Wetland Types – Inland Wetland Ecosystems

Wetland Types

• Inland Wetland Ecosystems– Freshwater Marshes– Peatlands– Freshwater Swamps (Forested)– Riparian Wetlands– Open Water

• Coastal Wetland Ecosystems– Tidal Salt Marshes– Tidal Freshwater Marshes– Mangrove Wetlands

Kinds of Wetlands

• Bog – peat-accumulating with no inflows or outflows; supports mosses

• Bottomland – lowlands along streams and rivers

• Fen – ground-water fed; peat accumulating

• Marsh – frequently inundated; emergent herbaceous vegetation

• Mire – peat-accumulating (Europe)• Moor – peat-accumulating (Europe)• Muskeg – Large expanses of

peatlands or bogs (Canada/Alaska)• Peatland – any wetland that

accumulates decaying plant matter

• Playa – marshlike ponds similar to potholes (southwest U.S.)

• Pothole – shallow, marshlike pond; found in Dakotas and Canada

• Reedswamp – marsh dominated by common reed (Europe)

• Slough – swamp or shallow lake system

• Swamp – wetland dominated by trees or shrubs

• Vernal Pool – shallow, intermittently flooded wet meadow

• Wet Meadow – grassland with waterlogged soil near the surface – without water for most of year

• Wet Prairie – similar to marsh but water levels intermediate between marsh and wet meadow

Vary based on geographic location, language, etc.

Source: Mitsch and Gosselink, 1993.

Inland Wetland Ecosystems

•Freshwater Marshes•Peatlands•Freshwater Swamps (Forested)•Riparian Wetlands•Open Water

Freshwater Marshes

• Very diverse group

• Nontidal, freshwater systems

• Dominated by grasses, sedges, and other freshwater emergent hydrophytes (nonforested)

• High productivity

• Approximately 20% of world’s wetlands

Hydrology

• Predominately surface water fed; some with groundwater

• Deep marsh plant communities have standing water depths of between 6 inches and 3 or more feet during the growing season

• Shallow marsh plant communities have soils that are saturated to inundated by standing water up to 6 inches in depth, throughout most of the growing season

Dominant Plant Species

• Deep marsh: major dominance by cattails, hardstem bulrush, pickerelweed, giant bur-reed, Phragmites, wild rice, pondweeds and/or water-lilies.

• Shallow marsh: herbaceous emergent vegetation such as cattails, bulrushes, arrowheads, and lake sedges characterize this community.

Wet Meadows

Hydrology and Soils

• Supported by groundwater and surface water runoff– Usually a high water table is present

• Typically drier than other marshes except during seasonal high water– Without standing water most of the year

• Occur in poorly drained soils– Soils typically nutrient rich

Dominant Plant Species

• hummock sedge (Carex stricta) • lake sedge (Carex lacustris)• Canada bluejoint grass (Calamagrostis

canadensis) • woolgrass (Scirpus cyperinus) • marsh milkweed (Asclepias incarnata) • arrow-leaved tearthumb (Polygonum sagittatum)• water pepper (Polygonum hydropiper)

Sedge Meadows

Hydrology

• Sedge meadows can be supported by groundwater and surface water runoff

Dominant Plant Species

• Sedge meadows are dominated by the sedges (Cyperaceae) growing on saturated soils (Carex dominates)

• Also present are Eleocharis (spike-rushes) and Scirpus (bulrushes)

hummock sedge (Carex stricta), Chippewa County, Wisconsin.

Wet Prairie

Hydrology

• High groundwater table and, to a lesser extent, surface runoff

Dominant Plant Species

• open, herbaceous plant communities dominated by native grass and grass-like species; at least half of the vegetative cover is made up of true grasses

• similar to fresh (wet) meadows, but are dominated by native grasses and forbs associated with prairies such as prairie cord-grass, big bluestem, gayfeather, New England aster, culver's root, prairie dock and sawtooth sunflower

Prairie Potholes

•Depressional Wetlands formed by glaciers

•Located in Upper Midwest•North Dakota, South Dakota, Wisconsin, and Minnesota

Hydrology

• Water source is from primarily snowmelt and rainwater

• Many hold water temporarily

Dominant Plant Species

• Submerged and floating aquatic plants take occur in the deeper water in the middle of the pothole while bulrushes and cattails grow closer to shore.

