Producers, Consumers, & Decomposers
Lesson 5 of 28
Objective: SWBAT identify and explain the roles of different organisms within an ecosystem.
Inquiry Based Instructional Model
To intertwine scientific knowledge and practices and to empower students to learn through exploration, it is essential for scientific inquiry to be embedded in science education. While there are many types of inquiry-based models, one model that I've grown to appreciate and use is called the FERA Learning Cycle, developed by the National Science Resources Center (NSRC):
A framework for implementation can be found here.
I absolutely love how the Center for Inquiry Science at the Institute for Systems Biology explains that this is "not a locked-step method" but "rather a cyclical process," meaning that some lessons may start off at the focus phase while others may begin at the explore phase.
Finally, an amazing article found at Edudemic.com, How Inquiry-Based Learning Works with STEM,very clearly outlines how inquiry based learning "paves the way for effective learning in science" and supports College and Career Readiness, particularly in the area of STEM career choices.
In this unit, students will first develop an understanding of the biotic and abiotic factors within ecosystems, the characteristics and classification of living organisms, and how plants and animals obtain and use energy to fulfill their needs.
Then, students will delve deeper into the NGSS standards by examining the interdependent relationships within an ecosystem by studying movement of matter between producers, consumers, and decomposers by creating models of food chains and food webs.
At the end of this unit, students will study ways that individual communities can use science ideas to protect the Earth's resources and environment.
Summary of Lesson
Today, I will open the lesson by asking students to sort pictures of living organisms within the Yellowstone National Park ecosystem anyway they like. Students then explore the roles of producers, consumers, and decomposers within in a ecosystem. At the end of the lesson, students reflect and apply their new understanding of ecosystem roles by classifying the living organisms in the Yellowstone ecosystem.
Next Generation Science Standards
This lesson will support the following NGSS Standard(s):
5-PS3-1. Use models to describe that energy in animals’ food (used for body repair, growth, motion, and to maintain body warmth) was once energy from the sun.
5-LS1-1. Support an argument that plants get the materials they need for growth chiefly from air and water.
5-LS2-1. Develop a model to describe the movement of matter among plants, animals, decomposers, and the environment.
5-ESS3-1. Obtain and combine information about ways individual communities use science ideas to protect the Earth’s resources and environment.
Scientific & Engineering Practices
For this lesson, students are engaged in the following Science & Engineering Practice:
Science & Engineering Practice 7: Engaging in Argument from Evidence
Students will research the roles of consumers, producers, and decomposers. Then, they will use this evidence to "argue" the role of specific organisms within the Yellowstone ecosystem.
To relate ideas across disciplinary content, during this lesson I focus on the following Crosscutting Concept:
Crosscutting Concept 6: Structure and Function
Students will begin examining the structures of living organisms and connecting these structures with the roles they fill within an ecosystem. For example, many consumers all have teeth for "consuming" their food and many plants have leaves for capturing the sun's energy.
Disciplinary Core Ideas
In addition, this lesson also aligns with the following Disciplinary Core Ideas:
PS3.D: Energy in Chemical Processes and Everyday Life
The energy released [from] food was once energy from the sun that was captured by plants in the chemical process that forms plant matter (from air and water). (5-PS3-1)
LS1.C: Organization for Matter and Energy Flow in Organisms
Food provides animals with the materials they need for body repair and growth and the energy they need to maintain body warmth and for motion. (secondary to 5-PS3-1)
Plants acquire their material for growth chiefly from air and water. (5-LS1-1)
LS2.A: Interdependent Relationships in Ecosystems
The food of almost any kind of animal can be traced back to plants. Organisms are related in food webs in which some animals eat plants for food and other animals eat the animals that eat plants. Some organisms, such as fungi and bacteria, break down dead organisms (both plants or plants parts and animals) and therefore operate as “decomposers.” Decomposition eventually restores (recycles) some materials back to the soil. Organisms can survive only in environments in which their particular needs are met. A healthy ecosystem is one in which multiple species of different types are each able to meet their needs in a relatively stable web of life. Newly introduced species can damage the balance of an ecosystem. (5-LS2-1)
LS2.B: Cycles of Matter and Energy Transfer in Ecosystems
Matter cycles between the air and soil and among plants, animals, and microbes as these organisms live and die. Organisms obtain gases, and water, from the environment, and release waste matter (gas, liquid, or solid) back into the environment. (5-LS2-1)
To add depth to student understanding, when I can, I'll often integrate ELA standards with science lessons. Today, students will work on meeting CCSS.ELA-Literacy.RI.5.1: Quote accurately from a text when explaining what the text says explicitly and when drawing inferences from the text. Students will be encouraged to find exact details from the text that support our research question, "What are the different roles of the living organisms within an ecosystem?"
Choosing Science Teams
With science, it is often difficult to find a balance between providing students with as many hands-on experiences as possible, having plenty of science materials, and offering students a collaborative setting to solve problems. Any time groups have four or more students, the opportunities for individual students to speak and take part in the exploration process decreases. With groups of two, I often struggle to find enough science materials to go around. So this year, I chose to place students in teams of three! Picking science teams is always easy as I already have students placed in desk groups based upon behavior, abilities, and communication skills. Each desk group has about six kids, so I simply divide this larger group in half.
Gathering Supplies & Assigning Roles
To encourage a smooth running classroom, I ask students to decide who is a 1, 2, or 3 in their groups of three students (without talking). In no time, each student has a number in the air. I'll then ask the "threes" to get certain supplies, "ones" to grab their computers, and "twos" to hand out papers (or whatever is needed for the lesson). This management strategy has proven to be effective when cleaning up and returning supplies as well!
