FIRE EFFECTS
SPECIES: Arctostaphylos patula | Greenleaf Manzanita 



IMMEDIATE FIRE EFFECT ON PLANT : 
Fire generally top-kills greenleaf manzanita, but severe fire may kill
it completely.  Fire generally scarifies the seed, which promotes later
germination [32,33,35].


DISCUSSION AND QUALIFICATION OF FIRE EFFECT : 
The seeds of greenleaf manzanita can survive temperatures in excess of
200 degrees Fahrenheit (93 deg C) for 40 minutes and still germinate
[66].


PLANT RESPONSE TO FIRE : 
Fire stimulates greenleaf manzanita seeds stored in the soil to
germinate [15,28,36,59,68].  Germination of these seeds occurs in the
1st postfire year [36].  It may take 10 or more years before these
seedlings mature and produce a significant seed crop [33].

Unless the entire periphery of the lignotuber is deeply charred, which
seldom occurs, vigorous sprouting occurs following fire [48].  Shrubs
produce new sprouts from dormant buds in the lignotuber in as little as
10 days to 3 weeks [23,24,43].  These new sprouts are capable of heavy
seed production by the 2nd postfire year [33].


DISCUSSION AND QUALIFICATION OF PLANT RESPONSE : 
Weatherspoon [68] reported on the effects of preharvest burning for
shrub control in a white fir (Abies concolor var. lowiana) stand in
California.  The density of greenleaf manzanita seedlings after
postharvest burning was considerably higher for spring burns than for
fall burns.  This seasonal difference was attributable to consistently
higher percent burned area in spring than in fall; in the fall burning
period the available fuels were wet due to rains.  

The density of greenleaf manzanita seedlings was not significantly
reduced by preharvest burning.  This may have been due to the relatively
low fuel-consuption levels in these burns [68].


FIRE MANAGEMENT CONSIDERATIONS : 
An understanding of the dynamics of shrub reestablishment after fire is
an important fire management concern.  This is dependent upon an
understanding of shrub reproductive strategies [33].

When fire is used for brush control, consumption level, as well as shrub
phenology, is an important factor contributing to mortality.
Phenologically, shrubs are more resistant to fire in fall, but more
fuels are generally available for consumption at this time.  Therefore,
more destructive heat can be generated around meristematic tissues and
root crowns [28].  It has been reported that the greatest mortality of
shrubs occurred during high consumption burns regardless of season, and
that burning during the active aboveground growing season appeared to
increase mortality regardless of the amount of duff consumed.  Timing
controlled burns to coincide with dryer fuel conditions and active
aboveground growth may result in the highest mortality rates [29].

Fire can also be used to reduce or eliminate the greatly increased fire
hazard of the standing dead brush, to set back resprouting brush a
second time, and to remove the impenetrable mass of dead brush resulting
from herbicide application [15].

Prescribed burning in the early spring, before active shrub growth, can
be used to increase palatability of foliage to wildlife [29].

Studies indicate that prescribed understory burning can used
successfully to kill or reduce the vigor of greenleaf manzanita shrubs
and seedlings, deplete the amount of viable residual seed in the soil,
and thus prepare a better seedbed for pine and white fir (Abies
concolor) regeneration [28,68].  An increase in understory slash depth
may reduce the density of manzanita seedlings [68].

Related categories for Species: Arctostaphylos patula | Greenleaf Manzanita