Wetlands

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Wetlands

• Kidneys of the landscape
• Nurseries for aquatic organisms, amphibians and
  reptiles
• Among the most important ecosystems in the world
• Form about 5-6 of the land surface, about the
  same as rain forests
• Role of water is key.

http//www.epa.gov/owow/wetlands/types/
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We talked about them before

• An earlier era (350-300 my ago)
• Carboniferous in Europe
• Mississippian or Pennsylvanian in North America
• A similar wet environment
• Habitat for coal formation

Image from Coal Forest exhibit, Field Museum,
Chicago
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Coal Seam

• Stratigraphic sections Scientists in a coal mine
  have color coded the successive layers of coal
  ball formation. Each layer represents an
  individual flood event in the coal swamp.

www.ucmp.berkeley.edu/carboniferous/
carbstrat.htm
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What is a Wetland?

• Ecotone
• Transitional environment between dry
  terrestrial conditions and aquatic conditions
• High biodiversity- species from both terrestrial
  and aquatic environments.

www.elkhornslough.org/research/ conserv_main.htm
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What is a Wetland?

• No single, universally recognized definition
• Form under a variety of conditions
• Take a wide variety of forms
• Working definitions Ecosystems whose formation
  has been dominated by water,whose processes and
  characteristics are largely controlled by water.
• A place that has been wet enough for a long
  enough time to develop specially adapted
  vegetation and other organisms (Malthy, 1986)
• "Wetlands are areas that are inundated or
  saturated by surface or ground water at a
  frequency and duration sufficient to support, and
  that under normal circumstances do support, a
  prevalence of vegetation typically adapted for
  life in saturated soil conditions. Wetlands
  generally include swamps, marshes, bogs, and
  similar areas. (Definition of wetlands as used
  by the U.S. Army Corps of Engineers (Corps) and
  the U.S. Environmental Protection Agency (EPA)
  since the 1970s for regulatory purposes.)

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Some Wetland Functions

• Fertile and highly productive ecosystems
• Support fisheries
• Absorb and store carbon greenhouse mitigation
• Sift dissolved and suspended material from
  floodwaters, -- encouraging plant growth and
  maintaining water quality
• Absorb and store floodwater mitigating flood
  peaks
• Act as barrier against storm surges

http//www.grenadaclimate.org/images/photo_gallery
_images/storm_surge_damage_in_carriacou/storm_surg
e_damage6(big).htm
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Some Wetland Functions

• Vital breeding grounds for waterfowl, animals,
  plants and provide refuges in times of drought
• Provide stable food plants
• Provide fuel (peat)
• Provide building materials (woods, reeds for
  thatch)
• Recreational use

http//www.epa.gov/watertrain/wetlands/values.htm
www.elkhornslough.org/research/ conserv_main.htm
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Water Storage

• Natural sponge absorbs and store water and
  gradually release it.
• 1 acre of wetland can store between 1 and 1.5
  million gallons of water.
• Slows waters momentum, thereby decreasing its
  erosive potential
• Reduces flood height
• Allows for groundwater recharge
• So reduces risk of costly property damage and
  loss of life
• US Army Corp of Engineers found that protecting
  wetlands along the Charles River in MA, saved 17
  million in potential flood damage

http//medent.usyd.edu.au/fact/wetland.jpg
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Water Storage - Examples

• 20 million acres of wetlands in the Upper
  Mississippi had been drained or filled, mostly
  for agricultural purposes
• Great Mississippi Flood of 1993.
• Billions of dollars in damage and 38 deaths
• Would the results have been different?
• The bottomland hardwood- riparian wetlands along
  the Mississippi River once stored at least 60
  days of floodwater. Now they store only 12 days
  because most have been filled or drained.

http//water.tamu.edu/images/wetland.jpg
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Water storage - Examples

• Minnesota Dept. of Natural Resources estimates
  (1991 dollars) that it cost 300 to replace each
  acre-foot of flood water storage.
• The cost to replace the 5,000 acres of wetlands
  lost annually would be 1.5 million.

