Florida's Natural Habitats part 1

A Hiker, Wildlife Watcher, and

Citizen-Scientist Guide to Identifying

FLORIDA’S NATURAL HABITATS

DEFINED AND SORTED BY

MOISTURE, SOIL TYPE, AND DOMINANT SPECIES.

These native habitats have been categorized and sorted by moisture level and duration, soil type, and dominant species to represent Florida’s terrestrial, freshwater, and marine ecosystems. The objective has been to group Florida’s diverse native habitats in a meaningful manner that can be easily understood by hikers, wildlife watchers, and everyday citizen-scientist. Some habitat definitions were taken from the public work entitled “Florida Fish and Wildlife Conservation Commission. 2005. Florida’s Wildlife Legacy Initiative. Florida’s Comprehensive Wildlife Conservation Strategy. Tallahassee, Florida, USA.”This book was designed as a field reference companion to “Boardwalks and Long Walks: Rediscovering Florida”© 2012 William Holcomb

 These habitat types are the natural habitats: those that are not in transition from one type to another, nor modified or damaged by man. These undisturbed, naturally occurring habitats are easier to identify and understand. Learning these naturally occurring habitats simplify the learning process to less than 40 well defined habitats. With over 181 habitat types listed in the "Florida Natural Areas Inventory", it is clear that there are many habitat areas that are in transition or have been modified by man. In the field habitats can be nested one within the other, or transition without a distinct border. 

 

The final entry includes a special case, that of the Shell Mound habitat type. It is so wide spread in Florida, with a huge cultural and historical significance, that it warrants its own entry. The Shell Mound Habitat is not naturally occurring, in that paleo-indians created these raised areas. Prior to 800 A.D. these mounds likely did not exist, and most have been left alone by man from the 1500's until the early 20th Century when many mounds were destroyed to be used as road fill. Chemically, they are composed of the calcium rich shells of shell fish in an area outside the normal calcareous  habitat areas of the exposed or underlying limestone of north central Florida. As unique, they are listed as a separate, if not "Natural Habitat".

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Marine Habitats generally from off-shore to in-shore order are: Pelagic, Coral Reef, Hard Bottom, Bivalve Reef, Beach/Surf Zone, Subtidal Unconsolidated Marine Estuary,  Coastal Strand, Mangrove Swamp, Inlet , Tidal Flat, Salt Marsh, and Coastal Tidal River or Stream.

Pelagic Habitat- The open ocean, the area of the ocean outside of coastal areas, is where you find some of the biggest marine life species. The sea floor is not included in the pelagic zone. Typical life you’ll find in this zone includes cetaceans and large fish such as bluefin tuna,  invertebrates such as jellyfish, and giant squid.

 Coral Reef Habitat- There are hundreds of coral species found in the world’s oceans. There are two types of corals: hard corals and soft corals, such as sea fans and gorgonians. Only hard corals build reefs. The majority of coral reefs are found in tropical and sub-tropical water within the latitudes of 30 degrees north and 30 degrees south. They are thought to support more than 1 million aquatic species. This includes several hundred species of coral, and thousands of fish and invertebrate species such as sponges, crabs, shrimps, lobsters, sea anemones, bryozoans, worms, sea stars and sea urchins, octopuses, squid, snails and nudibranchs. It is estimated that nearly one-quarter of the world’s marine species are sustained by the shelter and food provided by coral reefs.

Hard Bottom Habitat- Refers to a classification of coral communities that occur in temperate, subtropical, and tropical regions that lack the coral diversity, density, and reef development of other types of coral communities. These exposed areas of rock or consolidated sediments, distinguished from surrounding unconsolidated sediments, which may or may not be characterized by a thin veneer of live or dead biota, generally located in the ocean rather than in the estuarine system.

