10. Salt marshes and mangrove forests

In terms of wave energy, what type of coast could a salt marsh form on?

low energy Salt marshes form in low-energy **(protected)**, coastal locations. Often occur in estuaries

Describe the life cycle of a red mangrove. Are mangroves flowering plants?

(no they r not flowering plants) mature yellow 4 petal flower, ovary of flower grows into small fruit flowering plants fruits drop to ground, whhile viviparus, embryos develops inside of mother and mother gives live birth (red mangrove like this) **seed of the red mangrove germinate while fruit is still attached to the tree.** happens when the fruit isnt even really developed. like people, propagule this is how they propugate/ tip heavy/ float horizontally/ during high tide embed in water

Mangroves

video: Mangroves are forests occurring in the intertidal zone in tropical and subtropical areas. Mangroves replace salt marshes in tropical regions. **Both salt marshes and mangals occur in subtropical regions; there is overlap in the Gulf of Mexico, southern Australia, and New Zealand.** Mangrove forests occur in river deltas, estuaries, coastal embayments and lagoons. Mangrove forests fringe 60-75% of tropical coast lines. Mangroves were introduced by humans to the Hawaiian islands. **Just like salt marshes, mangroves thrive along relatively low-energy tidal shorelines. ** Mangals form highly productive ecosystems that can export energy and materials to adjacent, relatively deprived communities. Mangals also support a diverse heterotrophic food chain, including fish, crustaceans, birds, small mammals and numerous invertebrates. Unlike other coastal wetlands, mangals have been planted extensively for commercial purposes, particularly in the Philippines and Southeast Asia. Many plantations date from the 19th century. Mangals are also planted as shore protection, both for sediment stabilization and wave attenuation. More recently, mangals have been planted for esthetic and ecological reasons, often to hide unsightly dredge-waste banks. Most plantings are Rhizospora species. **Like salt marshes, mangals can have saline flats on the landward side of the forest. These flats can be colonized by cyanobacterial mats.** -------------------------------- lots of trees branches and roots canopy filters out light roots trap sediment lower part of root filter the salt right of the ocean refuge for small fish from nursey to coral

Key threats to salt marshes (7)

•Land reclamation (filling in salt marsh) •Coastal development (buirlding city and homes in marsh) •Dredging (remove sediment & form more marine environment) •Sea-level rise (SLR) •Hydromodification (modify amount of water that reaches the salt marsh affects) sediment delivery and fresh water input •Alteration of processes (e.g. sediment delivery, freshwater input) •Eutrophication. (suffocate surrounding grasses/ grass grow too tall)

Describe the mangal's role in carbon sequestration. How does it compare to salt marshes? How do estuarine and oceanic mangals compare?

•Mangroves are globally significant stocks of carbon (reason for large amount of organic carbon in soil or sediment)= •Low oxygen in sediments slow down decomposition •Root production is high •Roots trap sediment and carbon from elsewhere •Soil volumes increase over time with sea-level rise ----------------------------- stores more organic carbon than salt marshes can. store both Living biomass and soil organic carbon retain organic carbon in the sediment oceanic mangroves can store even more oganic cabon

Discuss the effect of sea-level rise on salt marshes. What determines whether a salt marsh can adapt to sea-level rise? What is coastal squeeze? (slide 28)

(sea level rise will have change in sediment supply= very important for if marsh will be able to survive sea level rise) •Salt-marsh fate depends on sediment supply. •If sediment supply cannot keep up with sea-level-rise, the marsh will drown •If sediment supply keeps up with sea-level-rise, the marsh will survive. (marsh will move farther in-land= leads to coastal squeeze) •To determine whether a salt marsh will survive sea-level rise you measure sediment supply. •Coastal squeeze will also be a factor (if the marsh doesn't have anywhere else to go and stopped by road for example then will be squeezed between road & ocean and more likely to disappear) -------------------------------- sea level rise tends to flush out sediment from the salt marsh coming in less then coming out/ marsh drown surface of marsh will decrease. sediment supply keep up with sea level rise= will survive will move more inland. need to measure sediment supply to see if they survive. coastal squeeze means that an ecosystem is trapped between the ocean and some form of structure. ---------------------- sediment coming in less then coming out, marsh will drown if sediment

