2 BULLETIN 34, U. S. DEPARTMENT OF AGRICULTURE. 
The serious decline in the carrying capacity of vast tracts of west- 
ern range lands can be traced almost wholly to failure to recognize 
the primary requirements of plant growth. During the " free-for- 
all " grazing period of earlier days the most palatable species were so 
closely cropped that they were unable to develop the necessary plant 
food, and so literally starved. In addition, the roots were frequently 
injured by trampling or killed by exposure. As a result, the best 
kinds of vegetation grew weaker from season to season, and, where 
the practice of early and close grazing was continued, the range at 
last became practically denuded. 
Fortunately, on the majority of Xational Forest lands not only ex- 
cessive grazing before the forage crop was mature but also continued 
close grazing was done away with before the vegetation was entirely 
killed out, although in many localities the best species had given way 
to less desirable ones. The discontinuance of premature grazing and 
overstocking, combined with improved methods of handling stock 
under Government regulations, has resulted in the improvement of 
range lands within the National Forests to the point where it is again 
possible to market large numbers of beef and mutton animals directly 
from the range — a thing which in many places could not be done 
during the last few years prior to the inclusion of the lands within 
Xational Forests. 
In order to know exactly how to maintain a satisfactory forage 
crop, and how to manage lands in need of improvement in the best 
and most economical way, a study was inaugurated by the Forest 
Service in 1907, in cooperation with the Bureau of Plant Industry, 
in which the life cycle of the leading range plants on sheep lands 
within the Wallowa Mountains of northeastern Oregon was carefully 
observed. This bulletin points out how, through carefully consider- 
ing the growth requirements and methods of reproduction of the 
forage plants, the carrying capacity of the range lands may be still 
further increased without decreasing the number of stock which use 
them. Statements and conclusions are based upon results secured 
from three years of careful study and two seasons of practical appli- 
cation in range management. The subject will be taken up in two 
parts: (1) The natural growth requirements of range plants; and 
(2) a grazing system, based upon these requirements, which will 
insure a maximum forage crop. 
REQUIREMENTS OF PLANT GROWTH. 
As it affects grazing management, the life cycle of forage plants 
may best be discussed under the following heads: (1) The produc- 
tion of foliage in the early growing season: (2) the production of 
flower stalks and seed crop; (3) the scattering and planting of seed; 
and (4) the establishment of seedling plants. 
