596 JOURNAL OF FORESTRY 



agement even though undesirable species predominated for the time 

 being. 



The foregoing statement refers to progressive or positive succession. 

 In the case of a range of maximum cover of desirable forage species 

 it would, of course, be preferred to interfere as little as possible, con- 

 sistent with maximum utilization, with the existing type of vegetation. 

 However, should the use of the range be such as to break up the sta- 

 bility of the climax cover, retrogressive or negative succession would 

 show itself, the rapidity and magnitude of which would depend upon 

 the extent to which the growth requirement of the vegetation was in- 

 terfered with. The element of instability of the permanent type 

 would become apparent, first by the disappearance of the most palatable 

 species, and later by the invasion of early maturing transitory species. 



In the event that the range is properly provided with quadrats 

 or sample plots and the normal density and composition of the vege- 

 tative cover known, one would be provided with data which would 

 show clearly the extent of progressive or retrogressive succession, 

 whichever the case might be, and the rate of improvement or depre- 

 ciation. 



Knowledge of the successional trend of the vegetation is well 

 nigh indispensable to the working out of a judicious system of man- 

 agement. Thus the management of grazing lands, like that of wood- 

 lands, is gradually being placed upon a scientific basis in which applied 

 ecology, and particularly succession, plays a prominent and highly im- 

 portant part. 



