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Topics Explored: Nitrogen Cycle, Transformation of Energy, Trophic Levels, Food Chains, Food Webs, Population Interactions

This case study explores the unique life cycle of periodical cicadas (Genus Magicicada) and their complex interactions with the ecosystem and humans, their unique adaptations to their environment, and their amazing impact both on the food web and the nitrogen cycle. Answer key included.

Case Study: Periodical Cicadas (Teacher & Student Edition)

  • ZIP file containing 2 PDF files 
    (1 Teacher Edition and 1 Student Edition)

  • Next Generation Science Standards (NGSS):
    HS-LS2-1. Use mathematical and/or computational representations to support explanations of factors that affect carrying capacity of ecosystems at different scales.
    HS-LS2-2. Use mathematical representations to support and revise explanations based on evidence about factors affecting biodiversity and populations in ecosystems of different scales.
    HS-LS2-6. Evaluate the claims, evidence, and reasoning that the complex interactions in ecosystems maintain relatively consistent numbers and types of organisms in stable conditions, but changing conditions may result in a new ecosystem.
    HS-LS2-7. Design, evaluate, and refine a solution for reducing the impacts of human activities on the environment and biodiversity.

    AP® Environmental Science Learning Objectives:
    1.5 Explain the steps and reservoir interactions of the nitrogen cycle. 
    1.8 Explain how solar energy is acquired and transferred by living organisms.
    1.9 Explain how energy flows and matter cycles through trophic levels.
    1.10 Determine how the energy decreases as it flows through ecosystems. 
    1.11 Describe food chains and food webs, and their constituent members by trophic level. 
    3.2 Identify differences between K- and r-selected species.
    3.3 Explain survivorship curves.


    AP® Environmental Science Practices:
    1: Explain environmental concepts, processes, and models presented in written format. 
    2: Analyze visual representations of environmental concepts and processes. 
    3: Analyze sources of information about environmental issues. 
    4: Analyze research studies that test environmental principles. 
    5: Analyze and interpret quantitative data represented in tables, charts, and graphs.
    6: Apply quantitative methods to address environmental concepts.
    7: Propose and justify solutions to environmental problems.


    IB® Environmental Systems & Societies Curriculum Topics:

    2.1.1 Distinguish between biotic and abiotic (physical) components of an ecosystem.
    2.1.2 Define trophic level.
    2.1.3 Identify and explain trophic levels in food chains and food webs selected from the local environment.
    2.1.4 Explain the principles of pyramids of numbers, pyramids of biomass, and pyramids of productivity, and construct such pyramids from given data.
    2.1.5 Discuss how the pyramid structure affects the functioning of an ecosystem.
    2.1.7 Describe and explain population interactions using examples of named species.
    2.5.3 Describe and explain the transfer and transformation of energy as it flows through an ecosystem.
    2.5.4 Describe and explain the transfer and transformation of materials as they cycle within an ecosystem.
    2.6.4 Describe the principles associated with survivorship curves including, K- and r-strategists.


    AP® is a registered trademark registered by the College Board®. IB® is a trademark registered by the International Baccalaureate Organization®. This work/product/service has been developed independently from and is not endorsed by the College Board® or the International Baccalaureate Organization®. 

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