Active erosion along the middle part of these crescents was ob- 

 served before planting. Waves had undercut the turf, leaving a verti- 

 cal scarp. A few loads of sand dumped along the eroding face provided 

 a plantable upper slope. The two bays were machine-planted about 2 

 weeks later [Figs. 21 and 22). 



The plantings in both bays were unusually successful. Survival 

 was excellent and growth was substantially above average (Fig. 23). 

 The superior growth was apparently due to nutrient supply coming from 

 the adjacent golf fairway and green. The best growth and greenest 

 plants were in the rows nearest the turf; vigor decreased with in- 

 creasing distance from the turf. Growth on bay 2, which was adjacent 

 to a green, was substantially better than that on bay 1, which border- 

 ed the less heavily fertilized fairway. The soil is sandy under both 

 the green and the fairway which lie 1 or more feet higher than the 

 plantings. The movement of nutrients, particularly nitrogen, into the 

 plantings is inevitable. An ample nutrient supply seemed important to 

 the rapid establishment of these plantings. 



The primary objective of this planting was to test the feasibility 

 of reestablishing marsh along shoreline that was eroding too rapidly 

 for the natural occurrence of revegetation. The appearance of the 

 plants in early April 1975 (Figs. 24 and 25) , supported by culm den- 

 sity counts (Table 10) , showed that these plantings were highly suc- 

 cessful. Marsh restoration was feasible and the resumption of erosion 

 in these bays is unlikely. 



V. MINERAL NUTRITION 



1 . Laboratory Studies . 



The roots of Spartina alterni flora normally grow under waterlogged 

 conditions. The plants' ability to produce substantial quantities of 

 dry matter under these conditions implies that the roots can function 

 effectively under low ambient oxygen concentration and when ammonium 

 is the dominant inorganic nitrogen form available. The following ex- 

 periments were undertaken to determine whether these conditions are 

 optimal for growth. The results indicate that they are. Aeration of 

 the root system and exposure to nitrate nitrogen were both detrimental. 



a. Experiment 1 . After germination, plants were transferred to a 

 nutrient solution culture of either an ammonium (NHi+) , a nitrate, or 

 an ammonium plus nitrate nitrogen supply (Table 1) . For each nitrogen 

 source, 20 plants were placed in each of two 4-liter containers, half 

 of which were aerated. All solutions were stirred with a magnetic 

 stirring bar in the bottom of the pot. Nitrogen concentrations were 

 monitored weekly and adjusted to maintain the levels given in Table 1. 

 The plants were grown in a growth chamber at a 16-hour day length and 

 a 29.4° Celsius temperature, and maintained with 1,500-foot candles at 

 the surface of the containers followed by an 8-hour dark period and a 

 temperature of 23.9° Celsius. 



42 