Lake Huron Shoreline http//www.yougrowgirl.com/ex
plore/saugeen01/images/wetland.jpg
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Water Filtration

• Water slowed down in the wetland moves around
  plants
• Suspended sediment drops out of water and settles
  to wetland floor
• Nutrients from fertilizer application, manure,
  leaking septic tanks and municipal sewage are
  often absorb by plant roots and microorganisms in
  the soil
• Example Congaree Bottomland Hardwood Swamp in S
  Carolina, - a water treatment plant to remove
  these substances would cost over 5 million (1991
  numbers)

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Wetland Value

• Value An estimate of the importance or worth of
  one or more functions to society
• Examples
• Revenue generated from sale of fish that depend
  on wetland
• US fish industry (1991) dockside value 3.3
  billion, 26.8 billion fishery processing and
  sales industry, employs hundreds of thousands of
  people
• Louisiana marshes commercial fish and shellfish
  1.3 billion pounds worth 244 million (1991
  figures)

www.miseagrant.umich.edu/ fisheries/
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Wetland Value

• Examples
• Tourist or recreational dollars generated. 1991
  wetland related ecotourism activities (hunting,
  fishing, photography, bird watching generated
  about 59 billion dollars.)
• Determining value not easy
• Different wetlands have different functions and
  different values

Sand Hill Cranes Proud Lake, Michigan http//www
.nsrider.com/images/images03/shc800.jpg
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1971- Convention on Wetlands of International
Importance

• Signed in Ramsar, Iran, gt 90 signatory countries.
• Promote conservation of wetlands,
• Establish wetland reserves
• Cooperate in the management of shared wetlands
  and shared wetland species
• Each of the gt 90 signatory countries must
  designate at least one wetland to be included in
  the list of ,Wetlands of International
  Importance
• 18 RAMSAR sites (http//www.ramsar.org/ ) in the
  United States. There are 1184 in the world

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Biodiversity Facts

• About half North American bird species nest or
  feed in wetlands
• Home to 31 of plant species
• 75 of commercially harvested fish are wetland
  dependent
• 95 if include shellfish
• 43 of the federally threatened and endangered
  species rely directly or indirectly on wetlands
  for their survival

http//ecosystems.fws.gov/graphics/wetland.jpg
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Productivity

• Some of most biologically productive natural
  ecosystems in world comparable to tropical rain
  forests and coral reefs in productivity and
  diversity
• Aquatic plant life flourishes in the
  nutrient-rich environment
• Plant energy moves up the food chain

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Types of Wetlands

• Marshes
• Tidal
• Nontidal
• Wet Meadows
• Prairie Potholes
• Vernal Pools
• Playa Lakes
• Swamps
• Bottomland Hardwoods
• Shrub Swamps
• Mangrove Swamps
• Bogs
• Northern Bogs
• Pocosins
• Fens
•  

http//www.epa.gov/owow/wetlands/types/
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Marshes

• Marshes are defined as wetlands frequently or
  continually inundated with water, characterized
  by emergent soft-stemmed vegetation adapted to
  saturated soil conditions.
• There are many different kinds of marshes,
  ranging from the prairie potholes to the
  Everglades, coastal to inland, freshwater to
  saltwater.
• All types receive most of their water from
  surface water, and many marshes are also fed by
  groundwater. Nutrients are plentiful and the pH
  is usually neutral leading to an abundance of
  plant and animal life.

Tidal marsh along the Edisto River, South
Carolina, http//www.epa.gov/owow/wetlands/types/m
arsh.html
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Non-tidal Marshes

• Most prevalent and widely distributed wetlands in
  North America.
• They are mostly freshwater marshes, although some
  are brackish or alkaline.
• Commonly occur along streams in poorly drained
  depressions, and in the shallow water along the
  boundaries of lakes, ponds, and rivers.
• Water levels in these wetlands generally vary
  from a few inches to 2-3 feet, and some marshes,
  like prairie potholes, may periodically dry out
  completely.

