Dunes+and+Coastal+Wetlands

=Dunes and Coastal Wetlands= Jayme Badoud, Jordan Cartie, Wes Wilson and Tiffany Cobb

=Coastal Wetlands=

What is a Wetland?
A wetland is an area that is either partially or completely sumerged by water periodically throughout the year, inluding the growing season. This submersion may be causes by several factors, the most important being seasonal flooding and tidal action. Depending on the source of submersion, there are two different classes of wetland: coastal wetland and inland wetland. Both categories of wetland support mainly hydrophytes and are domimated by undrained hydric soil. 9 ]

Coastal wetlands are the melting pot of coastal ecosystems. Often found as the bond between wide rivers and the vast ocean, coastal wetlands, also known as salt marshes, can be found alongside mudflats and coastal scrub. The characteristic feature of coastal wetlands is that they contain a mixture of fresh and salt water that part through swamp and marsh land forms. It is the combination of these features that make salt marshes one of the most unique and diverse ecosystems in the world. 6 ]

The diversity and uniqueness of coastal wetlands are due, largely in part, to their linkage to both the coast and to rivers. Located in estuaries, bays or subdued shorelines, their geographic position provides protection from surf but still allows for the tidal influence of the ocean. The influx of multiple water sources results in frequent fluctuations in temperature, salinity and pH. The constantly changing environmental conditions result in a unique set of adaptations in the plant and animal life that call the salt marshes home.

Plant **Life **
The plant life found within a given wetland varies greatly according to the biotic and abiotic factors present. Hydrological, position on the landscape, tidal exposure, substrate, fertility, climate, environmental stress and disturbances are among the most influential abiotic facors. Biotic factors include competition, facilitation and herbivory [1]. Depending on these factors, some wetland communities can offer a wide array of biodiversity and productivity while others are rather scarce.

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Costal salt marshes receive a majority of their water directly from the ocean with groundwater and precipitation only responsible for a minority of the total water contribution. As such, the dominant plant species found in the lower zones of the salt marshes are halophytes; plants that are highly tolerant to or even require salt to live. These plant species include //Salicornia// (also known as pickleweed) and //Distichlis spicata// (salt grass). Sedges, rushes and grasses dominantly populate higher marsh zones because they cannot survive in the high salinity present in the lower zones [2]. In the lowest salt marsh tidal zones, adjacent to the mudflats, a number of important algae species can be found.======

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//Salicornia// is a unique species of plant. It is a small succulent plant that has waxy outer leaves and small seasonal flowers. It possessesunique physiological adaptations that allow it to survive in extreme salinity. The roots of the pickleweed plant can uptake salt water from its environment because the plant’s cells are able filter the salt from the water. The salt is transported to the outermost leaves of the plant where it accumulates and over time turns the leaves red. When the concentration of salt becomes to great, the leaves simple fall off leaving the rest of the plant salt====== -free.[3]

//Distichlis spicata////,// or salt grass, lives in the mid-tide zone, which slightly further from the water than pickleweed. Salt grass is also specially adapted to survive in saline conditions. Its cells, much like pickleweed, filter salt crystals from the salt water absorbed from the environment. The salt crystals are then transported from the roots to the leaves of the plant where the crystals are excreted from special glands on the surface of the leaves//.[4]//

The diverse flora found in the salt marsh allows for an extremely productive ecosystem. Live plants serve as a food source for insects, while dead and decomposing plants, known as detritus, provide an excellent source of nutrition to many other marsh organisms including fish, worms and crustaceans, as well as to vital marsh bacteria. 6] On the bottom of the marsh food chain lie a variety of invertebrates including crustaceans, molluscs and insects, which are all vital residents of coastal wetlands. Some common invertebrate residents include mussels, crabs, snails, clams, beetles and flies. Vertebrates lie higher on the food chain. Many marsh invertebrates serve as a food source for juvenile and adult fish. Depending on the region, a variety of fish species can be found including: bay goby, stripped bass, California killfish and top smelt. 11] In the past, the bay pipefish used to be a common resident in most coastal wetland, but in recent years its population has sharply declined due to eel grass bed destruction. With the exception of some non-native mammal species such as coyotes and raccoons, birds are on the top of the salt marsh food chain. Wetlands on the West Coast of the United States are a common stopping point for winter migrant birds along the Pacific Flyway, which is one of the four major migratory bird pathways 8]. The many organisms living off of plants and detritus serve as an abundant food source for the migrant birds. Shorebirds and waterfowl are common migrants in the wetlands and can be found in the millions shortly before spring migration begins. The wetlands are also home to many permanent avian residents including herons and egrets. Herons and egrets are on the top of the food chain in wetland ecosystems and therefore, serve as important indicators of ecological changes.[5] The Great Egret ( //Ardea alba) //  is one of the most common egret species, as well as one of the top predators found in coastal wetlands. They can be found all over the world, not only in wetlands, but also in rivers, lakes, ponds and swamps. Some Great Egrets are migratory; while others stay as year round residents in their given location. Morphologically the Great Egret is white with long black legs and a long yellow bill. Their diet consists of fish, invertebrates, reptiles, small mammals and other birds. They forage by slowly stalking then quickly stabbing their prey. 7] 

