iqiq] HARVEY— coniferous SAND DUNE 421 



lower beach occupies a narrow steep margin only a few feet wide. 

 To the immediate west of the spit in South Pond are several iso- 

 lated sand islands (S.I.) mostly covered at high tide. To the west 

 of the dune complex a transitional zone some 50 ft. wide separates 

 it from an extensive salt marsh which is about a foot lower, and 

 whose average width is estimated at 1 200 ft. Several narrow salt 

 water lagoons traverse this area in a north-south direction. Ex- 

 tending out into the marsh some 600 ft. along the eastern border is 

 an area occupied by 10 or 15 old white pine stumps, approximately 

 100 years old, with well exposed roots, and standing in rows more or 

 less parallel to the axis of the spit. The south end of the salt marsh 

 and dune complex are suffering very active erosion under the daily 

 outgoing tidal currents. High tides and occasional storms ap- 

 parently sweep completely over the low duneless extremity of the 

 spit, greatly augmenting this erosion. We may now consider each 

 of these associations in greater detail. 



Middle beach 



The middle beach, which is extremely barren, is composed 

 mostly of a fine sand, but shingle of a coarser nature is not wanting. 

 The usual debris of the middle beach is encountered only to the east 

 of the dune complex (fig. 4). The 3 principal plants are Mertensia' 

 maritima, Euphorbia polygonifolia, and Ammophila arenaria, but 

 all are exceedingly scattered. The only other species noted were 

 Glaux maritima, Lathyrus maritimus, Salsola Kali, Cakile edentula, 

 and these are represented only by occasional individuals. 



Dune complex 



The facies of the dune complex is Picea canadensis with occa- 

 sional Abies balsamea. At the northern end the older trees were 

 estimated at 75 years, while those at the southern, eroding end are 

 scarcely 30-40 years of age. The southern (fig. 5) and eastern 

 fringes of the complex include the highest dunes, which range from 

 3 to 15 ft. above sea level, and are generally margined by a narrow 

 "grassy foredune'' (fig. 6) with its precipitous slope oceanward. 

 The sand binder is Poa compressa, a most unique condition. Am- 

 mophila, although scatteringly present, is of little importance in 



2 Nomenclature of Gray's New Manual, 7th ed. 



