solution. What particular features must 

 coastal plants possess to stabilize 

 dunes? They must have physiological and 

 morphological features that enable them 

 to live in the relatively severe habitat 

 at the land-sea interface. 



What have we accomplished along the 

 North Carolina coast in the last 15 yr 

 in terms of stabilizing the unstabilized 

 dune areas and in building dunes in some 

 areas where we thought they should be 

 placed? American beachgrass occurs nat- 

 urally around the Great Lakes and along 

 the Atlantic coast from Nova Scotia to 

 northern North Carolina. It is the prin- 

 cipal grass used to build and stabilize 

 dunes along the Atlantic coast, includ- 

 ing areas southward of its natural dis- 

 tribution. Why? Because it is relative- 

 ly easy to propagate in the nursery, is 

 relatively easy to handle and prepare 

 for transplanting, grows rapidly after 

 planting, has a relatively long growing 

 season compared to other grasses, and is 

 a very efficient sand-trapper and dune 

 builder. Nursery-grown strains of Amer- 

 ican beachgrass have been field-tested 

 for superior vigor under localized con- 

 ditions in both New Jersey and North 

 Carolina. Selections have been made 

 based on these tests and locally adapted 

 varieties are now available through com- 

 mercial growers. 



What about fertilization response? 

 Dune grasses respond favorably to fer- 

 tilization. The primary response is to 

 nitrogen with a minor response to phos- 

 phorus and little or no response to po- 

 tassium. A 30-10-0 fertilizer is recom- 

 mended, applied at the rate of about 23 

 kg/ha (50 lb/acre). Do not apply more 

 than this amount of nitrogen at a time. 

 Any amount in excess of this will, in 

 all probability, be leached from the 

 soil. Granulated fertilizers are readi- 

 ly available and easy to apply with a 

 cyclone seeder. Do not put the fertiliz- 

 er on when you plant. Wait until the 

 root systems develop; then apply it on 

 several occasions so that your total may 

 be 68 kg (150 lb) the first growing sea- 

 son. If planting takes place in February 

 or March, apply 23 kg (50 lb) of nitro- 

 gen in late Kay, the same amount in 

 July, and again in August or September. 

 With these split applications, plants 

 are able to make maximum use of the fer- 

 tilizer materials. If you have a large 



area of dune system to fertilize, a 

 helicopter can be used. Pelletized fer- 

 tilizer can be very evenly distributed 

 by helicopter. After the pellets absorb 

 water, they adhere to the sand. 



American beachgrass should not be 

 used alone in dune plantings along the 

 south Atlantic coast. It is less drought 

 tolerant and less tolerant of high tem- 

 peratures than either sea oats or bitter 

 panicum. Further, it is susceptible to 

 a scale insect ( Eriococcus carol inae ) 

 and also a fungal pathogen ( Marasmius ). 

 The fungus, which causes Marasmius 

 blight of American beachgrass, is not 

 known to occur north of North Carolina. 

 Any planting of American beachgrass made 

 south of about Oregon Inlet, North 

 Carolina, will be invaded by sea oats in 

 time, provided that there is a seed 

 supply of sea oats nearby. Usually, in 

 8 to 10 yr after a dune is planted to 

 pure American beachgrass, the beachgrass 

 is replaced by other species, primarily 

 sea oats. Still we use American beach- 

 grass to initiate dunes and provide the 

 initial cover. Why? Because beachgrass 

 establishes quicker and traps sand at a 

 faster rate than any of the other plants 

 available. 



Our major emphasis at present is to 

 determine the best adapted strains of 

 native plants and to determine the best 

 mixture of these plants to use for sta- 

 bilization. We have experienced almost 

 complete failure with saltmarsh cord- 

 grass ( Spartina patens ) except in a few 

 places. It is found on dunes, but does 

 not do well when planted alone. In mixed 

 plantings with sea oats, and sometimes 

 with bitter panicum, it does very well. 



Some of you may wonder why we do 

 not experiment with some other types of 

 plants besides grasses. We are looking 

 at some other species, such as seashore 

 elder ( Iva imbricata ), a succulent- 

 leaved semi-woody plant of the aster 

 family. We are studying its physiology, 

 germination capability, and response to 

 transplanting. In places, seashore 

 elder dominates the dune community, but 

 we do not think that it is a particu- 

 larly good stabilizer and recommend its 

 use only in mixed species plantings. 



Results of mixed species plant- 

 ings have led us to realize their 

 advantages over conventional monocul- 

 tures. A mixed species experimental 



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