NCER 2004 Wetland and tidal channel evolution affecting critical habitats at Cape Sable Everglades National Everglades National Park Park Wetland and tidal channel evolution affecting critical habitats at Cape Sable Brigitte Vlaswinkel Brigitte Vlaswinkel Harold Wanless Harold Wanless NCER 2004
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NCER 2004 Wetland and tidal channel evolution affecting critical habitats at Cape Sable Everglades National Park Wetland and tidal channel evolution affecting.
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NCER 2004
Wetland and tidal channel evolution affecting critical habitats at Cape Sable
Everglades National ParkEverglades National Park
Wetland and tidal channel evolution affecting critical habitats at Cape Sable
Brigitte VlaswinkelBrigitte Vlaswinkel
Harold WanlessHarold Wanless
NCER 2004
NCER 2004
Wetland and tidal channel evolution affecting critical habitats at Cape SableWetland and tidal channel evolution affecting critical habitats at Cape Sable
10 km
Study areaStudy area
Southwest FloridaSouthwest Florida
Everglades National ParkEverglades National Park
NCER 2004
What is happening?
3) Major hurricanes
Rapid ecosystem changes in past 80 years, due to…
1) Human modifications
(canals)
2) Sea level rise
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Major land- and seascape changes
1)Alteration of vegetation communities: freshwater marsh mangrove wetland
mangrove
freshwatermarsh
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Major land- and seascape changes
2) Small canals become large tidal inlets…
and new creeks evolve
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Major land- and seascape changes
3) Lagoons fill up with muddy sediments
N
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Take Home Message
Man-made canals acted as catalysts for interior freshwater marsh collapse (but with sea level rise, this would now be happening in any case)
Large amounts of organic material are released from collapsed freshwater marsh and redistributed within the system
Complicated connectivity of processes and products. Cape Sable may serve as an analog for other sensitive channeled saline-to-freshwater wetland complexes
NCER 2004
Main question is…
What are the sediment dynamics of
the system?
Sediment from where?Sediment from where?Where to?Where to?How fast?How fast?
10,000 Islands10,000 IslandsDegradation of mangroveDegradation of mangrove and transitional marshand transitional marsh
Gopher CreekGopher CreekCollapse of interior Collapse of interior mangrove wetlandmangrove wetland
Expansion of ‘White Zone’Expansion of ‘White Zone’ Collapse of transitional and freshwater marshes Collapse of transitional and freshwater marshes
North Cape Sable North Cape Sable loss of interior loss of interior
mangrove wetlandmangrove wetland
Rapid loss of saline and freshwater wetlands is also occurring in other areas in South Florida
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Impact of released organic matter ?
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Conclusions The Cape Sable geomorphic system is out of equilibrium and has evolved dramatically and rapidly
Man-made canals acted as catalysts for interior freshwater marsh collapse (but with sea level rise, this would now be happening in any case)
Large amounts of organic material are released from interior freshwater marshes and redistributed within the system
• The results illustrate the complicated connectivity of processes and products on this coast. Cape Sable area may serve as an analog for other sensitive channeled mangrove-to-freshwater wetland complexes
NCER 2004
AcknowledgementsEverglades National ParkStable Isotope Lab at RSMASMany field assistantsCape Sable Seaside Sparrow
With water, water everywhere, and no time left to think,Your battle will wage on
Among cash and good intentions.Slowly flying, slowly dying,
While the lifeblood of the River drainsPast the sawgrass bent in discontent.
Tom Fucigna
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1928• A narrow drainage
ditch was cut across the freshwater marsh in the 1920s
• It also cut across the marl ridge to the west
Mar
l Rid
ge
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1953• By 1953 the marsh
adjacent to the marl ridge had collapsed
Mar
l Rid
ge
1953
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1928
1999
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Sediment dynamic patterns on decadal scale
Soft sediment cores• Sediment constituents• Depositional processes (grain size, storm layers)• Average sedimentation rate through time