VALUE AND USE
SPECIES: Ambrosia dumosa | White Bursage 



WOOD PRODUCTS VALUE : 
NO-ENTRY


IMPORTANCE TO LIVESTOCK AND WILDLIFE : 
White bursage is an important browse species in several areas of the
Sonoran Desert.  Browsing pressure on white bursage is particularly
heavy during years of low precipitation, when production of winter
annuals is low [8].

White bursage is of intermediate forage value [21].  It is fair to good
forage for horses and fair to poor for cattle and sheep.  However,
because there is often little other forage where white bursage grows, it
is often highly valuable to browsing animals [24].  Webb [51] observed
that sheep browsed primarily on new growth and seeds.

In the Mojave Desert, 8 percent of mature white bursage plants were
browsed by black-tailed jackrabbits.  Forty-three percent of
transplanted seedlings were browsed.  Fourteen percent of browsed
seedlings were more than 90 percent consumed [26].

Many desert rodents, including kangaroo rats, eat white bursage seeds
[57].


PALATABILITY : 
White bursage is moderately palatable to cattle and sheep and slightly
more palatable to horses.  Closely cropped white bursage plants on
heavily stocked range indicates inadequate forage rather than high
palatability [23].

White bursage is palatable to feral asses.  Fecal analysis indicated
that white bursage was the primary forage used by feral asses in winter
[21].


NUTRITIONAL VALUE : 
The nutrient value of white bursage fluctuates seasonally; it is greater
in the spring and less in the fall [21].  In a 2-year study in the Lower
Colorado River Valley, white bursage had a gross energy value of about
4.2 kilocalories per gram.  Crude protein was highest in February at 10
percent, declining the rest of the year to 4 to 7 percent.  Phosphorus
content was highest in spring at 1,110 milligrams per kilogram of plant
material, declining to 500 milligrams per kilogram in August and
September [21].

In the northern Mojave Desert, Romney and others [38] estimated the
nutrient load of new white bursage leaves as follows:

Nitrogen        1.29   kg/ha
Phosphorous     0.114  kg/ha
Sodium          0.035  kg/ha
Potassium       1.70   kg/ha
Calcium         0.93   kg/ha
Magnesium       0.17   kg/ha

Reichman [56] estimated that white bursage seeds contain 3,838 calories
per gram or 23.72 calories per seed.


COVER VALUE : 
NO-ENTRY


VALUE FOR REHABILITATION OF DISTURBED SITES : 
White bursage may be used to revegetate disturbed sites in southwestern
deserts.  For instance, white bursage may be planted along California
highways where unirrigated perennial vegetation has not survived [12].

White bursage may be planted from containerized plants with a high
probability of success.  Plantings should be made in late winter or
early spring, although the time of planting is less important than the
vigor of the seedlings.  Rodent protectors should be used [12].



OTHER USES AND VALUES : 
White bursage is a host for sandfood (Pholisma sonorae), a parasitic
plant with a sweet, succulent, subterranean flowerstalk.  Sandfood was
a valuable food supply for desert peoples [58,59].


MANAGEMENT CONSIDERATIONS : 
Creosotebush-white bursage communities are poorly suited for livestock
grazing because of low productivity and low water availability [23].

White bursage is sensitive to browsing.  Browsing significantly
decreased the cover and volume of white bursage by 27 and 21 percent,
respectively, in the Mojave Desert [51].  In the Lower Colorado River
Valley, overbrowsing decreased the cover of white bursage from 2.26 to
0.04 percent [21].

Pollution from electric power generating facilities may also decrease
white bursage.  White bursage showed intermediate sensitivity to sulphur
dioxide and nitrogen dioxide fumigation [45].

Related categories for Species: Ambrosia dumosa | White Bursage