TheImprovement ofTropical and Subtropical Rangelands

RE1lAlJ1LlTATION TBOHNlQUBS 179
traceable to a particular genus (Levin et al., 1953). Three main
groups of animals are of concern: the rodents (including the true
rodents and the lagomorpha, or rabbits and hares), the ruminants
(or cud-chewing animals), and birds.
Competing vegetation is harmful except where needed to prevent
severe erosion, and plantings should be made before a competitive
sod forms or the sod should be scalped where the plant is inserted.
Scalping or removal of sod, brush, or other competing vegetation is
necessary on some sites to prevent stunting or killing of plants. This
occurs principally in three ways:
1. Root competition. This is most serious on dry sites, but
it may also be a factor on the wetter high-quality sites in dense
vegetation. Greatest damage occurs during the critical first year or
two when 86d and brush roots are feeding in the same root zone u
the transplant.
2. Competition for light. This is most serious on the better
sites, where the surrounding vegetation and brush shades or suppresees
the plant.
3. Smothering. This is most serious on sites that produce tall
grU888 and weeds that die in the fall and mat down over the plants.
Scalping of the area around the spot to receive a transplant is
done by the planters at the time ofplanting, using a planting mattock
or grub hoe. The depth and diameter of the l!ICalped area will vary
according to the density of the vegetative root systems and foliage.
SELECTED PRACTICES
Throughout the rangelands of the world, there are large areas
where desirable forage plants have been reduced in vigor or eliminated
by put abuse. Such lands produce few benefits and are a
detriment to adjacent lands. Even with controlled grazing by livestock
and, in some C&IIe8, complete protection, depleted areu might
require 20 or more years to develop d.ir~le plants. Secondary sueceuion
is very slow, or nonexistent in arid and semiarid rangelands
where the vegetation has been depleted. Revegetation is the only
means by which to establish desirable plants for protection and production
in a relatively short period of time. Some examples follow.
S1Jria. Transplanted container-grown seedlings of old man saltbush
survived very well in western Syria (Csa) when placed in furrows