1.6 SUMMARY OF CHAPTER 1 



Southern California coastal marshes 

 are confined to narrow stream outlets 

 along a coastline of rugged topography and 

 continuing geological activity. The 

 Mediterranean climate of the region 

 provides little rainfall, on the average, 

 so that tidal sea water is the major 

 source of moisture throughout all but the 

 brief winter wet season. 



Sand, deposited by longshore 

 currents, tends to build up along the 

 ocean inlets, and wetlands with small 

 tidal prisms are likely to become 

 completely closed to tidal circulation. 

 Various land use practices reduce tidal 



prisms, which in turn increase the 

 probability and duration of lagoon 

 closure. 



Extreme variations in intertidal soil 

 salinities occur between years of flooding 

 and drought. Lagoon closures cause 

 additional variability in salinity. Large 

 areas of southern California marsh habitat 

 are hypersaline throughout the spring to 

 fall growing season. The wide-ranging 

 salinities and long periods of hypersaline 

 conditions contrast greatly with brackish 

 tidal marshes elsewhere in the United 

 States. 



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