Mangrove ecosystem

1. Tropical Mangrove Ecosystem
Presented By:
Puja Banmali M4319013
Sujita Balami M4319018

2. Outline of Presentation
• Introduction: Mangrove ecosystem and
Mangrove
• Benefits of mangrove ecosystem
• Components : Biotic and Abiotic
• Sundarban Mangrove
• Threats
• Consequences of mangrove destruction
• Conservation of mangroves
• References

3. Mangrove ecosystem
• A tidal swamp ecosystem in tropical estuaries,
lagoons or islands
• Mangrove ecosystem are heterogeneous habitats
• Tidally influenced wetland ecosystem within
intertidal zone
• Covers 60-75% of tropical shores
• A highly valued ecosystem in terms of economy,
environment and ecology
• Considered one of the most productive ecosystem
in the world
• One of the most threatened ecosystem in the
tropics

4. Distribution: Dominates the coastlines of tropical
and sub-topical climates of world

5. Examples of Mangrove Ecosystem
• Sundarban Mangrove of India and
Bangladesh (2.4 million acres)
• Nam Can Mangrove of Southern
Vietnam
• Carribean Mangrove
• Mangrove of Thailand
• Mangroves of Bimini (Bahamas)

6. Mangrove
• The term mangrove refers to woody plants which
grow at the interface between land and sea
• Coastal tropics like Africa, Asia, Australia and
South America
• Taxonomically diverse
• Halophytic
• Thrive on both salt and freshwater
• Prefers humid climate and freshwater inflow
• Grows better in alluvial soils (fine textured, rich in
humus)
• Repeatedly flooded but well drained soils supports
good growth

7. Benefits of mangrove
ecosystem (IUCN, 2019)
Mangrove
Ecosystem
Wood
Climate
regulation
Coastal
protection
Fisheries
Tourism
Livelihood

9. Components
Abiotic
Climatic factors
Edaphic factors: Soil, nutrients
Biotic
Living factors

10. Abiotic Components
Soil pH Rainfall
O2 Salinity
Wind and
waves
Temperature Light Nutrients

11. Soil
• Most important elements that controls the distribution of flora
and fauna
Topsoil:
 Sand, silt and clay in different combinations
 lighter color
Sub soil:
 typically waterlogged, anoxic, darker color
 Rich in organic matter
 Saline
• pH
 Maybe acidic or alkaline
 pH found to be: 7.95- 8.42

12. Salinity
• Mangrove plants are facultative
halophytes
• Tolerance level varies according to
species
• Can tolerate up to 90 ppt
• Best growth between 5-75 ppt (Krauss
et al., 2008)

13. Salinity
Mangrove classification according
salinity tolerance:
• High salt tolerant (Ceriops and
Avicennia )
• Moderate salt tolerant (Exoecaria and
Bruguiera)
• Less salt tolerant ( Nypa and Heritiera )

14. Oxygen
• Anorexic nature of sediment:
 low oxygen content
 Home for anorexic bacteria
• Factors influencing DO:
 Tidal height
 Sunlight
 Flooding (5.4 mg/L )(Knight et al., 2013)

16. Wind and Waves
• Has drying power that effects mangrove
growth
• Required for seed dissemination
• Increases the evapo-transpiration of plants
• Strong wind hampers the growth of plants
• Coastal mangroves can mitigate high waves
even tsunamis
• Mangrove less developed in places exposed to
strong waves
• But an important factor for dispersion of seeds
and mangrove seedlings

17. Temperature
• Sensitivity to cold, mangroves restricted to
tropics and sub-tropics
• For optimal growth of mangrove species-
18°C-26°C
• Temperature requirement varies with
species
• Extreme temperature limits plant
processes, death
• Mangroves can tolerate air temperature as
low as 5°C

18. Light
• Vital for photosynthesis and growth
• Affects the respiration, transpiration,
physiology and physical structure of plants
• Mangrove plants - long day plants
 Requires high intensity full sunlight
 Optimal light requirement- 3000-3800
kcal/m2/day
 Excessive intensity can damage the mangroves
(Kathiresan and Bingham, 2001)
 Tolerance differs among species

19. Nutrients
• Produce large amount of litter in the form
of falling leaves
• Decomposition contributes to dissolved
organic matter
• Enrich coastal sea and support fishery
resources
• Nutrients not solely produced from within
ecosystem but also derived externally
• Import from sea and river

20. Rainfall
• Amount, duration and distribution of rainfall
determines the distribution of plants and
animals
• Can influence
 air and water temperature
 Salinity of surface and ground
 Survival of mangrove species
• Mangroves prefers: 1500-3000mm pa
• Develop best in region with abundant rainfall
• Wash out surface salt crust and leach , suitable
growth

21. Biotic Components
Flora
Mangrove
Ferns
Shrubs
Fauna
Fish
Crustaceans
Deer
monkey
Microorganisms
Bacteria
Fungi

22. Flora
• Includes different trees, herbs and shrubs
like:
Mangrove: Black, white and red
Palm tree (Phoenix paludosa)
Button wood
Fern
Orchids
Vines
Lilies
Grasses

23. Flora
Algae
• Important in mangrove ecosystem
• Epiphytic, grow on aerial roots of trees
and on the sediments
• Green, Red, Brown and Blue-green

