CHAPTER VI 

 PLANT GROWTH IN DRY AREAS 



In some respects plant growth in dry areas is, of 

 course, the same as in humid areas. The laws that govern 

 the processes of growth are the same the world over. 

 but the results may be widely different from the opera- 

 tion of those laws, because of modifications in their ap- 

 plication. These modifications are the outcome of 

 changed conditions. The leading characteristics of plant 

 growth peculiar to dry areas will be discussed in this 

 chapter. 



Some features peculiar to such growth. These in- 

 clude the following: (1) It is more sparse than in humid 

 areas. (2) It is more or less dwarfish. (3) It tends 

 to abundant fruitage. (4) It is made chiefly in the early 

 season. (5) It is less certain than in humid areas. 



The evidences of sparseness of growth in dry areas 

 are more or less present in all portions. The grass plants 

 are less numerous relatively on a given area. Even the 

 sage brush shrubs grow at some distance from one an- 

 other. A dense covering of grass such as results from 

 the growth of blue grass in moist situations is seldom 

 or never met with, nor is the land covered by a thick 

 growth of bushes save in proximity to streams, or that 

 are in some way supplied with ground water. So in- 

 variably is such sparse growth present that the degree 

 of the same furnishes a fairly reliable index of the amount 

 of the precipitation. The soil also, of course, has some 

 influence on the density or sparseness of the growth. 

 Such growth is a wise provision of nature to proportion 

 growth to the number of plants so that each may have 

 enough moisture to enable it to reproduce itself. It is 

 on the same principle that production which is the out- 

 come of cultivation is more satisfactory when the plants 



