USUAL CONDITIONS = HYPERSALINE SOILS 



Habitat becomes available for 

 colonization. 



Opportunistic species invade by seed 

 ( Salicornia virginica , S^. bigelovii , 

 Suaeda cal ifornica ). ~ 



Sal icornia virginica achieves early 

 dominance due to 



--high growth rates under 

 saline conditions 



--vegetative spread 



--perennial growth 



channel 



FLOODS OR HEAVY RAINFALL EVENTUALLY OCCUR 



Germination of halophytes is stimulated. 



Spartina foliosa may establish patches 

 if a nearby source is available. 



Spartina fol iosa may spread 

 vegetatively, especially at 

 lower elevations. 



LONG PERIODS OF HYPERSALINITY FOLLOW, INTERRUPTED BY OCCASIONAL WET YEARS 



Species distributions continue to 

 shift in response to environmental 

 changes; Sal icornia retains competitive 

 advantage under more saline conditions. 



Spartina foliosa expands substantially 

 during years of less saline conditions 

 and at lower elevations. 



A mixture of species results, with Spartina 

 foliosa restricted to the lower marsh. 



Figure 31. Conceptual model of species establishment and spread in southern 

 California salt marshes. 



39 



