schematic of the plot arrangement is shown in Figure 7. Percent sur- 

 vival, stem height, and stem density were determined in each plot during 

 monitoring periods in December 1977, and February and June 1978. 



V . RESULTS 



1 . Survey of Natural Cordgrass Marshes . 



a. General Observations . California cordgrass naturally establishes 

 in the middle to upper intertidal zone by either seed dispersal or the 

 fortuitous introduction of a dislodged plant with root or rhizomal tissue. 

 Individual plants spread laterally by rhizomal growth with new shoots 

 emerging up to 50 centimeters from the parent plant. New shoots grow 

 rapidly and often sprout one to five' or more basal shoots which generally 

 emerge within 1.5 centimeters of the parent shoot. Inflorescent (seed 

 head) development begins in August and seed dispersal occurs in November. 

 Most of the inflorescent-bearing culms dieback by January or February. 

 Most of the seed crop undergoes germination in February and March. Ver- 

 nal growth in established plants also begins during this period. Aerial 

 stems are present during all seasons. 



Plants exposed to strong wave action are generally stunted in appear- 

 ance. This may result from high stem mortality and continuous replacement 

 of lost stems with new shoots. 



b. Survey Results . Table 3 summarizes the data obtained from survey 

 of 23 natural marshes in November 1976. The average number of stems per 

 square meter area ranged from 224 to 1,460. Aerial biomass ranged from 

 367 to 2,030 grams per square meter area for the 23 sites. Mean stem 

 height ranged from 55 to 100 centimeters with a mean height of 79 centi- 

 meters. 



2 . Laboratory Studies on Seed Germination . 



Laboratory germination studies indicate that California cordgrass 

 seeds have twice the germination rate and also germinate faster in fresh- 

 water than in solutions of 10, 20, 30 parts per thousand saltwater (Fig. 

 8). Similarly, Mooring, Cooper, and Seneca (1971) noted that freshwater 

 stimulates the germination of smooth cordgrass (Spartina alterniflora) . 

 It may be assumed that under natural conditions seeds produced in the fall 

 either float in bay water or are deposited with debris in the strand line. 

 Winter rains cause a temporary reduction of salinity near the bay and 

 tributaries and probably stimulate seed germination. 



Laboratory studies also show that seed collected in November and 

 stored in 40 parts per thousand saltwater reached peak germination in 

 May (Fig. 9). This "after ripening" has also been observed in studies 

 of smooth cordgrass. A delay in peak germination in natural stands of 

 cordgrass until late winter or early spring, when climatological condi- 

 tions and salinities are more favorable, is an advantage to plant 

 survival. 



20 



