ALPINE COMMUNITIES 



253 



side of a high mountain one encounters variations in climate com- 

 parable to those encountered in going north or south from the 

 equator and these variations in climate lead to a recognition of more 

 or less definite belts of vegetation. Usually four of these belts or 

 zones of vegetation can be recognized, the lowermost being called 

 basal, the second montane, the third subalpine, and the fourth, or 

 uppermost, alpine. The basal zone consists of vegetation that is 

 similar to that of the adjacent plain or valley. The montane zone 

 is usually more luxuriant than the basal and ordinarily consists of 



Fig. 115.— Pinusjiexilis at timber line on Long's Peak, Colorado. 



by Raymond J. Pool.) 



(Photograph 



forest communities, either deciduous or coniferous. The subalpine 

 zone is more xeric. It consists largely of coniferous forest, but the 

 trees are dwarf and at timber line form the characteristic "elfin 

 timber" (Fig. 115). There are also frequent open spaces which are 

 occupied by grasses and flowering plants. Above the tree line is 

 found the true Alpine meadow which becomes more and more dwarf 

 as it ascends the mountain. The brilliance and profusion of bloom 

 encountered in the Alpine meadows cannot be matched anywhere 

 else. If the mountain is not too high the Alpine meadow may cover 



