VALUE AND USE
SPECIES: Atriplex canescens | Fourwing Saltbush 



WOOD PRODUCTS VALUE : 
NO-ENTRY


IMPORTANCE TO LIVESTOCK AND WILDLIFE : 
Fourwing saltbush is a valuable browse for many wildlife species and for
domestic livestock.  However, significant variation exists in
palatability and nutritional levels of individuals and populations of
fourwing saltbush [27].  Consumption varies annually and may be related
to differences in salinity of the foliage [59].  Research indicates that
some browsers such as jackrabbits may show a preference for either
pistillate or staminate plants [67].  On many cold desert sites,
accessions in which leaves and seed persist are browsed heavily during
fall and winter months [37,39].  Leaves usually remain succulent during
the hot, dry summer months and can provide some forage even in years
when annuals fail.  Fourwing saltbush generally provides good deer
browse during all seasons and is used by elk in winter [59].  Pronghorns
may feed on this shrub to some extent during all seasons of the year
[71].  Fourwing saltbush is a preferred browse of many rabbits and small
mammals [39].  Seeds are readily eaten by upland game birds, small
nongame birds, and rodents [39].

Fourwing saltbush has fair to good forage value for domestic sheep and
goats, and at least fair forage value for cattle [37].  In some areas,
leaves and twigs are consumed "in quantity" by cattle during the spring
and summer [25].  On rare occasions, fourwing saltbush has caused
scours, bloat, and anemia in domestic livestock [59].


PALATABILITY : 
Fourwing saltbush is palatable to livestock, pronghorn, and deer in all
seasons, and to elk in fall and winter [59].  However, palatability
varies seasonally and annually [27].  Seeds and, in some instances,
foliage are also preferred by many species of upland game birds, small
nongame birds, rodents, and lagomorphs [39].  Palatability has been
rated as follows [7,57]:

                         CO        MT       OR       UT       WY

  Cattle                Fair      Fair     ----     Fair     Fair
  Sheep                 Good      Good     ----     Good     Good
  Horses                Fair      Fair     ----     Fair     Good
  Pronghorns            Good      Poor     ----     Good     Good
  Bighorn               ----      ----     Fair     ----     ----
  Elk                   Good      ----     ----     Fair     Poor
  Mule deer             Good      Fair     ----     Good     Good
  White-tailed deer     Poor      ----     ----     ----     ----
  Small mammals         Fair      ----     ----     Fair     Fair
  Small nongame birds   Fair      ----     ----     Fair     Fair
  Upland game birds     ----      ----     ----     Fair     Poor
  Waterfowl             ----      ----     ----     Poor     Poor  


NUTRITIONAL VALUE : 
Fourwing saltbush is rated good in protein and energy value [7].
However, nutritional value is known to vary greatly by individual,
accession, plant part, and phenological development.  Crude protein
levels range from 5.3 to 24.2 percent, with ash ranging from 13.3 to 16
percent [37,60].  Welch and Monsen [61] reported a mean winter crude
protein value of 9.6 percent.  Nutrient content of fourwing saltbush has
been examined in detail [37,38,69].  The following values were obtained
from a Utah site in November [37]:

Crude Protein     Crude Fiber     Tannins      Oxalates     Carotene
    10.4%            22.6%        5.8 mg/g       1.9%       31.1mg/100g

Mineral content is as follows [38]:

               Ash       P     Fe     K      Ca     Na     
                        (percent dry weight)

              12.89    .23    .02    4.68   1.60   .18
              
In vitro digestibility of fourwing saltbush ranges from 29.1 to 46.9
percent or more, with an average value of 38.3 percent [61].  Wintering
white-tailed or mule deer require approximately 50 percent
digestibility, suggesting the need to mix fourwing saltbush with species
such as big sagebrush, and dormant grasses to satisfy nutritional needs
[61].


COVER VALUE : 
Fourwing saltbush has been planted to provide cover for upland game
birds in many parts of California since the 1960's [46].  In shrub tests
at a semiarid southern Idaho site, fourwing saltbush exhibited the
highest mean cover index (derived from crown diameter, growth form, and
leaf type and retention) for pheasant, California quail, and gray
partridge [46].  However, growth form and leaf retention and thus cover
value vary greatly by individual plant and accession.  Cover value of
fourwing saltbush has been rated as follows [7]:

                       CO            MT          UT         WY

Pronghorns            Poor          ----        Fair       Poor
Elk                   ----          ----        Poor       Poor
Mule deer             Poor          ----        Fair       Poor
White-tailed deer     ----          ----        ----       Poor
Small mammals         Fair          Fair        Good       Poor
Small non-game birds  ----          Fair        Fair       Poor
Upland game birds     Fair          Fair        Fair       Poor
Waterfowl             ----          ----        Poor       Poor


VALUE FOR REHABILITATION OF DISTURBED SITES : 
Fourwing saltbush has been widely used for rehabilitating mine spoils,
roadsides, and oil well reserve pits high in soluble salts [41].  It is
well suited for revegetating saline sites in southern and northern
desert shrublands, pinyon-juniper woodlands, and mountain brush
communities [72].  A number of cultivars have been developed including
'Rincon,' 'Wytana,' and 'Marana.'  'Rincon,' originally from
north-central New Mexico, is adapted to much of the Intermountain region
and grows well on sagebrush, pinyon-juniper woodland, and mountain
brushland sites ranging from 3,000 to 7,600 feet (915-2,318 m) in
elevation which receive 9 to 23 inches (23-58 cm) of precipitation
annually [3].  It is characterized by extremely rapid growth and high
productivity.  'Marana,' from southern California, is a hot desert
cultivar which has been widely planted from southern Arizona to western
Texas [53].  It does not survive temperatures below 10 degrees F (-12
degrees C).  'Wytana,' another widely used cultivar, originated from a
fourwing saltbush-saltsage cross.  It grows well on coal, uranium,
bentonite, and hard rock mine spoils in Montana and Wyoming [3].