Environmental Importance and Restoration
According to The Department of Environmental Protection, tidal wetlands are the most productive resources in the world behind tropical rainforests. Wetlands are important to the plant and animal life they support. The wide variety of vegetation in the wetlands provide food and nesting for shorebirds and serve as a safe nursery for a variety of fish species. Not only are wetlands important for the wildlife they support, they also serve an important geological purposes. Wetlands work as a filtering system for pollutants and nutrients from rivers draining into the coastal waters while also protecting shorelines by preventing erosion. In addition, they are an integral part to human life. It was not until the ecological study of the wetlands expanded that scientists started to see the sharp decline of the wetland population and its consequences for humans. For humans, the wetlands can serve as a place for nutrient cycling, water supply, disturbance (flood) regulation, and waste treatment. Along the coast, wetlands have been drained to provide for real-estate ventures with disastrous ecological results. As a result of the wetlands necessary and prominent role in coastal ecology and human life, it is important to make sure that there is adequate amount of quality wetland area along the coast of California to sustain the balance of water restoration and hydrology. The decline of wetland property has government associations like the United States Environmental Protection Agency involved in restoring damaged wetlands and maintaining wetlands that would otherwise be destroyed. Government and volunteer agencies re-establish wetlands with regards to physical, chemical, or biological properties with the goal of returning the area to its original or historic form. In some desperate instances, mitigation will be used in so far as creating wetlands to compensate for wetland losses.Aggregately, the goal of these agencies is to restore at least 100,000 acres of wetlands every year 10].

1) Batzer, Darold P. and Rebecca R. Sharitz, __Ecology of Freshwater and Estuarine Wetlands.__ London: University of California Press, 2006

2) Sumich, James L. and John F. Morrissey. __Introduction to the Biology of Marine Life.__ London: Jones and Bartlett Publishers, 2004 3) "Pickleweed" __Save the Bay__. 2005. February 22, 2009.  4) "Saltgrass" __Save the Bay__. 2005. February 22, 2009.  5)  "Wetland Bird Monitoring" __Wetlands Regional Monitoring Program Plan__ 2002. March 22, 2009.  6) “Dynamics of the Salt Marsh” __South Carolina Department of Natural Resources.__ 4 April, 2009. http://www.dnr.sc.gov/marine/pub/seascience/dynamic.html 7) “Great Egret” __All About Birds.__ 2003. Cornell University. 4 April, 2009. http://www.birds.cornell.edu/AllAboutBirds/BirdGuide/Great_Egret_dtl.html#habitat 8) "Birds of Southern California's Coastal Bays and Estuaries" __U.S. Fish and Wildlife Service.__ San Diego: Tecolote Publications, 1994. 9) "What are Wetlands" __U.S Enviornmental Protections Agency.__ 12 January, 2009. 12 April, 2009. http://www.epa.gov/owow/wetlands/vital/what.html 10) "River Corridor and Wetland Restorstion" __U.S. Enviornmental Protection Agency.__ 14 August, 2007. 19 April 2009. http://www.epa.gov/owow/wetlands/restore/ 11)  "California's Coastal Wetlands" __California Coastal Resource Guide__. 20 April 2009. http://ceres.ca.gov/ceres/calweb/coastal/wetlands.html

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6)References
=What are Coastal Dunes? =

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Coastal dunes are a unique ecosystem that consists of hills or ridges of sand formed on the outer shoreline of sandy beaches . These land forms are created by an accumulation of loose sand which is moved inland away from the water via wind action. 4 ] As the sand accumulates, plants are able to colonize the area. Plant colonization aids in the stabilization and further growth of the dunes due to the binding action of the roots.======

Coastal dunes are found worldwide by the oceans sandy shores, salt marshes, and rocky headlands. There are well-developed sand dunes as well as smaller sand dunes. Many coastal dunes are found in tropical regions, such as Southeast Asia. Countries such as Indonesia and Java boast dune fields with dunes up to 20 meters tall. Other countries, such as Thailand and the Philippines have only a few small dune fields. Coastal dunes are also characteristically found in Northern California in locations such as Moro Bay and Monterey Bay. In some instances, coastal dunes run adjacent to desert dunes, which makes differentiation between the two dune types difficult. 4 ]

=Dune Shapes and Configuration =

Shapes
__**Crescentic**__ Crescentic Dunes are a wide type of dune that form when winds blow from only one direction. Another name for this type of dune is called barchans which means a transverse dune. 2 ].  __**Star**__ Star Dunes are radial symmetrical and categorized as being pyramid like and extend about three or four arms, which also can be called slip faces or slopes from the center of their formation, making it look like a star. They like to form when wind is coming from more than one direction. These multidirectional winds cause the dune to look like a star. Star dunes are said to grow from the ground up. A major place that you can find star dunes are in Grand Erg Oriental of the Sahara. They occur in more deserts, but on the outer layer of the sandy beaches and seas especially in tropic areas. In the southeast Badain Jaran Desert of China, the star dunes have grown up to 500 meters. It is said that that these sand dunes in China could be the tallest on Earth.

