FIRE EFFECTS
SPECIES: Malosma laurina | Laurel Sumac 



IMMEDIATE FIRE EFFECT ON PLANT : 
Laurel sumac is typically top-killed by fire, although hot fire may
result in some shrub mortality.  A summer wildfire on Otay Mountain, San
Diego County, completely top-killed all laurel sumac [64].  Fall
wildfire in the Topanga-Tuna Canyon of the Santa Monica Mountains burned
100 percent of the plants.  Most shrubs were top-killed by this fire,
but some were completely killed.  Many laurel sumac snags were noted
when the burn site was inspected at postfire year 3 [49].  Westman and
O'Leary [59] reported that if fireline intensity is over 4,400 BTU/min/sq ft
(199 kcal/sec/sq m), laurel sumac lignotubers fail to sprout.


DISCUSSION AND QUALIFICATION OF FIRE EFFECT : 
The majority of the literature reports that laurel sumac is completely
top-killed by fire [1,27,43,49,52]; occasionally, however, a few stems
survive.  An "intense" wildfire started on November 3, 1949, in the San
Gabriel Mountains; ambient temperature was 90 degress Fahrenheit (32 deg
C), humidity was 9 percent, and fuel moisture was 0.5 percent.  Despite
these conditions, the largest branches of older laurel sumac leafed out
the next year [24].


PLANT RESPONSE TO FIRE : 
Top-killed plants sprout quickly.  Twenty-two percent of laurel sumac
top-killed by an October wildfire in mixed chaparral in the Santa Monica
Mountains sprouted within 15 days after fire.  By April of the following
year, 100 percent of the lignotubers of burned shrubs had sprouted.
Sprout length at the end of the first postfire growing season was 4.3
feet (1.3 m) [52].  Plumb [43] reported a similar response following a
July wildfire on the San Dimas Experimental Forest of the San Gabriel
Mountains.  One hundred percent of top-killed laurel sumac sprouted by
November, and 97 percent of sprouts were greater than 12 inches (30 cm)
in length by December.  Seventy-four percent of lignotubers supported 12
or more sprouts.  Postfire stem elongation through December is common
when fall rains are sufficient to support continued growth [57].
Chlorosis often occurs in the leaves of the rapidly growing sprouts
[11].

Postfire seed germination is moderate [63].  Density of seedlings
following a spring wildfire in the Santa Monica Mountains in mixed
chaparral was 0.6 plants per square yard (0.7 plants/sq m) [14].
Postfire seedling mortality is high unless rainfall is steady.  The year
following this wildfire was a drought year, and only 0.6 percent of
seedlings survived through summer [14].  Seedlings that germinated
following the previously mentioned October fire in the Santa Monica
Mountains exhibited the same response.  Seedling survival at the end of
the first postfire growing season was 51.5 percent with precipitation at
110 percent of normal.  The next year, with precipitation at 53 percent
of normal, survival dropped to 1.6 percent [52].


DISCUSSION AND QUALIFICATION OF PLANT RESPONSE : 
NO-ENTRY


FIRE MANAGEMENT CONSIDERATIONS : 
Elements to consider when developing a fire prescription for southern
California chaparral are available in the literature [16].

Related categories for Species: Malosma laurina | Laurel Sumac