Transcript Maritime Hammock - Wildlife Ecology and Conservation

Maritime Hammock
A Coastal Upland Habitat
Presentation by: Lorna McCallister
Coastal Uplands:
Mesic or xeric communities restricted to
barrier islands and near shore; woody or
herbaceous vegetation; other communities
may also occur in coastal environments
Definition of a Maritime Hammock
a.k.a. “Coastal hammock” or “Maritime forest”
Basic Components:
• Maritime- located near or next to the sea
• Hammock-stands of trees, usually hardwood, that form an
ecological island in a contrasting ecosystem
Maritime Hammock:
A predominantly evergreen hardwood forest growing
on stabilized coastal dunes lying at varying distances
from the shore.
Maritime Hammock
Distinguishing Characteristics of
Maritime Hammock

Statewide but rare in Panhandle and Keys

Stabilized coastal dune with sand substrate

Mesic-xeric

Evergreen closed canopy:

Temperate Maritime Hammock: live oak, cabbage palm, red bay,
red cedar

Tropical Maritime Hammock: gumbo limbo, seagrape, and white or
Spanish stopper

Rare or no fire

Marine influence
• Located on leeward side (the direction downwind) of dune
Distribution and Status

Present extent was established approximately 5,000 years ago,
becoming stabilized as sea level rise declined (Bellis 1995).

FNAI G2/S3 Imperiled globally because of rarity; found locally in a
restricted range or vulnerable to extinction from other factor

Outside of Florida:


Found inland from coastal strand communities on the Atlantic
coast and from coastal grassland communities on the Gulf coast.

On the East coast: North Carolina to South Florida
Within Florida:

Relatively continuous along the sandy Atlantic and southwest Gulf
coasts of the peninsula

Patchy along the Panhandle coast and rare in keys

In narrow strips from Jacksonville southward and from the Gulf
coast southward
Rare in
panhandle
Temperate
Tropical
Rare in
keys
Soil Structure

Stabilized coastal dune

Well-drained sand substrate

Mesic-xeric- little to moderate moisture levels

Occurs on deep well-drained acid quartz sands, such as Fripp soils on
Little Talbot Island

Or well-drained, moderately alkaline quartz sands mixed with shell
fragments, such as Palm Beach soils at MacArthur Beach State Park.
Plants and Animal Species

Must be able to tolerate:

strong winds

low nutrients


Benefits include:

Shelter from storms in
closed canopy
unpredictable supplies of
freshwater

Freshwater close to the
coast due to rains

erosion


sand-blasting
Rest and forage area for
species that migrate over
the Gulf or Atlantic waters

storm exposure


sand migration
Well-drained sand for
burrows

overwash from the ocean
during storm events
Canopy Structure


Temperate maritime hammock:

generally short forests (10 to 12 m)

monotonous canopy of Quercus virginiana, Sabal palmetto,
and Perrea borbonia

Structurally diverse understory of woody species including
small trees and shrubs which do not form clear layers.
Tropical maritime hammock:

South of northern Palm Beach County

Tropical canopy composed of a greater variety of trees,
including the three most common mentioned above
Salt Spray Effect

Salt spray from both the ocean and bay sides of islands
can enter and kill the upper buds, producing smooth,
“pruned” canopies of evenly increasing height away from
the coast

Tolerance to salt spray has been found to be the principal
factor that controls vegetative cover in maritime forests.

The low, streamlined profile deflects winds and generally
prevents hurricanes from uprooting the trees
Natural Processes of Change

Principally influenced by wind-borne salt spray, storm
waves, and sand burial.

If storm waves destroy the protective dunes seaward of
the hammock, sand can blow inland, burying the trees.

Tree mortality caused by standing salt water deposited in
low areas by storm surge
Temperate Maritime Hammock Canopy

1. Cabbage Palm (Sabal palmetto)

2. Live oak (Quercus virginiana)

3. Red bay (Persea borbonia)

4. Pignut hickory (Carya glabra)

5. Southern magnolia (Magnolia grandiflora)
1.
2.
5.
3.
4.
Temperate Maritime Hammock
Subcanopy

1. Red cedar (Juniperus virginiana)

2. American holly (Ilex opaca)
Shrubs

3. Yaupon (Ilex vomitoria)

4. Common Wax Myrtle (Morella cerifera)

5. Saw palmetto (Serenoa repens)
3.
4.
1.
2.
5.
Tropical Maritime Hammock
Characteristic Species

1. Seagrape (Coccoloba uvifera)

2. Gumbo limbo (Bursera simaruba)

3. Spanish stopper (Eugenia foetida)

4. White stopper (Eugenia axillaris)
2.
3.
1.
4.
Common Wildlife

Wading birds


Great blue herons (Ardea herodias), great egrets (Casmerodius
albus), snowy egrets (Egretta thula), little blue herons (Egretta
caerulea), tricolored herons (Egretta tricolor), night herons
(Nycticorax spp.), brown pelicans (Pelicanus occidentalis)
Birds of Prey

Red-shouldered hawks (Buteo lineatus), Cooper’s hawks (Accipiter
cooperii), bald eagles (Haliaetus leucocephalus)

Mammals


Eastern cottontails (Sylvilagus palustris), Norway rats (Rattus
norvegicus), river otters (Lontra canadensis), wild boar (Sus
scrofa)
Reptiles

Softshelled turtles (Trionyx ferox), gopher tortoises (Gopherus
polyphemus), cottonmouths (Agkistodon piscivorus), southern
black racers (Coluber constrictor priapus), eastern diamondback
rattlesnakes (Crotalus adamantus), indigo snakes (Drymarchon
corais couperi)
Rare and Obligate Plant Species
1.

