Marine Botany Mangals and Salt Marsh Study Guide

Where are mangrove and salt marshes found?

Low – energy coastal regions such as estuaries or coastal habitats protected by barrier islands

Xerophytes

have, morphological, anatomical, & reproductive adaptations to aid in the retention of water ( mangroves & salt marsh plants)

Zonation Patterns

In algae/intertidal, you have marine species trying to live as far up the land as possible, whereas with salt marshes, you have terrestrial species trying to live as far into the sea as possible

in other words: biotic factors limits upper versus lower limits

Salt Marshes

-typically areas of natural salttolerant herbs, grasses, or low shrubs growing on

unconsolidated sediments bordering saline water bodies whose water levels fluctuates tidally

Salt Marsh Zonation

flooding increases as you move closer to the ocean, salinity increases as you move farther away

Salt Marsh adaptations

Salt stress

• Epidermal salt glands

• Salt vacuoles – store salt in stem/leaf

-drop seasonally

• Thick cuticle – reduce contact

• Succulent

Soil anoxia:

• Aerenchyma = tissue with air spaces

• Lacunae = larger air channels

Ecological role of salt marshes

1. Primary Production- below ground biomass 90%, 10 x sequestration rates of terrestrial forest, 90% in soil so long term blue carbon storage

2. Food Sources- detrital food chain

3. Habitats-important nursery habitats for marine fish4. Stabilization of Sediments- root systems

5. Filtration- removal of organic waste by marshes lowers the sediment and nutrient loading to adjacent shores

Why conserve these ecosystems?

Even though global area is 1- 2 orders of magnitude smaller than terrestrial forests, contribution to carbon sequestration per unit area of coastal ecosystems is much greater

Accretion

the process by which salt marshes grow in elevation, primarily through the deposition of sediments and the accumulation of organic matter

why is accretion important?

basically natural levies and seawalls that can reduce the affects of sea level rise naturally. also nutrient rich

Farming on wetland…

subsides land, therefore releasing more carbon dioxide into atmosphere

Adaptations of mangrove leaves

-thick outer walls & cuticles

-salt is accumulated in leaves causing succulence and eventually shed glandular hairs- function in salt excretion

-lenticles- ”cork warts” secrete water & chloride

-hypodermis upper layer contains tannins

-lower layer contain hydrocytes- water containing cells

Adaptations of mangrove bark

lenticles- dense masses of cells that results in breaks in the bark

- function in gas exchange

- critical for root survival

Adaptation of mangrove roots

-Mechanical adaptations for attachment in soft sediment

-Aerial roots are common & specialized for diffusion of gases to subterranean portions.

-lacunae and aerenchyma

What are ecological roles of mangroves?

1. Coastal Resilience

2. Filtering land runoff

3. Stabilization of sediments

4. Trapping sediments

5. Primary Production

6. Nursery Habitats

Why are mangroves important for climate change?

Storm surge- low pressure & high winds raise water level at the coast-peak water levels can exceed 7m in heightfloodingMangroves can reduce storm surge and surface waves