1. Lakes and Freshwater Wetlands Guided Notes

2. 1. What is a lake? What are some of the basic characteristics/uses of lakes?
A depression in the ground that collects & holds water
Can accumulate water from streams/runoff
Most have outlets from which water flows to rivers/ocean
Ponds/wildlife/recreation
Reservoirs – storage of water

3. ORIGINS OF LAKES 2. What are the natural origins of lakes? Oxbow lake
Blockage of valley by landslide
Collapse of limestone caverns

4. LAKES UNDERGO CHANGE
3. What happens to lakes over hundreds of thousands of years?
Usually fill with sediment and become part of a new landscape
What is eutrophication?
Process by which lakes become rich in nutrients from the surrounding watershed
Results in a change in the kinds of organisms in the lake
May use all of the oxygen, causes lake to “die”

5. Wetlands include marshes, swamps, bogs
5. Wetlands = the soil is saturated with shallow standing water for a large part of the year
6. Types of wetlands:
Freshwater marshes = shallow water, Plants grow above the surface, form along mouths of streams & deltas
Constant supply of water = lush marsh grasses
Swamps = shallow water in forested areas, Low-lying areas, Have shrubs and trees, Ancient swamps developed into present-day coal reserves
Bogs = ponds covered in thick floating mats of vegetation, Receive water from precipitation (not streams), Soil rich in peat moss

6. LAKES UNDERGO CHANGE
7. What are the roles/uses of wetlands? a. Improves water quality by acting as a filtering system that traps pollutants, sediments, & bacteria b. Provides habitats for wildlife such as migratory waterfowl c. Soaks up flood waters 8. Between the late 1700s and the mid-1980s, the continental US lost 50% of its wetlands. By 1985, 50% of the wetlands in Europe were drained.

7. Wetlands are valuable
9. Wetlands are extremely valuable for wildlife, they slow runoff, reduce flooding, recharge aquifers, & filter pollutants.
10. People have drained wetlands, mostly for agriculture, Southern Canada & the U.S. have lost over 1/2 of their wetlands.
11. In 2006, the Supreme Court told the Army Corps of Engineers it must create guidelines to determine when wetlands are valuable enough to protect by law.

8. Watch the Mangrove video!

9. Tree Map
Create a tree map on Wetlands