Why are salt marshes important for Menhaden? slide 19

**one of the most important fishes for commercial fishing** The menhaden (Brevoortia) is one of the most important commercial fishes along the Atlantic and Gulf coasts of the US. Adult fish (1-3 years old) spawn offshore and the larvae will then drift with the tides and currents into estuaries, moving into shallow areas in the salt marshes to grow. We say one fish many fish, except when talking about fish species - then it is fishes ------------------------------------ serve as a nursery important function of marsh one of the most important fishes for commercial fishing menhaden fish that survives in marshes as young fish

List as many mangal ecosystem services as you can. Describe the mangrove's role in fisheries, wood sources.

1)coastal protection 2) nursery (just like SM) •Mangroves are nurseries for some fish species Mangrove forests are rich in resources for both grazers and predators •Economic value of mangroves for fisheries estimated at $37,500 per hectare 3) Mangrove Store Carbon •Timber and fuel •Support biodiversity •Provide physical protection for coasts •Retain sediments •Regulate nutrient and carbon exchange between land and ocean

Describe a black mangrove. What is a pneumatophore?

Black mangroves have many erect, aerial roots called pneumatophores, which branch from horizontal roots beneath the mud. These roots not only support the mangrove but also exchange gases for the buried roots. Without prop roots and pneumatophores the buried roots of these plants would suffocate, and the plants would die. To overcome salt excesses, the leaves of the black mangrove incorporate efficient salt glands, allowing salt nuclei to bleed from the sap. The salt is then washed from the leaves by precipitation. ---------------------------------- has prop roots too/ has pneumatophores= grow from underground roots of black mangrove support underground roots with oxygen has salt glands in leaves

Describe the more marine section of a salt marsh. What grows there and what lives there?

In the marine part of the food web, sea grasses, mud algae, and phytoplankton are the primary producers. Consumers include a range of bivalves(mussel) (shell has 2 parts), crustaceans(have a shell), fish and shore birds, (blue crab) examples: mussel, fiddler crab(c), amphipod(c), sand shrimp(c), isopod(c), zooplankton, soft shell clam(bivalve) Burrowing animals are very important in the overall marsh ecology. The burrowing brings nutrient-rich mud to the surface from deeper sediment and brings oxygen to the deeper sediment. ---------------------------------------------------------------------------------- primary producers mud algae phytoplankton// consumers= mussels burrowing animals important for salt marsh ecology bring oxygen rich sediment into the (important to oxygenate the sediment other wise anoxic) slide 8

Describe the more terrestrial section of a salt marsh. What grows there and what lives there? slide 8

In the terrestrial section of the food web, we have the marsh grasses as producers. Consumers include animals we consider terrestrial: insects, songbirds, raccoons and diamond backs. (ducks & geese) terrestrial part is the part that is dry at some time, insects, song birds raccons diamond back terrestrial organsims grasses form detritus/ little of material goes directly from primary producers to consumers

Compare the food webs in mangals and salt marshes. Similarities and differences?

Mangals also support a diverse heterotrophic food chain, including fish, crustaceans, birds, small mammals and numerous invertebrates.

How long does it take to reestablish a mangal after a storm? Does it occur naturally?

Mangrove forests provide wave protection for the shore. Both the root stems and the foliage aid in wave attenuation. The value of mangrove forests as coastal protection is estimated at $10,000 per hectare. Region III in the figure represents the area with the lowest wave energy in the figure. This is where mud flats can establish along mangrove shores. It has been shown that wave energy from tropical storms is mediated by mangrove forests. After cyclone Sidr hit Bangladesh in 2007, it was shown that areas behind mangals fared better than coastal areas without mangals ------------------------------- provide costal protection as an ecosystem service

Are deposit feeders or suspension feeders more common on the salt-marsh mudflat? Why? (slide 16)

