Coastal Strands and Barrier Islands
APB-4934
D. Bruce Means, Ph.D. Professor

Syllabus

Purpose.--The purpose of this course is to learn about the diversity of upland and wetland habitats in the coastal strands and barrier islands of the Gulf and Atlantic coasts of Florida and southeastern Georgia. Coastal strands are important uplands along the continental margins of the coasts of the world, affected in their plant and animal composition by wind, waves, and saltwater. Dry scrub habitats are formed along coastlines of the continent because of the actions of the three physical agents, producing very different biotic associations when compared to those on similar soils just a few hundreds of meters inland. Barrier islands, peninsulas, and spits are unique coastal environments created by wave and wind action, and affected by saltwater and intense sunlight. Islands are unique ecological and evolutionary laboratories containing plants and animals that are especially adapted for the harsh physical conditions on islands. Also, each barrier island is different, biotically, because of historical accidents of colonization and extinction. Fresh water, when it exists on barrier islands and peninsulas, teems with animal life and wetlands plants. Among the habitats we will explore are beaches, beach ridges, aeolian dunes, interdune swales, coastal scrub, slash pine maritime forest, sand pine forest, harwood maritime hammocks, and barrier island freshwater marshes, lakes, and ponds.

In this course, we will explore the differences among the Gulf coastal islands close to Tallahassee (St. Vincent, Crooked Island East and Shell Island) and two barrier spits (St. Joe Peninsula, Alligator Peninsula). We will explore the lower Apalachicola River floodplain and delta to understand the geological source of coastal sand bodies, then compare a Georgia or Florida coastal barrier island (Cumberland, Little St. Simons, or Amelia) on an overnight field trip for the course finale. The geological and physical processes that build-up and tear-down coastal strands and barrier islands will be thoroughly discussed in the classroom and in the field, with an examination of the effects upon humans--and the effects of human activities upon our coastlines.

Field Trip Itinerary:

Trip #1: Lower Apalachicola River. We go upriver from the town of Apalachicola into the floodplain swamps along the Brother’s River near Fort Gadsden. We walk the floodplain examining levees, tupelo-cypress swamp, mixed hardwood forest, point-bar plant succession, dredge-dumping sites, an old tram road through the swamp, and other riverine ecology. Field stops at archeological site upriver, mixed hardwood forest. Examine Apalachicola River riverine processes, high and low water hydrological regimes, low-water channel migration, oxbow lake. Discuss nutrient inputs to the Apalachicola Bay and visit sites where litter and organic muck are building up. Time permitting, examine the ecology of Alligator Peninsula on John H. Phipps Preserve. Look at human effects on coastal peninsula habitats, including man-made groundwater pond, control burning, and newly accreted peninsular tip.

Trip #2: Crooked Island East is compared with Shell Island, Tyndall Air Force Base. Examine Crooked Island East ecology in morning: drive peninsula to tip, walk beach, foredune field, backdunes, interdune flats, coastal grassland, coastal strand, Alligator Lakes, Hurricane Lakes, slash pine flatwoods, tip of peninsula accretion. Learn basic beach and dune ecology--wave- and wind-created sand deposits. Discuss St. Andrew Bay beach mouse evolution and ecology. Shell Island in afternoon. Walk from bay side through habitats to Gulf beach: cattail marsh, fresh water potholes, coastal grassland, coastal strand, slash pine flatwoods, back dunes and interdune flats, foredune field, beach. Discuss Choctawhatchee Bay beach mouse ecology, and compare what we have seen between the two different islands.

Trip #3: St. Vincent Island. Spend all day on the island, transported by USFWS people mover, by special arrangement. The island is a series of parallel beach ridges and interdune flat sets. There are about 12 different beach ridge sets, and about 180 separate beach ridges, averaging approximately 30 years per beach ridge. The beach ridges are usually close together, are not extremely high (20 feet above the flats), and are not very dune decorated. The highest dunes on the island are interior dunes that rise only to about 30 feet. The vegetation of the beach ridges varies from xeric mixed species scrub oak sandhills to exclusively liveoak-dominated sandhills, to liveoaks that have magnolias in them. Apparently liveoak is kept off the interdune flats by saturated and inundated soils during summer rains. Slash pine flourishes in the interdune flats and may be kept out of the beach ridges when young by shading from the liveoaks. We will visit a small stand of dwarf cyrilla in the center of the Island, but generally titis are wanting on the island and are replaced by buttonbush and, of all things, persimmon, in the low, wet sites in which one normally expects to see titi. About 200 Sambur Deer, Cervus unicolor, live on the island. This exotic deer with strong 3-pointed antlers weighs up to 650 lbs. We will visit "Tahiti Beach" on the east end, and another midden area on the northwest end of the island. These are 5-10 feet high oyster shell middens created by aboriginal man during the life of St. Vincent Id. (5,000-6,000 B. P.), and are up to 100-200 feet wide along the coastal margin. Note how much mollusk shell material was piled up by aboriginal human hands, favoring the establishment of cabbage palm, which has no doubt become the dominant tree on these sites since the middens were created. The midden on the northwest side of the island is a mixture of hardwoods (pignut hickory, southern magnolia, laurel oak, and wax myrtle and red cedar), all of large diameter.

Trip #4. Field trip to Cape San Blas, the largest cuspate foreland in western Florida, and St. Joe Peninsula. The Cape and peninsula have a complex recent history. Spend most of the day in St. Joseph Peninsula State Park examining beach dynamics, aeolian dunes, foredune herbaceous communities, backdune scrub communities, slash pine barrier island flatwoods, virgin sand pine stunted forest, hurricane blowouts, bayside marshes, midden hardwood hammock, and bayside beach wrack. Examine Atlantic ridley turtle nests. Compare and contrast St. Joe Peninsula with Crooked Island East and Shell Island.

Trip #5 & 6 Two-day, overnight field trip to coastal Georgia sea island. Day 1, drive to St. Mary's, take boat to Cumberland Island. Examine ancient relict dune communities on bay side of island in afternoon: magnolia-cedar-liveoak maritime forest, interdune swamps and ponds. Overnight camp out. Day 2, examine broad saltmarsh flats, wax myrtle and muhly grass sand ridges, back dune fields, foredunes, beach of sand and shells. Examine coastal zonation: marsh elder, sea oxeye, wax myrtle, muhlenbergia grass, bare sand. See alligators, wading birds, shore birds, marsh rabbits, and more. Compare Atlantic and Gulf barrier island habitats.

SUGGESTED REFERENCES FOR COASTAL STRANDS AND BARRIER ISLANDS COURSE

      Coastal Strands and Barrier Islands

Winds and waves sculpt sand into dunes and flats, barrier islands and spits, along the coastlines of the world. This course features pristine Gulf and Atlantic coastal strands, barrier islands, and their unique habitats: sea-oat dominated foredunes, scrubby backdunes, interdune grassland flats and swales, barrier island marshes, lakes, and ponds, slash pine flatwoods, and maritime hardwoods. Each island has its own unique mix of animals and plants, and all coastal islands teem with birds and wildlife. Spend some glorious time this summer on Shell Island, Crooked Island, St. Joe Peninsula, St. Vincent Island, John H. Phipps Preserve on Alligator Peninsula, Aucilla State Preserve, and one day in the mouth of the Apalachicola River where it all starts. Course finale is two days overnight on a beautiful Georgia sea island. Maximum enrollment is 15 persons. This course is approved for recertification credit.

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