LONG ISLAND VEGETATION 



201 



line. The dominant species are Fucus vesiculosus and Ascophyl- 

 lum nodosum. These brown leathery much-branched rockweeds 

 are conspicuous at all seasons of the year. They probably consti- 

 tute nine-tenths of the bulk of the formation. Their relative posi- 

 tions do not seem to be constant in this vegetation belt. At 

 Coopers Bluff for example the lower portion of the formation is 

 dominated by Ascophyllum, the upper by Fucus. At the head of 

 the harbor on the sea walls just the reverse is true in places. At 

 Coopers Bluff the associated plants of the lower levels are Enter- 

 omorpha clathrata, Ceramiuvi rubrum, and Rhabdonia tenera. 

 Growing abundant^ on the Ascophyllum as epiphytes are Melo- 

 sira granulata, Ceramium strictum, Polysiphonia fastigiata, and 

 Ectocarpus siliculosus. In the upper portion of the belt the most 

 conspicuous secondary species is Porphyra laciniata. 



At Lighthouse Point, Eatons Neck, in addition to the dominant 

 plants the following occm*: Ectocarpus littoralis, Enteromorpha 

 clathrata, Porphyra laciniata, Punctaria latissima, Ceramium rub- 

 rum, and Gracilaria multipartita. Kemalion multifidum and Clad- 

 ophora sp. are added to this list on the rocks of Lloyds Beach 

 beyond the lighthouse. In the inner harbors Monostroma is a 

 constant associate extending nearly into fresh water areas. 



In the outer harbors and along the Sound where rocks and piers 

 give some protection from the waves and deposition is taking 

 place, this formation is gradually encroached upon by the salt 

 reed grass (Fig. 4). Fucus and Gracilaria are among the last 

 plants to disappear. In all fully exposed situations the upper 

 portion of the lower beach is destitute of vegetation and the suc- 

 cession beyond the Rockweed Formation is interrupted (fig. 5). 



THE PROTECTED LOWER BEACH 



The Spartina-cynosuroides Association. In areas shielded 

 from intense wave action, the lower beach furnishes the habitat 

 for the salt reed grass. It attains its best development just below 

 the line of the neap high tides. With its strong erect stems and 

 closely interwoven roots and rootstocks, it not only withstands 

 considerable wave action but forms an important factor in deposi- 



