A diverse group of trees that are salt tolerant (halophyte) and are viviparous .

• shallow and protected tropical and subtropical regions • restricted to intertidal and adjacent marine habitats • temperature range: 10oC to 20oC

Open ocean <50 g C/m2/year Coral reefs 1000 g C/m2/yearMangroves 500 g C/m2/year Continental Shelf: Nonupwelling 200 g C/m2/year Coastal upwelling 300 g C/m2/yearSeagrass beds 1000 g C/m2/yearEstuaries and salt marshes 800 g C/m2/yearUpwelling 300 g C/m2/year

A few mangrove species can survive in freshwater, but are not good competitors with other species.

Mangroves have a high salt tolerance. They can survive well in 90%o soil salinity. The ocean averages 35 %o.

They need to prevent water loss by either:1. excrete salt at leaves 2. exclude salt at roots 3. salt excretion and abscission (remove of salt laden

organs)

Salt Tolerance:

What would happen if you watered your garden with salt water?

wave action: windward (more tidal flush) vs. leeward (get more anoxic conditions, stagnation, algae blooms)nutrientstidal flushriverine flowcanopy coversoil: low oxygen (anaerobic), high hydrogen sulfide, fine grain soils (muddy)

anaerobic sulfur reducing bacteriacalcareous shells of mollusks are acted upon

sulfur bacteria--- in turn get Ca++ nutrients that the mangrove and other animals need, also raises the alkalinity of the soil.

Physical Factors that Effect Growth and Development:

Stresses: 1. Channelization, drainage, and siltation2. Hurricane3. Herbicides and defoliants4. Pesticides and pollution5. Thermal loading (heat)

Most mangrove are viviparous, they drop propagules from branches, which are carried away by waves. No resting seed stage: fruiting body (propagule) is a seedling.

Physiology:

Prop roots help support the tree, also the root system can be very spread out.

Pneumatophores have a respiratory function. The soil is very anaerobic, so the pneumatophores stick out of the surface and take in O2. They also function by pushing nutrients to the upper soil layer.

Ecological Role of Mangroves:

1. Stabilize sediment2. Accumulate detrital or other foreign material3. Habitat for epiphytes4. Fish and invertebrate nursery5. Nesting/roosting sites for birds6. Limited role as a direct food source7. Major contributor to detrital food chain

• fish and shrimp cultivation• natural buffers against hurricanes • major detrital source• nursery for many different animals• food for: people, crabs, fungi, bacteria, other animals • coal• tanning material• finest honey

Mangrove Use: