded low marshes are characterized by Lyngbye's 

 sedge (Cavex tyngbyei) , tufted hairgrass {Desahampsia aaespitosa) , spike 

 rushes {Eleoahans spp.), pickleweed, three-square bulrush (Sairpus 

 aalifovniaus) , Baltic rush (Junaus baltiaus) , and seaside arrowgrass 

 (Tvigloahin maritima) (Fig. 5). As in the southern Pacific, saltgrass is 

 common in the high marsh but seldom dominant. 



Figure 5. Lyngbye's sedge marsh (Oregon) (photo courtesy 

 of D.L. Higley and R.L. Holton) . 



3. Establishing Coastal Marshes for Shore Stabilization. 



a. Invasion and Recovery in Natural Marshes . In established stands of 

 salt marsh, reproduction is principally vegetative; i.e., new plants arise 

 from the horizontal runners of parent plants. Within these marshes, new 

 growth is sheltered from wave activity by the surrounding vegetation. On 

 unvegetated shores, marsh plants may be established by seed or from fragments 

 of plant material dislodged from existing marshes. During establishment on 

 bare sediments, unsheltered plants are vulnerable to wave attack and mortality 

 is likely to be high. It is this vulnerability to wave attack during the ear- 

 ly stages of establishment that prevents the natural invasion of marsh plants 

 along much of the shoreline. Natural invasion only occurs in very sheltered 

 areas or in relatively exposed areas where plant introduction happens to 

 coincide with an extended period of low wave activity and an absence of severe 

 storms. Even in mature marshes stems are continually broken off by wave 

 action but new shoots arise to replace those lost. Stem density may be great- 

 ly reduced during storms while during periods of relative calm, the density 

 may increase considerably. However, severe storms may cause permanent damage 



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