mangroves

costal wetlands in the tropics

are mangroves

mangroves

- physical protection from wave energy essential

- extensively found near river deltas

- 140-170,000 km

mangrove vegetation

- foundational species

- like salt marsh

how many species do mangroves have

60-70 species

- very low species diversity

- taxonomically divers

where is the highest diversity

malaysia

red mangrove

- most common

- prop roots (rhizophores)

black mangrove

- most cold tolerant

- peg roots (pneumatophores)

white mangrove

- have none

- languncularia

mangrove adaptation: salinity (xeromorphic adaptations)

- thick wall epidermis

- heavy cuticles on leaves

- recessed stomata on leaf underside

- succulent leaves

mangrove adaptation: salinity (salt regulation)

- salt exclusion

- salt secretion from leaves

- accumulation

mangrove adaptations: roots

- low AG:BG rations

- various root systems

mangrove adaptations: vivipary

- red mangroves

- seeds germinate while still on parent plant

- allows quick growth

- some species release seeds as tide changes

fringe mangrove

- found along protected shorelines

- large tidal impact

- low detrital accumulation

- salinity= seawater

- intermediate size and productivity

- red mangrove dominate

riverine mangrove

- along rivers and creeks

- less tidal influence

- less saline (5-20ppt)

- high nutrients from river

- lowest harshness= large size and productivity

- mixed species, mainly red mangroves

basin mangroves

- inland depressions near coastline

- isolated except during highest tides

- much higher salinity than seawater

- black and white mangroves

dwarf mangrove

- isolated, low nutrient depressions

- often very saline

- rarely flooded

- rel minor importance

- variable species

mangroves strong zonation seen as

land builders as sediments and organic matter accumulate

- view is strongly challenged now

crabs are important!

- physical: bioturbation

- chemical: litter decomposition

- biotic: seed predators, predators, and prey

crabs are mangroves

keystone species

mangrove productivity

- very high NPP (2700 gC)

- higher than rainforest

blue carbon

the carbon captured by the world's oceans and coastal ecosystems

- 30-50x higher than terrestrial uplands

mangroves energy flow

- most biomass not directly consumed

- so most energy likely detrital

litter decomposition: crabs

- key shredders of leaf litter which facilitates decomposition and decay

seeding predation: crabs

- selectively remove seedlings

- control location and species of vegetation

- up to 75% seedlings consumed by crabs

burrowing in sediments: crabs

increase sediment aeration (lowers redox, sulfides, and ammonium)

crabs are key prey for

birds and many fish