The Arizona STEM Acceleration Project

Investigating Ecosystem Dynamics at the San Pedro River

Investigating Ecosystem Dynamics at the San Pedro River

A 9-12 Grade STEM Lesson

Wendy Mehl

May 2024

Notes for Teachers

This lesson is designed to take about a week (5-ish) days, and requires transportation to a river, lake, active water source etc nearby. We used the San Pedro River.

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Students should already have background knowledge of food chains/food supply/ecosystem cycling.

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Students can download apps on their phones for identifying plants and animals if they choose.

List of Materials

• Pencils & Sharpies
• Small baggies and vials for sample collection if desired
• Data collection sheets
• Measuring tapes and rulers
• Thermometers
• pH meters
• Soil and water sampling kits
• Cameras or smartphones for documenting
• Clipboards
• Plastic box for each group to put field trip supplies in
• Laptops or tablets for data analysis (classroom)
• Graphing software (e.g., Excel, Google Sheets)
• Poster boards and markers for presentations

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Standards

Arizona State Science Standards

• HS.L2U1.19: Develop and use models that show how changes in the transfer of matter and energy within an ecosystem and interactions between species may affect organisms and their environment.
• HS+B.L2U1.3: Use mathematics and computational thinking to support claims for the cycling of matter and flow of energy through trophic levels in an ecosystem.

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Arizona State Math Standard

• HSF.IF.B.5: Relate the domain of a function to its graph and, where applicable, to the quantitative relationship it describes.

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Objectives:

• Collect and analyze data on matter and energy transfer within the San Pedro River ecosystem.
• Develop and use models to show changes in matter and energy transfer and interactions between species.
• Use mathematics and computational thinking to support claims about the cycling of matter and energy flow.
• Present your group’s findings and models to the class.

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Agenda (4 days in class + ½ day field trip)

Day 1: Field Trip to San Pedro River (½ day)

• Objective: Collect data on the ecosystem, focusing on matter and energy transfer and species interactions.
• Activities:
• Introduction and safety briefing
• Divide students into small groups for data collection
1. Each group will measure abiotic factors (temperature, pH, soil moisture) and biotic factors (plant and animal species present)
• Record observations and take samples where appropriate
• *Note: Pictures are wonderful ways to document things w/o taking physical samples
• Return to school and store any samples for further analysis

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Day 2: Data Analysis

• Objective: Begin analyzing the data collected from the field trip.
• Activities:
• Review and organize data in small groups
• Input data into spreadsheets
• Create initial graphs and charts to visualize data
• Discuss any initial findings or patterns observed
• Introduce mathematical concepts related to the domain of functions and how they relate to the collected data

Agenda

Day 3: Model Development

• Objective: Develop models to show how changes in matter and energy transfer within the ecosystem may affect organisms and their environment.
• Activities:
• Use the data to develop models of the San Pedro River ecosystem
• Incorporate changes in matter (e.g., nutrient cycling) and energy flow (e.g., food webs)
• Use mathematical functions to support claims about these processes
• Each group creates a draft model on poster boards or digitally

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Day 4: Finalizing Models and Preparing Presentations

• Objective: Finalize models and prepare presentations.
• Activities:
• Refine models based on feedback from peers and teacher
• Ensure models clearly demonstrate the impact of changes in matter and energy transfer
• Prepare a presentation that includes an explanation of the model, data analysis, and mathematical support
• Create visual aids (e.g., posters, slides) to enhance the presentation

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Agenda

Day 5: Presentations and Reflection

• Objective: Present findings and models to the class and reflect on the learning experience.
• Activities:
• Each group presents their model and findings to the class
• Peer review and feedback on each presentation
• Class discussion on the importance of understanding ecosystem dynamics
• Reflection activity where students write about what they learned and how it applies to real-world ecosystem management

Intro/Driving Question/Opening

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How do changes in matter and energy transfer within the San Pedro River ecosystem impact the interactions between species and the overall health of the environment?

Hands-on Activity Instructions

• Suggested group structure
• I like to have groups of no more than 3, and have them rotate jobs periodically.
• 1 student for recording data
• 1 student for sample gathering (photography etc)
• 1 student for taking measurements

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• IMPORTANT THINGS TO NOTE:
• Students are going to get wet, muddy, dirty, and possibly scratched.
• Make sure you have sunscreen, towels, clean bottled water and bandaids with you.
• Next year I am going to try to get tackle boxes or something similar to put thermometers, pH strips, small baggies etc. Something that will stand up to being wet, muddy and dropped.

Test kits on Amazon: $16

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Infrared thermometer on Amazon: $8

Examples of Data Collection Sheets

Have students come up with categories and then discuss and agree.

Examples of Data Collection Sheets

Have students come up with categories and then discuss and agree.

Examples of Data Collection Sheets

Have students come up with categories and then discuss and agree.

Example of Graph

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Assessment

Formative: Observe group work, provide feedback during model development, and check for understanding through questioning.

Summative: Evaluate group presentations and models using a rubric that includes criteria for accuracy, completeness, clarity of explanation, and use of mathematical and computational thinking.

(see exemplar rubric on next slides)

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Assessment

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Assessment

Assessment

Differentiation

• One-on-one support is recommended for students who may struggle with this project.
• I often have students who volunteer to pair with students who need more one-on-one support and it works out very well. You may use aides or parents etc.
• You can create less difficult collection sheets (fewer categories, larger boxes etc).
• Additional time if necessary

Remediation

Extension/Enrichment

Investigate the long-term impacts of human activities on the San Pedro.

Example scenarios:

• Someone cut down the cottonwood trees on the embankment.
• A backyard farmer has fertilizer runoff that is entering the river.