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I.
Flowering Plants (Anthophyta)
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Few truly marine species
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Seagrasses entirely submerged most of the time; other
marine angiosperms intolerant of prolonged immersion
Secondary “invaders” of marine ecosystems
Expend considerable energy coping with effects of
salt water
Seagrasses (66 species)
A.
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Monocots
Not true grasses (related to lilies)
Hydrophytes (usually immersed)
Roots, stems and shoots grow from horizontal rhizome
Flowers typically small and inconspicuous (Why?)
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Pollen carried by water currents (hydrophilous pollination);
No need to attract pollinators
Highest diversity in Indo-West Pacific (lowest in Atlantic)
Fig. 7-15
- Lacunae: Gas transport and buoyancy
- Nodes: Growth and lateral branching
- Sheath: Protects base of blade
- Roots: Root hairs for absorption of minerals
Aerenchyme
- Gas transport
- Buoyancy
- Liquid not
transported by
lacunae
Fig. 7-17
Eelgrass (Zostera marina)
Surf Grass (Phyllospadix scouleri)
Turtle Grass (Thalassia species)
Paddle Grass
Halophila sp.
Fig. 7-16
Leaves cylindrical
Manatee Grass
Syringodium filiforme
Fig. 7-16
Leaves in pairs
I.
Flowering Plants (Anthophyta)
A.
Seagrasses
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Leaves – periods of growth & senescence
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Small blades/rapid senescence  few epiphytes
Large blades/slow senescence  more epiphytes
Relatively weak attachment of leaves
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Protects rhizome from breakage
Facilitates recovery following damage from storms, grazing
Important in sediment deposition, stabilization
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Enhance deposition of fine particles
Reduce flow, resuspension of sediment
Support diverse ecosystem
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Many species inhabit seagrass beds
Below sediment-water interface: rhizosphere
Symbiotic associations with lucinid clams (Zostera)
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Roots oxygenate sediments
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Clams oxidize sulfide (van der Heide et al. 2012)
I.
Flowering Plants (Anthophyta)
B.
Salt Marsh Plants
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Facultative halophytes
Shallow roots and rhizomes
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1.
backbaybirds.com
Stabilize soils and sediments (esp. grasses & rushes)
Cycle nutrients (esp. phosphorus)
Food for terrestrial animals
Cordgrass (Spartina)
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Salt-tolerant true grass
Salt glands in leaves excrete excess salts
Inhabit temperate soft-bottom coastal areas
Important sources of
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Detritus for estuarine food webs
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Habitat for birds, fishes, etc.
Primarily propagate vegetatively
Fig. 7-21
Cordgrass (Spartina alterniflora)
Fig. 7-19
I.
Flowering Plants (Anthophyta)
B.
Salt Marsh Plants
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Needlerushes
Saltworts
Glassworts
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Succulent leaves, cuticle help to retain water
Pickleweed (Salicornia)
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Occurs at higher levels in marsh with less
inundation by salt water
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Edible (sea beans)
Needlerush (Juncus)
Saltwort (Batis)
Pickleweed (Salicornia)
Glasswort (Sarcocornia)
Fig. 7-20
I.
Flowering Plants (Anthophyta)
C.
Mangroves
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Salt tolerant shrubs, trees, palms, ferns (54+ species)
Tropical terrestrial plants living in protected areas with
soft sediments, often organic-rich, anoxic
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All share certain characteristics
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Avicennia germinans
eolspecies.lifedesks.org
Poor competitors
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Shallow, broad root system and aerial roots with
pneumatophores (pores for gas exchange)
Salt tolerance (halophytes)
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Salt exclusion at roots
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Tough, succulent leaves: thick cuticle, reduced stomata,
storage of water & salt, senesce
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Salt glands: excrete excess salt
Viviparity (mainly seaward spp.)
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Embryo grows on parent plant  propagule
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Hypocotyl develops, buoyant after separation from
parent (red mangroves)
Red
Mangrove
Red mangrove
- Propagules
w/hypocotyl
Black mangrove
- Propagules
Buttonwood
- Floating seeds
White mangrove
- Floating seeds
Fig. 7-24
I.
Flowering Plants (Anthophyta)
C.
Mangroves
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Root systems designed for immersion in soft,
anoxic sediments
Mostly horizontal, shallow
Pores for gas exchange
Black mangrove
Red mangrove
Fig. 7-22
Red mangrove
- Prop root
Black mangrove
- Cable root
Fig. 7-23
I.
Flowering Plants (Anthophyta)
C.
Mangroves
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Mangrove forests = mangals
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Broad distribution in tropics
Co-occur with coral reefs but more tolerant of
temperature extremes than hermatypic corals and
occur over a wider geographic range
Maximum diversity in Indo-West Pacific
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Some mangals may contain up to 30 species
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Ten species in New World, three in Florida
Fig. 14-19
I.
Flowering Plants (Anthophyta)
C.
Mangroves
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Mangrove forests (mangals)
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Extremely productive systems
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High levels of solar radiation, efficient nutrient
recycling
Provide important habitat for many spp., including
larval and juvenile life stages
Protect shorelines against erosion and wave action
Create new land
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Ex: Marco Polo visited port city of Palembang
(Sumatra) in 1292 when city was directly on coast
- As of 1967, Palembang was 50 km inland, a land
accumulation rate of 73 m y-1 over 675 y
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Ex: Java - Accumulation rates of ca. 200 m y-1
have been reported from Bodri Delta of east Java
I.
Flowering Plants (Anthophyta)
C.
Mangroves
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Mangrove forests (mangals)
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Horizontal zonation: Transition from terrestrial to
marine conditions
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Onshore-offshore zonation of mangroves also may
represent stages in succession from offshore
“pioneer zone” with early successional stages to
later successional stages onshore
I.
Flowering Plants (Anthophyta)
C.
Mangroves
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Mangrove forests (mangals)
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Caroline Rogers
Vertical zonation: Transition from canopy to subtidal
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Above-water forest
- Arboreal habitat (birds, reptiles, insects,
crustaceans)
- Senescing leaves fuel detrital food web
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Intertidal swamp
- Includes mud flats, community shifts with tides
- Mobile and sessile epibionts on/in stilt roots
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Subtidal zone
- Burrowing fauna (worms, snails, shrimp, crabs)
- Important nursery grounds
Fig.
14-24
Mangrove Food Web
Fig. 14-22