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Topic(s):
No topics assigned.
Concepts
1).
Significant amounts of wetlands have been drained in the last two centuries. Draining wetlands makes land available for farming and building.
2).
Wetlands are important ecosystems. They have unique species some of which become endangered when wetlands are drained.
3).
Lack of wetlands has lead to water quality problems. Drained wetlands lead to non-point source pollution, i.e. sediment and nutrients in streams. This negatively affects aquatic species habitat.
4).
Wetlands were viewed as an environmental hazard that need to be drained to improve the landscape. Mosquitoes associated with wetlands can lead to illnesses such as malaria.
5).
Cutting down a forest of a wetland reduces evapotranspirtation potentially leading to warming of the area.
6).
Wetlands can produce methane through the decomposition of organic matter by bacteria and are the most significant natural source worldwide.
7).
Wetland soils contain significant amounts of organic matter. Wetlands can produce methane through the decomposition of organic matter by bacteria and are the most significant natural source worldwide. Deforestation of wetlands can lead to more carbon dioxide in the atmosphere.
8).
Wetlands can be drained by ditches and underground tiles. Draining wetlands can lead to flooding because there is more moisture available for runoff.
9).
In the 1800's, wetlands were viewed as sources of disease.
Scenario: Since the 1600's, it is estimated that over half of the area of wetlands, over 100 million acres, have been drained from the lower 48 states of the United States. Wetlands are areas where the saturation of the soil is the dominant feature in the formation of soils and the ecosystem. Prior to the 1900's, wetlands were viewed as unusable land that needed to be developed. Wetlands bred mosquitoes that spread disease such as Malaria. They smelled and were impassable to travel.
There are many different kinds of wetlands. There are forested wetlands, prairie wetlands, mangrove swamps, tidal wetlands, bogs, fens, etc. Coastal wetlands protect the coast from hurricanes like the ones around the Gulf of Mexico.
All states have seen a reduction in wetlands. Ohio and California have had the greatest loss of wetlands. It is estimated that Ohio has lost 90% and California has lost 91% of their wetlands. Much of the wetlands were drained for agricultural use as the rich soils are very fertile. The Great Black Swamp that stretches from Ohio to Michigan and Indiana was one of the largest wetlands in the United States before it was drained to develop agricultural fields. The Great Black Swamp was part of Lake Erie as the glaciers receded from the area over 10,000 years ago. There are many stories of the difficulties the Great Black Swamp created due to its size. Now, the area is very fertile agricultural land with heavy, clay or silty soils. The landscape of the area that included the Great Black Swamp was a forested wetland prior to settlement.
The silty-clay soils that were laid down by the post-glacial Lake Erie drain very poorly. The Black Swamp was drained in the late 1800's with a series of drainage ditches. In the 1930's, clay tile were put into the fields to drain the excess water. More recently plastic tubes with perforations are used to drain the fields. They are put in the field about three feet below the surface.
The area of the Great Black Swamp is drained by the Maumee River. Conversion of the swamp to agricultural fields has lead to non-point source pollution in the basin. The silty-clay is very fine. Once it enters the water system, it makes its way all of the way to Lake Erie.
Conserving the remaining wetlands has become important due to the rapidly declining loss. Wetlands are now protected under Section 404 for the Clean Water Act. It states that there will be no net loss of wetlands. In an attempt to stem the destruction of wetlands, the federal government authorized the formation of the National Wetlands Inventory to assist with decision making in regards to wetlands.
Task: The majority of wetlands in the United States have been drained or destroyed. Laws have been passed to protect wetlands from further damage and degradation. What are the potential impacts of converting significant areas of the Great Black Swamp back to wetlands? How will this affect the balance of the region?
Authors:
Kevin Czajkowski, University of Toledo
kczajko@utnet.utoledo.edu
419-530-4274
Mikell Lynne Hedley, University of Toledo
mikell.hedley@utoledo.edu
Date: 4/6/2009
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Scenario Images
Image of a forested wetlands in Michigan in the Great Black Swamp area.
Historic marker for the Great Black Swamp describing the area.
Extent of the Great Black Swamp in Ohio, Michigan and Indiana.
An ephemeral gully eroding soil from a drained farm field adding sediment to the waterways.
Farmers put in plastic tubing (yellow) called tile drains about 3 feet (one meter) below the surface of the field to drain water off of the fields into nearby ditches.
This MODIS satellite image shows a sediment plume going into Lake Erie on the western end from runoff from the Maumee River. The Maume River prior to draining of the swamp is said to have been free from sediment. Now, the river is known as the Muddy Maumee because of its chocolate milk color.
Standards:
- Science
National Science Education Standards - Science Content Standards
http://www.nap.edu/readingroom/books/nses/html/overview.html#content
The science content standards outline what students should know, understand, and be able to do in the natural sciences over the course of K-12 education.
- K-12 UNIFYING CONCEPTS AND PROCESSES
The understandings and abilities associated with the following concepts and processes need to be developed throughout a student's educational experiences:
- Systems, order, and organization
- Form and function
- GRADES K-4 CONTENT STANDARDS
- Science as Inquiry (Std A)
- Abilities necessary to do scientific inquiry
- Understanding about scientific inquiry
- Life Science (Std C)
- Organisms and environments
- Science and Technology (Std E)
- Abilities to distinguish between natural objects and objects made by humans
- Science in Personal and Social Perspectives (Std F)
- Personal health
- Changes in environments
- Science and technology in local challenges
- GRADES 5-8 CONTENT STANDARDS
- Science as Inquiry (Std A)
- Abilities necessary to do scientific inquiry
- Understanding about scientific inquiry
- Life Science (Std C)
- Populations and ecosystems
- Science in Personal and Social Perspectives (Std F)
- Populations, resources, and environments
- GRADES 9-12 CONTENT STANDARDS
- Science as Inquiry (Std A)
- Abilities necessary to do scientific inquiry
- Understanding about scientific inquiry
- Physical Science (Std B)
- Interactions of energy and matter
- Life Science (Std C)
- Matter, energy, and organization in living systems
- Earth and Space Science (Std D)
- Energy in the earth system
- Science in Personal and Social Perspectives (Std F)
- Personal health
- Natural resources
- Environmental quality
- Geography
Geography for Life: National Geography Standards, 1994
- PLACES AND REGIONS
The identities and lives of individuals and people are rooted in particular places and in those human constructs called regions. The geographically informed person knows and understands:
- The physical and human characteristics of places
- PHYSICAL SYSTEMS
Physical processes shape Earth’s surface and interact with plant and animal life to create, sustain, and modify ecosystems. The geographically informed person knows and understands:
- The characteristics and spatial distribution of ecosystems on Earth’s surface
- HUMAN SYSTEMS
People are central to geography in that human activities help shape Earth’s surface, human settlements and structures are part of Earth’s surface, and humans compete for control of Earth’s surface. The geographically informed person knows and understands:
- The processes, patterns, and functions of human settlement
- ENVIRONMENT AND SOCIETY
The physical environment is modified by human activities, largely as a consequence of the ways in which human societies value and use Earth’s natural resources, and human activities are also influenced by Earth’s physical features and processes. The geographically informed person knows and understands:
- How human actions modify the physical environment
- How physical systems affect human systems
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