Common Cattail (Typha latifolia) is a freshwater
and estuarine marsh species http//www.epa.gov/owo
w/wetlands/types/marsh.html
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Freshwater Marshes

• Wet Meadows - Form in poorly drained areas such
  as shallow lake basins, low-lying depressions,
  and the inland between shallow marshes and upland
  areas. Precipitation is their primary source of
  water so over dry in warm weather

This wet meadow is in Rocky Mountain National
Park in Colorado. http//www.epa.gov/owow/wetland
s/types/wmeadows.html
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Freshwater Marshes

• Prairie Potholes - Develop when snowmelt and
  rainfall fill the pockmarks let on the landscape
  by glaciers.
• Some are temporary and others are permanent
• Groundwater input is also present in some.

The prairie potholes of Canada, Minnesota and
North and South Dakota were formed by glaciers
scraping over the landscape during the
Pleistocene. http//www.epa.gov/owow/wetlands/type
s/pothole.html
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Freshwater Marshes

• Playa Lakes small basins that collect rainfall
  from the surrounding land. Today these regions
  are found in the Southern High Plains of the US
  and Death Valley. The were common in the
  Triassic of CT!

This playa lake may serve as a source of
irrigation water to the surrounding
fields http//www.epa.gov/owow/wetlands/types/play
a.html
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Vernal Pools

• Covered by shallow water for variable periods of
  from winter to spring, but may be completely dry
  for most of the summer and fall.
• Have either bedrock or hard clay layer in the
  solid that helps to keep water in the pool.
• Range in size from small puddles to shallow lakes
  and are usually found in a gently sloping plain
  of grassland.
• Particularly important for amphibians

http//www.epa.gov/owow/wetlands/types/
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Tidal Marshes

• Found along protected coastlines in middle and
  high latitudes worldwide.
• They are most prevalent in the United States on
  the eastern coast from Maine to Florida and
  continuing on to Louisiana and Texas along the
  Gulf of Mexico.
• Some are freshwater marshes, others are brackish
  (somewhat salty), and still others are saline
  (salty), but they are all influenced by the
  motion of ocean tides.
• Tidal marshes are normally categorized into two
  distinct zones, the lower or intertidal marsh and
  the upper or high

The Great egret (Casmerodius albus) winters in
the tidal marshes along the Gulf
Coast http//www.epa.gov/owow/wetlands/types/marsh
.html.
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Swamp

• Any wetland dominated by woody plants.
• Many different kinds of swamps, ranging from the
  forested red maple, (Acer rubrum), swamps of the
  Northeast, to the extensive bottomland hardwood
  forests found along the sluggish rivers of the
  Southeast.
• Swamps are characterized by saturated soils
  during the growing season, and standing water
  during certain times of the year.

Bald cypress (Taxodium distichum), Swamps
frequently support highly diverse vegetation
because of the many layers of vegetation present
shrubs, saplings, and herbacous plants.
http//www.epa.gov/owow/wetlands/types/swamp.html
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Swamp

• The highly organic soils of swamps form a thick,
  black, nutrient-rich environment for the growth
  of water-tolerant trees such as cypress (Taxodium
  spp.), Atlantic white cedar (Chamaecyparis
  thyoides), and tupelo (Nyssa aquatica).
• Plants, birds, fish, and invertebrates such as
  freshwater shrimp, crayfish, and clams require
  the habitats provided by swamps.
• Many rare species, such as the endangered
  American crocodile depend on these ecosystems as
  well.

The rings on the bases of these trees show that
the water level is often higher in this
forest. http//www.epa.gov/owow/wetlands/types/swa
mp.html
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Swamp

• Some swamps are dominated by shrubs, such as
  buttonbush or smooth alder.
• Swamps may be divided into two major classes,
  depending on the type of vegetation present
• Forested swamps
• Bottomland hardwood forests (river swamps)
• Shrub swamps
• Includes mangroves

The rings on the bases of these trees show that
the water level is often higher in this
forest. http//www.epa.gov/owow/wetlands/types/swa
mp.html
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Mangrove Swamps

• Coastal wetlands found in tropical and
  subtropical regions.
• They are characterized by halophytic (salt
  loving) trees, shrubs and other plants growing in
  brackish to saline tidal waters.
• These wetlands are often found in estuaries,
  where fresh water meets salt water and are
  infamous for their impenetrable maze of woody
  vegetation.
• Important habitat for many animals
• Important for dissipating the energy of storm
  surges

Black mangrove (Avicennia germinans) is the most
common mangrove in the United States outside of
the everglades. The straw-like spikes surrounding
this plant are pneumatophores. http//www.epa.gov
/owow/wetlands/types/mangrove.html
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Bogs

• Bogs are one of North America's most distinctive
  kinds of wetlands.
• Characterized by spongy peat deposits, acidic
  waters, and a floor covered by a thick carpet of
  sphagnum moss.
• Receive all or most of their water from
  precipitation
• Low in the nutrients needed for plant growth, a
  condition that is enhanced by acid forming peat
  mosses.

