• Wetland Ecology
• Wetlands of the World
• Extent of the world’s wetlands
• 7 – 10 million km2 ~ 5 to 8 percent of land surface
• North America 43.6 million ha. (lower 48)
– 71 million ha. in Alaska
– 127 million ha. in Canada
– 30 % of world’s wetlands
• All are impacted by humans but remain functional
• Wetlands include:
• Swamps
• Bogs
• Marshes
• Mires
• Fens
Every continent except Antarctica (from tropics – tundra)
• Definitions
• Swamp – Tree/shrub dominated wetland
• Bog – peat accumulating wetland, no significant in/outflow, supports bryophytes
• Marsh – Frequently/permanently flooded, supports emergent vegetation
• Mire – Synonymous with any peat accumulating wetland (Europe)
• Fen – Peat accumulating wetland, receives drainage from mineral soil, marsh-like vegetation
• Peatland – Wetlands that accumulate organic matter
• Slough – A swamp/shallow lake system in north/Midwest (slowly flowing shallow swamp/marsh in southeast U.S.)
• Worldwide Wetland Losses
• North America Wetland Changes
• 53% have been lost since 1780’s – 1980’s
• States with > 80% loss
– Illinois, Indiana, Iowa, Kentucky, Missouri, Ohio + California
– Collectively a loss of 14.1 million ha in 200 yrs – What caused this loss?
• States with highest densities of wetlands
– Minnesota, Illinois, Louisiana, and Florida had greatest rate of loss of total area.
– 2.6, 2.8, 3.0, & 3.8 million ha respectively
– Canadian Wetland Changes
• Less population density
• 65 – 80 % loss near Atlantic & Pacific regions
• 71% loss in the lower Great Lakes
• 71% loss in the prairie pothole region
• North America
• Florida Everglades from Lake Okeechobee – Florida Bay has 3 major types of wetlands
– 34,000km2 area
• The Everglades
• Big Cypress Swamp
• Coastal Mangroves
• Everglades
• Dominated by Cladium jamaicense (sawgrass)
• Can be flooded >1m in summer
• Common tree islands (hammocks)
• Hardwoods, palms, orchids, and other air plants common
• Big Cypress Swamp
• Expansive area
• Dominated by Taxodium spp. interspersed with pine flatwoods & wet prairie
• 125 cm of rainfall/yr.
• Coastal Mangrove
• Forms impenetrable thickets where sawgrass and cypress swamps meet saline waters of the Atlantic
• Everglades is the site of the largest wetland restoration project ever conducted
• ½ lost to agriculture
• 8 billion dollar effort
• Okefenokee Swamp • Means “Land of Trembling Earth”
• Atlantic Coastal Plain of southeastern GA.
• 1,750km2
• Headwaters of two rivers:
– Suwanee River
– St. Mary’s River
• Six major wetland communities comprise the Okefenokee
• Emergent & Aquatic bed prairie
• Broad-Leaved Evergreen forest
• Broad-leaved shrub wetland
• Mixed cypress forest
• Black gum forest
– Taxodium distichum, Nyssa sylvatica, Magnolia virginiana are the dominant trees
– Panicum, Carex, & Nymphaea are dominant herbaceous plants
• Carolina Pocosins
• Mean “swamp on a hill”
• Evergreen shrub-bogs found on Atlantic Coastal Plain: Virginia – northern Florida
• Typically nutrient poor; were once categorized as bogs in 1954 survey
• Pinus serotina is dominant pine
• Said to “grow on waterlogged, acid, nutrient poor, sandy or peaty soils located on flat topographic plateaus, usually removed from large streams
• Great Dismal Swamp
• Northern most ‘southern swamp’
• Once primarily bald-cypress gum swamp that contained extensive stands of Chamaecyparis thyoides (white cedar)
• Lake Drummond found in center of swamp
• George Washington built a canal to establish farms on the basin
– Failed miserably
• Swamp Rivers of the South Atlantic Coast
• Cut by large rivers that drain the Piedmont – Roanoke, Chowan, Little Pee Dee, Great Pee Dee, Lynches, Black, Santee, Congaree, Altamaha, Cooper, Edisto, Combahee, Coosawhatchie, & Savannah
• Made up of several lake-wetland systems
– > 500,000 of these
– Suggested to be made from meteor showers, wind or groundwater flow
• Congaree Swamp in S.C. includes the world’s largest virgin cypress-tupelo swamp
• Prairie Potholes
• North Dakota, South Dakota, & Minnesota
– Manitoba, Saskatchewan, & Alberta
• Only 10% of original wetlands remain
• Formed by glacial action
• Know for waterfowl habitat and ties nicely with the Mississippi River as major summer breeding area
– Migratory waterfowl fly by us to reach wintering grounds
– 50 – 75% of waterfowl come from this region
• Nebraska Sandhills & Great Plains Playas
• Largest stabilized dune field in the Western Hemisphere
• Much has been lost to agriculture
• 25,000 playas (Spanish for beach)
• The Great Black Swamp
• Northwestern Ohio
• Named for the rich, black muck in poorly-drained areas
• Louisiana Delta
• One of the most wetland-rich regions of the world
• Atchafalaya River is characteristic of the riverine portion
• Has long history of human intervention
• Freshwater & Saltwater wetlands are decreasing at a rapid rate ~ 60 – 100 km2 /yr
– What is the cause of this?
