Coastal Wetlands
Marsh = vegetated intertidal environment covered by grasses
Swamp (Mangal) = covered by shrubs and trees (typically mangroves)
Range from normal marine salinity to brackish water
Typically form above the neap high tide (lower of the high tides) in an area that is undisturbed
for fine, organic-rich sediment
Low marsh = neap tide to mean high tide
High marsh = mean high tide to spring tide
Plants that occur are a function of elevation and latitude
Marsh Characteristics
Depend on
Protection from wave action
Tides
Rate of sea level rise
Topography
Substrate
Features:
Channels (point bars and levees like rivers)
Crevasse splays and oxbow lakes
Flat areas like floodplains
Young -> old marsh (low -> high). Maturity of the marsh increases with more sediment, fewer
channelsmore marsh vegetation, land plant encroachment onto the marsh.
Marshes are sediment sinks until sea level changes
Sea level rise and sedimentation balance makes large marsh environment deposit
Mangrove swamps-mangroves can’t tolerate a hard freeze (latitute/climate control)
Restricted to sluggish current and small wave areas
Very protective of sediment during large storms like hurricanes.