 Bivalve Reef Habitat- This habitat is comprised of dense, expansive concentrations of sessile mollusks that attach to hard substrates and each other. Bivalve Reefs occur in both intertidal and subtidal zones to depths of 40 feet. The Bivalve Reef habitat is a diverse ecological community that provides nursery grounds, refuge, and foraging areas to a wide variety of wildlife species. This habitat is comprised mostly of eastern oyster and the animals that feed on them.

 Beach/Surf Zone Habitat- This is the long, often narrow strip of sand and shells between the tides.  Daily flooding by salt water and moderate- to high-energy waves prohibit plant growth except for some inconspicuous algae. Low-energy beaches provide important spawning habitat for horseshoe crabs and feeding habitat for multiple species of shorebirds. Beach dunes are mounds of windblown sand that are periodically inundated by seawater during extreme high tides and storms. Vegetation on beach dunes varies regionally in Florida but is restricted to a few highly specialized terrestrial plants. Florida beaches are important nesting sites for several species of shorebirds and wintering grounds for others. Beaches are also vital nesting sites for many sea turtles and support numerous other mammals and invertebrates. The surf zone is an important nursery and feeding habitat for many species of fish including Permit and Florida Pompano.

Subtidal Unconsolidated Marine Estuary Habitat- This habitat consists of mineral based natural communities generally characterized as expansive, relatively open areas within subtidal, intertidal, and supratidal zones that are less than 10 percent colonized by Submerged Aquatic Vegetation or corals. Substrates include coralgae, marl, mud, mud/sand, sand or shell.  This habitat category may support large populations of infaunal, transient planktonic and pelagic organisms like tube worms, sand dollars, mollusks, isopods, amphipods, burrowing shrimp, and an assortment of crabs. The intertidal and supratidal zones are important feeding areas for many shorebird and invertebrate species. Furthermore, infaunal organisms in subtidal zones can reach very high densities making these areas important feeding grounds for many bottom feeding fish.

Coastal Strand Habitat- This habitat encompasses dunes and more landward areas typically described as coastal strand, as well as areas that may be described as upper beach and coastal rock formations. Coastal Strand is the vegetated zone that typically occurs between open beach and maritime hammock habitats. Coastal Strand occurs on deep, well-drained, sandy soils that are largely wind-deposited and washed or sorted by wave action to some extent. This habitat generally occurs in long, narrow bands along high-energy shorelines, parallel to the open waters of the Atlantic Ocean, Gulf of Mexico, and some coastal bays or sounds in both north and south Florida. Vegetation in this habitat is strongly affected by wind, wave action, and salt spray and consists of low-growing vines, grasses, and other herbaceous plants and salt-tolerant shrub species that, in some areas, may form dense thickets. Typical plant species of Coastal Strand include beach morning glory, railroad vine, sea oats, saw palmetto, Spanish bayonet, yaupon holly, wax myrtle, and sea grape.  

 

Maritime Hammock Habitat is a predominantly evergreen hardwood forest growing on stabilized coastal dunes lying at varying distances from the shore. The low, streamlined profile deflects winds and generally prevents hurricanes from uprooting the trees. Canopy species include pignut hickory  and southern magnolia with subcanopy species like red cedar and American holly. Wax myrtle, and saw palmetto are typical shrubs with little herbaceous layer.  Maritime hammock occurs on deep well-drained acid quartz sands, or well-drained, moderately alkaline quartz sands mixed with shell fragments. Live oak, cabbage palm, red bay, and eastern red cedar are characteristic of temperate maritime hammock. Gumbo limbo, seagrape, and white or Spanish stopper are characteristic of tropical maritime hammock.

 Mangrove Swamp Habitat- Mangroves form dense, brackish-water swamps along low-energy shorelines and in protected, tidally influenced bays of southern Florida. This community type is composed of freeze sensitive tree species and, with some limited exceptions, mangroves which are distributed south of Cedar Key on the Gulf coast and south of St. Augustine on the Atlantic coast. These swamp communities are usually composed of red mangrove, black mangrove, white mangrove and buttonwood mangrove. Depending on slopes and amounts of disturbance, mangrove swamps may progress in bands of single species from seaward the red mangrove, to landward the white mangrove areas. Buttonwood mangroves usually occur in areas above high tide. Often vines  such as rubber vines and morning-glory clamber over mangroves, especially at swamp edges.

