KUCHLER TYPE DESCRIPTION
Kuchler Type: Southern mixed forest


PHYSIOGRAPHY : 
The Coastal Plain portion of this type is characterized by marine
terraces, on the seaward side of which are often found fossilized sand
dunes.  Stream channels run throughout the southern mixed forest, and in
places subsidence has resulted in "drowned" river mouths.  This type is
also characterized by bays, sounds, barrier islands, and wide estuaries.
Along the coasts in Florida and the Carolinas, the terraces are poorly
drained and may be saturated for part of the year.  Inland terraces are
narrower and more dissected than coastal terraces.  Relief may be
greater:  105 feet (35 m) compared to 45 feet (15 m) along the coast.
Differences in relief of only a few meters can affect vegetation in
these predominantly sandy soils [19].


CLIMATE : 
The southeastern Coastal Plain receives more than 48 inches (1,220 mm)
per year of precipitation.  This area has the highest frequency of heavy
downpours combined with the most rain-free days per year.  It also has
the highest evaporation rates in the East [19].  For the whole area
average annual precipitation is between 40 and 60 inches (1,000-1,520
mm) and average annual evaporation is 42 to 48 inches (1,060-1,220 mm).
In the eastern part of this region precipitation is lowest in the fall
and highest in midsummer.  In the west it is lowest in winter and spring
[7]. The southern mixed forest is subjected to annual hurricanes,
especially along peninsular Florida and the Gulf Coast.

The southern mixed forest experiences mild winters.  Average monthly
temperatures from December through February are above 40 degrees
Fahrenheit (4 deg C), with inland areas slightly cooler than coastal
areas.  Frost-free days occur from April first to November first, and
the growing season usually exceeds 210 days.  Florida is the warmest
area in the southern mixed forest with milder winters, longer growing
seasons, and more frost-free days than elsewhere in the region [19].


SOILS : 
Most of the soils in the Coastal Plains area are sandy [19], but range
from sandy or gravelly to moderately fine textured [7].  Soils in the
longleaf-slash pine type are typically acidic, low in organic matter,
and deficient in many essential plant nutrients [7].  In some places
older calcareous soils have been exposed by erosion.  Phosphate-rich
calcareous soils are common in peninsular Florida and scattered
throughout the region [19].


VEGETATION : 
The southern mixed forest region has been referred to as the oak-hickory
association or the beech-magnolia association based on potential natural
vegetation in the absence of fire [19].  Dominant overstory vegetation
is listed as American beech (Fagus grandifolia [not in central
Florida]), sweetgum (Liquidambar styraciflua), southern magnolia
(Magnolia grandiflora), slash pine (Pinus elliottii), loblolly pine (P.
taeda), white oak (Quercus alba), and laurel oak (Q. laurifolia) [10].
Loblolly pine now outnumbers the once abundant longleaf pine (Pinus
palustris) and slash pine.  Maps of the presettlement range of
fire-maintained longleaf pine savannas have been reconstructed [19].

Presettlement forests of the Southeast, which were savanna woodland fire
types, survive only as scattered relicts.  Now the vegetation is largely
postlogging, successional mixed pinehardwood forests [19].  Important
nondominant species include pignut hickory (Carya glabra), mockernut
hickory (C. tomentosa), redbay (Persea borbonia), and shortleaf pine
(Pinus echinata) in the northern range of this type; southern sugar
maple (Acer barbatum), American hornbeam (Carpinus caroliniana),
flowering dogwood (Cornus florida), inkberry (Ilex glabra), American
holly (I. opaca), yellow-poplar (Liriodendron tulipifera), wax myrtle
(Myrica cerifera), and eastern hophornbeam (Ostrya virginiana) in all
but central Florida; south Florida slash pine (Pinus elliottii var.
densa); cabbage palmetto (Sabal palmetto) in the eastern part of the
type; and southern red oak (Quercus falcata), bluejack oak (Q. incana),
turkey oak (Q. laevis), blackjack oak (Q. marilandica), post oak (Q.
stellata var. margaretta), live oak (Q. virginiana) and saw-palmetto
(Serenoa repens) in Florida and coastal areas [10].  Understory species
include wiregrass (Aristida stricta).  Also found here are tickclover
(Desmodium spp.), lespedeza (Lespedeza spp.), butterfly pea (Clitoria
mariana), senna (Cassia spp.), tephrosia (Tephrosia virginiana),
galactia (Galactia spp.), wild indigo (Baptisia spp.), and Heterothea
graminifolia [19].

A publication listing vegetation types of the southern mixed forest
follows.
   
Vegetation of the Archbold Biological Station, Florida: an example of
  the southern Lake Wales Ridge [1]


WILDLIFE : 
The southern mixed forest is home to an array of animals that includes
opossum, raccoon, white-tailed deer, feral pigs, squirrels, warblers,
woodpeckers, the cardinal, flycatchers, quail, snakes, frogs, and
turtles [19].  For a list of endangered species see WILDLIFE VALUES.


ECOLOGICAL RELATIONSHIPS : 
Before European settlement within the range of longleaf pine, mixed
forests dominated by American beech, southern magnolia, other hardwoods,
and semievergreen oaks may have been limited to small areas.  Relict
old-growth stands are still found on slopes, swamp islands, and upland
flats on peninsulas.  Due to a variety of moisture regimes and the
historic prevalence of periodic fires, the potential climax vegetation
following longleaf pine forests in the southern mixed forest is
difficult to predict.  Various authors have tried to extrapolate this
information from trees present in second growth-forests [19].  See FIRE
EFFECTS ON VEGETATION.

Longleaf pine usually occurs in pure stands on dry sites and is
considered fire subclimax [6,20,21].  It is a pioneer on areas cleared
by stand-replacing fire and is maintained by fire on dry sites
[12,20,21].  Slash pine has shallow spreading roots and is found on more
wet sites that may seasonally flood.  The two species may occur together
where fire has been absent for 5 to 10 years [21].  Loblolly pine occurs
on both well-drained and poorly drained sites and can establish
following fire [21].

Fire exclusion favors slash pine over longleaf pine in Florida and
favors loblolly pine over longleaf pine in the northern Coastal Plain.
On mesic sites where soils are rich in phosphate and calcium, American
beech and southern magnolia eventually replace pines in fire's absence
[8].  Sandy or nutrient-deficient soils usually do not support hardwoods
[3].

For more detailed information on community dynamics refer to Christensen
[5], Ware and others [19], and Eyre [21].  For more detailed information
on community dynamics related to fire in the southern mixed forest refer
to Ware and others [19].

Related categories for Kuchler Type: Southern mixed forest