Part 3 Florida's Natural Habitats
The
Dry Land Habitats listed from
dry to damp are: Sandhill, Scrub, Dry
Prairie, Pine Rockland, Natural Pineland, Hardwood Hammock Forest, Mixed
Hardwood-Pine Forest, Tropical Hardwood
(Rockland) Hammock. Many of these habitats only vary slightly by the
underlying soil type and the dominant tree species.
Sandhill Habitat- Sandhill communities occur only in north and
central Florida in areas of gently rolling terrain on deep, well-drained,
mostly yellow, sterile sands. This xeric community is dominated by an overstory
of widely spaced, scattered longleaf pine, along with an understory of turkey
oak, sand post oak, and bluejack oak. The park-like ground cover consists of
various grasses and herbs, including wiregrass, lopsided Indian grass,
bluestems, blazing star, partridge pea, beggars tick, milk pea, queen's
delight, and others. Due to the poor water retention properties of the soils
and open canopy, temperature and humidity fluctuate rapidly and frequently in
this habitat compared to highmoisture closed-canopy forests. However, many temporary
wetlands are found throughout Sandhill landscapes and are an integral part of
this habitat type, providing breeding and foraging habitat for many wildlife
species. Sandhill is a community that is sustained by ground fires with short
return intervals to reduce hardwood intrusion and to promote flowering of many
grasses and herbs. In the absence of fire, Sandhill will eventually succeed
into a xeric hammock. Sand pine can quickly invade Sandhills where seed sources
are available and fires are suppressed.
Scrub Habitat- This habitat occurs on areas of deep,
well-drained, infertile sandy soils that are typically white or near white.
Scrub has a patchy distribution and occurs in both inland and coastal areas,
from the panhandle through subtropical regions of the peninsula. The largest
and most important patches of Scrub occur along the central ridge of the
peninsula near Ocala and in Polk and Highlands counties. This habitat is
fire-dependent; it is maintained by fires that are usually very hot or intense,
but occur infrequently at intervals of 10-20 years, or more. Generally, Scrub
is dominated by evergreen, or nearly evergreen, oaks and/or Florida rosemary,
with or without a pine overstory. A relatively large suite of plant species is
endemic to Scrub, the rarest endemic plant species are restricted to the Lake
Wales area of the central (Lake Wales) ridge. Some species of wildlife also are
endemic or largely restricted to Scrub habitat like the Florida scrub-jay and
sand skink. Several types of Scrub are recognized. Oak Scrub is a hardwood
community typically consisting of clumped patches of low growing oaks
interspersed with patches of bare, white sand. Pines are uncommon or absent.
Oak Scrub is dominated by myrtle oak, Chapman's oak, sand-live oak, inopina oak,
scrub holly, scrub plum, scrub hickory, rosemary, scrub palmetto, and saw
palmetto. Sand Pine Scrub occurs on former shorelines and islands of ancient
seas. This plant community is dominated by an overstory of sand pine and has an
understory of myrtle oak, Chapman's oak, sand-live oak, rusty lyonia, wild
olive, scrub bay, and scrub holly. Ground cover is usually sparse to absent,
especially in mature stands, and rosemary and lichens occur in some open areas.
Rosemary Scrub has few or no sand pines or scrub oaks but is dominated by
rosemary with scattered lichen cover, scrub hypericum, and paper nailwort. Many
temporary wetlands are found throughout the Scrub landscape and are an integral
part of this habitat type, providing breeding and foraging habitat for many
wildlife species. One of the most pristine examples of the Scrub Habitat is protected and maintained at the Archbold Biological Station. The station is open to the public, and has operating scientific research on a daily basis.
Dry Prairie Habitat- Dry Prairies are large native grass- and
shrub-lands occurring on very flat terrain interspersed with scattered cypress
domes and strands, bayheads, isolated freshwater marshes, and hardwood
hammocks. This community is characterized by many species of grasses, sedges,
herbs, and shrubs, including saw palmetto, fetterbush, staggerbush, tar flower,
gallberry, blueberry, wiregrass, carpet grasses, and various bluestems. The
largest areas of these treeless plains historically occurred just north of Lake
Okeechobee. In central and south Florida, palmetto prairies, which consist of
former pine flatwoods where the overstory trees have been thinned or removed,
are also included in this category. These sites contain highly scattered pines
that cover less than 10 to 15 percent of an area.
Pine Rockland Habitat- Pine Rockland is a unique type of pine
flatwoods that is found exclusively on limestone substrate in the Florida Keys,
the Big Cypress Swamp, and the Miami Rock Ridge (the limestone outcropping that
rises from the Everglades to heights of 23 feet above sea level. The overstory
of Pine Rockland habitat contains a single canopy species, South Florida slash
pine. The dominant pines tower over a savanna-like understory of saw palmettos,
locust berry, willow bustic, beauty berry, broom grasses, silver palms, and a
rich herbaceous layer. This community is often associated with rockland hammock
and other short-hydroperiod freshwater wetland communities. These sub-tropical
pine trees and understory plants have adapted to seasonal wildfires and the
lack of soil on the exposed limerock. Pine Rockland communities are globally
imperiled and support federal and state listed plant species, such as deltoid
spurge and Small’s milkwort which only occur in this habitat.
