Mangrove ecosystem

MANGROVE ECOSYSTEM

Kumpulan 14

Hasilatul Hana Hamzah

Siti Nor Sheereen Maarof

Muhammad Aizad Hassan

WHY WE CALL IT AS MANGROVE?

The word “mangrove’ may have originated from the Malay word ‘manggi-manggi’ for the mangrove plant Avicennia and combined with the Arab word ‘el gurm’, to become ‘mang-gurm’.

MANGROVE FOREST

Found in coastal areas all over the tropics

Primarily in brackish water

salty and fresh mix

Cover approximately 22 million hectares in

tropical and subtropical coasts

DISTRIBUTION OF WORLD MANGROVES

DISTRIBUTION OF WORLD MANGROVES

REGION AREA

(km2)

%

South and SE Asia 75,170 41.4

The Americas 49,096 27.1

West Africa 27,995 15.4

Australasia 18,788 10.4

East Africa and Middle East 10,348 5.7

DISTRIBUTION OF WORLD MANGROVES

COUNTRY MANGROVES

(1000 Ha)

%

Global

Indonesia 4250 30

Brazil 1376 10

Australia 1150 8

Nigeria 970 7

Malaysia 641 5

Bangladesh 611 4

Myanmar 570 4

Vietnam 540 4

Cuba 530 4

Mexico 525 4

FUNCTIONS & THREATS

Serve as an important buffer between sea and land

Lessen impact of intense storms

Reduce erosion and increase sedimentation

Important coastal pioneer species

Act as basis for a complex, biologically diverse, and productive ecosystem

Increasingly threatened

Human development is most intense along coasts

IMPORTANT TERMINOLOGY

Mangal

Is the place where Community of organisms in the mangrove habitat

Mangrove

Trees that flourish in the mangal

So, What is this ?

CHARACTERISTICS OF MANGAL

Inundation with tides

Increasing salinity towards ocean

Sandy clay soil

Nutrient poor

Nitrogen & Phosphorus are limiting

Limiting mangrove growth only

Organic nutrients deposited via siltation

Fresh water streams & down-shore currents

Most all are of terrestrial origin

In sum: Mangal is a harsh place to live

MANGROVES?

Trees and shrubs that grow in saline coastal habitats in the tropics and subtropics;

They grow in loose, wet soils, salt water, and are periodically submerged by tidal flows;

Their distribution throughout the world is affected by climate, salinity of the water, fluctuation of the tides, type of soil;

Unique ecosystem generally found along sheltered coasts

Diverse - about 110 species - only about 54 species in 20 genera from 16 families constitute the "true mangroves",

TYPES OF MANGROVE PLANT: The most common tree species are Rhizophora, Avicennia, Bruguiera, Sonneratia, Xylocarpus and Nypa species

HOW ABOUT THEIR ECOSYSTEM?

1. Intertidal ecosystem; anaerobic environment; plants able to tolerate high salinity.

2. High productivity; place where sediment is collected.

3. Allows organic matter to be transported to other system eg. Coral reefs and sea grass; via the flushing action of the waves.

4. The mangroves leaves, use the sunlight and convert carbon dioxide to other organic compounds via photosynthesis.

5. Carbon absorbed by plants via photosynthesis and nutrients from the soil will be converted to raw materials for the growth of the plants.

6. The living and dead mangrove leaves together with the roots will produce carbon and nutrients to be used by other organisms in the ecosystem.

MANGROVE ECOSYSTEM

Divided into :

1. Abiotic component

2. Biotic component

ABIOTIC COMPONENT

1. Soil (sand+mud + silt)

- ‘topsoil’ divided to sandy or clayey.

2. pH

- neutral or slightly acidic due to the ‘sulfur reducing bacteria’ and the presence of acidic silt.

3. Oxygen - Dissolved oxygen : low – anoxic area - can only be home for anaerobic bacteria, which releases

hydrogen sulfide gas (bad smell) when the bacteria bread-down the organic matter without oxygen.

ABIOTIC COMPONENT

4. Nutrient - Because the soil is perpetually waterlogged, there is little free

oxygen. Anaerobic bacteria liberate nitrogen gas, soluble iron, inorganic phosphates, and methane, which makes the soil much less nutritious.

5. Wind and waves

- windy and wavy depends on the movement of the sea water.

6. Light, temperature

- low light and temperature at low ground.

8. Salinity - high content of salt.

Clayey-type topsoil

Sandy-type topsoil

BIOTIC COMPONENT

Divided to : 1. Vegetation 2. Zonation

VEGETATION

- Mangroves are ‘obligate inhabitants’, which cannot be found anywhere else

Adapted to survive in swampy area

HOW DO THE VEGETATION ADAPTED TO THE MANGROVE AREA ? WHAT DO THEY NEED TO ADAPT TO?

