85 

 Lecture 19, August 11, 1900. 



2. xs£fi£li2£il(i .laaaii. 



Pound coifliiionly along exposed shores ; least nifirled in liarl;ors. 



Ex. Fire Island. 



1. A case where "t)eacli is encroaching upon the shore. 



a. BqIqw low t.lde complete subiaergenoe, flora not xerophytio. 



On a protected heach, flora is 



"b. Below hi.-:h tide . Alternation of submergence and dry land. Here 



we find xerophytio plants forms of Algae. 



c. Lower ueach from high tide line to that of liifjliest summer storms. 



* • 



During most of year conditions excessively xeropliytic, preventing 

 water forms, while the occasional suhmergence prevents xerophytic 

 typf5s, so this is a desert 2one. In very wet seasons and in spring 

 Algae sometimes grows here. 



d. Middle "beach from limit of summer to limit of winter storms. 

 This is quiescent in sumiaer, hence Annuals can grow there. Salsola, 

 Cakile, Xanthium, etc. 



e. Up^3er beach or fossil beach, above line of storms, so-called 

 since it once was a beach. Here perennials may grow. A'-iiraophila, 



Lathyrus, etc. 



f. Dunes . A wind-blown structure while beach is wave-produced. 

 Dime sand more uniform and finer than beach sand. Heavier elements, 

 not blown up to form dunes as seen in the garnet if erous and magnltite 

 sands on the beach at Fire Island. 



