ix, c, b Gates: Pioneer Vegetation of Taal Volcano 417 
represented on the volcano in the vicinity of the former town, 
Pirapiraso, by a number of plants of Gliricidia senium, occurring 
in the grassland as parts of the parang association rather than 
as a separate consocies. The plants show more than usual 
xeromorphy. 
The Morinda consocies . — On Taal Island, Morinda bracteata 
fills a somewhat different role than customary. In addition 
to being one of the dominant species in the general parang, 
it characterizes a consocies which invades unvegetated ground in 
the eastern and southern parts of the island. In appearance 
it differs from Ficus indica in being dark green. It alternates 
with Ficus indica in pioneer parang invasion, but the distri- 
bution of Morinda on the island is more limited. It differs from 
Ficus indica in readily being assimilated as a unit in general 
parang. 
TREE CONSOCIES 
The Trema consocies . — The Trema consocies is one of a group 
of parang consocies in which small trees rather than shrubs 
are the dominant species. While this consocies may invade open 
ground, and frequently invades grassland, it is particularly suc- 
cessful in young thickets. The dominant species, Trema am- 
boinensis, is a very rapid grower and a very intolerant tree. 
Once started it soon outstrips other trees and then may obtain 
dominance in the area. If it were more tolerant, it might 
establish itself longer and better, but it seldom lasts more than 
one generation as a dominant tree. More usually this tree does 
not obtain controlling dominance in an area, but is only one 
among several trees, coming into notice so particularly on ac- 
count of its very rapid growth which gives it a decided start. 
The tree seeds abundantly and sprouts easily. Although there 
are large numbers of seedlings in certain of the ash-covered 
slopes of the northern side of the island the largest trees, many 
of which are from 25 to 30 cm in diameter and 7 meters high, 
are sprouts which have come up from old trees buried beneath 
the ash. This was particularly demonstrated along an erosion 
channel which was filled with ash which was later washed away 
exposing sprouts 20 cm in diameter from a trunk 35 cm in 
diameter. The Trema consocies becomes mixed up with others 
before very long and so merges into the general parang, which 
may include trees of Trema for a long time. 
The Cordia consocies . — The consocies dominated by the tree 
Cordia myxa is present on a number of the northern slopes, being 
established on the sides of ridges just below the crest, where 
