et ay Oh a ee ae. Tae ie ee ae 
667 
_ 
The 5 kilometers of coast line pertaining to the Lamao Reserve offers 
insufficient data for a true conception of the vegetation of the seashore 
of the Philippines, yet in this very situation a dilute expression of all 
the formations of the strand which have been made classic by the work 
of Schimper and others may be encountered. In order to render clear 
the genetic relations of these formations it is advisable to make use of 
data gathered outside of the area under consideration, and then to 
classify the stages in the development found at Lamao. 
The material composing the beaches either is derived from rocky 
promontories or is washed into the sea by streams. If the shore cur- 
rent and waves are sufficiently strong to handle all this material then 
no accretion to the shore line takes place, but if, on the other hand, 
as is more often the case, the shore current can not bring this about, 
then an encroachment of the land on the sea results with a consequent 
development of new habitats for plants. If the shore current can not 
take care of the finer particles of the material eroded from cliffs or 
washed in by rivers, then obviously the heavier ones settle on the strand. 
Thus the size of the material composing the beach is determined by the 
power the current possesses of controlling the suspended matter carried 
by it, and, as a consequence, pebbly, sandy, or muddy shore lines may 
result. On some strands the very force which prevents the deposit of 
fine particles, excludes the growth of nearly all vegetation between the 
lines of low and high tide, so that, with the exception of scattered sea- 
weeds, these places are destitute of vegetation. On the other hand, 
where the hydrodynamic conditions favor the deposit of materials lighter 
than sand, then they are also favorable for the establishment and growth 
of vegetation. In such places the characteristic formation not found 
anywhere outside of tropical countries is developed. ‘Therefore, it will 
be seen that because of the physiographic forces at work along shores, 
two distinct habitats are established. Following Schimper, with some 
minor changes, the vegetation corresponding to these may be divided 
into— 
1. Sandy beaches lying above high tide. 
(a) Pes-capre formation. 
(b) Barringlonia-Pandanus formation. 
2. Strand, lying below high tide. 
(a) Mangrove and Nipa formations behind sandy beaches. 
(b) Mangrove and Nipa formations not behind sandy beaches. 
a. Formations at the mouths of rivers. 
8B. Formations at the base of cliffs. 
1. SANDY BEACHES, ABOVE HIGH TIDE. 
(a) The Pes-capre formation.—The beach is built up most rapidly 
at the mouths of rivers. In the case of the Lamao River, for instance, 
two spits are at present being formed, one on each side; at high tide, 
