will be influenced by factors such as (1) the care taken by the planter, (2) 

 the occurrence of severe storms, (3) the impact of foot and vehicular traffic, 

 and (4) the wildlife predation. 



As noted earlier, fetch, shore configuration, and sediment grain size 

 appear to be useful indicators of wave climate severity and the potential of 

 planting success. The relationship between these parameters (Figs. 12 to 15) 

 and success in controlling erosion (successful or partially successful) have 

 been condensed into a single form, the Vegetative Stabilization Site 

 Evaluation Form (Fig. 16). This allows the user to estimate the potential 

 success rate of plantings made under conditions similar to the site being 

 evaluated. The user measures each shore characteristic (item 1) for the area 

 in question, identifies the descriptive categories (item 2) which best 

 describe the area, notes the success rate (item 3) associated with each 

 descriptive category, calculates a cumulative score (item 4), and interprets 

 the cumulative score by noting the corresponding success rate (item 5). The 

 major advantage of this system is that it is easy to use. 



The reader is cautioned that the evaluation form is used only for evaluat- 

 ing wave climate. Other shore conditions and characteristics discussed 

 earlier in this section must also be considered in the total site evaluation 

 process. 



IV. SELECTING PLANT SPECIES, PLANT MATERIALS, AND PLANTING TECHNIQUES 



1. Selecting Plant Species. 



a. Principal Species . In the planting of salt marsh for the protection 

 of eroding shorelines, the intertidal zone is critical. This is the region in 

 which erosion normally begins; continuing erosion of the lower slopes in this 

 region will undermine and weaken well-stabilized upper slopes. Consequently, 

 the primary emphasis will be on the planting and management of the few spe- 

 cially adapted species found useful for this purpose. Often the establishment 

 and maintenance of a healthy band of intertidal salt or brackish marsh along a 

 shore will eventually result in the natural growth of vegetation on the slope 

 behind it. 



Four species of pioneer plants have demonstrated potential in stabilizing 

 the part of the intertidal zone which is in direct contact with waves. Smooth 

 cordgrass iSpartina dltemiflova) is an effective erosion control plant along 

 the gulf and Atlantic coasts. Pacific cordgrass {Spavtina foliosa) is 

 effective on the southern Pacific coast from Humboldt Bay, south to >fexico, 

 and Lyngbye's sedge {Cavex lynghyei) and tufted hairgrass {Besdhampsia 

 aaespitosa) are effective for stabilization in the northern Pacific coast from 

 Humboldt Bay to Puget Sound. Detailed planting specifications for these 

 principal species are given in Section VI. 



b. Other Useful Species . There are cases in which the planting of an 

 entire slope is advisable to control erosion caused by storm surges, surface 

 runoff, and wind, or is desirable for esthetic or other reasons. Planting can 

 restore vegetation on the slope immediately above the high tide line when 

 damage has occurred during site preparation. Planting will be required in 

 some instances as protection against runoff from adjacent uplands. Several 



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