Wetlands

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Wetlands

• 20 April 2007
• AWER 4500

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Wetland Definition(U.S. Fish and Wildlife
Service)

• Wetlands are transitional between terrestrial and
  aquatic systems where the water table is usually
  at or near the surface or the land is covered by
  shallow water.
• Wetlands must have one or more of the following
  three attributes
• 1. A least periodically, the land supports
  primarily hydrophytes
• 2. The substrate is predominately undrained
  hydric soil
• 3. The substrate is non-soil and saturated with
  water or covered by shallow water at
  some time

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Current Status of Wetlands

• 6 of Earths Surface
• The world may have lost 50 of all wetlands,
  mostly for agriculture since 1900

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Wetlands Gradient from Terrestrial gt Wetland
-gt Aquatic
Biogeochemistry in Freshwater Wetlands and Lakes
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Distribution of Wetlands in U.S.
Source Lewis, W.M. Jr. 2001. Wetlands
Explained. Oxford
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Types of Wetlands
Mangrove
www.bobzook.com/pix/world20tour202001/
Tidal Wetland
www.facstaff.bucknell.edu/jtrop/carolina22.jpg
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Types
Prairie Pothole
www.usgcrp.gov/usgcrp/images/ocp2007/gallery-large
/
Everglades
www.flmnh.ufl.edu/fish/SouthFlorida/images/
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TypesNorthern -Southern Wetlands
Bog (New Zealand)
www.stanford.edu/jubersax/photos/2005_New_Zealand
/
Fen (Telluride, CO)
www.mountainstudies.org/Research/images/fen2.jpg
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Types
Deepwater Swamp (Okefenokee, GA)
http//www.uwec.edu/biology/StudentFieldExp/ Stude
ntfieldImages/Okefenokee.jpg
Riparian (Littoral) Wetland (Finland)
www.aslo.org/photopost/
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Importance

• Habitat
• Ecosystem services
• (flood control water quality)
• Wastewater treatment
• Greenhouse gases (methane CO2)

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Ecosystem Primary Production.xls
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Nitrogen Removal by artificial wetland
Water retention time (Days)
Source Lewis, W.M. Jr. 2001. Wetlands
Explained. Oxford
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Wetland Food Web
Dodds (2002)
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Detrital Pathway Often Dominant, But.
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Ecological Determinism on the Orinoco Floodplain.
2000. W.M. Lewis et al. BioScience 50
681-692
Despite massive amounts of carbon in grass mats,
stable isotope analyses indicated that most
invertebrates and fish derived their carbon from
either attached algae or phytoplankton
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Physical characteristics
1. Shallow (relative to lakes) -
resuspension of sediments - light
penetration 2. Slow water movement
(lentic) 3. Anoxic and oxic zones in close
proximity - high nutrient cycling - often
high productivity
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Comparison of Aquatic Systems
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outline

• Wetlands
• A. Importance
• 1. Habitat
• 2. Ecosystem services (flood control water
  quality)
• 3. Wastewater treatment
• 4. Greenhouse gases (methane CO2)
• B. Definition
• US Fish and Wildlife Service
• Wetlands are transitional between terrestrial and
  aquatic systems where the water table is usually
  at or near the surface or the land is covered by
  shallow water. Wetlands must have one or more of
  the following three attributes
• 1. A least periodically, the land supports
  primarily hydrophytes
• 2. The substrate is predominately undrained
  hydric soil
• 3. The substrate is nonsoil and saturated with
  water or covered by shallow water at some time

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Wetlands an example of nutrient transformations

• Saturated sediments
• Biological plant uptake
• Trapping and retention of nutrient bearing
  sediments
• Denitrification - unlimited removal potential

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Wetland reconstruction protection

• No net loss of wetlands
• Protect strategic wetlands.
• Current effort to reconstruct some drained
  wetlands.