This interrupted case study presents published data on the effect of coyote removal in Texas. It was designed to help students in introductory level biology courses understand trophic level relationships and the role of keystone species. Students interpret data presented graphically and predict how changes at one trophic level may affect populations and communities at other trophic levels.
In this fictional case study, the state of Oklahoma has profited by giving incentives for companies to build power plants in rural areas of the state. The "scrubbing" systems used to minimize air pollution create potentially hazardous solid waste.To contain this waste, an impoundment facility has been built on unsuitable land from which water-soluble toxins can leach into groundwater. Student teams design a prototype sensor capable of measuring dissolved oxygen and fluorescein dye in water in order to analyze the runoff from the impoundment facility for toxins. The case was developed for an undergraduate laboratory course in photonics for junior- and senior-level students.
Managing the St. Croix River has sparked tremendous controversy due to conflicting uses of the river. At risk is the water quality and aesthetic value of this National Scenic Riverway. The drama unfolding around the St. Croix River is used in this case study to illustrate water resource concepts and the difficulties that can arise when making decisions about natural resources. Designed for a water resources course taken primarily by undergraduate juniors and seniors, the case could be used effectively in classes covering water quality, water policy, environmental policy, limnology, stream ecology, environmental studies or science, or environmental decision making.
In this case study, two students have been asked to conduct a "systems analysis" study to determine whether ethanol derived from corn or biodiesel prepared from soybeans is the more energy efficient alternative fuel. The students must investigate the two systems very broadly to determine all energy inputs and outputs. When the corn-to-ethanol system turns out to be less energy efficient, the students are asked to consider the political and economic consequences of this and the role that science plays in making policy decisions. The case is designed for general chemistry courses and non-science majors' chemistry courses.
Students explore material properties in hands-on and visually evident ways via the Archimedes' principle. First, they design and conduct an experiment to calculate densities of various materials and present their findings to the class. Using this information, they identify an unknown material based on its density. Then, groups explore buoyant forces. They measure displacement needed for various materials to float on water and construct the equation for buoyancy. Using this equation, they calculate the numerical solution for a boat hull using given design parameters.
Sexual selection has led to the evolution of interesting traits and behaviors in many animal species. In widowbirds, males undergo a dramatic change in plumage coloration and produce exceptionally long tail feathers during the breeding season. This change in appearance has facets of both intrasexual and intersexual selection. As students work through this interrupted case, they develop hypotheses and propose corresponding experiments. They are then presented with data from actual experiments on sexual selection in widowbirds that they must analyze and interpret. Developed for introductory-level biology students, the case could be adapted for upper-division ecology and evolution courses.
This case is based on a research paper about the lignin content of genetically modified corn published in the American Journal of Botany. Students are asked to analyze and discuss the paper, focusing on questions related to experimental design and interpretation and a critique of the statistical data presented. Developed for use in an upper-level undergraduate course in plant ecology and a graduate biostatistics course, the case could also be used in courses in plant anatomy, plant physiology, soil ecology, agriculture, or genetics.
The release of toxins into the environment and the federal government's tracking of that using the Toxic Release Inventory (TRI) compiled by the U.S. Environmental Protection Agency (EPA) are the focus of this case study, which uses GIS to explore the potential impacts of the release of such substances. The case was developed for an introductory environmental studies course. It would also be appropriate for use in an introductory GIS course or cartography course where some analysis is required, an introductory chemistry course for non-majors (with some more prep work on partitioning coefficients and fate and transport), or a basic soils course where remediation techniques are emphasized. The case study requires ESRI's ArcView 3.3 software in a computer lab setting, although it could easily be adapted for use with ArcGIS 9.x.
Students conduct experiments to determine the flow rate of faucets by timing how long it takes to fill gallon jugs. They do this for three different faucet flow levels (quarter blast, half blast, full blast), averaging three trials for each level. They convert their results from gallons per second (gps) to cubic feet per second (cfs).
Developed for an introductory environmental studies course, this case study explores the ecological, economic, and legislative issues associated with land development and wetland loss. Students role-play the points of view of four different stakeholders and then write a report that provides specific recommendations for the mayor of a city considering an expansion of the metropolitan airport that will result in the loss of wetlands. Biodiversity is a topic that students typically associate with tropical regions of the world. A strength of this case is that it brings this topic home by connecting biodiversity with tradeoffs involved in local economic development, with the functional value of wetlands, and with the controversy surrounding wetland "mitigation" as a means of achieving the national "no net wetland loss" policy goal.
