FIRE EFFECTS
SPECIES: Helianthus maximiliani | Maximilian Sunflower 



IMMEDIATE FIRE EFFECT ON PLANT : 
Maximilian sunflower is probably top-killed by fire during the growing
season.  It survives by sprouting from persistent rhizomes [17,44].


DISCUSSION AND QUALIFICATION OF FIRE EFFECT : 
NO-ENTRY


PLANT RESPONSE TO FIRE : 
Fire usually enhances Maximilian sunflower, probably by removing litter,
allowing more sunlight to reach the soil surface, and reducing
competition.

Maximilian sunflower was burned in prescribed fires in May, 1970 and
May, 1971 in east-central North Dakota.  It increased in cover more than
100 percent within the first 2 postfire years [23].

When dead vegetation mulch was burned in North Dakota in 1968 and 1969,
Maximilian sunflower and other plants grew taller, stiffer, and seeded
more vigorously [40].

Tallgrass prairie sites containing Maximilian sunflower in northwestern
Minnesota were subjected to prescribed fire in early May, 1972.  The
removal of litter by fire varied with the site.  In undisturbed prairie
on a mesic site, flowering decreased significantly following fire.  On a
wet-mesic site in highly disturbed prairie, there was a slight,
nonsignificant decrease in flowering.  On a wet swale in undisturbed
prairie, there was a very significant increase in flowering [32].


DISCUSSION AND QUALIFICATION OF PLANT RESPONSE : 
NO-ENTRY


FIRE MANAGEMENT CONSIDERATIONS : 
In southwestern Minnesota, a degraded prairie that had been invaded by
shrubs and cool-season grasses was burned each spring from 1983 to 1987.
Native warm-season grasses and forbs, including Maximilian sunflower,
increased in dominance, and the prairie became more open each year.
Maximilian sunflower showed increased vigor, and new individuals were
established [2].

In the High and Rolling Plains of Texas, prescribed fire is used every 3
to 5 years to maintain optimum quail habitat in the grass stands where
Maximilian sunflower occurs [6].

In the Northern Great Plains, the best increases in Maximilian sunflower
vigor, canopy cover, and seed production are obtained with late spring
(May-June) fires [19].

Related categories for Species: Helianthus maximiliani | Maximilian Sunflower