The Arizona STEM Acceleration Project

Learning Through Leaf Packs!

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Lesson 4 of 8: Leaf Pack Dissection

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Learning Through Leaf Packs

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Leaf Pack Dissection

(Lesson 4 of 8)

A Middle School (6th-8th) STEM Lesson

Susan Brown & Carrie Jenkins

12/19/22

Learning Through Leaf Packs

Note for Teachers: This is an 8 lesson unit that is designed to be used together to learn about the health and diversity of your local watershed by placing leaf packs into a water source (natural or man-made ponds, lakes, streams, and rivers) and attracting macroinvertebrates. Links to lessons are on the next slide.

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Why do this?!

• Connection to science standards
• Engage students in the scientific process
• Authentic science
• Citizen science (Global database)
• Collaboration with community members
• Students LOVE it!!!

Carrie Jenkins, 6th math & science

You don’t need a water source. This unit has a virtual option to collect data!

Lesson Sequence

Lesson 1: What is a leaf pack?

Lesson 2: Stream Food Webs

Lesson 3: Dichotomous Keys

Lesson 4: Leaf Pack Dissection

Lesson 5: Data Analysis and the Leaf Pack Network

Lesson 6: Stream Sleuths

Lesson 7: Using Biotic Index to Infer Water Quality

Lesson 8: Chemical Water Testing to Assess Water Quality

Susan Brown, 7th science

Notes for teachers prior to lesson to prep leaf packs for student use:

• Instructional video on placing packs here. You need to leave them in water source 2-4 weeks.
• Instructional video on retrieving packs here. Collect the leaf packs from the water source(s). You can do this the day prior and place the leaf packs in old ice chests overnight.
• If you don’t have a water source, you can do a virtual simulation of this lesson here.
• Sorting and identification video here.
• Soliciting help from community partners (local scientists or experts), university students and parents is helpful.

List of Materials

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• sink or a way to rinse the leaf packs
• 1 6″ sieve, 500 micron mesh
• set of MacroLens™,
• 1 set of 6 Laminated, Spiral-Bound Freshwater Macroinvertebrate Dichotomous Keys
• 1 set of 6 Biotic Index Data Sheets
• 60 Petri dishes or similar clear dishes to place on sorting sheets
• 12 artist’s paint brushes
• 6 plastic sorting trays
• 6 hand lenses
• 1-2 plastic spoons for each group
• buckets
• dissecting microscopes
• sink
• flashlights
• dichotomous keys
• macroinvertebrate picture cards
• gloves for each student (optional)

Notes for teachers continued:

• This lesson takes at least 1 class period---preferably a longer class period of 60-90 minutes.
• Prior to students arriving, it will be important to have all materials for each group set up to save time.
• Pre-rinse packs and place in tray.
• Make sure students are familiar with tools -- hands lenses, dichotomous keys, microscopes, and how to record data in the data table.
• Define lab groups (3-4 students per pack).

Arizona Science & Ed Tech Standards

Life Science

6.L2U1.13 Develop and use models to demonstrate the interdependence of organisms and their environment including biotic and abiotic factors.

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6.L2U1.14 Construct a model that shows the cycling of matter and flow of energy in ecosystems.

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Ed Technology (if doing simulation)

Knowledge Constructor

6-8.3.d. Students explore real world problems and issues and actively pursue solutions for them.

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Science & Engineering Practices

• ask questions and define problems
• develop and use models
• plan and carry out investigations
• analyze and interpret data
• use mathematics and computational thinking
• construct explanations and design solutions
• engage in argument from evidence
• obtain, evaluate, and communicate information

Arizona Science Standards

Life Science Standards

Students develop an understanding of the flow of energy in a system beginning with the Sun to and among organisms They also understand that plants and animals (including humans) have specialized internal and external structures and can respond to stimuli to increase survival.

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6.L2U3.11 Use evidence to construct an argument regarding the impact of human activities on the environment and how they positively and negatively affect the competition for energy and resources in ecosystems.

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Core Ideas

6.L2U3.12 Engage in argument from evidence to support a claim about the factors that cause species to change and how humans can impact those factors.

● Ecosystems are dynamic in nature, their characteristics can vary over time. Disruptions to any physical or biological component of an ecosystem can lead to shifts in all its populations.

● Human activities have significantly altered the biosphere, sometimes damaging or destroying natural habitats and causing the extinction of many other species.

Objective(s):

• Today we will learn how to dissect a leaf pack and identify the macroinvertebrates.

Agenda (60-90 minute class period)

One 60-90 minute class period

Dissect leaf packs

Sorting and Identifying macroinvertebrates

Add data to tally sheet

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Intro

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How many and what kinds of macroinvertebrates are we finding in the leaf packs?

Hands-on Activity Instructions

• Students get in lab groups.
• Take apart leaves carefully looking for organisms.
• Place organisms in petri dish.
• Using the dichotomous key, identify the organisms.
• Check that your identification is correct BEFORE adding to tally.
• Add data using tally marks on the Experiment Summary Data Sheet here.

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Source: https://leafpacknetwork.org/

Source: https://www.freepik.com/premium-vector/tally-marks-count-prison-wall-sticks-lines-counter-lost-day-tally-numbers-counting-slash-lines_31362391.htm

• Group name
• What leaf type
• Confirm organism before adding to tally.

Assessment

Formative Assessment: Using a dichotomous key, students will be identifying macroinvertebrates that they find in the leaf packs. Once they identify the macroinvertebrates, the student will verify with the teacher or an adult helper.

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Summative Assessment: Students will be writing a scientific conclusion to this investigation based on the data collected.

Differentiation

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Lab groups should be strategically organized.

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Adult/older helpers can be placed at each lab group to assist with identification.

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Post large pictures of common macroinvertebrates to aid in the identification.

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Remediation

Extension/Enrichment

• Keep larvae in classroom in tank and watch the larvae mature to adult stage.
• Collect macros using netting out in a stream.
• Ask student to look under rocks in local stream and report back what they find.
• Bring in USGS or other community partners to share research or job that includes macros.