In this case study, students speculate on what may have caused a major fish kill in an estuary in North Carolina. In the process, they explore how land runoff and excess nutrients affect aquatic communities, and learn about the complex life cycle of the dinoflagellate Pfiesteria. The case is appropriate for an introductory environmental science course, a general biology course that covers ecology, or a general zoology course.
In this case study, students examine data from a number of published studies of the effects of Pacific salmon on freshwater and riparian ecosystems. The case focuses on the interesting phenomenon of spawning salmon acting as nutrient conveyor belts, transporting nutrients from the ocean upstream into freshwater spawning areas and, in some cases, even onto land, reversing the more-typical downstream movement of nutrients. As students work at analyzing and interpreting graphical data, they will also increase their understanding of the principles of biogeochemical cycling and gain an appreciation for the interconnectedness of different types of ecosystems. The topic is appropriate for any course covering ecosystem ecology including, for example, general ecology, freshwater or marine ecology, and environmental science.
This "clicker case" addresses the eutrophication of aquatic systems caused by human activities. "Susan" is a biology student working at a seafood restaurant on the Gulf of Mexico. She discovers that the restaurant doesn't serve locally caught shrimp because shrimp populations are in decline. While searching for an explanation, Susan learns about the nitrogen cycle as well as interactions between species, the abiotic and biotic environment, and multiple ecosystems (terrestrial and aquatic). Developed for a large introductory biology course, the case combines the use of student personal response systems ("clickers") with case teaching methods and formats. It is presented in class using a series of PowerPoint slides (~3.8MB) punctuated by questions that students respond to using their clickers. The case could be adapted for use without these technologies.
Students experience firsthand one of the most common water treatment types in the industry today, flocculants. They learn how the amount of suspended solids in water is measured using the basic properties of matter and light. In addition, they learn about the types of solids that can be found in water and the reasons that some are easier to remove than others. Encompassing the concepts of force and motion, attraction and repulsion of charged particles, and properties of matter, during the associated activity students see scientific concepts they already understand through the eyes of engineers who apply them to the removal of solids from water via chemical flocculants.
In the Flow Rate Experiment, students perform hands-on experiments with a common faucet, as well as work with the Engineering Our Water Living Lab to gain a better understanding of flow rate and how it pertains to engineering and applied science. Students calculate the flow rate of a faucet for three different levels (quarter blast, half blast, and full blast). Building on these calculations, students hypothesize about the flow rate in a nearby river, and then use the Engineering Our Water Living Lab to check their hypothesis. For this lesson to be effective, your students need to have a visual feel for the flow in a nearby river.
During a scavenger hunt and an art project, students learn how to use a handheld GPS receiver for personal navigation. Teachers can request assistance from the Institute of Navigation to find nearby members with experience in using GPS and in locating receivers to use.
Using problem-based learning and role-playing, students analyze the geological origins of the Galapagos Islands, their colonization, species formation, and threats to their biodiversity in this story of a graduate student caught between local fishermen and government officials fighting for control of the islands' natural resources. The case was designed for an introductory biology course where the focus is on evolution. It would also be appropriate for courses in ecology, conservation biology, and natural resources management.
This case study, developed for a general chemistry course, is intended to teach students the interdisciplinary nature of environmental science. Students take on the role of environmental chemists. Using atomic absorption spectroscopy, they test for lead contamination in groundwater samples taken from an old mining district in Lake County, Colorado. After researching remediation methods, students propose practical solutions to local soil contamination.
In this lesson, students will investigate error. As shown in earlier activities from navigation lessons 1 through 3, without an understanding of how errors can affect your position, you cannot navigate well. Introducing accuracy and precision will develop these concepts further. Also, students will learn how computers can help in navigation. Often, the calculations needed to navigate accurately are time consuming and complex. By using the power of computers to do calculations and repetitive tasks, one can quickly see how changing parameters likes angles and distances and introducing errors will affect their overall result.
In this lesson, students learn how to determine location by triangulation. We describe the process of triangulation and practice finding your location on a worksheet, in the classroom, and outdoors.