i. Summary . 



(1) Plant types - sprigs, pot-grown seedlings, or plugs. 



(2) Plant spacing - 1.0 meter on sheltered sites (10,000 propa- 

 gules per hectare); 0.5 meter on exposed sites (40,000 propagules per 

 hectare) . 



(3) Minimum planting width - no minimum on sheltered sites; for 

 exposed sites 6.0 meters or 60 percent of the intertidal zone, 

 whichever is larger. 



(4) Planting zone - slightly above MLW to MHW where tidal range 

 is less than 2.0 meters; mean tide level (MTL) to MHW where tidal 

 range is greater than 2.0 meters. 



(5) Salinity range - 5 to 35 parts per thousand. 



(6) Optimal planting dates - northern range in April and May; 

 Mid-Atlantic in March, April, and May; southern range in February, 

 March, April, and May. 



(7) Fertilization - 1 to 3 kilonewtons of nitrogen (N) and 1 

 kilonewton of phosphate (P2O5) per hectare. 



2. Pacific Cordgrass {Spavtina fot-iosa) , Southern Pacific Coast . 



This grass is similar in appearance to the smooth cordgrass of the 

 Atlantic and gulf coasts but does not grow quite as tall, is less vigorous, 

 and is slower to establish. Pacific cordgrass (Fig. 24) is the dominant 

 flowering plant in regularly flooded, intertidal marshes from Humboldt Bay 

 southward to Mexico. 



Pacific cordgrass is adapted to inundation and anaerobic soils through its 

 oxygen transport system (Kasapligil, 1976; Wong, 1976; Pride and Lingue, 

 1976). Hollow, air-filled tissue in the stem carries oxygen from the leaves 

 to roots and rhizomes . This mechanism also introduces oxygen into the soil 

 surrounding the root and rhizome system. The plant tolerates salt by excret- 

 ing it through salt glands. 



Two forms of Pacific cordgrass have been identified in San Francisco Bay: 

 a medium, stout form (0.3 to 1.2 meters high) that grows in the lower zone, 

 and a dwarf form (0.2 to 0.3 meter high) that occurs mixed with pickleweed at 

 higher elevations (Mason, 1976). It is not known whether these forms have a 

 genetic basis or are due to environmental features. Short-term field tests 

 suggest that the two forms react differently to elevation (Harvey, 1976). The 

 dwarf form was more successful than the stout form when transplanted in higher 

 zones. A particularly stout, woody form of Pacific cordgrass has been 

 observed in the high intertidal zone in Humboldt Bay, California. It appears 

 to be extremely resistant to wave action and was initially considered to be a 

 species or variety separate from Pacific cordgrass. Gerrish (1979) found that 

 the stout, woody form belongs to the same chromosomal population as Pacific 

 cordgrass. 



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