Figure 5.7. Changes in average height of 

 cordgrass. Means are based on the total 

 number of stems measured each year. 



Figure 5.9. Changes in the density of 

 cordgrass stems. Means are from the number 

 of quadrats in which cordgrass was present 

 each year (Figure 62). 



1 oo 



30 



70- 



1980 



1982 

 Year 



1984 



Figure 5.8. Changes in the maximum height of 

 cordgrass. Means are from the number of 

 quadrats in which cordgrass was present each 

 year. 



September 1983 followed freshwater 

 influence that was of lower volume than the 

 1980 floodflows but of longer duration. 



Finally, in September 1984, we found 

 extremely low TSL due to poor growth and 

 heavy mortality of cordgrass following 

 drought conditions. The effect of drought 

 became even more apparent in 1985, when 

 the lowest TSL was documented. Both density 

 and height were lower than ever before 

 recorded. The delayed reaction of cordgrass 

 TSL measurements was due to the longevity of 

 the plant. Individual stems live 1.5-2.0 

 years, and the 1984 measurements included 

 stems with some live material from the 

 previous growing season. By 1985, there 

 were few plants from the previous year and 

 few individuals from 1985, even though tidal 

 flushing had been reinstated throughout the 

 entire growing season. 



To interpret these variations in cordgrass 

 growth requires consideration of the effects of 

 hydrological change on pickleweed, because 

 pickleweed is the competitive dominant 

 (Zedler 1982; Covin 1984) and its 

 distribution overlaps with cordgrass 

 throughout most of the lower marsh. Years of 

 high pickleweed cover were 1979, 1981, and 

 1984-85 (Figure 5.4). These same years 

 had low cordgrass biomass. Cordgrass TSL can 

 be high when two conditions are met. First, 



1 1 