Natural Pineland Habitat- This category includes natural pine forests,
excluding pine rocklands, sandhills, and sand pine scrub, which are listed as
separate categories. Natural Pineland habitats include mesic, hydric and
scrubby flatwoods, and upland pine forests. Pine flatwoods occur on flat sandy
terrain where the overstory is characterized by longleaf pine, slash pine, or
pond pine. The type of pineland habitat present is usually related to soil
differences and small variations in topography. Hydro-period is an important
factor determining what kind of pineland is represented. Generally, flatwoods
dominated by longleaf pine occur on well-drained sites while pond
pine-dominated sites occur in poorly drained areas, and slash pine dominated
sites occupy intermediate or moderately moist areas. The understory and ground
cover within these three communities are somewhat similar and include several
common species such as saw palmetto, gallberry, wax myrtle, and a wide variety
of grasses and herbs. Generally, wiregrass and runner oak dominate longleaf
pine sites; fetterbush and bay trees are found in pond pine areas, while saw
palmetto, gallberry, and rusty lyonia occupy slash pine flatwoods sites.Scrubby
flatwoods habitat typically occurs on drier ridges, many of which formed
originally on or near old coastal dunes. Longleaf pine or slash pine dominates
the overstory, whereas the ground cover is similar to that present in xeric oak
scrub habitat. Cypress domes, bay heads, titi swamps, and freshwater marshes
are commonly interspersed in isolated depressions throughout natural pineland
habitats. A wide variety of animals utilize this habitat including the
white-tailed deer, eastern diamondback rattlesnake, red-cockaded woodpecker,
and pine woods tree frog. Fire is an important factor that helps to maintain
and shape Natural Pineland communities; almost all of the plants and animals
found here are adapted to having fires occur at least every one to eight years.
Hardwood Hammock Forest Habitat - This class includes the major upland
hardwood associations that occur statewide on fairly rich sandy soils.
Variations in species composition and the local or spatial distributions of
these communities are due in part to differences in soil moisture regimes, soil
type, and geographic location within the state. Mesic and xeric variations are
included within this association. The mesic hammock community represents the
climax vegetation type within many areas of northern and central Florida.
Characteristic species in the extreme north include American beech, southern
magnolia, Shumard oak, white oak, mockernut hickory, pignut hickory, sourgum,
basswood, white ash, mulberry, and spruce pine. Mesic hammocks of the peninsula
are less diverse due to the absence of hardwood species that are adapted to
more northerly climates, and are characterized by laurel oak, hop hornbeam,
blue beech, sweetgum, cabbage palm, American holly, and southern magnolia.
Xeric hammocks occur on deep, well-drained, sandy soils where fire has been
absent for long periods of time. These open, dry hammocks contain live oak,
sand-live oak, bluejack oak, blackjack oak, southern red oak, sand-post oak,
and pignut hickory. Also included in this category are cabbage palm-live oak
hammocks. This class is characterized by cabbage palms and live oaks occurring
in small clumps within prairie communities. These hammocks typically have an
open understory which may include such species as wax myrtle, water oak, and
saw palmetto. Cabbage palm-live oak hammocks are also often found bordering
large lakes and rivers, and are distributed throughout the prairie region of
south central Florida and extend northward in the St. Johns River basin.
Cabbage palms often form a fringe around hardwood “islands” located within
improved pastures.
Mixed Hardwood-Pine Forest Habitat- This community is the southern extension of
the Piedmont southern mixed hardwoods, and occurs mainly on the rolling hills
of sandy clay soils of the northern Panhandle. Younger stands may be
predominantly pines, whereas a complex of various hardwoods become co-dominants
as the system matures over time through plant succession. The overstory
consists of shortleaf and loblolly pine, American beech, mockernut hickory,
southern red oak, water oak, American holly, and dogwood. Also included in this
category are other upland forests that occur statewide and contain a mixture of
conifers and hardwoods as the co-dominant overstory component. These
communities contain well developed associations of longleaf pine, slash pine,
and loblolly pine in mixed company with live oak, laurel oak, and water oak,
together with other hardwood species characteristic of the Hardwood Hammock
Forest community type. In this habitat, the ground is usually covered with a
thick layer of leaf mulch which helps in the retention of moisture. Adding to
the mesic condition is a thick canopy with low air flow and light penetration.
Due to this damp environment, Mixed Hardwood-Pine Forests seldom burn.
Tropical Hardwood Hammock Habitat- These upland hardwood forests occur only in
south Florida and are characterized by tree and shrub species on the northern
edge of a range that extends southward into the Caribbean. These communities
are sparsely distributed along coastal uplands south of a line from about Vero
Beach on the Atlantic coast to Sarasota on the Gulf coast. They occur on many
tree islands in the Everglades and on uplands throughout the Florida Keys. This
cold-intolerant tropical community has very high plant species diversity,
sometimes containing over 35 species of trees and about 65 species of shrubs.
Characteristic tropical plants include strangler fig, gumbo-limbo, mastic,
bustic, lancewood, ironwoods, poisonwood, pigeon plum, Jamaica dogwood, and
Bahamalysiloma. Live oak and cabbage palm are also sometimes found within this
community. Tropical Hardwood Hammocks in the Florida Keys may also contain
several plants, including lignum vitae, mahogany, thatch palms, and manchineel,
which are extremely rare within the United States.
(C) 2012 Companion book to "Boardwalks and Long Walks" Will Holcomb
