1. Wetlands Characteristic hydric soil and hydrophytic vegetation as signs of frequent surface saturation or inundation. Many types of wetlands: (Dodds, 2002; Table 4.3) –Salt-marshes and (temperate, seawater influence) –Mangrove forests (tropical, seawater influence) –Tidal & non-tidal freshwater marshes –Deepwater (cypress) swamps –Northern (bogs & tundra) wetlands –Riparian forests/wetlands –Man-made (rice paddies & bioremediation) Function as nutrient and sediment traps; slow runoff and facilitate recharge; most are highly productive.

2. Global Distribution (Matthews, 1993) Coastal Mangrove Depressional Peatland bog

3. Wetland ecosystem types are based on hydrologic regime, climate, geomorphology, nutrient input and vegetation. (Dodds, 2002; Table 4.5) Geomorphic: Peatlands; Coastal; Riverine; Depressional. Hydrologic Regime: –Permanence, predictability (e.g. tidal), seasonality –Primary water source: Precipitation; low throughput (ombrotrophic) Riverine; potentially high throughput (minerotrophic) Groundwater Climate determines the balance of precipitation and evapotranspiration. (E.g., much less precipitation is required for tundra wetlands than that for a tropical savanna wetland.)

4. Human Impacts on Groundwaters; Streams and Wetlands Groundwater or surface pumping: –agriculture –industry –drinking waters. Clearing riparian forests & wetlands Draining and filling for “development”. Damming and flooding Diversion channels for water supply.

5. Levee

7. Arkansas River (?)

8. Vanishing Florida Wetlands

11. Wetland loss since 1780. 70% Riparian Forest lost in USA. Worldwide estimates are >50%; half due to agriculture.