356 THE FUTURE OF ARID LANDS 
seeding) the grazing animals did not damage the seedlings, but, 
on the contrary, reduced the competition provided by the annuals, 
is a fundamental one and points the way to the improvement of 
the California range.”’ 
Eight years of tests on a livestock ranch confirmed the prelimi- 
nary tests (38, 39, 40, 45). Thus it was that Murphy, Love, and 
Berry (52) were able to recommend grazing methods following 
the biological control of Hypericum perforatum. 
These experiments have brought into focus the fourth element 
of our complex climate-soil-plants-livestock. 
Some of the ecological interrelationships of range plants were 
learned from these experiments. For instance, good stands and 
growth of desirable winter annuals, particularly legumes, reduced 
the succeeding population of summer weeds such as Hemizonia 
spp. and Trichostema lanceolatum (38, 44). The latter can grow 
only in fields where undesirable winter annuals mature before all 
subsurface moisture is exhausted, leaving some available for the 
summer weeds. 
Admitting the importance of increasing drought resistance and 
improving screening procedures, perhaps these are not of the most 
immediate urgency. Even more urgent now is the need to create 
a more favorable environment for the adapted plants already 
available. The way to create this more favorable environment is 
by the application of agronomic principles of crop production to 
range improvement. Consider the complex of range species as a 
crop (with weeds, to be sure) and learn how to harvest this crop 
by livestock. Manage the area to encourage the crop and discour- 
age the weeds. Love and Sumner (45) defined this agronomic 
aspect of range improvement as ‘‘the process of replacing a rela- 
tively undesirable population of plants with a more desirable 
type of forage.” 
In the last decade, particularly, men trained in fields other than 
ecology have taken an increasing interest in range improvement. 
New concepts are being developed. A typical purely ecological 
definition is that of Sampson (1952 ): “Range management is the 
science and art of procuring maximum sustained use of the forage 
crop without jeopardy to other resources or uses of the land.” 