Mudflats occur between the saltmarsh and the ocean. ***They are dominated by deposit feeders.** ------------------------------- ****because The large amount of silt in the water tends to clog the feeding of suspension feeders (have hard time to survive).*** However, there are some suspension feeders on the mudflat. oxygen is often depleted is salt marsh sediment surface is of mudflat pale, then sediment is black because of anoxic sediment Mudflats only have oxygen in the top 10 mm (1/4 inch), below that the mud is anoxic (has no oxygen). The oxygen-containing layer is visible as a brownish top layer in the mud. The anoxic mud is black from sulfur ------------------------- Examples of mudflat infauna (infauna means organisms that live in the substrate, in this case mud) are clams, mud shrimp, lug worms . Mudflat epifauna (organisms that live on top of the substrate) include mollusks, crustaceans, and polychaete worms -------- side towards water have mudflats/ muddy areas that r inundated in the tide/ figler crab organism ----------------------------------

What is the global latitudinal distribution of salt marshes?

Salt marshes occur in middle and high latitudes worldwide and are largely replaced by mangroves in the subtropics and tropics. They are found on every continent except Antarctica. In the US, salt marshes occur on every coast. In temperate and northern areas, salt marshes form in low-energy environments

Describe the difference in salt marsh numbers between the east coast and the west coast.

The Atlantic and Gulf Coasts are passive margins and this is where most salt marshes form. The steep active margin of the Pacific has fewer salt marshes. -------------------------------- the Gulf of Mexico has the highest concentration of salt marshes within the US - about 50% of US salt marshes occur along the Gulf coast.

Why are salt marshes so productive? Compare salt-marsh productivity to productivity of other ecosystems.

The daily tidal surges bring in nutrients, which tends to settle in roots of the plants within the salt marsh. The high productivity is caused by this daily renewal of inorganic nutrients. Salt marshes are one of the most biologically productive habitats on the planet, ----------------------------- salt marshes have very high productivity because they r innuadated daily with the tide/ salt water makes up tidal fluctuations bring in the nutrients daily renewal of inorganic nutrients. ---------------------------- photosynthetic organism= grasses r the most productive/ make up more then 50% of the productivity on the salt marsh slide 5

Describe a red mangrove. What is the purpose of the prop roots?

The most common mangrove along southern Florida, Caribbean, Gulfs of California and Mexico Characteristic prop roots Grows as high as ˜30 feet **The red mangrove is the most common species of mangrove along the shores of Southern Florida, the Caribbean, and the Gulfs of California and Mexico. ** It lives right on the shore and is easily identified by its peculiar prop roots, which branch downward and support the tree like stilts. Prop roots grow from the trunk and branches and aid in gas exchange for the roots buried in the mud. (roots that prop up the trees) Flexible aerial roots drop down from the higher branches, helping extend the tree laterally. The trees can be as high as 9 m. ----------------------------------- reddish color of prop roots magroves need fresh water to grow need to get rid of salt water. mangrove tree excretes salt onto its leaves. gas exchange take in oxygen to support root that is buried in mud. grow from trunk to branches. serve to expand mangrove forest sideways (laterally) supporting prop roots causes the magroves to grow high

Compare mangal diversity in the US with that in southeast Asia. What type of mangrove occurs in the US? How many mangrove species globally?

There are approximately 60 species of mangrove in the world of which the majority are found in Southeast Asia and Micronesia. Only about 20% of the species occur around the Atlantic. The left figure shows global mangal diversity. (Remember that diversity refers to the number of species in an ecosystem). Note the low diversity in the Americas. The highest diversity occurs in Southeast Asia.

In what form does a salt marsh provide organic matter to an estuary?

They serve as depositories for a large amount of organic matter and are full of decomposition, which feeds a broad food chain of organisms from bacteria to mammals. Many of the halophytic plants such as cord grass are not grazed at all by higher animals but die off and decompose to become food for micro-organisms, which in turn become food for fish and birds. *unsure if right* The salt marsh is very rich in organic detritus. Bacteria in the marsh degrade the organic matter in respiration. Respiration uses oxygen and salt marsh sediments therefore often become anoxic. (slide 15)

Discuss similarities and differences between salt marshes and mangals. Include wave energy on shore where they form, global distribution, role in organic matter export, woody plants, commercial use.

