Slide 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. Slide 2 Global Distribution (Matthews, 1993) Coastal Mangrove Depressional Peatland bog Slide 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.) Slide 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. Slide 5 Levee Slide 6 Slide 7 Arkansas River (?) Slide 8 Vanishing Florida Wetlands Slide 9 Slide 10 Slide 11 Wetland loss since 1780. 70% Riparian Forest lost in USA. Worldwide estimates are >50%; half due to agriculture.