24. Zonation and succession of mangrove vegetation at
Ca Mau Cape(Hong & San 1993)

25. Red Mangroves
(Rhizophora
apiculata)

26. White Mangroves
(Laguncularia racemosa)

27. Black Mangroves
(Avicennia germinans)

28. Powder Puff Tree
Mangrove Apple
(Sonneratia
caseolaris)

29. Button Wood
(Conocarpus erectus)
Orchids (Spray
orchid)

30. Criteria for Adaptation
1. High salinity:
Higher tolerance than terrestrial plants
Salt excretion from, Leaves: crystals of
salt
Xylem at endodermis of roots

31. Criteria for Adaptation
2. High sedimentation
• Anoxic environment
Root aeration
 Pneumatophores: Avicennia
Prop roots/stilt roots: Rhizophora spp.
Knee roots: Bruguiera
Buttress root: Xylocarpus granatum

32. Buttress Root

33. Knee roots

34. Stilt roots

35. Pneumatophores

36. Criteria for Adaptation
3. Reproduction
 Vivipary: reproduction and growth of young
plant in parent plant
 Reproduction regulated by water tides
 Pollination: depends on species (Rhizophora)

37. Fauna
• Includes both aquatic and terrestrials
organisms:
Aquatic: Crabs, oysters (Crassostrea),
barnacles (Balanus), sponges, snail, fish
like sea bass, mud skippers
Terrestrial: snakes, crocodiles, lizard,
insects, birds like king fisher, egrets,
dove, pelicans

38. Turtles

39. Crocodiles

40. Mangrove snails

41. Fish (Red Snapper, Sea bass, Mullet)

42. Mangrove or
Fiddler crab
( Uca lacteal)
Crabs are the keystone species in mangrove ecosystem.

43. Tiger (Panthera tigris)

44. Mangrove fauna adaptation
1. Migratory shore birds
• Different bill shapes and lengths- probe the mud at
different depths for feeding

45. Mangrove fauna adaptation
2. Mud skipper
• Has modified fins
• Helps to move on land
• Breathes through damp skin when on land
• Huge eyes on top- allows for hunting and escape
from predators
Mudskipper
(Periophthalmus)

46. Mangrove fauna adaptation
3.Tree climbing crabs
• Climbs up a tree to avoid high tides and being eaten
by predatory fish

47. Microorganism
• Bacteria and fungi play vital role like:
Decomposition of mangrove foliage
Regeneration of nutrients
Mineralization
Detritus formation
• Bacteria: major participants in carbon,
sulfur, nitrogen and phosphorous cycles
in mangrove forest

48. Microorganisms
• Anaerobic bacteria: Methanobacterium,
Methanococcus, Methanospirillium
• Free-living nitrogen fixing bacteria:
Azotobacter, Desulfovibrio
• Sulfate reducing bacteria: primary
decomposers in anoxic mangrove sediments
• Fungi: degrade cellulose, lignin, resin and
carotenoids of mangrove leaves

50. Sundarban mangrove
• Lies in Asia (India 40% & Bangladesh 60%)
• Worlds largest area of mangrove forest- approx.1
million ha
• A World Heritage Site with unique tidal wetland
from the point of view of its biodiversity and ecology
• Protects- Threatened and endangered species like
Estuarine crocodile, Indian python, Bengal tiger

51. Sundarban mangrove…
Famous biodiversity hotspot- harbors
(Chakraborty, 2011)
Birds 200 species
Reptiles 59 species
Mammals 39 species
Amphibians 7 species
True mangrove plants 34 species
Fish 250 species

52. Threats to Mangrove ecosystem
Natural Threats
Climate change
Cyclones
Diseases
Tsunamis

53. Destruction of mangrove
due to Tsunami

54. Threats to Mangrove ecosystem
Anthropogenic Threats
Urban development
Pollution
Agriculture
Salt Extraction
Forestry
Aquaculture

55. Former Mangrove Forest
Shrimp farm in Southern Belize

56. Urban Development

57. Pollution

58. Pollution

59. Consequences of mangrove
destruction
According to GFW- world lost 192,000 ha
(474,000 acres) of mangroves from 2001 to
2012 (1.38%)
• Decline of biological resources
• Increasing fallowed land and CO2
concentration
• Salinity intrusion
• Silt accumulation
• Soil and water pollution

60. Conservation
• Afforestation
• Protection
Conservation areas, parks, reserves
• Legislation
Different law and policies for
conservation

61. Afforestation

62. Protection Of Mangroves

63. References
• Kathiresan, K., & Bingham, B. L. (2001). Biology of mangroves and mangrove
Ecosystems. Advances in Marine Biology, 81–251. doi:10.1016/s0065-
2881(01)40003-4
• Quang Bao, T. (2011). Effect of mangrove forest structures on wave attenuation
in coastal Vietnam. Oceanologia, 53(3), 807–818. doi:10.5697/oc.53-3.807
• M.D. Hossain and A.A. Nuruddin, 2016. Soil and Mangrove: A
Review. Journal of Environmental Science and Technology, 9: 198-207.
• Das, S., M. De, D. Ganguly, T.K. Maiti, A. Mukherjee, T.K. Jana and T.K. De,
2012. Depth integrated microbial community and physico-chemical properties
in mangrove soil of Sundarban, India. Adv. Microbiol., 2: 234-240.
• Krauss, K. W., Lovelock, C. E., McKee, K. L., López-Hoffman, L., Ewe, S. M.,
& Sousa, W. P. (2008). Environmental drivers in mangrove establishment and
early development: a review. Aquatic botany, 89(2), 105-127.
• Chakraborty, S. K. 2011. Mangrove ecosystem of Sundarbans, India;
Biodiversity, ecology, threats and conservation. Mangroves; Ecology, biology
and taxonomy. 83-112