Students become aware of the unique chemical, hydrologic, and vegetative aspects of a specialized wetland known as a bog. Students also learn about the formation of this community and finally assist in the preservation of this ecosystem. This activity is a full immersion off site activity. Clothes used in this activity are usually ruined, and people will get wet at least to their knees.
INFORMATION FOR THE TEACHER
This activity is appropriate for life science, biology, and environmental classes.
Materials can be specialized science sampling devices or home-made equivalents Creativity is the only limiting factor.
This activity requires students to tour, collect data and analyze a pristine bog community. A bog is a wetland which is limited by nutrients, which causes a vegetative plant mat to grow out from the shore along the surface of the water. Students begin the lesson with an overview of wetland types and benefits.
Students gather field equipment and journey into a bog community collecting physical, chemical, and biological data on this unique wetland type. Physical data includes the water temperature above and below the vegetative mat, the soil structure below the mat as it changes from sand to peat, and the water clarity below the mat. Chemical measurements include the pH of the water above and below the vegetative surface, dissolved oxygen content, phosphates and nitrates and the smell of the water. During the biological survey students map the general vegetative zones of the bog as it progresses from an alder thicket to open water.
Teachers highlight several unique plants including spaghnum moss (the predominant plant of the vegetative mat), four different carnivorous plants (one of which is endangered in Wisconsin) and an unusual orchid. Using this data, students next use this data to draw a map and a cross section of the bog. They super-impose the data over an aerial photograph of the area. Finally, students write about the conditions which lead to the formation of this bog community.
I consider this lab successful for several different reasons. While walking into a bog students are sometimes on dry ground, sometimes wading in knee deep water and occasionally find that they fall through (only to the waist) the plant mat. Students intimately learn about the physical structure of this floating mass and at the same time develop an emotional attachment to this unique community. An appreciation and even love of this ecosystem has grown out of the wet, sometimes muddy, and often smelly encounter.
The mapping exercise demonstrates the interdependency of the physical, chemical, and biological components of this ecosystem. Examples of the interdependency include vegetative zones related to the depth of the water under the mat and the lack of oxygen in the underground water supply which leads to the slow decay rate of the plants and then forms peat. Students have collected field data, used the information to demonstrate the interdependency of the environment and start asking sophisticated research questions.
Assessment of this unit includes a written laboratory report, including the a demonstration of the interdependency of several components of the ecosystem. Students also must answer test questions on the structure, chemistry and vegetation of the bog. Another question asks for students to discuss the interdependency in this wetland. Students have returned to complete additional research projects which include a quantitative vegetation analysis of the bog, succession of the bog community, and a dissolved oxygen diurnal study to analyze the exchange of water under the mat. Research teams have presented their bog findings at the Wisconsin Science Congress for several years now.
Information has also been shared with the Bureau of Endangered Resources of the Wisconsin Department of Natural Resources and Big Bay State Park. I would like to digitize the data and include it in a Geographic Information System program. I am also learning about ARC View and the possibilities for contributing our data with The Wisconsin Land Information Center.