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.