GRAZING RANGES IN SOUTHERN ARIZONA. ae 
If allowance is made for the facts (1) that these pastured areas 
produce more feed than other parts of the area under observation, 
(2) that they are carrying more under the present form of manage- 
ment than they would if an average number of animals were kept 
on them continuously, and (3) that there is some indication that they 
are slightly overstocked, it 1s seen that the results obtained from the 
pasturing experiments are in reasonably close agreement with the 
average for the whole reserve derived by other means and presented 
elsewhere in this bulletin. (See p.'21 et seq.) 
MISCELLANEOUS NOTES. 
The effects of fire-—The complete protection of the reserve for a 
number of years has resulted in a rather heavy crop of dry grass, 
which burns readily, especially in the dry, hot weather of May or 
June, just before the summer rains begin. Several such fires have 
occurred, due to lightning, carelessness of passers, or incendiarism. 
The only serious damage they do is to burn off the fence posts and 
let the fences fall. These fires are always extinguished as quickly 
as possible after they start, but sometimes considerable areas have 
been burned over. Attention has been called to the effect on the 
mesquite bushes. The spines of the cacti are usually singed off, and 
some of the stems blistered, and a few are killed. Opuntia spinosior 
seems to suffer more seriously than any of the other species. In 
June, 1914, occurred one of the largest and hottest fires, which 
burned over about four sections of the heaviest grass. Along the 
arroyos where the grass was highest and thickest the mesquite 
bushes were killed completely in several places, and many were 
killed back to stumps. The following growing season on the burned 
area there was a much larger proportion of annuals in the summer 
collections and a particularly noticeable abundance of one grass, 
Bouteloua parryi, which has not been observed in any abundance 
recently. It was common in many parts of the reserve in the earlier 
years of the experiment. Whether or not the burn was responsible 
for these occurrences the writer is unable to say. The fire was doubt- 
less responsible for a noticeable decrease in the hay crop obtained on 
part of the burned area this season.t Of the grasses, Bouteloua 
erippoda and Heteropogon contortus suffered most, though old stools 
of Aristida divaricata also showed retardation and some killing. 
The mesquite bean crop—An important part of the forage of this 
region is furnished by the herbage and flowers of the cat’s-claw 
(Acacia greggit) and the mesquite (Prosopis velutina), as well as by 
beans of the latter. Two measurements were made of the crop of 
mesquite beans from medium-sized trees in 1914. The blossoming 
1 See Table IV, p. 24: Proctor’s records for 1914. 
