Table 8, 



Comparison of biomass of smooth and 

 California cordgrasses in laboratory 

 experiments [Barko and Smart, 1976). 



Species 



Ground 

 levels 



Biomass^ fg/m^ 



) 





Sand 



Silty clay 



clay 



Smooth 

 Cordgrass 



Above ground 

 Below ground 



Totals 



112 

 143 



255 



1,131 



773 



1,904 



3,056 

 1,614 



4,670 



California 

 Cordgrass 



Above ground 

 Below grouhd 



Totals 



36 

 109 



145 



83 

 112 



195 



390 

 355 



743 



-^Means of two replicates. 



VI 1. CONCLUSIONS 



1. At the end of the 1976 growing season (November), biomass of the 

 aerial parts of 23 natural cordgrass marshes averaged 1,062 grams per 

 square meter. The average density of stems was 650 per square meter and 

 average stem height was 0.79 meter. This is comparable with measurements 

 made in smooth cordgrass marshes in North Carolina. 



2. Seeding was not effective in stabilizing an eroding shoreline in 

 San Francisco Bay. 



3. Plugs were more tolerant to wave activity than sprigs; however, 

 neither technique will stabilize eroding banks in San Francisco Bay 

 unless the plants are protected from waves. 



4. Plugs from cordgrass-mussel communities are the most useful for 

 bank stabilization in the absence of wave protection. Cordgrass-mussel 

 bioconstructs survived and spread during the 1-year study in an area 

 exposed to a 7-kilometer fetch. Further observation is needed to deter- 

 mine if this planting method will lead to long-term bank stability. 



36 



