Ecology of South Florida (EVR 3013) LECTURE 19

UPLAND COMMUNITIES IV
BEACH STRAND AND DUNES

AT TEN THOUSAND ISLANDS

Discarded pens shells
write a wavering sentence
along gulf sand
marking the shore
with iridescent ink.
The tide punctuates the lines
with capitals of coral,
commas of sea grape.

Black mangroves wade into the surf
on legs of salt-impervious roots
widening a jungle island that clings
to the limestone pinnacle of rock
of this shallow sea.
Anhingas dive,
ospreys hide,
herons pose.

The lone pelican
soars free and far.
The sea is his, the sky is his.
He knows the ways of the people
along the beach,
yet none of them can know
into which dark corner
of the sunset he goes.

William Mundell (1989) [in Jones and O'Sullivan 1995]
HANDOUTS: Species List for Beach Strand and Dunes

I. DEFINITIONS - STRAND AND DUNE

Florida has 1,900 km of coastline, excluding the Keys
1,200 km of coastline is sandy with well-developed barrier islands
Sandy shores are high energy shores - low energy shores are dominated by mangroves or salt marshes

II. PHYSICAL FEATURES

A. Distribution

high energy coastlines

B. Physical Attributes

1. Sloping shore lines

2. Barrier Islands

Barrier islands are linear islands of sand than form parallel to the shore.

3. Harsh physical conditions

wind
waves
salt spray - wind pruning

4. Unstable jetties

5. Zonation

upper beach and fore dune
i. open
ii. vine
iii. grass
iv. prickly
dune front (strand)
back dune

C. Geology and Soils

1. North vs. South

Northern Florida beaches composed of quartz sands. Southern beaches composed of quartz and calcium carbonate.

2. Origins

Quartz comes from Appalachians in SE US. Coastal plain receives little sediment. Important sources of sediment are the Apalachicola and Ochlockonee Rivers in the panhandle and the Santee, Savannah, and Altamaha Rivers in Georgia and South Carolina.

3. Anthropogenic sediments

Sediments of modern beaches come from reworked offshore deposits rather than directly from source areas.

4. Gradiation

Calcium carbonate increases toward the south:

Jacksonville		10%
Miami		40%
Cape Florida		100%

D. Hydrology

Extremely well-drained

III. PLANTS

A. Physiognomy

1. fore dune

vine, grass, spiny herbs

2. dune front

stunted shrubs, grasses

3. back dune

shrubs changing to hammocks depending on age and protection

B. Species

1. vine

Canavalia rosea (seaside bean) and Ipomoea pes-caprae (railroad vine)

2. grass

Distichilis spicata (saltgrass), Helianthus debilis (Beach sunflower), Uniola paniculata (sea oats) - growth and tillering stimulated by burial.

3. prickly

4. dune front

Coccoloba uvifera (sea grape) & Serenoa repens (saw palmetto) may be salt sensitive

5. back dune

hammock species

C. Plant species diversity

Relatively low.

D. Related communities

Hammocks, scrub.

E. Endemics, exotics and diversity

1. Endemics

include 22 taxa in Florida
Cereus gracilis var. Simpsonii
Helianthis debilis
Jacquemontia reclinata

2. Exotics

Casurina equisetifolia (Australian pine)
Scaevola taccada
Schinus terebinthifolius (Brazilian pepper)

3. Diversity

**Plant species list for beach strand & dune**
1. Vines
Railroad vine		Ipomoea pes-caprae
Seaside bean		Canavalia rosea
2. Herbs
Sea oats		Uniola paniculata^SSC*
Beach sunflower		Helianthus debilis
Saltgrass		Distichilis spicata
3. Shrubs
Saw palmetto		Serenoa repens
Ink berry		Scaeovola plumeiri^T
Spanish bayonet		Yucca aloifolia
4. Trees
Sea grape		Coccoloba uvifera
Australian pine		Casurina equisetifolia^ex

IV. ANIMALS

Animal species diversity is relatively high, especially birds

**Animal species list for beach strand**
1. Birds
Brown pelican		Pelicanus occidentalis^SSC
Double-crested cormorant		Phalacrocorax auritus
Fish crow		Corvus ossifragus
Great blue heron		Ardea herodius
Laughing gull		Larus atricilla
Osprey		Pandion haliaetus^SSC
Ring-billed gull		Larus delawarensis
Royal tern		Stern maxima
Ruddy turnstone		Arenaria interpres
Sanderling		Calidris alba
2. Mammals
Gray fox		Urocyon cineroargenteus
Opossum		Didelphis virginiana
Raccoon		Procyon lotor
3. Reptiles
Green sea turtle		Chelonia mydas^T
Loggerhead turtle		Caretta caretta^T
Red rat snake		Elaphe guttata
4. Butterflies
Giant swallowtail		Heraclites cresphontes
Gulf fritillary		Agraulis vanillae
Monarch		Danaus plexippus
Zebra		Heliconius charitonius [state butterfly]
5. Insects
Black saltmarsh mosquito		Aedes taeniorhynchus
Honey bee		Apis mellifera
6. Gastropods
Horse conch		Pleuroploca gigantea [state shell]
Queen conch		Strombus gigas^SSC
7. Jellyfish
Portuguese man-of-war		Physalia physalia
8. Polychaetes
Honeycomb tubeworm		Phragmatopoma lapidosa

For superscript by species name: C = commercially exploited, SSC = species of special concern, T = threatened. Florida Game and Freshwater Fish Commission listings. EX = exotic.

V. ECOLOGICAL PROCESSES

A. Fire

unknown

B. Productivity (g C m-2 yr-1)

C. Succession

Hammock species such as Metopium toxiferum, Swietenia mahogoni and Bursera simarouba, and Dipholis salicifolia increase in the absence of fire.

D. Hurricanes

V. HUMAN EFFECTS

A. Pre-Colombian

aboriginal burning - importance is unknown
hunting
mound building

B. 18th and 19th century

Homesites and agriculture
Development

Commodore Munroe:
... Of all the hard problems, I think of making the seawall look like anything but what it is --- a fright of masonry --- has been hardest. I don't like sea-walls, and will never have one on my place. I have traveled the world over, and cannot recall a single one which I would like to have always within sight. . . .
And now you tell me that the beaches are to go---these delightful things which lured us to Biscayne Bay years ago, and still haunts us with their charm.
There is something to me truly pathetic in the spectacle of one of the oldest pioneers on Biscayne Bay having to stand up and cry out, like John the Baptist crying in the wilderness, 'For God's sake save the beaches of the Bay!' Is there nobody among the winter residents who will stand beside you and help you fight the battle?
Wishing you, my dear Commodore, everything that you deserve, I remain

David Fairchild
(p. 337 in R. Munroe and V. Gilpin, The Commodore's Story).

C. 20th century

Wide scale development
Stabilization
Exotic species

Back to start, Back to lecture 10, 11, 12, 13, 14 &15, 17, 18, On to Practice Test II

UPLAND COMMUNITIES IV BEACH STRAND AND DUNES