Chapter 5-Hydrology and Physiography

Even though there are not one single sound definition for wetlands, however what does the USFW say about wetlands.

Wetlands are lands transitional between terrestrial and aquatic systems where the water table is usually at or near the surface, or the land is covered by shallow water. Wetlands must have one or more of the following three attributes: (1) at least periodically, the land supports primarily hydrophytes, (2) the substrate is predominantly undrained hydric soils, and (3) the substrate is non-soil and saturated with water or covered by shallow water at some time.

Study These wetland types

Tidal Salt Marsh, Tidal Freshwater Marsh, Mangrove,Freshwater marsh, Northern wetland, Deepwater swamp, Riparian wetland.

What is the characteristics of Freshwater Tidal Marshes?

Low-Salinity (less than 5 ppt)

Influenced by tides

Higher diversity than salt tidal marshes

What are the characteristics are Salt tidal marsh?

Harsh habitats, Brackish (salinities between 5 and 15ppt)

Influenced by the tides

Dominated by Spartina and Juncus

What are characteristics of Mangroves?

Dominated by halophytic mangrove trees and the wave action is minimal and sediments accumulate

What are the characteristics of Floating marshes?

Common in some coastal areas (mississippi delta, confluence of Tigris and Euphrates)

Characterized by vegetation that forms thick mats of roots that along with associated organic matter such as peat, float on the water.

What is the difference between a Marsh and a Swamp?

•In the U.S. we differentiate the two based on the vegetation. Swamps have trees, marshes have grasses and sedges.

•This differentiation does not hold up world wide.

•Typically included in riparian systems associated with river floodplains.

What is a depressional?

Formed by the depression of the ground creating low-lying areas

What is a fringe?

Wetlands associated along edges of lakes, rivers, and other freshwater sources

What are prairie potholes?

Formed through depressional processes (Glaciers)

Ephemeral to nearly permanent

Fresh to Saline waters

What are Peatlands?

•Wetlands that accumulate decaying organic matter from mosses, sedges, and other wetland plants over time because the production of organic matter exceeds the rate of decomposition.

•Store over 1/3 of all carbon even though they represent only 3% of the land area of the planet.

What are bogs?

A common type of peatland that have no significant water inflows or outflows and are thus ombrotrophic (precipitation is the only water source). Very acidic.

What are Fens?

Are similar to bogs but they are fed by additional sources of water and are minerotrophic (fed by groundwater and surface water sources primarily). Typically neutral to alkaline. Poor fens – more like a bog, Rich fens – more like a marsh.

What are the three primary sources of water?

Precipitation

Surface water

Groundwater

•Plant transpiration is more noticeable in wetlands than in rivers and lakes.

•Tidal influxes result in bidirectional flow.

•Rivers moving through a wetland create unidirectional flow.

•Riparian areas get sporadic unidirectional flow followed by stagnation.

How can wetlands be influenced by global change?

Water levels are the product of a delicate balance between rates of precipitation and evapotranspiration

Higher temperatures can affect decomposition rates and thus oxidative losses.

What are Wetlands?

Ecotones- However are defined by plants that are present (hydrophyte) or absent and distinct soils (hydric soils)