mangrove flora
TRANSCRIPT
Content :
1.Introduction
2.Meaning of Spawning
3.Fish Spawning
4.Biology of Spawning
5.Types of Spawning
6.Induced breeding for Spawning
7.Role of Environmental factors
8.Summary
9.Conclusion
10.Reference
What is mangrove??The word "mangrove" is obscurely
connected with the Portuguese
word "mangue" and the English
word "grove“.
Mangroves are plants living in the
tropical and subtropical tidal
coastal areas specifically at the
intertidal zone that lies between
sea and land.
This includes the swampy and saline
(brackish water) intertidal zone of
deltas, lagoons, marine shorelines
and estuaries.
CONT…
Mangroves are necessarily tolerant of high salt levels and have mechanisms to take up water
They draw up saltwater by maintaining a lower hydrostatic pressure in their above-water cells (osmosis).
Mangroves exclude a great deal of salt at or near their roots, but still have a salinity level approximately 10 times higher than most other plants.
Mangrove Distribution
Mangroves are commonly found
throughout the world between latitudes 32°N and 38°S. ]
Mangroves are found practically in almost all the continents, excepting Europe, the Arctic and Antarctic.
Best mangroves are found in Asia, especially in India and Bangladesh - the Sunderbans are the largest mangrove forest in the world both in size as well as biodiversity.
The total area of mangroves in India is about 6,740 sq. km, which is about 7% of the world's total area of mangroves
Of the total mangroves 80% are present along the east coast, mostly forming the Sunderbans, Bhitarkanika and the Andaman & Nicobar mangrove
The remaining 20% mangroves are scattered on the west coast from Kutch to Kerala.
The major plant species forming the mangrove ecosystemhave aerial roots
1. prop roots2. cable roots3. stilt roots
Rhizophora spp (Red mangroves) have prop roots It descends from the trunk and branches It provides a stable support system
Other mangrove species, including the white mangroves obtain stability with an extensive system of shallow, underground “cable roots”
It radiate out from the central trunk for a considerable distance in all
directions. pneumatophores extend from these cable roots.
○ EXAMPLES:- A. marina
Stilt roots are the main organs for breathing especially during the high tide.
Stilt roots also serve to anchor the plants.
They are important in aeration, because the mangrove mud tends to be anaerobic
EXAMPLES:-Avicennia marina
Avicennia offficinalis
Rhizophora mucronata
Its stilt roots extend more than a meter above the soil surface and contain many small pores (lenticels) which at low tide allow oxygen to diffuse into the plant and down to the underground roots by means of open passages called aerenchyma.
The lenticels are highly hydrophobic and prevent water penetration into the aerenchyma system during the high tide.
Aeration occurs also through lenticels in the bark of mangrove species.
:
These are the special vertical roots, called pneumatophores
It forms from lateral roots in the mud often projects above soil
to a height of 20-30 cms It permits some oxygen to reach the
oxygen-starved submerged roots. The density, size and number of
pneumatophores vary per tree. They are green and contain
chlorophyll.
EXAMPLES:- Avicennia, Sonneratia
MANGROVE FLORA
Rhizophora mucronata Fruit & Folwer of Sonneratia alba Avicennia marina
Fruits of Derris trifolate Fruits of Avicennia marina Flowers & fruits of
Avicennia marina
•This zone is towards
water front
•subject to regular tidal
effect
•They are having stilt
roots, prop roots for
stability and anchorage
Rhizophora apiculata
R. mucronata
2. it develop a strong hold
fast in the form of knee
roots or bent roots as a
supporting organ
Lumnitzera racemosa
•It occurs towards island
area mangroves
•The duration of tidal
submersion is low in this
zone compared to front
mangroves.
Heritiera littoralis
Xylocarnus spp
TYPES OF MANGROVESNAME DESCRIPTION ROOT SEED
•Individual trees may
grow up to 20-25
meters in height.
•The Black Mangrove
is tolerant of high
saline conditions.
•Roots look like tubular
bristles. These bristles
are known as
pneumatophores.
•Roots stick out
vertically and trap
oxygen for its oxygen-
starved root systems.
•The seeds are
viviparous in nature
•Black mangroves
produce seeds in
abundance which
occur throughout the
year.
•It reaches 5.6 meters
and a diameter of 30
centimeters
•This species normally
grows in the back
portion of mangrove
swamps.
•The roots are fibrous,
and this species
coppices reasonably
well.
•They have un-
buttressed roots.
•Germination is
epigeous.
•This is an evergreen
tree
•It grows to about 25
meters in height and
40 centimeters in
diameter at breast
height.
•elaborate prop and
aerial root system
•The roots contain a
waxy substance that
helps keep salt out.
•The seed-like parts -
the propagates - are
large pre-germinated
'seedlings' known
locally as 'monkey
whistles'.
Sundarbans, the largest mangrove on the planet earth
The Sundarban, covers about one million ha in the delta of the rivers:
1. Ganga,
2. Brahmaputra
3. Meghna
It is shared between Bangladesh (~60%) and India (~40%).
It is famous for its marine and estuarine fish resources
Sundarban boast around:-
1. 172 species of fishes
2. 20 species of prawn
3. 44 species of crabs
The Sundarban has been extensively exploited for timber, fish, prawns
and fodder
SUNDARBAN FLORA
ECOLOGICAL IMPORTANCES OF MANGROVE
IMPORTANCES OF MANGROVE IN FISHERY
Major Threats
Hurricanes
2. Root clogging from increased water turbidity
3. Damage from boring organisms and parasites.
1. Deforestation:
Since mangroves are either slow to recuperate from cutting or do not re-sprout after being cut (e.g. the red mangrove), they will never return unless replanted.
2.Diversion of freshwater for irrigation
3.Land reclamation has destroyed extensive mangrove forests.
4.In the past several decades, numerous tracts of mangrove have been converted for aquaculture, fundamentally altering the nature of the habitat
THREAT OF MANGROVES IN INDIA
Mangrove forest destruction and depletion of its natural resources pose one of the most serious social problems in India.
The problem is particularly observed in the western coast where the extent of the remaining mangrove forests is only about 40,000 ha (total area of Indian mangroves is about 350,000 ha).
Conservation measures and afforestationare therefore essential.
Steps taken towards Mangrove Conservation
The Government of India had set up the
National Mangrove Committee at the Ministry of Environment and Forests in 1976 to advise the government about mangrove conservation and development.
Mangrove afforestation project in Goa & Maharashtra:-
Activities sponsored by the UNDP/UNESCO Regional mangrove Project have greatly contributed to mangrove awareness in India.
Three government agencies, assisted the mission
1. the NIO at Goa
2. Forest Department of Goa
3. Social Forestry Circle of Maharashtra State.
CONCLUSION
REFERENCES:
1.WWW.GOOGLE.COM
2.
3.WWW.WIKIPEDIA.COM