Inlet Habitat- Inlets are natural or man-made cuts in the shoreline that link coastal and inland water bodies. This habitat is defined as the subtidal area within a two-kilometer radius of the throat of the Inlet. These features tend to be hot spots of biodiversity and are critical in the recruitment of many fish and invertebrate species. Inlets provide habitat for the settling larvae from coastal areas and provide an emigration conduit for outgoing juveniles. They also are essential spawning habitat for several marine fishes.

 Tidal Flat Habitat- Tidal flats are non-vegetated areas of sand or mud protected from wave action and composed primarily of mud transported by tidal channels. An important characteristic of the tidal flat environment is its alternating tidal cycle of submergence and exposure to the atmosphere.

 Salt Marsh Habitat- Salt Marsh is vegetated almost completely by herbaceous plants, primarily grasses, sedges, and rushes. This community type occurs within the intertidal zone of coastal areas and may be inundated by salt or brackish water. Salt Marsh develops where wave energies are low and where mangroves are absent. Mangroves may extirpate shade-intolerant marsh species. The size of a Salt Marsh depends on the extent of the intertidal zone in which it occurs. Salt Marshes of larger sizes are usually dissected by numerous tidal creeks. Areas that have low topographic relief and relatively high tidal ranges are likely to have larger Salt Marsh extents. Within Salt Marsh, plant species are often distributed unevenly, especially in transitional areas. Species distributions are affected by variables such as elevation, substrate type, degree of slope, wave energy, competing species, and salinity.  Smooth cordgrass typically occupies the lower elevations and is usually adjacent to tidal creeks and pools. Needlerush dominates the slightly less frequently inundated zone. Vegetation at the higher elevations forms transitional areas to uplands and may contain species such as marsh-hay, glassworts, saltwort, saltgrass, sea ox-eye daises, marsh-elder, and saltbush as well as many other species. The Salt Marsh habitat is among the most productive communities in the world. Primary production is greatly affected by soil salinity and tidal frequency.

Coastal Tidal River or Stream Habitat- Coastal Tidal River or Stream habitat includes the freshwater or brackish portions of a river or stream adjacent to an estuary or marine habitat in which the effects of tides cause the rise and fall of water levels. The effect of the tides at the upper limits of influence may lag several hours behind tides on the coast. The amount of water movement is controlled by the height of the tides, tidal range, downstream freshwater flow rates, rainfall, and wind. Saltwater wedges are formed in many of these systems, enabling numerous species a mechanism to move up or down river. Water flow is bidirectional in coastal tidal rivers and streams; as the tide rises, water flows toward the head of the river and, as the tide retreats, the water flows toward the coastal outlet. This habitat bridges the freshwater and marine realms, with aquatic communities ranging from tidal freshwater to tidal brackish; salinities can vary from freshwater to approximately that of seawater. This variation, along with temperature and water clarity, determines the flora and fauna of the Coastal Tidal River or Stream. Typical plants may include cord grass or submerged aquatic vegetation such as sea grasses and algae. The Coastal Tidal River or Stream comprises the dominant stream habitat in the south Florida region. The most extensive area of this habitat occurs in the lower St. Johns River. Other coastal bay systems such as Choctawhatchee Bay, Pensacola Bay, Tampa Bay, and Charlotte Harbor are also included in this habitat. Numerous small tidal creeks and coastal rivers are also included, especially in the Big Bend region of Florida’s Gulf coast along with the lower portions of other large rivers including the Suwannee and Escambia.

 (C) 2012 Part 1 of 4 Companion to "Boardwalks and Long Walks"  Will Holcomb

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