KUCHLER TYPE FIRE ECOLOGY AND MANAGEMENT
KUCHLER TYPE: Mosaic of bluestem prairie and oak-hickory forest



FUELS, FLAMMABILITY, AND FIRE OCCURRENCE : 
Fuels and Fuel Accumulation Rates:  In the prairie-hardwood transition
areas fires tended to occur at intervals coinciding with the length of
mid- to late-seral stages.  Fuel accumulation was sufficient to support
fire severe enough to top-kill hardwoods.  In Illinois, available fuel
increased along a gradient from sand prairie through a prairie-forest
transition to closed forest.  

Severe fire converts closed forests to open woodlands with less fuel and
less severe fire.  Periodic fire that reduces fuel loads would probably
maintain open forests [8,9].

Presettlement Fire Frequency:  In southern Illinois, presettlement
vegetation on what is now the Sand Prairie-Scrub Oak Nature Preserve was
a patchwork of prairies, savannas, and forests of various densities.
The fire frequency of individual habitats within the preserve varied
from nearly annual fire in the grasslands to fire exclusion for
centuries in some forests [10].  Mean fire intervals estimated for
gallery forest sites on the Konza Prairie, Kansas, averaged 19 years
(ranging from 23-40 years) [2].

On the Prairie Peninsula, presettlement fire frequency may have been
enhanced by aboriginal cultural practices, and fire severity reduced by
bison and elk grazing [2].  Frequency of fires in historic times was
also controlled by topographic relief and the distribution of
firebreaks; sites with rough topography experienced fewer fires than
smooth or rolling landscapes [7].

Postsettlement Fire Frequency:  Following settlement, fire frequency and
severity decreased because of road construction, settlement (towns tend
to act as prairie firebreaks), cattle grazing, active suppression of
wildfire, and recommendations against prescribed fire [2,3].  Gallery
forests in Kansas and elsewhere have experienced decreased fire
incidence and have increased in extent since European settlement [2].


FIRE EFFECTS ON SITE : 
NO-ENTRY


FIRE EFFECTS ON VEGETATION : 
Prairie-forest transition plants are highly adapted to fire.  The trees
have thick bark and sprout from the root crown after fire injury or
top-kill [53].  Oaks are relatively resistant to fire; on some sites,
even frequent fire does not eliminate oaks [23].  Bur oak, for example,
sprouts from the root crown following fire damage.  If bur oak sprouts
are not burned for 12 to 15 years, they grow large enough to survive
most surface fires [53].  In gallery forests prescribed burned in 2
successive years, sapling and shrub cover was reduced but large diameter
trees suffered little or no damage [2,3].  Herbs, mostly grasses, have
growing points beneath the soil surfaces and are protected from fire
[38].

Lorimer [41] rated upland oaks in order of decreasing bark thickness:
bur oak, black oak, white oak, and northern red oak.  The relatively
thin bark of northern red oak may explain why bur oak and white oak are
maintained in gallery forests whereas frequent fire reduces northern red
oak to shrubby clumps originating from sprouts [24].

At Howe's Prairie, Indiana, tree basal areas decreased with prescribed
fire, largely as a result of top-kill.  The proportion of trees killed
was positively correlated with fireline intensity and negatively
correlated with tree diameter at breast height [21].

A single spring headfire was conducted in a bur oak-white oak-shagbark
hickory stand in Wisconsin.  The vast majority of seedlings sprouted
after top-kill.  Damage was inversely related to stem diameter.  Oaks
were slightly less susceptible to fire damage than black cherry and
hickorys [34].

Most ecologists believe that fire was important in maintaining the
complex patterns of vegetation types in the prairie-forest interface
[29].  The regional effect of fire on vegetation was influenced by a
variety of factors, including precipitation patterns before and after a
fire, prefire vegetative composition, topography, and season of burning
[26].  According to Hulbert [35], fire is necessary to keep woody plants
from replacing tallgrass prairie, but fire alone does not make prairie.
It is the combination of fire, climate, substrate, and topography that
accounts for prairie [14,35].

Fire, perhaps more than any other factor, maintained grasslands and the
parklike aspect of the Ozarks [13].  Harty [62] suggested that the low
density and basal area of presettlement forests in the Shawnee Hills,
Illinois, were similar to those of present day forests that have been
disturbed by light cutting and fire.  Bryant and others [18] stated that
the particular role of fire in this ecosystem is not clear since each
fire has a different impact on vegetation.  Tallgrass prairie in moist
situations is quickly converted to woody vegetation without fire
[38,15].  Woodlands have increased in extent in the central Great
Plains, and in many areas succession to shade-tolerant hardwoods has
occurred or is occurring [2,3].