-HIGH SALINITY -HIGH SEDIMENTATION -REPRODUCTION

SALT WATER PROBLEM

If a normal plant is watered with sea water, it will die because the sea water will extract the water from the plant

High salinity will increase the salt concentration in the plant tissues and this will damage the metabolic processes and leads to death.

ADAPTATION TO HIGH SALINITY

1. Waxy Leaves

Leaf that has coated

on the outer side

with a waxy cuticle

that prevents water

loss.

ADAPTATION TO HIGH SALINITY

2. Salt exclusion at leaves

ability of a mangrove to exclude salt at the

surface of their leaves. So, that the salt

content in the plant can be regulated.

ADAPTATION TO HIGH SEDIMENTATION

1. Prop roots

An adventitious root that arises

from the stem, penetrates the soil,

and helps support the stem

ADAPTATION TO HIGH SEDIMENTATION

2. Pneumatophores

Pneumatophores or breathing roots

(Sonneratia) are roots from the

underground root system, which appear

laterally. These roots are used for

respiration of the plant.

ADAPTATION TO HIGH SEDIMENTATION

3. Buttress root

Buttress roots (Bruguiera) are roots

from the tree trunk and expanded

to a structure which looks like a

‘flattened blade’. These roots

provide mechanical support for

plants that grow in soft and instable

substrates.

ADAPTATION TO HIGH SEDIMENTATION

Stilt roots

Stilt roots (Rhizophora), are roots from

the tree and grow into the substrate.

These roots are mechanical support for

plants growing in silt and muddy

substrate.

ADAPTATION TO REPRODUCTION

1. Vivipary normal

Reproduction and growth while still attached to plant

Fertilization

Propagule growth (a ready-to-go seedling)

Young propagule a.k.a. Hypocotyl

Mature

propagule

ADAPTATION TO REPRODUCTION

2. Maturity -> Drop off maternal plant

3. Float horizontally initially

Dispersal to novel environments ideally

4. Float vertically with appropriate environmental conditions

5. Rooting and growth

Germination cycle of a mangrove seedling

ADAPTATION TO REPRODUCTION

6. Pollination

Pollination method varies by species

Wind (Rhizophora)

bat or hawk moth (Sonneratia)

birds and butterflies (Bruguiera)

bees (Acanthus, Aegiceras, Avicennia, Excoecaria, Xylocarpus)

fruit flies (Nypa)

other small insects (Ceriops, Kandelia)

ZONATION

Intraspecific Differences in Environmental Tolerances

1. Salinity variations and adaptations for excreting salt

2. Tidal Inundation and adaptations for gas exchange

3. Low soil stability, Shore morphology, and adaptations for rooting

4. Sedimentation rates and types

MANGAL HABITAT TYPES

Riverine

Often found in river deltas

Constant influx of freshwater

Great changes in salinity levels

Basin Mangroves

Inland, behind coastal mangroves

Little change in tides, no wave action

Often higher salinity than others (evaporation)

Tide-Dominated

Coastal front habitats

Frequent sedimentation

Unstable morphology due to coastal erosion

MANGROVE SPECIES ZONATION

Bruguiera

gymnorrhiza Ceriops

australis

Avicennia

marina

Rhizophora

stylosa

Salinity Decreasing Soil Stability

Sedimentation Rate

All increase toward shore

MANGROVE ANIMALS ADAPTATION

Migratory Shorebirds.

Different species of

migratory shorebirds have

different bill shapes and

lengths allowing each

species to probe the mud at

different depths to find food.

For the reason, large number

of different shorebirds can

feed on the same mudflat

without competing with each

other for food.

MANGROVE ANIMALS ADAPTATION

The mudskipper is really a fish.

It has modified fins which help

it to move on land. When on

land, it breathes through its

damp skin and by holding water

in its mouth. Huge eyes on top

of it to see better, allowing it to

hunt for prey and also to

escape from predators. These

structural adaptation help the

Mudskipper cope with the

mangrove environment, catch

prey and escape predators!

MANGROVE ANIMALS ADAPTATION

Tree-climbing Crabs.

During high tide, the Tree-climbing Crab climbs up a tree avoid being

eaten by predatory fish. Once out of the water, it must remain still to

avoid being spotted by predators like the kingfishers and water

monitor lizards. The above behavioural adaptations help the Tree-

climbing Crab escape predators.

THREATS TO MANGROVES

Degradation and Destruction of Mangroves

CAUSES OF MANGROVE DEGRADATION

Degradation : change of a chemical compound

to a less complex compound.

Nature‐induced changes, tropical storms and

tsunami.

Diseases.

Biological pests and parasites.

CAUSES OF MANGROVE DESTRUCTION

Destruction : The action or process of causing

so much damage to something that it no longer

exists or cannot be repaired.

Urbanization

Agriculture

Cutting for timber, fuel and charcoal

Oil pollution