Researchers strongly recommend matching the cultivar or strain to be
used to the site in which it is to be grown.  Cold-tolerant cultivars
may sometimes survive in warm climates, but hot desert cultivars often
succumb during harsh cold winters [68].  Evidence from a California
study suggests that rabbits and small rodents prefer strains from
distant areas to those adapted to the site [35].  Nonadaptive plants may
be seriously damaged or killed by these herbivores.

Seed may be broadcast or drill-seeded, but broadcasting often produces
better results [39].  However, seeding success is generally somewhat
sporadic.  Seeding specifications by habitat zones are as follows [39]:

         habitat             broadcast (lbs/acre)      drilled (lbs/acre)

Big sagebrush                     1                          0.5
Big sagebrush-severely            2                          2
   disturbed
Blackbrush                        5                          2.5
  (Coleogyne ramossisima)
Black greasewood                 1-2                        0.5-1
Inland saltgrass                  4                           2
  (Distichlis stricta)
Mountain brushland                1                          0.5
Shadscale saltbush                1.5                          1
  (Atriplex confertifolia)

Seedlings, which tend to be more drought tolerant and less susceptible
to predation, may be transplanted with good results [46,72].  Seedlings
are generally transplanted during the early spring, since 3 weeks or
more of good soil moisture is required for establishment [9].  On
coal-based acidic spoils, pH adjustment through the application of lime,
and the addition of phosphorus may be necessary [45].  Sand or ash may
be spread over the spoils, the sand top-dressed, and sand or shale
incorporated into the spoils to improve fourwing saltbush growth [45].

Seedling survival is generally greater in areas lacking significant
amounts of perennial grasses [4].  A number of studies have documented
seedling success, relative costs, and growth rates on various types of
mine sites in several western states [1,20,30,32].  Pertinent data are
presented below.

Wyoming-
Seeding success and expenses at a Wyoming mine site were as follows
[20]:

Seeding rate   Cost per acre   Established seedlings  Cost per
per acre                       per 1,000 seeds        seedling  

1.0 lb            $20.00             3.30              0.12
52,000 seeds

First-year survival of bareroot transplants was estimated at 84 percent,
with a cost per plant of $0.24 [20].

Nevada-
On a seeded mine site in north-central Nevada, fourwing saltbush
seedlings grew rapidly and matured within 4 years [30].

New Mexico-
A New Mexico mine rehabilitation project was direct-seeded with fourwing
saltbush without irrigation and drip-irrigated transplants.  Growth here
after 5 years was as follows [1]:

        Survival        Height       Crown Diameter
Plot 1     62%           72.4 cm          55.4 cm
Plot 2     88%           62.2 cm          59.7-98.3 cm

Arizona-
Fourwing saltbush successfully reestablished on southwestern Arizona copper
mine spoils with the following soil characteristics [32]:

             pH     Sol. salts    Organics    Na      P      NO3N
                      (ppm)         (%)     (ppm)   (ppm)    (ppm)
Tailing    7.75        355          .21       66     31        22
Overburden 7.85      2,452          .14      135      2         7

Mulching and irrigation are often required for establishment on mine
spoils [59].  Seven years after planting, growth of fourwing saltbush
was as follows [32]:

                  Plant Height (m)        Diameter of Cover (m)
Tailing                1.4                         2.6
Overburden             1.5                         3.1


OTHER USES AND VALUES : 
Fourwing saltbush has been planted along many highways in the Southwest
[46].  It has been used to stabilize roadsides and other disturbed areas
and to improve production of depleted rangelands.  It can be of great
value in watershed rehabilitation by trapping sediments on alluvial
floodplains [1].


MANAGEMENT CONSIDERATIONS : 
Grazing:  Fourwing saltbush often increases in response to heavy grazing
[65] and generally shows good recovery even when grazed fairly heavily
during the spring and fall [44].  In an Idaho study, up to 50 percent
utilization of annual growth by cattle did not adversely affect fourwing
saltbush [44].  The amount of available forage typically increases
throughout the growing season as follows [44]:

                       12 g/sq m              May
                       33 g/sq m              July
                       43 g/sq m              August

Livestock poisoning:  Fourwing saltbush grown in selenium-enriched soil
can accumulate selenium in excess of 160 p/m, creating a hazard to
browsers using large amounts of the plant [5].  Dayton [6] noted that
fourwing saltbush could sometimes poison sheep and if fed in
concentration could possibly cause scours in cattle.

Biomass:  Fourwing saltbush herbage production has ranged from 5,195 to
5,379 pounds/acre (5,903-6,113 kg/ha) [37].  Herbage production could be
increased to 6,679 to 8,949 pounds/acre (7,590-10,169 kg/ha) by closely
spacing plants [37].  Productivity per plant ranges from 0.43 to 3.20
pounds (197-1,451 g) but averages approximately 1.49 pounds (664 g)
[61].  The cultivar 'Rincon' can produce from 5.72 to 9.69 pounds per
plant (2,600-4,400 g) [61].  Diploids tend to be more productive than
tetraploids, although variation by individual and accession is common
[37].

Interaction with grasses:  The presence of fourwing saltbush enhances
growth of grasses such as crested wheatgrass (Agropyron cristatum).  A
greater concentration of nitrogen and other minerals under the fourwing
saltbush canopy may contribute to increased grass density [37,44].

Related categories for Species: Atriplex canescens | Fourwing Saltbush