The Ohio Naturalist. 
[Vol. VIII, No. 6' 
318 
THE BEACH-SAXD PLAIN-HEATH-FOREST SUCCESSION. 
This is the more common succession on the Cedar Point sand 
plain where the habitat is of several years duration. It is 
doubtful, if this succession were introduced onto the Bar Section, 
that it could reach maturity. In che Dune Section the heath 
and forest stages are essentially identical with the dunes and 
blowouts and, as the former often merge imperceptibly into the 
latcer two formations the discussion of these stages will be 
taken up in connection with the discussion of the dune and 
blowout vegetation. 
THE DUNE AND BLOWOUT SUCCESSIONS. 
Under the above heading may be included a number of second¬ 
ary formations which, taken together, make up most of the vege¬ 
tation of the Dune Section of Cedar Point, ds Moseley has 
pointed out, 18 this part of the peninsula represents a portion of 
the original mainland upon which has been heaped the loose 
sand, coincident with the rise of the w aters of the Lake. There 
can be no doubt that the land was originally covered here with 
forest, probably an Ulmus-Acer forest formation, which later 
perhaps gave way to marsh vegetation but upon which, still 
later, has been heaped the loose sand bringing about conditions 
suitable for the present dune and blowout formations. 
The Ammophila Fringing-Dune Formation. 
Along most of the Lake shore of the Dune Section the Drift 
Beach extends up to a w T ell-marked Ammophila fringing dune. 
This species of grass has the ability to grow upwards for a number 
of feet if continuously buried more deeply by accumulating sand 
and as the sand accumulates around the ever higher obstruction 
a gently sloping ridge is finally built up. The height of such a 
dune or ridge is determined by the height to which the grass can 
grow vertically, the amount of obstruction which it offers the 
drifting sand, and, finally, the force of the wind w r hich tends to 
tear the dune down again. 
The structure of the Ammophila Fringing-Dune Formation is 
quite simple: 
Facies: Ammophila arenaria. 
Principal Species: Psilocyhe ammophila. 
Secondary Species: 
Euphorbia polygonifolia, Andropogon scoparius, 
Artemisia caudata , Strophostyles helvola, 
Cakile edentula, Panicum virgatum, 
Salix interior. 
18. Moseley, E. L. 1. c. pp. 220—223. 