Unlike salt marshes, mangals are dominated by woody plants - mangrove trees. Mangroves are flowering land plants adapted to the intertidal. **Both salt marshes and mangals occur in subtropical regions; there is overlap in the Gulf of Mexico, southern Australia, and New Zealand.** **Just like salt marshes, mangroves thrive along relatively low-energy tidal shorelines. ** **Like salt marshes, mangals can have saline flats on the landward side of the forest. These flats can be colonized by cyanobacterial mats.** ----------------------------------- There are approximately 60 species of mangrove in the world of which the majority are found in Southeast Asia and Micronesia. Only about 20% of the species occur around the Atlantic. The left figure shows global mangal diversity. (Remember that diversity refers to the number of species in an ecosystem). Note the low diversity in the Americas. The highest diversity occurs in Southeast Asia. These shrubs and trees may form thick forests. Mangrove forests may reach as far inland has 320 km in Southern New Guinea and some islands in Indonesia, where the influence of the tides extends far up estuaries. As sediment and detritus accumulate among the roots, mangroves gradually extend the coastlines seaward actually creating new land. When enough material has accumulated, the mangroves may be replaced by land plants. Thus, mangrove forests can be considered a stage of ecological succession between marine and terrestrial communities. Mangal communities are adept at natural re-establishment and recover over 2-20 year periods following tropical storm damage. Protection, conservation and even restoration and creation are practiced.

Describe how the Sundarban mangal is special.

bangledesh sunder indigeoneos ppl live there largest single mangrove forest in the world mismanagement, corruption, \ black marketeers choping down flowers clearing the trees honey now not sweet forest officers biggest problems wont give permit if u dont bribe them. corruption their biggest problem. respect for the forest ppl should be apart of the converdstion about the forest, but gov wont let them

Define salt-marsh sections/zones and how they differ. What is the zonation based on? (slide 11)

based on salt tolerance Low marsh is flooded with almost every tidal cycle -More salt tolerant plants live in the lower marsh High marsh is flooded only during spring tides --------------------------- during highmarsh= Salt pannes are areas where salt water pools during flooding and can't drain. Instead water evaporates creating areas with very high salinity. (in the ground where the salty water comes in during a high tide/ water sits there and evaporates over time which increases salt concentration=high salinity Tidal creeks, freshwater streams, salt pannes and mudflats occur in the saltmarsh. The term wetlands is sometimes used for saltmarshes and fresh-water marshes. ---------------------------- side towards water have mudflats/ muddy areas that r inundated in the tide/ figler crab organism salt pannes have high salinity

What conditions are necessary for mangals to occur far inland? How do mangals create new land?

depends of how far the tides move inland

Plants in Salt Marsh (not on list) (slide 14)

primary producers for the marsh. Smooth cordgrass (Spartina alterniflora), pickle weed (Salicornia pacifica), eel grass (Zostera marina). Smooth cord grass is the most common plant in northeastern marshes. Pickle weed is common in the northeast and also occurs in northwestern salt marshes. Salt grass (Distichlis Spicata). Eel grass grows in the water just below the actual salt marsh. Spartina is rarely eaten by organisms - it is too rough. It dies back in the fall and becomes detritus that is exported fro the marsh. Spartina can be made into rope, which is the origin of the name. The ancient greeks made rope from Spartina. Rope in greek is spartine. Cord grass needs water for growth and has to get rid of the salt. Salt is excreted through pores on the leaves. On a hot day, Spartina stands glisten white from salt crystals on the leaves.

slide 43

producers: mangrove tree all producers add to detritus. herbevorivores: crabs and insects carnivores: fishes, birds salt marsh and mangrove forest high amount of silt in water/ more filter feeders in mangrove, water a little clearer filter feeders= oyster, barnicles. detritis important to salt marsh and mangrove

Describe a mangrove ecosystem. Who is the primary producer? Who aerates the soil? What type of organisms occur?

