Lakes and Lakes and Freshwater Freshwater WetlandsWetlands

SWBAT explain the formation of SWBAT explain the formation of freshwater lakes and wetlands; freshwater lakes and wetlands;

describe the process of describe the process of eutophication; recognize the eutophication; recognize the

effects of human activity on lake effects of human activity on lake developmentdevelopment

Origins of LakesOrigins of Lakes

Lake Lake A depression in the surface material of a A depression in the surface material of a

landscape that collects and holds waterlandscape that collects and holds water What are some ways lakes can form?What are some ways lakes can form?

Oxbow lakes form when a river changes Oxbow lakes form when a river changes course, and streams can get blocked.course, and streams can get blocked.

Glaciers create lakes through gouging Glaciers create lakes through gouging the land, moraines can create dams, the land, moraines can create dams, cirque lakes form in mountains, and ice cirque lakes form in mountains, and ice melting on an outwash plain creates melting on an outwash plain creates kettle lakes. kettle lakes.

Get your Lab notebookGet your Lab notebook Title: Surface materials determine where a Title: Surface materials determine where a

lake can form.lake can form. Watch the demonstration and answer the Watch the demonstration and answer the

following in complete sentencesfollowing in complete sentences Create a 3 columned chart, and label the Create a 3 columned chart, and label the

columns: Clay, Gravel, Sandcolumns: Clay, Gravel, Sand Describe what happened to the 500 mL of Describe what happened to the 500 mL of

water that was added to each container.water that was added to each container. How is this activity similar to what happens How is this activity similar to what happens

on Earth’s surface when a lake forms?on Earth’s surface when a lake forms? What can you infer about the Earth What can you infer about the Earth

materials in which lakes most commonly materials in which lakes most commonly form?form?

Lakes Undergo ChangeLakes Undergo Change

Eutrophication Eutrophication Process by which lakes become rich in Process by which lakes become rich in

nutrients from the surrounding nutrients from the surrounding watershed, resulting in a change in the watershed, resulting in a change in the kind of organisms found in the lakekind of organisms found in the lake

Wetland Wetland Land area that is covered with water for Land area that is covered with water for

a large part of the year a large part of the year

Wetland EnvironmentsWetland Environments

BogsBogs Bogs are a wetland that gets its water Bogs are a wetland that gets its water

from precipitation, not from streams. from precipitation, not from streams. The soil is rich is sphagnum (peat The soil is rich is sphagnum (peat moss). The soil also tends to be acidic moss). The soil also tends to be acidic and supports unusual plants such as and supports unusual plants such as Venus flytraps, pitcher plants, sundew.Venus flytraps, pitcher plants, sundew.

Wetland EnvironmentsWetland Environments

MarshesMarshes Marshes form along mouths of streams Marshes form along mouths of streams

or delta areas. They have lush growth or delta areas. They have lush growth of grasses with shallow roots, which of grasses with shallow roots, which anchor silt deposits, slowing the water anchor silt deposits, slowing the water and expanding the marsh. Grasses, and expanding the marsh. Grasses, reeds, sedges, and rushes are reeds, sedges, and rushes are commonly found here.commonly found here.

Wetland EnvironmentsWetland Environments

SwampsSwamps Swamps are low-lying areas near Swamps are low-lying areas near

streams. They develop from marshes streams. They develop from marshes that have filled in enough to support that have filled in enough to support shrubs and trees.shrubs and trees.

Freshwater WetlandsFreshwater Wetlands

How do wetlands help the How do wetlands help the environment?environment? Wetlands improve the water quality by Wetlands improve the water quality by

filtering pollutants, sediments, and filtering pollutants, sediments, and bacteria.bacteria.

Wetlands also provide habitats for birds Wetlands also provide habitats for birds and other wildlife.and other wildlife.

In your GroupsIn your Groups

Answer questions 1-4 on page 231 in Answer questions 1-4 on page 231 in complete sentences.complete sentences.

Finish for homework.Finish for homework.