BOTANICAL AND ECOLOGICAL CHARACTERISTICS
SPECIES: Atriplex gardneri | Gardner's Saltbush 



GENERAL BOTANICAL CHARACTERISTICS : 
Gardner's saltbush is a native, spreading, low-growing, evergreen,
perennial subshrub.  It grows from 8 to 20 inches (20-50 cm) in height
and has alternate leaves 0.5 to 2.2 inches (15-55 mm) long.  Herbaceous
flowering stems rise above the woody, decumbent portion of the plant
[17].  Plants are typically dioecious, although some monoecious
individuals also occur [17].  Roots of two-foot-tall (61 cm) plants near
Riverside, California, measured 3.5 to 4.5 feet (107-137 cm) deep, with a
lateral spread of 5 to 7 feet (152-213 cm) [21].

Polyploidy, which may afford drought tolerance, is common in Gardner's
saltbush.  Diploid forms are widespread in low-lying valleys, whereas
tetraploid populations more often occupy higher, steeper terrain [32].
Evidence suggests that the more drought-resistant tetraploids are
increasing at the expense of diploids.  Diploids and tetraploids are
very similar morphologically [34].


RAUNKIAER LIFE FORM : 
   Phanerophyte
   Chamaephyte


REGENERATION PROCESSES : 
Gardner's saltbush regenerates from long-lived, wind-dispersed seed.
Most species of the genus Atriplex first bear seed at 2 to 4 years of
age.  The genus is characterized by wide annual fluctuations in seed
production [11].  Gardner's saltbush produces seed in abundance.  Seed
may remain on the plant for up to 2 years.

Gardner's saltbush undergoes an average afterripening period of 3 months
in order to overcome seed dormancy [11].  Under laboratory conditions, a
combination of stratification, scarification, washing, and dry
afterripening increased germination of Gardner's saltbush.  This
suggests that any combination of the above processes may help overcome
seed dormancy in the natural environment [1].  The percentage of filled
seed is highly variable, and may depend upon genetic factors.  In one
study, seed planted in spring or fall exhibited the best germination and
survival, with seedlings emerging in 6 to 20 days [11,26].  

Gardner's saltbush reproduces vegetatively by layering and sprouting
from the root [6,19].


SITE CHARACTERISTICS : 
Gardner's saltbush is most common on saline, poorly developed, or clay
soils with a pH of 7.8 to 8.6.  Soils are typically low in available
phosphorous, nitrogen, and potassium [12].  Gardner's saltbush also
grows on sodic, silty, or sandy soils [5,10,12,17].  Sites are usually
harsh and arid, with widely fluctuating temperatures and high winds
[1,19].
                    
Elevational range of Gardner's saltbush in Utah is from 4,300 to 6,500
feet (1,311-1,982 m) [8].


SUCCESSIONAL STATUS : 
Facultative Seral Species

Gardner's saltbush is a climax indicator in several saltbush-greasewood
and saltbush-grassland plant communitites.  McKell and Goodin [18],
however, note that it is not a climax species on many desert rangelands.
It can be an abundant species during early secondary succession.


SEASONAL DEVELOPMENT : 
Gardner's saltbush begins annual growth in the spring.  The flowering
period extends from May through July, depending on ecotype and climatic
factors, with intermittent flowering after periods of heavy rain [47].
Foliage remains succulent even during the hot, dry summer months [4,33].
In Utah, seeds mature from September 10 through March 1 [24].  Seed
dispersal is variable, but typically begins in late fall and lasts until
the following April or May.  It is not unusual to find 1- and 2-year-old
fruits on some shrubs [11].

Related categories for Species: Atriplex gardneri | Gardner's Saltbush