14] 



VEGETATIONAL TYPES OF TROPICAL LANDS 



469 



characteristically blanketing the trunks and also hanging from 

 almost every possible point, so that they create far more of a ' show ' 

 than in the three-storied rain forest— hence the name of ' mossy 

 forest ' frequently applied to such types. 



Fig. 162. — P'piphytes on trunk of tree near upper limit of montane rain forest 

 in the Philippine Islands. 



Often the subalpine zone is little marked, except by reduction 

 in the size of the trees and in their foliage which may gradually 

 acquire a morexeromorphic structure, or, in some cases, be deciduous. 

 In time, as we ascend, only a single storey is left, corresponding to 

 the lowest tree one of the tropical rain forest. Often it is exceedingly 

 mossy. As the trunks of the trees become shorter and relatively 

 thicker, the branches tend to enlarge, at least in proportion, until 

 growth becomes irregular as elfin wood is reached. In this the 

 trees are twisted and stunted, being especially low and grotesque 

 in the extreme forms known as ' Krummholz ', though still commonly 

 festooned with Mosses etc. (Fig. 163). This elfin wood and finally 

 Krummholz marks the termination of the forest and the beginning 

 of the treeless alpine zone which is vegetated by scrub, tundra, and 