rich ecosystem Many marine and land animals live in mangrove forests. Crabs are particularly common in mangrove forests: species of Sesarma and Cardisoma feed on the abundant leaf litter that accumulates below the mangrove trees. These crabs spend most of their lives on land, but when eggs are ready to hatch, females must release the larvae at sea. Several species of fiddler crabs excavate burrows in the mud. As in temperate mud flats and saltmarshes, burrowing crabs help oxygenate sediment. Many organisms attach to, or take shelter among, the submerged mangrove roots. •On the west coast of Florida, the roots eventually become encrusted with a purple oyster called the coon oyster This oyster gets its name because it is a favorite food of raccoons. •On the east coast of Florida, mussels and acorn barnacles are dominant. Periwinkle snails that are related to the marsh periwinkle graze on algae that grow on the stems and prop roots of the mangroves as well as on the shells of the sedentary organisms attached to them. The King's crown conch, a carnivorous snail, feeds on oysters by prying open their valves with its strong muscular foot and then digesting the contents. Mangrove crabs go through their larval stages in the water beneath the mangroves. When mature, they crawl up on the mangroves and feed on the leaves. Large sponges living on the roots have been found to provide significant amounts of nitrogen to mangrove plants. They also help protect roots from borrowing isopods, which may cause considerable damage. The muddy bottom around many mangroves is inhabited by a variety of deposit and suspension feeders, as on temperate mud flats. These include polychaetes, mud shrimps, and clams. The channels that cross mangrove forests are rich nurseries for many species of shrimps, spiny lobsters, and fishes. Birds make their homes in the branches and feed on fishes, crabs, and other prey. Snakes, frogs, lizards, bats, and other land animals also live in mangrove forests. ------------------------------------ largest individual numbers happens between the crabs. organisms that freely swim amoung the water roots small fish jellyfish an ghost fish periwinkles, oysters that attached to roots. larve that r released from these organisms/ magrove crab= release larve periwinkle crawl along eat algae that is along the root both deposit and suspension feeds: poly keeps, mud shrimp clams sponges

What are the main threats to salt marshes? (4)

sldie 26 1)**from filling in the salt marshes** 2) Estuarine pollution from organic, inorganic, and toxic substances is a worldwide problem. 3) Marshes have been drained, diked, ditched, grazed and harvested. (marshes used to be common lan) 4) Invasive species going in marshes They have been sprayed for mosquito control, and have been invaded by a range of non-native species that have altered their ecology. As one example, Massachusetts, United States of America, has lost 41 per cent of its salt marshes since the 1770s, with a loss of 81 percent in Boston (Bromberg and Bertness, 2005; Figure 2). central Seattle. This area once looked like the wet lands we see in the upper picture. These wet lands were filled in for urban development. ----------------------------------- fill in salt marshes/ seatle city was marsh that was filled in with city

Describe the role of environmental stress in salt marshes. What is the main cause of environmental stress in a salt marsh? How does environmental stress affect species diversity in the salt marsh?

slide 12 •High and variable salinity cause high stress •Halophytic plants (can tolerate salin waters) dominate •Few species can survive => low species diversity (high stress cause low species diversity) •Compare with estuaries! ------------------------------- High and variable salinity is an important factor contributing to the relatively low species diversity. The salinity variation is a source of stress. Like estuaries, salt marshes have few species but many individuals of each species. A salt marsh is dominated by halophytic (salt tolerant) herbaceous plants.

Describe oxygen consumption in salt marsh sediments. What consumes oxygen in salt-marsh sediments? How is organic matter and oxygen usage linked in salt-marsh sediments?

slide 15 •Sediment oxygen is renewed with incoming tides. Between tidal flooding, bacteria consumes sediment oxygen (in the process of responsiration)=> salt marsh sediments often become anoxic. (bacteria use up all the oxygen in the sediment) •Spartina roots need oxygen - (one of their adaptations) the stem is hollow to allow oxygen transport to the root of the grass ------------------- The salt marsh is very rich in organic detritus. Bacteria in the marsh degrade the organic matter in respiration. Respiration uses oxygen and salt marsh sediments therefore often become anoxic. ------------------------------- burrowing organisms inportant for replenishing oxygen

