Plants, Animals, and Humans 
in Arid Areas 
ENRIQUE BELTRAN 
Instituto Mexicano de Recursos Naturales Re- 
novables, Mexico 
Gambling on the climate may be possible 
in semiarid regions, but the dweller in an 
arid region has to play safe or perish— 
R. W. Bailey. Yearbook of Agriculture, 
1941. 
In discussing the possibility of improving conditions for pro- 
duction and the standard of living in arid zones, major emphasis 
is usually placed on bettering and propagating domestic plants 
and animals. 
This is, without doubt, especially important, but I believe that 
within the whole it 1s necessary to fit the arid zone-wild plants and 
animals-human population-domestic plants and animals complex. 
Taking into consideration the four components of this complex, 
one should try to discover the elements which may serve to balance 
them from a desirable economic and social viewpoint. 
Arid Zone 
This is the basic element, the stage on which the drama is set, 
and its principal characters will be largely determined by the 
degree of aridity surrounding them. This element does not notice- 
ably change throughout history.* 
* T do not forget the profound change which may take place in an arid 
zone if it is supplied with water; but, in that case, it takes on new char- 
acteristics and, therefore, it is no longer necessary to consider it an 
mAtIGeZonen: 
419 
