2 BULLETIN 580, U. S. DEPARTMENT OF AGRICULTURE. 
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Ss. . A Approx area of the two states... |51000.000A 
ee Ve Lo VA pprox area. of WesternYellow Pine 8800,000A. 
Fig. 1.—Yellow pine in Arizona and New Mexico. 
SCOPE AND METHOD OF STUDY. 
An intensive study was made on the Coconino National Forest, 
in the north-central portion of Arizona, where grazing and timber 
conditions are typical of the forests of the Southwest, and where 
the problem of securing satisfactory timber reproduction is often 
serious. This was supplemented by general observations, covering 
a period of two years, on other Forests in Arizona and New Mexico. 
The observations were confined chiefly to the yellow-pine type, but 
for purposes of comparison some observations were made in the 
Douglas fir and pifon-juniper types. 
Early in the season of 1910 a preliminary reconnaissance was 
made on the Coconino Forest. This was followed during that year 
by a detailed study, in which observations were made upon 150 plots. 
Further observations were made in 1912 on additional plots. - Alto- 
gether 250 plots were observed within a radius of 25 miles of Flag- 
staff, in the heart of the Forest. 
The plots were located so as to include the following range condi- 
tions: 
(1) Areas embracing all conditions of range normally grazed by 
different classes of stock. 
(2) Areas embracing all conditions of range overgrazed by dif- 
ferent classes of stock. 
(3) Areas supporting a good stand of forage normally grazed by 
all classes of stock. 
(4) Areas supporting a poor stand of forage normally grazed by 
all classes of stock. 
(5) Areas supporting chiefly bunch grasses, grazed by different 
classes of stock. 
(6) Areas where cattle congregate. 
