Environment - Mangrove

1) Mangrove

• Tree (genus Rhizophora) that dominates saline coastal habitats in tropical and subtropical climates

• Community of Mangroves is called Mangal

• Ecologically and economically one of the most important plants in all of Vietnam

• Span the interface between marine and terrestrial environments

• Occurs in estuaries and marine shorelines

2) Characteristics of Mangroves

• Of 110 known worldwide species, 29 occur in Vietnam (mainly in the South)

• Evergreens with big leafy vegetation

• Grow to be about 10 – 20 m in height

• Inundated by brackish water

• Many contain aerial roots for air exchange and mechanisms for salt excretion

• Distribution is based on zonation depending on evolutionary adaptations

3) Mangroves Evolutionary Adaptation

• "Breathe" through pores in their bark

• Limit salt intake by having roots which are suberised to prevent sodium uptake

• Also have mechanisms for excreting excess salts

• Limit water loss by closing stomata during periods of high sun

• Also can change the orientation of their leaves during these same periods

• Nutrient uptake directly from atmosphere via anaerobic bacteria that liberates N+, Fe+, PO4-, SO3-, and CH4, thus the pungent odor

• Truly viviparous plant, live seedlings are sent released on water

4) Sexual Reproduction of Mangroves

• Mangal are very exclusive; not more then twenty species of plants will occur within a Mangal

• Cross pollination occurs via birds, bees, wasps and other small insects

• "Budding" is not asexual reproduction method but the tree is one of the few viviparous trees in the world, giving "birth"

• Seedlings, partially budding, fall into the water and carried away to take root on other land

5) Mangrove Benefits

• Large root system acts as an energy dissipater for waves and or tides normally but especially during storms

• Root system also acts as sediment deposit when tides come