RE VEGETATION OF TAAL VOLCANO 199 



hracteata were characteristic of the more open high slopes. 

 Acacia farnesiana, Tabernaemontana subglobosa, Pithecolobium 

 dulce, Macaranga tanarius, Antidesma ghaesembilla, Psidium 

 guajava, Trema amboinensis, Ficus ulmifolia, Cordia myxa, 

 Casearia cinerea, Bridelia stipidaris, and Callicarpa blancoi 

 dominated at lower elevations. In October, 1913, but one shrub 

 {Ficus indica) was present on the outside of the crater wall above 

 150 meters. In April, 1914, a few shrubs of Acacia farnesiana, 

 Ficus indica, and Wendlandia luzoniensis were present on the 

 north rim of the crater and the high ridge, known as Mount 

 Pinag-Ulbuan, leading northeast from it. A small bush of 

 Ficus indica was growing on a ledge inside the crater some 50 

 meters below the rim. 



The invasion of shrubs was general, taking place on the crests 

 as well as on the sides of ridges. The crests of ridges present 

 severe xerophytic conditions and are usually invaded only by 

 such species as Ficus indica. Acacia farnesiana, and Tabernae- 

 montana subglobosa. By October, 1913, the pioneer shrubs were 

 themselves bearing seeds. The shrub grows up with the grass 

 and spreads out over it. The resulting shade leads to the 

 elimination of the grass and thus facilitates both the further dis- 

 tribution of shrubs and the invasion of trees. The spread of 

 shrubs from such centers of distribution leads to the develop- 

 ment of parang — thicket-like growth — and the final exclusion of 

 the cogon grasses By April, 1914, this had been accomplished 

 in a few places, notably in the region of the northeast cape. A 

 large number, of shrubs, many vines and lianas and a few trees 

 had converted the area into a jungle. 



In the short time thus far elapsed, only a few tree species were 

 present. Trema amboinensis and Cordia myxa, small parang 

 trees, were most abundant. Their dominance was complete in 

 certain places in the northern parts of the island. 



It was quite e\ddent that the trend of vegetation is towards 

 the development of a tree cover over the greater part of the 

 island. From bare ground, both grass and parang usually pre- 

 cede the development of trees. By April, 1914, the tree form of 

 vegetation was further represented by seedlings and small trees 