__**Dome**__ These dunes are circular and usually do not have a slope that faces away from the wind. Where as star dunes, which we discovered have slopes, or slip faces that face away from the wind.

__**Parabolic**__ U-shaped dunes of sand that bulge or curve outward followed by extending arms are called //parabolic dunes// . __**Linear**__ Linear dunes are parallel to the sandy shoreline and are seen as ridges. They reach about 30 to 50 feet close to the sea shore.

Types
__**Sub-aqueous dunes**__ These dunes form on sand or gravel when there is much water flow coming from an abundance of channels consisting of estuaries and rivers. They can also form under manmade pipelines and canals. __**Lithified dunes**__ This is a type of sandstone that is formed when the wind carries and deposits sand so that it can become compacted and eventually hardened.3 ]

Dune Configuration
Dunes can occur in three forms which include simple, compound, and complex. Simple dunes have a small variety of slip faces or slopes and have basic form. Compound dunes are formed on a larger scale compared to smaller dunes with only one type of forming characteristic, but with complex dunes, scientist can see a mix of two or more types of dunes. A crescentic dune with a star dune intertwined on its peak is the most common complex dune. Simple dunes are an easy form to study because the current winds do not change to become stronger. The wind stays constant and does not change direction since the dune was formed. This is the exact opposite of the compound and and complex dunes that feel a constant change in the intensity of the wind and which direction it is coming from. 2 ]

Plant Life
====The ecological environment of dunes is very stressful and only specially adapted plants can survive. For example, plants must be adapted ot harsh conditions such as fluctuations in wind intensity, high salt concentrations, and low nutrient sand. A very common plant found in dunes is the ice plant or //Carpobrotus Edulis//. Ice plant is invasive and perennial. It poses a threat to the habitat of the coastal dunes because it chokes surrounding vegetation which lowers biodiversity. It was once introduced to the coastal dunes in Point Reyes in order to control natural erosion. In the end it prevented the natural process of sand erosion almost entirely.====

Photo Courtesy of: http://www.mzephotos.com/gallery/cacti/hardy-ice-plant.htmlnother plant

Another species of plant that is common in dunes is lichen. Lichin is a pioneer species. It has a symbiotic relationship between algae and moss. As a pioneer species, lichen is generally one of the firsts species of plant to inhabit colonize an uncolonized are. As a pioneer species, they appear in just about every type of climate imaginable. LThis is why lichen is able to thrive in sch a harsh environment as the coastal dunes.



Photo Courtesy of Tiffany Cobb

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Coastal dunes have few permanent animal residents due to the harshness of the ecosystem. However, birds are very prevalent in and around the dunes. Such birds include seagulls, or the //Larus californicus.// The California Gull eats just about any and everything from fish to discarded food and insects.======



The monarch butterfly, or the //Danaus plexippus// also makes its home on and around the coastal dunes. Though it is best known as a North American butterfly,it has been sighted in places such as Western Europe and Australia.

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Photo Courtesy of: http://newarklibrary.wordpress.com

Coastal dunes are vital to the environmental health of shorelines. There most basic function is that of a barrier between land and sea.The most significant danger that the dunes face now comes from humans. With ocean front real estate booming. Sand from dunes is being evacuated for the purposes of expanding cities as well as to create beach front tourist attractions. Also for the purposes of tourism, many native plants have been removed from dunes and replaced with tropical plants. Though this is appealing to tourism, it's depleting irreplaceable ecosystems. The degredation of sand dunes has caused significant problems with storm control.

7) “California Coastal Sand Dunes” California Coastal Resource Guide. 20 April 2009. http://ceres.ca.gov/ceres/calweb/coastal/dunes.html <span style="font-family: 'Times New Roman',Times,serif;">8) “Voles” __Pests in Gardens and Landscapes.__ University of California. Jan 2001. 20 April 2009. http://www.ipm.ucdavis.edu/PMG/PESTNOTES/ pn7439.html 9) “California Legless Lizard” __California Reptiles and Amphibians.__ 20 April 2009. http://www.californiaherps.com/lizards/pages/a.pulchra.html 10) "Coastal Sand Dune Form and Function" __Department of Conservation.__ 21 April 2009. http://www.doc.govt.nz/publications/conservation/native-plants/pikao-or-pingao-the-golden-sand-sedge/coastal-sand-dunes-form-and-function/#importance 11) "Strategy Habitat: Coastal Dunes" __Oregon Department of Fish and Wildlife__. Feb, 2006. 21 April 2009. http://www.dfw.state.or.us/conservationstrategy/document_pdf/b-habitat_3.pdf