Wetlands: Nature’s Wetlands: Nature’s natural filternatural filter

You will understand the You will understand the importance and value of importance and value of wetlands for environmental wetlands for environmental ecosystemsecosystems

Intro to WetlandsIntro to Wetlands

Recall: What provides the main water source Recall: What provides the main water source to most River systems?to most River systems?

What is Run-Off?What is Run-Off? Water that is not absorbed by the land; water Water that is not absorbed by the land; water

runs across land picking up sediment and runs across land picking up sediment and pollutants before it enters the riverpollutants before it enters the river

How does Nature clean this “dirty water”?How does Nature clean this “dirty water”? Wetlands are a valuable source in cleaning Wetlands are a valuable source in cleaning

the water before it re-enters the ocean or the water before it re-enters the ocean or enters a River Systementers a River System

Wetlands: 3 Main TypesWetlands: 3 Main Typesdefined by Plant defined by Plant vegetationvegetation Swamp- wetland primarily composed Swamp- wetland primarily composed

of treesof trees Marsh- wetland composed primarily of Marsh- wetland composed primarily of

grassesgrasses Bog- found in extreme Northern areas Bog- found in extreme Northern areas

(near Artic) primary vegetation moss(near Artic) primary vegetation moss Wetland is an area of land that is Wetland is an area of land that is

either seasonally or permanently either seasonally or permanently covered by a thin layer of water covered by a thin layer of water

Understanding How Wetlands form:Understanding How Wetlands form:Normal Non Wetland diagramNormal Non Wetland diagram

Unsaturated Zone

Saturation Zone

Aquitard (igneous rock)

(Aquifers)

3 Forms of 3 Forms of Groundwater Groundwater “returning” to surface“returning” to surface Geysers/Hot Springs- magma Geysers/Hot Springs- magma

“bubble” underground heats “bubble” underground heats water and forces water to surfacewater and forces water to surface

Artesian Well- Large block of hard Artesian Well- Large block of hard igneous rock deflects water to igneous rock deflects water to surfacesurface

Wetland- Water table takes up all Wetland- Water table takes up all available space in top layers of available space in top layers of soil/rock creating wetlandsoil/rock creating wetland

A Wetland Diagram: A Wetland Diagram: What Zone is Missing?What Zone is Missing?

Wetland

Transition zone

Normal

Saturation

Zone

Wetland Formation-Wetland Formation-

All wetlands form when the All wetlands form when the unsaturated zone disappears or unsaturated zone disappears or becomes a saturation zone at the becomes a saturation zone at the land’s surface levelland’s surface level

Wetlands will never “dry up” as long Wetlands will never “dry up” as long as Water table remains at its normal as Water table remains at its normal level; therefore humans are main level; therefore humans are main reason for their disappearance reason for their disappearance

How Wetlands help How Wetlands help “Clean” the water“Clean” the water NNitrates in water are transformed to harmless itrates in water are transformed to harmless

nitrogen gas :nitrogen gas :Bacteria in the water transform the nitrates to Bacteria in the water transform the nitrates to harmless nitrogen gas (Nharmless nitrogen gas (N22) which goes back into the ) which goes back into the air. This process is called denitrification. air. This process is called denitrification.

Nutrients are taken up by wetland plants in the Nutrients are taken up by wetland plants in the water water Through growing plants remove excess chemicals. Through growing plants remove excess chemicals.

Wetlands act as filters Wetlands act as filters Phosphorous, heavy metals and certain toxic Phosphorous, heavy metals and certain toxic compounds get trapped in the sediments of the compounds get trapped in the sediments of the wetlands. wetlands.

Peat forming Peat forming During the formation of peat coal, nitrogen and heavy During the formation of peat coal, nitrogen and heavy metals are incorporated into the peat. metals are incorporated into the peat.

Why do humans Why do humans remove Wetlandsremove Wetlands Desire for land; for city growth or Desire for land; for city growth or

agriculture needs; drained soil very agriculture needs; drained soil very fertile for long periods of time.fertile for long periods of time.

““Unpleasantness” : Odor and look of Unpleasantness” : Odor and look of wetland very unappealing to most; wetland very unappealing to most; Filtration effects of wetlands give off Filtration effects of wetlands give off bad odors as nutrients and wastes are bad odors as nutrients and wastes are broken downbroken down

Health; disease carrying insects find Health; disease carrying insects find homes here homes here

What happens with What happens with removal of Wetlands?removal of Wetlands?

River and Ocean water quality drastically River and Ocean water quality drastically goes down; more pollutants enter free goes down; more pollutants enter free water (rivers and oceans)water (rivers and oceans)

Animals become endangered; birds, fish Animals become endangered; birds, fish and mammals all find wetlands a rich and mammals all find wetlands a rich source of food and great protection for source of food and great protection for their youngtheir young

Storms and flood damage increases Storms and flood damage increases dramatically; No natural barrier to trap dramatically; No natural barrier to trap flooding water or reduce storm surge flooding water or reduce storm surge impact. impact.

Actual Images: Actual Images: Remote Remote SensingSensing of Wetland of Wetland ImpactImpact

NC Hurricane Flood NC Hurricane Flood Impact Impact

Before Floyd

After Floyd