wetlands ch 9

Mangrove salinity variation

salinity varies widely annually and higher salinity occurs when soil water fluctuates less

Competitive advantage of saltwater

saltwater not essential but gives mangroves a competitive advantage

Saline soils inland

saline soil conditions extend farther inland when soil water fluctuation is low

Red mangrove zone

fringe zone closest to water with highest salinity around 59

Black mangrove zone

mid‑zone with salinity around 39

White mangrove zone

farther inland with mixed salinity around 30–40

Rhizophora mangle red

has large prop roots stabilizes sediment grows up to 30 ft has waxy leaves excludes salt at roots produces pencil seeds that germinate on tree

Red mangrove propagule

seedling that germinates on tree drops and roots when it hits sediment

Avicennia germinans black

has pneumatophores grows in anaerobic mud secretes salt through leaf pores leaves may show salt crystals

Pneumatophores

upward snorkel roots that allow oxygen intake above sediment

Laguncularia racemosa white

farthest from water cannot tolerate flooding excretes salt at leaf base

Conocarpus erecta buttonwood

not a true mangrove found in transition zone does not excrete salt

Lenticels red mangrove

small openings on prop roots that allow gas exchange through aerenchyma

Vivipary red mangrove

seedlings germinate while attached to parent tree

Sea level rise no retreat

mangrove surface area decreases when sea level rises and landward retreat is blocked

Sea level fall

mangroves expand seaward when sea level drops

Interior marsh definition

wetland with grasses and reeds no trees can be fresh or salt

Interior marsh function

protects land from flooding and reduces storm surge energy

Low water table marsh

long term drop in water table shifts marsh toward shrub bog or swamp