• Plan 2050 will sink billions of dollars into rebuilding barrier islands lost due to dredging and levee control – i.e. sediment losses
• San Francisco Bay
• One of the most impacted wetlands in the U.S. • 95% of marshes have been destroyed
• Dominated by Spartina foliosa and Salicornia virginica
• Demise began after the gold rush
• Great Lakes Wetlands/St. Lawrence Lowlands
• Important habitat for waterfowl
• Snow geese leading to decline of marshes
• Mexico Wetlands
• Underrepresented in # and area of Ramsar wetlands
– Only 7 sites designated in 2001
– Now 65 Ramsar sites covering 5.3 million ha
• Cuatro Ciénegas is one of driest areas in Chihuhuan Desert but contains 200 springs
– Pozas (small springs)
– Lagunaas (larger spring-fed lakes)
– Playa Lakes (lakes without outlets)
– Ciénegas (shallow swamps)
– Manmade channels
• Central & South America
• Orinoco River Delta
• The Llanos
• The Pantanal
• The Amazon
• Oronoco River Delta
• Economy based on cattle farming, cacao and palm heart canning.
• Grazing & illegal hunting have decimated area’s flora & fauna
• The Llanos
• Sedimentary basin
• Winter wet season and summer dry season
– Wetland dominated by savanna grasslands & scattered palms rather than floodplain forests
• Pantanal
• One of the largest wetlands of the world • Geographic center of South America
• 4x size of the Everglades
• Bird richest wetland in the world
– 463 species of birds
– 13 species of herons & egrets
– 3 stork species
– 6 ibis species
– 6 duck species
– 11 rail species
– 5 kingfisher species
• Jabiru found here (largest bird in the western hemisphere
• Largest rodent found here
• Amazon
• Wetlands cover 25% of the 7million km2 Amazon basin
• Flooding reaches 15m in some areas
• Europe
• Mediterranean Sea Deltas
– Rhone River Delta
– The Camargue one of the world’s 25 major flamingo nesting sites
– Rhine River in the Netherlands is the most hydraulically controlled locations on Earth
• Inland Deltas – Volga River (on edge of Caspian Sea) forms one of the largest inland deltas
• Large percentage of the world’s sturgeon comes from the Caspian Sea
• Peatlands in Ireland, Scandinavia, Finland, & northern Russia
– ~20% of Europe
– Endla & Berezinski Bog are best examples
• Okavango Delta is divided into 3 hydrologic zones
– Permanent swamp
– Seasonally flooded floodplains
– Occasional floodplains
• 71 species of fish found here • Congolian Swamp Forests
• Largest / least studied swamp forest in world
• Congo River has 2nd highest flow of any river
• Forests remain because of isolation
– Lowland gorilla
– Forest elephants
– Forest buffalo
• Middle East
• Mesopotamian Marshlands of southern Iraq & Iran
– Tigris & Euphrates rivers
• Dams & drainage systems have eliminated flood-pulses essential for wetland maintenance
• Australia / New Zealand
• Billabongs
– Not permanent (intermittent & seasonal)
• Asia
• Western Siberian Lowlands
– Peatlands important for carbon sequestration
• Indian Freshwater Marshes
– Many natural disasters due to anthropogenic manipulation
• Asian River Deltas
– Mud flats, swamp forests, arctic tundra & mangrove forests
• China
– Many are artificial (rice paddies) & fish ponds