FIRE EFFECTS
SPECIES: Digitaria californica | Arizona Cottontop 



IMMEDIATE FIRE EFFECT ON PLANT : 
Arizona cottontop is intermediate among semidesert grasses in its
susceptibility to damage from fire [7].  If a wet summer follows a fire,
cottontop will probably recover completely during the first growing
season.  If the fire is followed by a dry summer, complete recovery will
probably require two summers [6,8].


DISCUSSION AND QUALIFICATION OF FIRE EFFECT : 
NO-ENTRY


PLANT RESPONSE TO FIRE : 
Arizona cottontop survived a late March fire in light to moderate fuels
(1,000-4,000 pounds [454-1,816 kg] per acre of fine fuel) to provide
forage during a period of less than normal precipitation from May
through August in western Texas [18].  After a range fire in western
Texas, Arizona cottontop increased production for one to three growing
seasons after fire [37].  Also in western Texas, Arizona cottontop was
harmed by fire during dry years, but not during years when fire was
followed by favorable moisture [7].

In Texas, hot fires with 3,037 pounds fuel per acre [3,417 kg/ha] on
herbicide treated mixed brush released Arizona cottontop [39].

On an unburned site in southern Texas, low value forage species
predominated; perennial bunchgrasses were scattered and of low vigor.
By 3 to 5 years after a prescribed fire program, the site was dominated
by Arizona cottontop and other perennial bunchgrasses [33].

Wright [41] states that in shortgrass prairie with less than 13 to 15
inches (330-380 mm) of annual precipitation, grasses do not benefit
from burning, except when shrubs or litter have stagnated grass growth.

In the mixed-grass prairie of the Southern Great Plains, Arizona
cottontop was tolerant of fire, showing increased yield 1 year after
fire when moisture was adequate.  Seed production was very prolific in
this species after being burned [40].


DISCUSSION AND QUALIFICATION OF PLANT RESPONSE : 
NO-ENTRY


FIRE MANAGEMENT CONSIDERATIONS : 
In places where fire suppression has allowed invasion of original
semidesert grassland by woody plants, burning can reduce heavy brush
cover and suppress invasion.  A maintenance fire should be a
dormant-season, relatively cool fire initiated under high relative
humidity and low wind speed.  A reclamation fire should be hot, with low
relative humidity and relatively high wind speed to move fire across
fine fuels and into woody crowns.  A first burn may not be uniform, but
with the release of Arizona cottontop and other grass species, fine fuel
will increase, and the second or third burn will be more uniform [33].

In southern Texas brushlands, mechanical roller chopping of brush
without fire led to increased production of forbs and sedges.  With
burning after chopping, production shifted to predominantly perennial
grasses, including Arizona cottontop [33].

In western Texas, winter-spring precipitation was the key to successful
response of Arizona cottontop to fire.  Species that accumulated the
most litter, including Arizona cottontop, benefited the most [40].

Related categories for Species: Digitaria californica | Arizona Cottontop