TheImprovement ofTropical and Subtropical Rangelands

RBlIABILlTATlON TEOHNIQUES 141
to high management inputs, is required if these risky, costly practices
are employed. During the planning phase of intensive range
rehabilitation progr&IIUI, site potential must be carefully aasessed.
Subsequent consideration might be given to the use of plant species
from other locations in the world that may be more productive or
better able to meet a particular requirement than the plants currently
growing on the site. Generally, control of unwanted plants,
revegetation, and fertilisation are intensive practices for rangelands.
Combined Practlc..
Few, if any, land managers use intensive practices exclusively on
a unit of rangeland. Rather, intensive and extensive practices are
combined. To increase plant production and soil protection, each
unit of rangeland must be managed to maximize economic, political,
and social factors while maintaining or improving the basic resource.
For example, in the Northern Great Plains of Canada and the United
States, this may mean eeeding part of the range unit with Russian
wildrye P,otla,ro,tocla" ;unceo) and standard crested wheatgrass
(Agrop,,"on tle,ertorum), and using nitrogen fertilizer on both native
and introduced species. In portions of the Northern Plains, the best
practices may include judicious burning of some native rangeland
areas and plowing up the native sod on some of the better sites and
seeding wheat for forage, or for forage and grain.
On the semiarid southern Great Plains of the United States
and the 8880Ciated grasslands of Mexico, a useful strategy may include
seeding weeping lovegrass (Erogro,tU curwlo), side-oats grama
(Bot&telouo curtipentlulo), common wheat (Triticum oe,tinm), and
Sudan grus (Sorglaum ntlonen,e). In the arid portions of the southwestern
United States and northern Mexico, efforts to increase range
productivity sometimes include the control of mesquite (Pro,ops,
spp.) and tarbush (Flourenfto cernutl), and seeding with Lehmann
lovegrass (Ertlgro,ts,lelamonniono) and Boer lovegrass (E. claloromelu),
and fourwing saltbush (Atriplez ctlne,ceu). On some rangelands
dominated by big sagebrush (Artemuto tritlenttlttl), control of
the sagebrush and seeding with fairway crested wheatgrus (Agrop,­
ron crUtotum) results in greater productivity and soil stability than
would be obtained without sagebrush control and seeding. In some
instances, composition of plant species may be manipulated to improve
wildlife habitat, while at the same time maintaining or improving
livestock production. Suitable proportions of trees, shrubs,