The fact that nitrogen and phosphorus are the limiting factors in 

 growth of S. alterniflora in some salt marshes has several ecological 

 implications. It is possible that the marsh may act as a buffer for the 

 estuarine system providing a sink for excess nutrients which may stem 

 from municipal wastes and land runoff. In the marsh, excess nutrients 

 would produce increased growth of S. alterniflora which would provide 

 an increased supply of food energy and nutrients to the detritus food 

 chain of the estuary rather than altering energy pathways as often happens 

 when the phytoplankton system receives excess nutrients. This ability 

 of the salt marsh to use more nitrogen and phosphorus may be important 

 in managing estuarine systems. Disposal of wastes high in nutrients 

 (such as sewage effluent) may be less disruptive to the estuarine ecosys- 

 tem if dumped in the salt marsh rather than in open water. With proper 

 management such disposal might actually enhance estuarine productivity. 

 Further research is needed to determine the exact nature of the nutrient 

 cycle in the marsh-estuarine system and the capacity of the marsh to 

 receive excess nutrients. 



Nitrogen and phosphorus fertilizers were shown to enhance growth of 

 seedlings and transplants artificially established on dredged material. 

 Since establishing a substantial vegetative cover rapidly may be critical 

 in stabilizing an area, application of fertilizer may be of some practi- 

 cal benefit. However, the dredge spoil was sandy at both locations; 

 hence, the nutrient-supplying capacity was low. Response to fertilizer 

 would be expected to vary with the inherent fertility of the substrate 

 material . 



VII. PLANTINC SPECIFICATIONS - S. ALTERNIFLORA 

 1. Transplanting . 



a. Plants. Healthy, single stems from uncrowded stands should be 

 used, keeping as much of the root system intact as possible. Rhizomes, 

 small shoots, and flowering stalks from the previous year may be removed 

 or trimmed so as to not interfere with transplanting. Plants from the 

 immediate area are preferable. If they are brought from any great dis- 

 tance, trial plantings should be made to test adaptation. Plants may be 

 stored indefinitely by heeling-in in the intertidal zone. 



b. Planting. Hand- or machine-plant 10 to 15 centimeters (4 to 6 

 inches) deep, taking care that soil is firmed around plant immediately 

 to prevent the plant from "floating out" of hole or furrow. 



c. Spacing. Under average conditions, plants set on 1 -meter center 

 will provide complete cover early in the second growing season. Closer 

 spacings, 0.5 and 0.3 meters (19 and 12 inches), may be warranted on 

 critical sites, keeping in mind that planting costs are in almost direct 

 proportion to the number of plants planted. 



147 



