48 



and the abundance of vegetation appears to depend largely upon 

 adequate supply of organic material in the form of drift. Probably 

 the most effective plant in preventing the advance of shingle is the 

 shrubby sea blite (SKO'da fniticosa), which in its reaction to burying 

 by shingle is similar to the pioneer sand-dune plants. The value 

 of this species is very evident on some banks where the regions of 

 landward advance correspond to gaps in the protective zones of 

 Sii(/(la. 



The most conspicuous source of accretion is that due to the 

 action of the Salt Marsh Plants. The earliest colonizers of the 

 sand and mud are in this case filamentous seaweeds that ramify 

 between the submerged soil particles, reducing their mobility and 

 tending to trap further deposit. The algfe are followed by the salt- 

 worts which again give place to such plants as sea aster, sea 

 plantain, thrift, and sea lavender. With the increasing density 

 of vegetation there is a corresponding increase in level, and to this 

 the sea manna grass {Gb/ceria wantima) contributes greatly. Here 

 again, we have a plant that exhibits repeated growth when buried, 

 and the mat-like turf, which its vegetative organs form, is not only 

 an eflScient trap for further additions of silt, but also an admirable 

 protection for that already deposited. Eventually the level is raised 

 above that of all but the highest tides, so that further rise is de- 

 pendent upon the slower accumulation of organic debris, or in some 

 cases silt carried down by drainage from the land. The Salt Marsh 

 flora eventually becomes replaced by that of the mainland. Such 

 low-lying reclaimed land is to be seen around many parts of our 

 coast furnishing some of the best pasturage in the country. 



