Mangroves

True or flase mangroves can NOT be found in ecoregions

TRUE

What type of system are mangrove swamps?

Woody systems (“swamps”) with halophytic trees/shrubsWoody systems (“swamps”) with halophytic trees/shrubs

How many mangrove species exist worldwide?

More than 50 species

What condition do mangroves require?

Protection from wave action

Where are mangroves commonly found?

Protected shallow bays, estuaries, lagoons, leeward sides, behind spits/shell islands

Why is slow-moving water important?

Allows fine sediments to accumulate

What is a key physical feature of mangroves?

Tangle of prop roots

What do mangrove roots do?

Slow water and stabilize plants

What are major stressors for mangroves?

Flooding (anoxia) and salinity

Where do mangroves replace salt marshes?

Subtropical and tropical areas

Minimum temperature for mangroves?

>16°C (~60°F)

Ideal salinity range?

Moderate (3–27)

Other important factors?

Sediment, energy, high tidal amplitude

Fringe mangroves?

protected shorelines or along narrow berms

forests along bays and lagoons, experience full sun, strong tidal imact

Riverine mangroves?

along tidal rivers, high productivity

within river floodplain, heavily influenced by season (wet and dry)

Basin mangroves?

Inland depressions

extend far island, may occur in inlets, deep bays, and coves, Seaward/ inland variation

Dwarf mangroves?

limited in productivity lack of nutrients or fresh water, low nutrients HIGH salinity, poor underlying soils

What limits mangrove distribution?

Frosts

Where are mangroves in the U.S.?

Florida, Puerto Rico, Gulf Coast (LA, TX, some MS & AL)

True or False are mangroves native to Hawaii

FALSE

Global mangrove coverage?

~138,000–170,000 km²

Where is highest diversity?

Indo-West Pacific (Old World)

Overwash (sometimes lumped with fringe)

similar to fringe forest except is an island flooded at high tide isolated from mainland

Key traits of true mangroves?

Salt tolerance, specialized roots, vivipary, obligate intertidal

How many “true” mangroves?

~54 species

New World species count?

<10 species

3 dominant species in South Florida?

Red, White, Black mangroves

Do mangroves require salt?

No, but it gives a competitive advantage

Purpose of roots?

Oxygen uptake & stability in soft sediment

Types of roots?

Prop roots, drop roots, pneumatophores

prop roots

provide stability

drop roots

extend from branches to the ground and root into sediment

Pneumatophores

maintained oxidized rhizosphere

Lenticels

• small, lens shaped pores

• facilitate gas exchange

• oxygen absorbed from air at low tide

• transportred to roots to maintain aerated layer

Plant Adaptations

salinity controls in tissues

roots- absorb only fresh water from saltwater (ultra-filters)

leaves- active salt excretion of salt

Vivipary

seeds germinate and will grow while still on tree- LIVE BIRTH

-enhances seeding success, root on sediment if falls there, drift until settles on firm ground

• when dropped float upright so roots can take hold when they float into into shallow water

Ecosystem Function

-Net primary productivity ranges from 570-2,700

-riverine mangroves most productive class

-controls on productivity: tide/storm surges, freshwater discharge, substrate, water-soil chemistry

-Detritus- based food web

Services

stabilizes the coastline, reducing erosion from storm surges, currents,waves, and tides

-natures storm buffers

-important for export of organic matter to coastal food webs

-intricate root system attracts: food, shelter from predators

Marsh vs Mangrove: SImiliarites

refuge function

detrital source

structural habitat in an otherwise low structure area

morphology important to function

Marsh vs Mangrove

Quality and quantity of detritus

type of structure

canopy vs none

substrate type

associated invertebrates