BOTANICAL AND ECOLOGICAL CHARACTERISTICS
SPECIES: Buchloe dactyloides | Buffalo Grass 



GENERAL BOTANICAL CHARACTERISTICS : 
Buffalo grass is a warm-season, native perennial shortgrass [20].  It is
drought-, heat-, and cold-resistant [106].  Foliage is usually 2 to 5
inches (5-13 cm) high, though in the southern Great Plains foliage may
reach 12 inches (30 cm) [55,100].  Buffalo grass is usually dioecious.
Plants are occasionally monoecious, sometimes with perfect flowers
[48,49,54,61].  Flowerstalks are 4 to 8 inches (10-20 cm) tall [100].
The male inflorescense is a panicle; the female inflorescense consists
of short spikelets borne in burlike clusters, usually with two to four
spikelets per bur [48,104].

Buffalo grass sends out numerous, branching stolons [54,106];
occasionally it also produces rhizomes [85].  Roots are also numerous
and thoroughly occupy the soil [100].  The numerous stolons and roots
form a dense sod [54,106].  Buffalo grass roots are finer than those of
most plains grasses, being less than 1 mm in diameter.  Weaver [100]
found that in the Great Plains, buffalo grass roots in silty loam
reached 5 feet below ground, with 70 percent of roots (by weight)
occurring in the first 6 inches (15 cm) of soil.


RAUNKIAER LIFE FORM : 
   Hemicryptophyte


REGENERATION PROCESSES : 
Primarily dioecious, buffalo grass usually outcrosses by wind
pollination [77].  The monoecious sex form is more common in peripheral,
sparse populations, and monecious plants may be self-fertile [56].  Seed
production on native grasslands in Kansas was greatest when
above-average rainfall occurred in May and June; seed production was
lowest when rainfall during that period was below average [27].  At
dispersal the entire bur, with seeds still inside, abscises from the
plant.  Burs usually disperse close to the parent plant; they cling only
briefly, if at all, to animals or clothing [76].  Fresh seed is usually
dormant, requiring abrasion or overwintering to break dormancy.  Degree
of dormancy, however, has been found to vary between populations [78].
Light is required for germination [43].  Ahring and Todd [2] found that
prechilling at 41 to 50 degrees Fahrenheit (5-10 deg C), drying seeds
for 6 to 48 hours at 104 to 158 degrees Fahrenheit (40-70 deg C), or
soaking seeds 1 to 72 hours in sodium hypochlorite greatly increased
germination.  Fulright and others [43] provide a summary of recommended
buffalo grass seed stratification regimes.  Reports of germinative
capacity of fresh seed that has been stratified and scarified range from
45 to 70 percent.  Seed has remained viable in the seedbank for at least
7 years [29].  Twenty-five-year-old seed recovered from the walls of an
abandoned sod house in Kansas was 15 to 78 percent viable [64].
Germination rates are usually better when seed remains within the bur
[76].

In a seedbank study on the Central Plains Experimental Range, Colorado,
buffalo grass seedling density in fine-textured soil samples gathered
over a 15-month sampling period averaged 112 plants per square meter
[25].  Seedlings grow rapidly under favorable conditions.  They have
produced stolons by 2 months of age.  By the end of their first summer,
seedlings grow a thick root mass that extends 2 feet (0.6 m) below
ground [100].

Vegetative reproduction through spreading stolons is rapid given
favorable environmental conditions [29].  Buffalo grass stolons have
grown as rapidly as 2.25 inches (5.72 cm) per day [69].  Buffalo grass
also spreads by tillering [106].  Following drought in western Kansas,
buffalo grass cover increased vegetatively from 2 percent in 1940 to 93
percent in 1943.  Buffalo grass has been reported to spread vegetatively
following depletion even when heavily grazed [101].  Although blue grama
is more drought resistant, buffalo grass usually recovers more quickly
after drought through vegetative reproduction [29].


SITE CHARACTERISTICS : 
Buffalo grass occurs on all soil textures [10,21].  It is most common on
clay, then fine-textured loam.  It is rare on sandy soils [10,81].
Soils supporting buffalo grass are usually alkaline [10,19,49], with a
high water-holding capacity (33-66%) [49].  Buffalo grass grows mostly
on dry uplands and/or disturbed sites in mixed- and tallgrass prairie
[3,48].  It grows best in regions of the Great Plains where annual
precipitation ranges between 12 and 25 inches (305 and 635 mm) [106].
It is widely adapted, however, to extremes in climate and elevation
[21,106].  Elevation at which buffalo grass occurs ranges from 2,000
feet (600 m) in Montana to 6,300 feet (1,890 m) in Wyoming [36].


SUCCESSIONAL STATUS : 
Buffalo grass appears in early to mid-stage secondary succession [4].
Costello [28] described an old-field successional sequence in
north-central Colorado where the inital stage was dominated by annuals,
followed by perennial forbs.  Buffalo grass appeared after the perennial
forbs, 10 to 20 years after abandonment.  

Buffalo grass is common on disturbed sites such as prairie dog towns
[1,117].  In a pattern similar to old-field succession, buffalo grass
established after forbs and three-awns (Aristida spp.) but before
mid-grasses such as silver bluestem (Bothriochloa saccharoides) and
sideoats grama (Bouteloua curtipendula) on an abandoned black-tailed
praire dog town in Oklahoma tallgrass prairie [71].

Buffalo grass often establishes dominance in mixed-grass prairie with
drought or heavy grazing, and may invade tallgrass prairie under such
conditions [59,89].  Buffalo grass may not require disturbance in order
to maintain dominance on all sites, however.  It dominated fine-textured
clay soils in a remnant mixed-grass Kansas prairie that had not been
grazed or burned for 68 years [57].  Van Auken and Bush [97] found that
honey mesquite (Prosopis glandulosa var. glandulosa) was unable to
invade high-density buffalo grasslands in Texas.

Buffalo grass is somewhat shade tolerant, but cannot tolerate dense
shade [10,106].

Clements [23] described buffalo grass-blue grama shortgrass prairie as
"proclimax:"  a community held indefinitely from reaching "climax
condition" by the natural disturbances of grazing and fire.


SEASONAL DEVELOPMENT : 
Buffalo grass growth begins in late spring and continues through summer
[54,89].  In the Great Plains flowering occurs mostly from April to
June, but male plants may flower until late summer or fall [48].  Period
of heaviest flowering varies by location.  Flowering is reported from
July through August in eastern Colorado [35].  August flowering is also
reported from Kansas, with male plants beginning flowering slightly
before female plants [103].  Seed ripens from early summer to late fall,
depending upon location.  Early July seed ripening is reported from
Kansas [27].

Related categories for Species: Buchloe dactyloides | Buffalo Grass