1. Section 3: Lakes and Freshwater Wetlands
As the amount of water changes and the amount of sediments increases, lakes can be transformed into wetlands and eventually into dry land. K
What I Know W
What I Want to Find Out L
What I Learned

2. Essential Questions How do freshwater lakes and wetlands form?
How is the process of eutrophication described?
What are the effects of human activity on lake development?
Lakes and Freshwater Wetlands
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3. Vocabulary Review New kettle lake eutrophication wetland
Lakes and Freshwater Wetlands
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4. Origins of Lakes
Natural lakes, bodies of water surrounded by land, form in different ways in surface depressions and in low areas.
Some lakes form when stream flow becomes blocked by sediment from landslides or other sources.
Other lakes, such as moraine-dammed lakes, cirque lakes, and kettle lakes, have glacial origins.
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Lakes and Freshwater Wetlands

5. Lakes Undergo Change
A depression that receives more water than it loses to evaporation or use by humans will exist as a lake for a long period of time.
However, over geologic time, most lakes are temporary features.
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Lakes and Freshwater Wetlands

6. Lakes Undergo Change Eutrophication
The process by which bodies of water become rich in nutrients that stimulate excessive plant growth is called eutrophication.
Although eutrophication is a natural process, it can be sped up with the addition of nutrients, such as fertilizers, that contain nitrogen and phosphorus.
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Lakes and Freshwater Wetlands

7. Lakes Undergo Change Freshwater wetlands
A wetland is any land area that is covered with water for a part of the year.
Wetlands include environments commonly known as bogs, marshes, and swamps, which have certain soil types and support specific plant species.
Lakes and Freshwater Wetlands
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8. Lakes Undergo Change Freshwater wetlands
Wetlands play a valuable role in improving water quality.
They serve as a filtering system that traps pollutants, sediments, and pathogenic bacteria contained in water sources.
Lakes and Freshwater Wetlands
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9. Lakes Undergo Change Freshwater wetlands
The area of wetlands in the United States was drastically reduced until the 1980s. Since then, efforts have been made to preserve wetlands.
Lakes and Freshwater Wetlands
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10. Review Essential Questions Vocabulary
How do freshwater lakes and wetlands form?
How is the process of eutrophication described?
What are the effects of human activity on lake development?
Vocabulary
lake
eutrophication
wetland
Lakes and Freshwater Wetlands
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