BOTANICAL AND ECOLOGICAL CHARACTERISTICS
SPECIES: Sporobolus wrightii | Big Sacaton 



GENERAL BOTANICAL CHARACTERISTICS : 
Big sacaton is a native, perennial bunchgrass 3 to 6 feet (0.9-1.8 m)
tall [5,14,27,47] that grows in dense clumps up to 3 feet (0.9 m) in
diameter [47,48].  Leaves are up to 12 inches (30 cm) long [47,48].
Seedheads are open and 1 to 2 feet (0.3-0.6 m) long [48].



RAUNKIAER LIFE FORM : 
   Hemicryptophyte


REGENERATION PROCESSES : 
Big sacaton reproduces exclusively by seed.  It lacks specialized
morphological seed dispersal mechanisms.  In saline habitats of the
Chihuahuan Desert, seed may be dispersed by ducks [24].  Big sacaton
seed has low germination and establishment rates under high temperatures
such as those found in the desert southwest [38].  Establishment of big
sacaton seed increased with a reduction of soil temperature from an
average of 104 degrees Fahrenheit (40 deg C) to 79 degrees Fahrenheit
(26 deg C) [38].  In the laboratory, big sacaton germination was 84
percent under optimum conditions (alternating temperatures of 68-95
degrees Fahrenheit [20-35 deg C] and alternating light and dark periods)
[52].  Emergence, average shoot height, average root and shoot weight,
and average root length were all less in soils at temperatures of 127
degrees Fahrenheit (53 deg C) than in soils at temperatures of 102
degrees Fahrenheit (39 deg C) [38].


SITE CHARACTERISTICS : 
Big sacaton grows mainly on low alluvial flats, bottomlands, and arroyos
subject to flooding [6,14,23,47,48].  It also occurs in wide floodplains
[53].  In southeastern Arizona and southwestern New Mexico big sacaton
forms nearly monotypic stands on broad floodplains [4].  It is also
found on open, unshaded areas such as rocky slopes, plateaus, and mesas
[30,46].  It generally grows on sand, sandy loam, silty clay loam
[12,14,36], and saline soils [24,45].  Big sacaton occurs at elevations
of 2,000 to 5,000 feet (600-1,500 m) in Arizona and 3,100 to 7,000 feet
(930-2,100 m) in New Mexico [30,47].


SUCCESSIONAL STATUS : 
Big sacaton is shade intolerant [53].  In the early 1900's, the
Southwest had extensive stands of big sacaton grassland.
Channelization, drought, grazing, and fire suppression have all
contributed to the invasion of these grasslands by mesquite (Prosopis
spp.) and juniper (Juniperus spp.) [8,28,36,49,55].


SEASONAL DEVELOPMENT : 
Big sacaton initiates leaf production in both summer and winter; winter
leaves form within a protective sheath and expand in early spring [14].
Plants have some green foliage throughout the year [14,23].  Flowering
occurs from April to May in California and from July to October in
Arizona [32,45].

Related categories for Species: Sporobolus wrightii | Big Sacaton