FIRE EFFECTS
SPECIES: Cupressus macnabiana | Macnab Cypress 



IMMEDIATE FIRE EFFECT ON PLANT : 
Most fires probably kill MacNab cypress.  Cypress thickets are conducive
to crown fires, which usually kill almost all trees in the stand [27].
At the Rancho Santa Ana Botanic Garden in southern California on October
8, 1943, a severe fire killed all but three MacNab cypress trees [24].

Cones of the California cypress open as the resin melts and boils.
Rapid charring of the thick cone scales extinguishes the flames, leaving
seeds unburned [2].


DISCUSSION AND QUALIFICATION OF FIRE EFFECT : 
NO-ENTRY


PLANT RESPONSE TO FIRE : 
MacNab cypress release large quantities of seed after fire [24].  In
Lake County, it occurs on recently burned areas with Sargent cypress
[16].  

In Aukum, California, many decadent MacNab cypress were reported in
1948.  The prevalence of "overmature and decadent" Macnab cypress trees
was attributed to the absence of fire, which was veiwed as unusual for
this species.  A few miles south, in Hooker Canyon, Sonoma County, a
chaparral atand of chamise and California scrub oak contained a few old
MacNab cypress, numerous burned MacNab cypress stumps, and many young
MacNab cypress trees [24].

Seedling regeneration is not as extensive for MacNab cypress as for
other cypress species, possible due to low germination rates [24].


DISCUSSION AND QUALIFICATION OF PLANT RESPONSE : 
NO-ENTRY


FIRE MANAGEMENT CONSIDERATIONS : 
Fires occurring too frequently in McNab cypress groves may destroy them,
as reproduction could be eliminated before it had a chance to produce
cones.  Conversely, fire suppression could threaten the species.

Related categories for Species: Cupressus macnabiana | Macnab Cypress