1. Biscayne prickly ash (Zanthoxylum coriaceum)

2. Silver palm (Coccothrinax argentata)

3. Small-flowered lily thorn (Catesbaea parviflora)

4. Globally imperiled aboriginal prickly apple (Cereus gracilis var. aboriginum)

5. West coast prickly-apple (Cereus gracilis var. simpsonii)
2.
3.
4.
5.
Rare/Obligate Animal Species
Temperate and tropical maritime hammocks are crucial resting and foraging areas for
songbirds on their fall and spring migrations to and from the tropics.

1. Northern prairie warbler (Dendroica discolor)

2. Indigo bunting (Passerina cyanea)

3. Kirtland’s warbler (Setophaga kirtlandii)

4. Florida prairie warbler (Dendroica discolor paludicola)
Also:

Bald eagle (Haliaeetus leucocephalus)

Peregrine falcon (Falco peregrinus)

Florida panther (Puma concolor)

Eastern indigo snake (Drymarchon couperi)

Gopher tortoise (Gopherus polyphemus)
1.
3.
2.
4.
Habitat Issues and Management
Fire

Fires are naturally rare due to their coastal location with
water barriers on at least one, if not two sides.

Very spotty, especially on the narrower barrier islands

Fires may weaken the canopy trees making them more
susceptible to damage by other coastal stresses, such as
salt spray, storm winds, and invasive species.

Not a suggested tool for management for maritime
hammock but is used in surrounding coastal upland
habitats
Invasive Species

Australian pine and Brazilian pepper invade following storm
disturbance

Australian pine also colonizes newly formed barrier islands, thereby
pre-empting succession to native maritime hammock

Laurel Wilt Disease-fatal to trees of red bay over 1 inch dbh

is caused by a fungus spread by the exotic red bay ambrosia beetle
Management

Australian pine and Brazilian pepper: removal of whole plant + roots.
Herbicides, girdling, frilling, pulling, cutting stumps, basal bark herbicide
use, seedling removal. (The Maritime Hammock Sanctuary; Archie Carr National Wildlife Refuge)

Gradual introduction of native, low-growing, woody species to avoid salty
spray burn on taller species and erosion.

Laurel Wilt: As of 2009, there was no known means of treating. Control
firewood movement into habitats.

Removal of feral animals
Hydrology

Sea level rise- flooded sand and salt are not well tolerated by some
species, particularly the obligate species like the aboriginal prickly
apple.

Humans pumping fresh water from water lense disrupts salt and
freshwater balance, causing increase in salt water
Management

Plant more native shrubs/trees and add sand fences.

Control human traffic on coastal dunes (boardwalks). Limit/ban
fresh water pumping on barrier islands

Restore natural wetland areas- install ponds and plant with native
species (Maritime Hammock Preserve Cocoa Beach)
Anthropogenic Effects


Trees killed by salt spray after installation of parking lots
expose them to winds off the water
Coastal development and dune erosion
Management


Preservation of natural habitat- replanting of native
shrubs to prevent erosion, walkways, fencing, etc.
Greenways for wildlife, monitor water quality, natural
and boardwalk trail development, smarter park designs
(Maritime Hammock Preserve Cocoa Beach)

Grass parking lots with drainage.
Beach)
(Maritime Hammock Preserve Cocoa
How to Differentiate Maritime
Hammock from other Habitats
Maritime hammock is distinguished from coastal strand and coastal
grassland by the presence of distinct tree canopy and understory layers.
Coastal Strand
Maritime Hammock
Coastal Grassland
Maritime hammock and coastal berm may be similar in species
composition.
Distinguished primarily by location along a high wave energy sandy
coast, rather than a low- energy mangrove-dominated coast, and
the presence of a distinct canopy layer.
Coastal Berm
Maritime Hammock
Temperate maritime hammock is distinguished from mesic hammock
primarily by their occurrence on coastal sand dunes, the presence of
red bay in the canopy, and by an even, spray-pruned canopy shape.
Mesic Hammock
Maritime Hammock
Maritime hammock can be distinguished from xeric hammocks by the live
oak canopy, instead of sand live oak, and by the presence of cabbage palm
(Sabal palmetto).
Xeric Hammock
Sabal Palmetto
Maritime Hammock
Maritime hammocks differ from hydric hammock by their
occurrence on better drained soils and the absence of signs of
flooding in the understory.
Flooded Hydric Hammock
Maritime Hammock
In summary, Maritime Hammock:

Statewide on coasts, but rare in Panhandle and Keys

Leeward side of stabilized coastal dune

Sand substrate; mesic-xeric

Evergreen, spray-pruned, closed canopy:

Temperate: live oak, cabbage palm, red bay, red cedar

Tropical: gumbo limbo, seagrape, and white or Spanish stopper

Important for migrating song birds

Management of invasives, dune erosion, and hydrology

Major invasive species: Red ambrosia beetle, Australian Pine, and
Brazilian pepper