MANGROVES OR MANGAL “Rainforest by the Sea” Associations of halophytic trees, shrubs or other...
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Transcript of MANGROVES OR MANGAL “Rainforest by the Sea” Associations of halophytic trees, shrubs or other...
MANGROVES OR MANGAL
• “Rainforest by the Sea”• Associations of halophytic trees,
shrubs or other plants growing in brackish to saline water
• Found on tropical and subtropical coastlines
• Inundated daily with sea water but protected from heavy waves
• Limited by frost
ADAPTATIONS
• Salinity Control – salt exclusion or secretion
• Viviparous seedlings
• Prop roots and pneumatophores
SALINITY
• Facultative halophytes – found over a wide range of salinity; 10-60 ppt
• Competitive advantage over freshwater species
• Survive wide annual fluctuations
Rhizophora mangle Red Mangrove, Mangle Rojo
•Opposite, evergreen leaves & white flowers•Prop roots – grounded and ungrounded•Viviparous
Avicennia germinansBlack mangrove, Mangle negro
•Opposite, leathery leaves; yellowish to dark green above, downy beneath with salt glands •pneumatophores
Laguncularia racemosaWhite mangrove, Mangle blanco
•Leathery, opposite leaves with rounded tips and 2 salt glands on petiole
Conocarpus erectus Buttonwood, Mangle de botón
•Leaves alternate, elliptical, with a row of salt glands along the rachis
SUCCESSION
• Peat accumulation balanced by tidal export, fire and hurricanes
• Advance and retreat of zones according to the fall or rise of sea level
• Stressed or youthful ecosystems– Slowed or arrested succession– Low diversity– Open nutrient cycles
FACTORS CONTROLLING PRIMARY PRODUCTIVITY
• Tides and water chemistry intertwined– Transport of oxygen to roots– Removal of toxins and salt from pore
water– Control of sediment accumulation– Regeneration of nutrients lost from root
zone
• Water chemistry alone– Pore water salinity– Concentration of nutrients
ORGANIC EXPORT
• 50% of productivity exported as detritus
• May supply as much as 52% of the fixed carbon available for secondary productivity
• Detritus primary food source to invertebrates and forage fish
• Roots provide nursery areas and solid substrate
• Proximity to and extent of exchange between coastal waters, especially coral reefs
• Presence or absence of algae• Tidal amplitude• Competitive interactions• Predation, particularly intraguild predation
ANIMALS ASSOCIATED WITH RED MANGROVE
PROP ROOTS
http://jrscience.wcp.muohio.edu/html/tropecoimages.html#Anchor-mangroves
GENERAL FAUNAL TYPES
• Adjacent to coral reefs, e.g. Carrie Bow Cay, Belize– Sponges, tunicates, hydroids,
anemones, polychaetes
• Isolated from reefs– Isopods, barnacles, molluscs,
algae, amphipods
Laguna Boca Paila
•Water very clear
• Bottom either covered with Halodule wrightii, Ruppia sp., or leaf litter, otherwise sand/shell
• Tree heights 10-22 ft.
• Protected embayment with only a small inlet to Caribbean
DOMINANT SPECIES
•Isopods
Sphaeroma terebrans
•Amphipods
Hyale plumulosa
Ericthonius brasiliensis
Parhyale fascigera
•Algae
Polysiphonia sp.
Anotrichium tenue
Bostrychia montagnei
Batophora oerstiddi
EFFECTS OF ALGAE
TRENDS IN INVERTEBRATE DENSITY AND BIOMASS IN RELATION TO
ALGAL BIOMASS
-1012345
Invertebrate Density (ind./100cm2) in hundreds
Invertebrate Biomass (g/100cm2)
Algal Biomass (g/100cm2)
ALGAE-DOMINATED ROOT
Many small, motile invertebrates, especially amphipods•Low diversity•High abundance
Nematode
Sphyraena barracuda
Callinectes portunus
Eleotris pisonis
Sphoeroides testudinus
Lutjanus apodus
Palaemonetes vulgarisMacrobranchium acanthurus
Nodolittorina lineolata
Littoraria angulifera
Cassidinidea ovalis
Cyathura cubana
Copepods Ostracods
Bathygobius mystacium
Gobiosoma bosc
Mugil cephalus
Mytilopsis leucophaeata
Ischadium recurvum
Hyale plumulosa
Ericthonius brasiliensisNereis pelagica
Pachygrapsus gracilis
Detritus PhytoplanktonVaunthompsonia minor
Cyclaspis sp.
LAGUNA BOCA PAILA: PROPOSED FOOD WEB FOR R. MANGLE PROP ROOT COMMUNITY
Concrete relationship
Inferred relationship
Green algae Primary producer
Terminal carnivore
INTRAGUILD PREDATION
• Common in communities with many interference competitors
• Typical in mangrove prop root communities
• Defined as killing and eating of competitors
• Interference competitors at Laguna Boca Paila:– Lutjanus-Callinectes– Sphyraena-Lutjanus– Palaemonetes-Bathygobius
IMPORTANCE TO LOCAL COMMUNITIES
• Traditionally managed by local communities– Food, medicine, tannins, fuel
wood, construction materials– Sustainable, dependable, cultural
• Minimize property damage & deaths due to tropical weather
• Useful for treating effluent