Carlisle Bog in Alaska. Unlike the rest of the
United States, Alaska still has most of its
wetlands.http//www.epa.gov/owow/wetlands/types/bo
g.html
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Bogs

• 2 primary ways that a bog can develop
• bogs can form as sphagnum moss grows over a lake
  or pond and slowly fills it (terrestrialization),
  or
• bogs can form as sphagnum moss blankets dry land
  and prevents water from leaving the surface
  (paludification).
• Over time, many feet of acidic peat deposits
  build up in bogs
• The unique and demanding physical and chemical
  characteristics of bogs result in the presence of
  plant and animal communities that demonstrate
  many special adaptations to low nutrient levels,
  waterlogged conditions, and acidic waters, such
  as carnivorous plants.

Top pitcher plant Bottom eastern red
salamander .http//www.epa.gov/owow/wetlands/types
/bog.html
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Fens

• Fens, are peat-forming wetlands that receive
  nutrients from sources other than precipitation
  usually from upslope sources through drainage
  from surrounding mineral soils and from
  groundwater movement.
• Fens differ from bogs because they are less
  acidic and have higher nutrient levels.
• They are therefore able to support a much more
  diverse plant and animal community. These systems
  are often covered by grasses, sedges, rushes, and
  wildflowers.

Fens, like bogs, are peatlands, but because they
are fed by groundwater they are not so acidic as
bogs. http//www.epa.gov/owow/wetlands/types/fen.
html
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Bad Ol Days

• People thought wetlands were wastelands and
  harmful (cottonmouths, alligators, mosquitoes
  (malaria)
• Swamp Land Act 1849, gave away vast tracts of
  submerged acreage to anyone who would reclaim
  them
• 1700 215 million acres of wetlands, today fewer
  than 99 million

More than half of all prairie potholes have been
drained or altered for agricultural
use. http//www.epa.gov/owow/wetlands/types/pothol
e.html
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Wetlands Under Attack!

• Estimates- world has lost more than half of its
  wetlands since 1900
• Between 1986 and 1997, an estimated 58,500 acres
  of wetlands were lost each year (EPA numbers,
  Niering says 300,000) in the conterminous United
  States.
• Primarily due to development and agriculture

http//www.epa.gov/owow/wetlands/vital/epa_media/d
raining.jpg
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http//www.epa.gov/owow/wetlands/vital/epa_media/u
sa.gif
35

• http//www.epa.gov/owow/wetlands/vital/epa_media/b
  ar_chart.gif

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Direct Human Threats

• Drainage for crops, timber, mosquito control
• Dredging and stream channelization
• Filing for waste disposal and land claim
• Construction of dykes, dams and sea walls for
  flood control and storm protection
• Discharge of materials (e.g. pesticides,
  nutrients from sewage and sediments) into waters
  and wetlands
• Mining of wetland soils for peat, coal, gravel
  and other minerals

http//www.epa.gov/owow/wetlands/vital/epa_media/m
ining.jpg
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Indirect Human Threats

• Sediment diversion by dams and other structures
• Hydrological alterations by canals, roads, etc.
• Subsidence from extraction of groundwater, oil,
  etc.

http//www.epa.gov/owow/wetlands/vital/epa_media/i
ndustrial.jpg
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Natural Threats Direct and Indirect

• Subsidence
• Seal level rise
• Droughts
• Major storms (hurricanes, Noreasters)
• Erosion

http//sofia.usgs.gov/publications/fs/156-96/fig1.
gif
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Wells, Maine

• Earth Day, 2004
• President Bush announced a goal of creating or
  preserving 3 million wetland acres over five
  years.

http//home.teleport.com/eewilson/wetlands.gif