GEAZIN"G EAjSTGES I^ST SOUTHEEISr AEIZOjSTA. 5 



areas of certain species, and probably of the associations, had been 

 much displaced by the previous grazing conditions to which the 



Fig. 8. — Map of the Santa Rita Range Reserve, Ariz., sliowingthepresent distribution of the 

 principal forage-plant associations : No. 1, The six-weeks-grass association. No. 2. The 

 blacli-grama association. No. 3. Tlie crov/foot-grama association. No. 4. The needle- 

 grass association. No. 5. The oak belt. No. 6. The forested area. Those parts of 

 the reserve upon which the mesquite {Prosopis velutina), the cat's-claw (Acacia greggli) , 

 and other shrubs or low trees occur, more or less abundantly, are indicated by dots 

 (No. 7") on the map. In the same way, the crosses (No. 8) and the cheek marks 

 (No. 9) sljow where the tree cactus (Opuntia spinosior) and the cholla (Opuntia 

 fulfjida) are important members of the plant associations (PI. I, fig. 2). 



region had been subjected, and that under the protection of the fence 

 these plants have been and are still readjusting themselves to the 

 normal ecologic conditions. Maps of this kind made at various in- 