Describe beak adaptations in shore birds. What drove the adaptation?

slide 18 The most significant predators in the mud flat are wading birds. The different beak lengths allow them to forage for different types of prey. --------------------------------- examples of dif wadding birds: -godwit -dowitcher -willet -western sandpiper -least sand piper ------------------------------ different beak length mean they can go over different type of prey -godwit (goes after burrowing clams and mud shrimp) (longest beak) -dowitcher(burrowing clams that go less deep) -willet( -western sandpiper( -least sand piper( beaks get shorter and shorter

Briefly describe the life style of a Fiddler crab. Male versus female. What do they eat? What part of the salt marsh system is their habitat?

slide 20 Live on mud flats. Mostly tropical and subtropical, but can come as far north as Boston -Feed on mud -Burrows in the mud lifestyle dependent on the tides ----------------------------------- All fiddler crabs arrange their lives around the tides. They are active at low tide and retreat to their burrows at high tide. They very clever seal their burrows before high tide, enclosing an air bubble inside. (dependent on keeping air in it when tide comes in) The little mud balls outside their burrows are excavated from the inside of the burrow. (spit outs of muds that have been cleaned from the organic mater) ----------------------------- Fiddler crabs also feed on mud. They take the mud into their mouths and mix it with seawater. The seawater floats the food out of the mud. They swallow the food and spit out a little ball from the remaining mud. Fiddler crabs that are captured and removed from the tidal environment still act as though the tide was there. They feed during low tide and sit quietly during high tide. They have a biological clock. **The males advertise for females by waiving their big claws. The female comes over to check out the burrow. If she likes the home, she stays, otherwise she will leave and look for another male.** The claws are also used to fight over females. However, the fiddler crabs seem to be pretty careful in their fighting. Loosing a claw means that they have to wait until a new one grows out before they can mate again can only mate if they have an intact claw. -------------------------- feed during low tide and stay still in low tide large claw male used to advertise for female go to burrows during high tide

Microbial mats: What drives zonation in a microbial mat? How are cyanobacteria and diatoms different? How are they similar? Which two ways do cyanobacteria use to get organic matter? How do cyanobacteria get inorganic N-containing nutrients? How are purple sulfur bacteria different from cyanobacteria and diatoms? How are long-wave sulfur bacteria different from purple sulfur bacteria?

slide 24 Microbial mats occur in protected, constantly moist, saltmarsh areas. If you touch or pick up a piece it feels like cooked lasagna. Microbial mats are composed of layers of algae and bacteria, where each layer and its inhabitants have specific characteristics. The population in the microbial mat is arranged according to their light requirements and oxygen tolerance. (Note hat they are arranged according to oxygen tolerance, not oxygen need. These bacteria need oxygen-free cells). **Both light and oxygen will decrease with depth. This is another example of zonation.** In the top layer we have the photo synthesizers. This is where we find diatoms, which are algae, and cyanobacteria which are photosynthesizing bacteria. Cyanobacteria are fascinating - they can both photosynthesize to make their own organic matter and consume organic matter produced by other organisms! In addition they can fix nitrogen, which means that they can take gas-phase nitrogen from the atmosphere and put it into nitrate and ammonium. C and N are both essential to produce organism tissue and cyanobacteria can fix both! It is thought that cyanobacteria are examples of early life on Earth, long before we had oxygen-containing atmosphere. Cyanobacteria occur everywhere on Earth, carry out more than half of the primary production in the ocean and are thought to be responsible for creating the oxygen that gives us today's oxygen -containing atmosphere. We encountered them when talking about harmful algal blooms. Cyanobacteria create the green tides seen in fresh water systems in Florida. Below the oxygen-containing photosynthesizing layer, we have another layer of photosynthetic organisms that cannot tolerate oxygen and do not produce oxygen in the photosynthetic process! Instead, they use sulfur and produce granules of pure sulfur in the photosynthetic process. There are two layers of sulfur bacteria. The top layer uses the more energetic short-wave length light, and the next layer has to make do with the longer wavelengths of less energetic light. 1) cyanobacteria and diatoms (greeb) 2) Purple Sulfur proteobacteria (purple) 3) long wavelength purple bacteria (white) release pure sulfur= pure color ------------------------------------- unique zonation have old type of bacteria. composed of layers of algae and bacteria oxygen tolerance** all bacteria in mat has to remove oxygen from cell dont need oxygen light and oxygen reduce with depth through mat example fo early life on earth doesnt not requiere

