FIRE EFFECTS
SPECIES: Encelia farinosa | Brittle Bush 



IMMEDIATE FIRE EFFECT ON PLANT : 
Brittle bush is often top-killed or completely killed by fire.  Nearly
all brittle bush plants in a coastal sage scrub community were
top-killed or killed by a June 1981 fire [26].  Following a fast-moving,
low-severity fire in creosotebush scrub, brittle bush plants were mostly
scorched.  Only leaves and branches near the ground burned, leaving
foliage on ultimate stems.  However, brittle bush suffered 93 percent
mortality [7].  A hot summer fire in Sonora, Mexico, killed 32 percent
of mature brittle bush plants and 60 percent of seedlings.  Burning in 2
consecutive years killed 70 percent of mature plants and 90 percent of
seedlings.  The remaining plants were injured and had not recovered
after 3 years [53].


DISCUSSION AND QUALIFICATION OF FIRE EFFECT : 
NO-ENTRY


PLANT RESPONSE TO FIRE : 
Brittle bush wind-dispersed seeds readily invade postfire environments
and often become well established [7,22].  Following prescribed fires in
the upper Sonoran Desert, brittle bush underwent an initial 83 percent
reduction in density, but within 9 months it increased to 762 percent of
preburn density.  This was a result of very successful seed germination
and subsequent seedling establishment [9].  In southern California
coastal sage scrub, fires were followed by rapid brittle bush seedling
establishment.  Brittle bush accounted for most of the seedlings
observed during the first growing season.  Recent fires have converted
cresotebush scrub at Palm Springs, California, to brittle bush coastal
sage scrub [7].

Brittle bush is categorized as a weakly-sprouting species [7,26].  Three
to five growing seasons after fire in creosotebush scrub, brittle bush
sprouting was rare [7].  Following a June 15, 1981 wildfire in coastal
sage scrub, only 4 to 30 percent of the top-killed brittle bush shrubs
regenerated by crown sprouting.  Maximum sprouting occurred on
north-facing slopes.  The likelihood of brittle bush recovery from fire
by sprouting is greater on cool, less xeric sites where fires are often
less severe, and less on the hot, xeric sites [26].  However, 1 year
after a hot, summer fire in Sonora, Mexico, surviving brittle bush
plants sprouted vigorously [53].

Postfire brittle bush densities for east and west exposures 1.5 years
after a June coastal sage scrub fire were 79 to 205 percent of prefire
densities on east, south, and west exposures.  On north-facing slopes,
postfire brittle bush density was less than 4 percent of prefire
density.  More than 90 percent of the regeneration consisted of
seedlings [26].



DISCUSSION AND QUALIFICATION OF PLANT RESPONSE : 
NO-ENTRY


FIRE MANAGEMENT CONSIDERATIONS : 
NO-ENTRY

Related categories for Species: Encelia farinosa | Brittle Bush