Mangrove ecosystem

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Flux of energy and matter through ecosystem = Mangrove

ecosystem as an example

Mangrove ecosystem

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most fertile coastal ecosystem

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essential to the life cycle of marine life

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Soft, silty & shallow.

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Grow a lot in saline soil & brackish water because

of regular presence of fresh and salt water inundation (something being

abundant)

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Frequent changes in salinity & water level.

Air banyak naik turun, air pasang and air surut. / tide coming to shore and

ebbing (flow away)

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Grows in sheltered estuaries(the tidal mouth of a large river, where the tide meets the stream.) & inlets (An inlet is an indentation of a shoreline, usually long and narrow, such as a small bay or arm, that often leads to an enclosed body of salt water, such as a sound, bay, lagoon, or marsh.)

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Or grow in extreme saline/ brackish coastal

habitats & location

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Regularly water-logged & anoxic = lacking

aeration / deficient in oxygen

IMPORTANCE

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Supports all organisms & achieves a

perfectly balanced cycle.

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Provide resources such as timber, fuel, food,

medicinal herbs & other forest products for coastal communities

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Can be harvested for wood, charcoal etc

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Ecotone(a region of transition between two biological communities.)

between land and sea. Partially

submerged during high tides & exposed at low tides.

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Breeding ground for many marine animals, fishes

crabs prawns. Essential for maintaining a viable fishing industry

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Able to absorb heavy metals & trap nutrients

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Protection frombank erosion, serve as natural

barriers

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Prevent salt water from going into rivers

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RCRR, retain, concentrate & recycle nutrients

& remove toxicants. Natural filtering process.

Mangrove

Source of natural resources (food, fuels, medicine, building materials)

Traps sediment to build new land

Shelter for terrestrial & aquatic life

Shoreline protection from wave actions

Source for food for mangrove food web

habitat for many animals

nursery area for juvenile fish.

Seagrass beds

filter sediments

roots bind the sediments

habitat for animals.

Coral reef

Protect coastline from high seas

Produce sand for beaches

Habitat for fish & other animals

Snorkelling & diving areas

Beaches

Protect land from flooding

Protect coastal infrastructure

Habitat for animals

Beach boats

Recreation

Hill Slopes

Vegetation holds soil

Habitat for animals

Sites for develoment

Organic matter (mangroves) ---> Food web in deeper water :

Detrital transport : minute particles & dissolved organic matter moving

Ontogenetic migration : movement in migrating animas = banana prawns

Trophic relay = Prey predator interactions = Crabs & larvae ----> fish (glassfish, gobies, juvenile mullet) ----> other fish (flathead)

Recycling of organic matter in mangrove ecosystem.

- Key processes that allows mangrove ecosystem to function as a nutrient sink = Exchange of nitrogen & accumulation of nutrients in mangrove sediments.

Recycling process = reabsorption/ retranslocation of nutrients. This occurs because of leaf fall & nutrients in leaf litter that doesn't move during decomposition. The pattern of the cycling process has an effect on productivity of the mangrove communities.

Example : Nitrogen concentration increase when decomposition occurs at the forest floor.

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UNIQUE ADAPTATIONS

Mangrove trees

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Tough root systems. The trees root from the main stem & have

branches that grow vertically (straight downwards). This gives additional

support like stilts. Aerial/ Prop roots (pneumatrophores/respiratory roots)

& buttressed trunks.

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Special barks & leaf structures.

Plants

Challenges are : High salinity of water, unstable substrate

like shifting sand, anoxic(lacking of oxygen), high and low tides & wave

action.

Adaptation :

1.

Salinity : Mangroves are halophytes(plant that grows in waters of high salinity)

2. Hydrophytes (a plant that grows only in or on water.) They have air pockets in the base of their leaves. This helps the flower to float. It also allows breathing & growth of the plant.

High salinity

1. Salt excretion : They excrete excess salf thru special glands. (Avicennia matrina)

2. Salt tolerance : Can tolerate high concentration of salt without injury (Rhuzophora mucronata)

3. Salt accumulation : Some mangroves accumulate salt on their leaves & shed leaves at regular intervals. (Rhizophora mucronata)

Muddy, waterlogged & anoxic conditions.

Seed establishment

- Seeds need firm soil which is aerated & lots of oxygen present which is important for shoot development.

- Mangroves = the only true viviparous plants

Vivipary = condition = seeds will germinate but still attached to fruit = fruit is still attached to mother plant. = is an adaptation to long-distance dispersion in order to survive in extreme saline conditions.

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Viviparous plants.

Seeds --> germination --> embryo with long hypocotyl that sticks out --> fall from the trees.

Low tides = The seedling lodges it self upright into the soft mud (shard hypocotyls) & proceed to grow.

High tides = float along & stick into the soft mud when water recedes(go or move back or further away from a previous position.)

Viviparity & seeding/propagules allow mangrove to disperse over a large area.

Aeration problems

Specialised roots to secure oxygen & attain anchorage

Prop roots = roots rise from the stem & support trees in structure and aeration.

Aerial roots = roots arise from branches and used for aeration

Pneumatophores = vertical roots protrude(extend beyond or above a surface.) erect out the mud for aetration

Knee roots : horizontal roots grow upwards up outside the soil & turn downward (knee) bent for aeration.

Mangrove forest that are mature has zones. Types of plants change further than the sea. This is related with the changes in water and salinity level.

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Animals adaptation

Mudskipper fish

Amphibious

Has pectoral fins, located at each side of the body

The fins help the mudskipper to walk on land

Able to feed out of water & defend habitats when necessarY

Long-legged herons

Has long & heavy bills (beak)

Can wade (walk thru water/liquid) in deep water to hunt big fishes & crabs

Small herons (Striated heron)

Able to move very fast.

Short legs, stand on the roots, lean down and stab fishes.

Mangrove ecosystem :

1. Filter - RCRR - retain, concentrate, recycle nutrients & remove toxicants.

2. Nutrients - mangrove ecosystem as a nutrient sink

3. Protection = acts as a barrier from harsh wave action

4. Nurseries = habitat for juvenile fishes and other marine habitats.

5. Habitats = Habitat for lots of animals & marine organisms.