Sept. 25, 1997

Habitats -
All wetlands have 3 characteristics in common: vegetation - support predominantly hydrophytes hydrology - saturated soil, flooded for some time in a year soil - hydric soil or non-soil substrate (gravel or sand)

1) Wetlands

Type                                Distribution                                 Aquatic Plants                       Hydrology  

Freshwater marshes         widespread                    grasses, sedges (Carex)             seasonal to permanent flooding

Tidal Marshes                     coastal                   halophytic grasses,sedges(Juncus)   daily, monthly (salt and brackish) flooding

Prairie Potholes           Northern Plains           grasses, sedges, temporary to herbaceous plants           permanent flooding

Fens                       near mineral rich soil        grasses, sedges,shrubs, and trees      permanently flooded with flowing water      
(peat accumulating)

Bog (moor)            only in Northern climates      sphagnum moss, shrubs, trees, desmids                    frequent precipitation
(peat accumulating)      -caused by glaciation

Swamp                   fairly widespread                large trees (Cyprus, Gum)                              prolonged standing water

Bottomlands          rolling hills w/ rivering           large trees (Oaks, Maples)              seasonal flooding but also an annual
                             or stream systems                                                                        dry period

Mangroves         tropical/subtropical regions       red,white,black mangrove spp.       tidal flush & freshwater coming in

Bays, Lagoons             coastal areas                  seagrasses (Eelgrass,turtlegrass)                    open salt water

Playas                       southwest U.S.                 only along edges, grasses, some sedges          seasonal wetland
(closed basin, water
settles on bottom)

Riparian Areas     widespread, any type of          grasses, sedges, trees                       periodic flooding, high water table
                            rivering environment                                                                       sometimes staurated soils

-In the southwest US and Mexico a similar ecological zone is called a bosque - a gallery forest, usually in a riparian zone. These are populated by mesquite trees and grasses, and are usually only flooded in really big storms)
-Riparian zones represent an area between aquatic environments and terrestrial ecosystems.
-Riparian zones are extensive in the eastern US. One survey reported 22.9 million hectares in the continental US (mostly in the east) plus 12 million more in Alaska.
-These areas have been heavily settled, farmed, logged, and irrigated.
-Arizona has about 100,000 hectares left.
-In higher elevations, alders and poplars are common riparian trees. Cottonwood, willows, and ash are found in lower elevations.

3) Open Water Habitats

Definitions:
                 Lentic - open water ponds and lakes having submergent plants in the middle, some emergent vegetation along the sides, and sometimes floating plants, especially in the tropics.
                 Lotic - flowing waters, streams and rivers, mostly having submerged and emergent plants.

The plant distribution in open water is controlled by the turbidity of the water, the availability of sunlight for photosynthesis (competition with algae), and water motion.

4) Anthropogenic (manmade)

Reservoirs and irrigation systems are examples of manmade aquatic environments. These are dependent on substrate (sometimes concrete or soil conveyance systems), water flow, and nutrients (return water is nutrient rich in an irrigation system).

-Pondweed, Potamogeton, Spiny Niad, and Chara are all common on concrete substrates.