List as many salt-marsh ecosystem services as you can. Include all four ecosystem-service groups.

slide 29 listen to audio •Filter out nutrients, pollutants and sediment from terrestrially-derived and marine water •Habitat for commercial fish, and a large number of other organisms •Shelter the coast from flooding, wave erosion, storms (including hurricanes) •Store a large carbon amount in peat and sediments, preventing C from entering the atmosphere as CO2 (called blue carbon) •Recreation •Education and research --------------------------- 6 most important over half of commercial fishes of east coast use marsh in some time fo their life

How will climate change affect mangals? What is being done to protect mangals?

slide 52/38 •Mangrove forests will be affected by •Sea level rise (most severe) (coastal squeeze) •Increased CO2 concentrations (co2 observed by water increase acidity(mangrove dont like// increase in air too (they like) •Elevated temperatures •Changes in rain fall (more flooding in estuary) •Changes in winds and waves (storminess) --------------------------- •Mangroves have decreased globally with ˜30% •Shrimp pond construction is common in mangals. Used for a few years. Soil becomes acidic and includes sulphate instead of sulphide => mangroves cannot regrow •Mangroves can be restored and have been rebuilt •Just like salt marshes, mangals are affected by coastal squeeze. *Coastal squeeze will be a major issue as sea-surface level increases*

What drives mangal zonation? Describe the succession of mangal species going from the area closest to the shore all the way to a mudflat.

•Mangroves separate based on ability to withstand salt-water inundaton, soil salinity, and low oxygen concentrations - the substrate (sediment in which the tree grow in) is usually anoxic. •Red mangroves grow closest to the coast •Inside the red mangroves are black mangroves •Farther inland still are white mangroves •Sometimes, white mangroves are followed by high-salinity mud flats. They form by high evapotranspiration. ------------------------------ As in salt marsh plants, the various species of mangroves have different tolerances to immersion by high tide. Partly as a result of these differences in tolerance, they show a distinctive zonation in the intertidal, from a marine to a progressively terrestrial environment. The outer seaward edge of the forest is dominated by the red mangrove (a community with mangroves is termed a mangal). As in Florida and most of the western hemisphere, the coastal red mangrove is followed by the broad belt of black mangrove Avicennia germinans. Farther inland is the white mangrove Laguncularia racemosa. The various types of mangroves usually remain separated by their ability to tolerate flooding by salt water during high tide, their different tolerances to soil salinity and soil oxygen concentration. ----------------------------------- tree need to be able to withstand anoic conditions near roots zonation of different type of trees, ability to tolerat sediment in which

How they r protected

•Secure land for wetland expansion (to improve coastal squeeze) •Remove barriers to landward movement •Redraw boundaries around wetland reserves •Ensure sediment supply is maintained (dams and levees) •Reduce pollution inputs (inorganic, organic, or pollutants) •Reduce unsustainable extraction •Restore

Why is it important to replenish oxygen in salt-marsh sediments? How is that done? How do marsh grasses supply their roots with oxygen?

•Spartina roots need oxygen - the stem is hollow to allow oxygen transport to the root

What happens to marsh grasses when too much nutrients are added to the marsh? How does that affect the marsh as a whole? (slide 13)

•Too much nutrients (eutrophication) causes marsh grasses to grow too tall and tip over.(not good for marsh) •The fallen grass shade their neighbors, which decreases primary production in the marsh so marsh can not tolerate an endless supply of inorganic nutrients/ marsh will respond in a negative way very high primary productivity in marsh