The influence of fire on the maintenance of bluestem prairie-oak-hickory
mosaic is not well understood.  Cole and others [22] suggested that in a
region where some vegetation types are more fire-adapted than others,
fire-created mosaics are self-perpetuating.  A severe fire may open up
an area occupied by less fire-adapted vegetation to invasion by
fire-adapted species.  The fire-adapted species may be more fire prone
and therefore self-maintaining.  Once severe fire eliminates forests,
frequent high temperature fires in grasslands prevent reinvasion by
woody species.  The mosaic of forest and grassland could therefore only
be perpetuated where firebreaks prevent spread of fire into forest, or
where forest floor fuels are sufficiently moist to slow down or prevent
fire spread into the forest [22].

Fire regime is closely related to the extent of gallery forests; their
limited extent prior to European settlement has been attributed at least
in part to frequent grass fires that prevented establishment of woody
vegetation [2,3].

Open forests occur on slopes of glacial moraines that were historically
subjected to occasional fires at longer intervals than prairie;
vegetation of these types is relatively shade-intolerant and moderately
fire resistant.  Closed forest occurs in stream valleys and protected
areas adjacent to waterways and contains vegetation that is more
mesophytic and more shade tolerant, but less fire resistant [7].

In Missouri the effects of fire suppression (initiated in 1936) had
become apparent by the late 1960's.  Many areas had experienced
increases in eastern redcedar and cool-season exotic grasses; thousands
of acres of glades and prairies were affected [20].


FIRE EFFECTS ON RESOURCE MANAGEMENT : 
NO-ENTRY


FIRE USE CONSIDERATIONS : 
At Howe's Prairie, Indiana, (a complex of oak woods and prairie
communities), prescribed fires in oak woods and mesic woods dominated by
red maple (Acer rubrum) produced lower aboveground temperatures and
higher belowground temperatures than fires in wet or mesic prairies
[21].  Creeping fires in oak woods often only burned litter, sometimes
producing no high temperatures above 8 inches (20 cm) when burning
downhill [22].


FIRE MANAGEMENT CONSIDERATIONS : 
The use of fire in central deciduous forest has declined with
abandonment of open range practices and intensification and
specialization in land use [54].  Fire is applied in hardwood and mixed
forests as a wildlife management tool [59] and to modify understory
composition or size class structure [55,31].  Recently, fire has been
reintroduced to restore and maintain prairie-forest transition zone
characteristics [45,46].

Anderson and Brown [8,9] examined the role of fire in maintaining the
mosaic of prairie, savanna, and open forest on sand deposits along the
Illinois River in central Illinois.  Here, fire maintained sand praires,
savannas, and open forests, but destabilized closed oak forest [8,9].
In southern Illinois fire is used by the Illinois Department of
Conservation to maintain a mosaic of grassland, savanna, and closed
forest [8].  The sand prairie in this area has been burned at 4-year
intervals since 1976.  Initially, substantial differences occurred in
insect populations, but by the third postfire growing season most of the
differences disappeared [10].

On the Shawnee National Forest in Illinois, restoration and maintenance
of a complex mosaic of woodlands, forests, and barrens is being carried
out with landscape-scale prescribed fire and other techniques.  Where
conditions allow, large areas of grasslands are ignited and allowed to
burn.  Fire spread into adjacent forest and open woodland is regulated
by local topography and local weather and fuel conditions [51].

In many prairie preserves fire management has included burning
grasslands and preventing fire spread into adjacent woodlots.  This
approach maintains a mosaic of grassland and forest, although it may not
resemble the presettlement bluestem prairie-oak-hickory forest mosaic.
Presettlement vegetation included transitional areas of various widths
in which trees were farther apart and understory vegetation had a strong
prairie influence [47].

Abrams [2] suggested that long-term annual burning may prevent
succession from bur oak to hackberry; it will probably result, at least
temporarily, in oak savanna.  Annual fire, however, may remove all tree
reproduction and establish prairie as existing oaks die.

Season of burning affects results, but most woody plant species are
reduced by most fires [4].  Fall burning appears to be more effective
than spring burning in reducing woody species in Iowa [35].


REHABILITATION OF SITES FOLLOWING WILDFIRE : 
NO-ENTRY

Related categories for Kuchler Type: Mosaic of bluestem prairie and oak-hickory forest