• Sedge marshes lie next to the upland.

Photo: http://www.epa.gov/owow/wetlands/types/pothole.html

Vernal Pools

•Seasonal depressional wetlands (ephemeral)

•Occur predominately in West Coast but Eastern vernal pools also occur

•Range in size from small puddles to shallow lakes and are usually found in a gently sloping plain of grassland

Hydrology• Pools collect water during winter and spring

rains– Change in volume responding to varying weather

patterns– Pools may fill and dry several times – In years of drought, some pools may not fill at all

• Generally isolated but are sometimes connected to each other by small drainages known as vernal swales

• Beneath vernal pools lies either bedrock or a hard clay layer in the soil that helps keep water in the pool

Vegetation

• Wildflowers bloom in circles following the receding shoreline of the pools

• When water has evaporated, soil is brown, barren, and cracked

Photo: http://www.epa.gov/owow/wetlands/types/vernal.html

Playa Lakes

• Ephemeral, round hollows in Southern High Plains of the United States – West Texas, Oklahoma, New Mexico,

Colorado, and Kansas

Hydrology

• Playa origin:– either carved by wind or formed by land

subsidence.

• Freshwater collects in the round depression after spring rains

• Saltwater-filled playas– Underlying aquifers bring salt as it percolates

up through the soil.

Vegetation

• Grow and flourish when water is present– Recede and die when water evaporates

• Wildlife depend on water and plants after spring rains

Photo: http://www.epa.gov/owow/wetlands/types/playa.html

Peatlands

Fens

Hydrology

• Upwelling, calcareous groundwater discharge

• Small, calcareous streams frequently originate in the fen complex due to the groundwater discharge

Dominant Plant Species

• sterile sedge (Carex sterilis)

• beaked spike-rush (Eleocharis rostellata)

• fen beak-rush (Rhynchospora capillacea)

• whorled nut-rush (Scleria verticillata)

• common valerian (Valeriana edulis) twig-rush (Cladium mariscoides)

• white lady-slipper (Cypripedium candidum)

Bogs

Hydrology

• Ground water sourced with peaty soils saturated to the surface

Dominant Plant Species

• sphagnum mosses (Sphagnum spp.)• bog sedge (Carex oligosperma) • tawny cottongrass (Eriophorum virginicum)• three-way sedge (Dulichium arundinaceum)• leatherleaf (Chamaedaphne calyculata)• bog rosemary (Andromeda glaucophylla)• bog buckbean (Menyanthes trifoliata) • poison sumac (Toxicodendron vernix) • broad-leaved cattail (Typha latifolia)

Gros Morne National Park, Newfoundland, Canada.

Pitcher plant

Freshwater Swamps

•Cypress-tupelo Swamps•Southeastern U.S.

•White Cedar Swamps•Atlantic and Gulf Coasts

•Red Maple Swamps•Northeastern U.S.

Hydrology

• Groundwater discharge (seepages), rainwater, overland flow, floodwater

Dominant Plant Species – Midwest

• black ash (Fraxinus nigra), red maple (Acer rubrum), formerly American Elm

• groundlayer dominated by – lake sedge (Carex lacustris), – ostrich fern (Matteuccia struthiopteris) and – marsh marigold (Caltha palustris)– wood reedgrass (Cinna latifolia) – jewelweed (Impatiens capensis)– jack-in-the-pulpit (Arisaema triphyllum) – giant goldenrod (Solidago gigantea)

Riparian Wetlands

Hydrology

• Seasonal flood pulses

• Inundated during spring flood events and heavy summer rainfall events

Dominant Plant Species

• silver maple (Acer saccharinum) • wood nettle (Laportea canadensis) • honewort (Cryptotaenia canadensis) • green ash (Fraxinus pennsylvanica),• eastern cottonwood (Populus deltoides), • riverbank grape (Vitis riparia), • jewelweed (Impatiens capensis),• stinging nettle (Urtica dioica),

Shallow Open Water

Hydrology

• Generally have water depths of less than 6.6 feet (2 meters)

• Ponds, river oxbows, shallow bay of a lake

Dominant Plant Species

• Submergent, floating and floating-leaved aquatic vegetation including pondweeds, water-lilies, water milfoil, coontail, and duckweeds characterize this wetland type.