1. Wetlands  Wetland – “those areas that are inundated or saturated by surface or groundwater 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.” --- EPA Clean Water Act enforcement definition

2. Wetlands  Emergent macrophytes (vegetation) effectively define wetlands.  Marsh = dominated by non-woody vegetation.  Swamp = dominated by trees.  Aquatic Marginal Wetlands = emergent macrophytes can grow around a body of surface water (lake, stream, ocean). – presence depends on substrate and water conditions (Can emergent macrophytes grow there?) -Fringe wetlands – almost always wet -Flood wetlands – seasonally or less frequently wet

3. Wetlands  Mires = where emergent macrophytes can grow BUT are not around an open body of water and are permanently waterlogged. – depend on groundwater and/or reliable runoff -Fens – “fed” by groundwater and runoff; nutrient rich -Bogs – “fed” runoff (above the water table); nutrient poor; mosses of the genus Sphagnum.

4. Lake to Fen to Bog

5. Sphagnum

6. Wetland Conditions  Waterlogged soils less/low/no oxygen (decomposition uses + low diffusion) Usually low in Nitrate (N) because of effects of low oxygen on bacteria. If organically rich, anaerobic bacteria create hydrogen sulphide (H 2 S).  If flooded and dried or f ringing and subject to water motion conditions usually have more oxygen and nitrate in the soil.

7. Cypress Knees

8. Carnivorous “Bog” Plants

9. Wetland Primary Production  Primary production in some tropical fringing marshes equals that in tropical rainforests.  Primary production in some polar fens and bogs is very low (equivalent to tundra).  Few organisms consume the emergent macrophytes directly (only some mammals), most energy in the system relies on detritus.  Many terrestrial and aquatic organisms depend upon wetlands as “visitors.”

10. Saltmarsh Food Web

11. Wetlands & Lakes

12. Wetland Human “Benefits”  Riparian flood wetlands reduce flow variation and intensity of flood events. (Katrina & New Orleans)  Ocean flood wetlands (salt marshes) reduce the effects of storm surge. (Katrina & New Orleans)  Serve as areas of groundwater infiltration. (Florida aquifers)  Fringing and flood wetlands remove sediments and nutrients from water flowing through them.

13. Wetlands: Human Impacts  Development – Many drained and then built upon or used for agriculture. Some have been removed for mosquito control.  Water diversion – Many wetlands have been eliminated because their water sources have been diverted for other use.  Sediment starvation – some salt marshes off New Orleans lost due to reduced sedimentation after Mississippi alteration.  Peat/Sphagnum mining – Many mires damaged or removed.

14. Whooping Cranes

15. Wetland Mitigation