To prepare for today's lesson, I collected pictures of living organisms within Yellowstone National Park. To build upon background knowledge and connect lessons, I specifically gathered pictures of plants and animals that were also featured on the Yellowstone Poster from yesterday's lesson.
I want to inspire interest in today's lesson and capitalize on student curiosity, so I hand out a page of pictures to each team, Yellowstone Pictures, and ask students to cut out the pictures and to begin sorting them in groups. I purposefully don't tell students how to sort the pictures. I want them to think deeply, collaborate, and share prior knowledge.
As students begin sorting, I walk around the room to ask probing questions and to observe student reasoning. Students develop a variety of ways to categorize the pictures:
- Predators & Prey
- Food Chain Roles (Decomposers, Producers, Consumers)
- Meat-Eaters, Plant-Eaters, Meat & Plant Eaters
- Animals & Plants
During this conference, Predators & Prey, students at first wanted to categorize the pictures by biomes. Then, they gravitated toward predators and prey. One student connects their categories with the food chain and explains that plants are at the bottom of the food chain and predators are at the top.
Here, Animals & Plants, students categorize the pictures by animals and plants. I want to push their thinking a bit so I ask them to further categorize their pictures. One student mentions meat-eaters and then the group takes off!
This group, Meat & Plant Eaters does a great job categorizing the living organisms by what they eat. I ask them to explain their thinking about bacteria. Most students in the class are confused about bacteria, if it's really living, and if it is a plant or in it's own category.
After about ten minutes of sorting, we discuss how each group sorted their pictures as a class. Then, we pushed the pictures aside into a pile and moved on with the lesson!
Changes with Pictures
As a side note, I have added a few more pictures to the Yellowstone Pictures document since I taught this lesson. Next year, I would want to provide more examples of Yellowstone decomposers: earthworms, thermophile (archaebacteria that thrives in Yellowstone thermal features), and beetles. I almost omitted the picture of the sun as it isn't a producer, consumer, decomposer, or a living organism for that fact, however, it inspired great conversations with students (Is the sun a producer? What category is the sun in?) so I decided to leave it!
Lesson Introduction & Goal
I introduce today's learning goal: I can identify and explain the roles of different organisms within an ecosystem. I explain: Yesterday, we began learning about the variety of living organisms in Yellowstone National Park. However, what we didn't talk about is the fact that each organism has a very special role. So today, we are going to take our learning one step further by investigating the different roles that organisms fill within an ecosystem.
To explore the roles of organisms within an ecosystem further, each group of three students will work together and take turns collecting notes on one poster. To make sure all students in the group are equally involved, I continually encourage students to share the role of writing throughout this time period. I make sure to celebrate groups (mid-lesson) that are successful at sharing research responsibilities!
I set out 10 sheets of 11 x 17 construction paper, each a different color. I ask one student from each team (such as the #3 students) to grab their team color and a black sharpie.
Teacher Note: The construction paper doesn't have to be different colors. Often, students love being able to pick a color that makes their team different from all the others.
I also invite another student from each group (such as the #1 students) to grab their computers and to open the following link that I had emailed to all students prior to the lesson. This way, each team will share one computer.
Finally, I ask one student from each group (such as the #2 students) to create a 3-Column Chart on their poster paper to keep track of their group's research. I then encourage all students to take turns reading and writing throughout the research process.
Once more, I pose the research question: What are the different roles of organisms within an ecosystem? In no time, students are off and excited to research!
Monitoring Student Understanding
Once students begin working, I conference with every group. My goal is to support students by asking guiding questions (listed below). I also want to encourage students to engage in Science & Engineering Practice 7: Engaging in Argument from Evidence.
- What patterns have you noticed?
- Why do you suppose ____?
- What have you found so far?
- Has your thinking changed?
- What evidence do you have?
- How did you decide _____?
- What conclusion can you draw about ____?
- How are the roles different?
- How are the roles similar?
- Can you give me an example of a Yellowstone organisms that fits into this category?
In this conference, Discussing Produce & Consume, I encourage students to make the association between producers and produce as well as consumers and consume. We then discuss the fact that eating food provides consumers with energy.
Here, Researching Producers & Consumers, the students begin to make connections between the Yellowstone ecosystem and the roles they are researching.
This group, Different Types of Consumers, digs deeper into the many types of consumers. We then discuss which role the students fill in an ecosystem and the more specified role of scavengers. The goal of this conference, and all conferences for that fact, is to help make this abstract information as meaningful as possible to students.
Here are few examples of student work at this time:
Reflect & Apply
Now that students have built meaning and understanding by observing, questioning, and exploring, it is important to provide students with the opportunity to share their findings. For this reason, I want to circle back to our Yellowstone Poster from yesterday and provide students with the opportunity to identify and explain the roles of organisms in the Yellowstone ecosystem.
I invite each students to get out the Student Yellowstone Poster from yesterday as well as a red, green, and orange marker.
When finished with this lesson, the Yellowstone poster will have notes along the sides (producers in green, consumers in red, and decomposers in orange), and each organism will be circled green, red, and orange accordingly: Yellowstone Poster After.
We begin by discussing student research on producers and taking notes: Producers. I write notes on the large poster while students record notes on their own Yellowstone posters. I then ask students to identify consumers in the Yellowstone ecosystem (gray willow, wheatgrass, lodge pole pine, etc.) The students and I circle all the producers with our green markers: Categorizing Organsims Based on Roles. The goal is for students to make connections between their research and the real world.
Next, we discuss and take notes on Consumers. We also discuss the specific types of consumers (herbivore, carnivore, etc.). Then, students raise their hands to identify one of the many consumers on the Yellowstone poster (mayfly, gray wolf, grizzly bear, etc.) In a later lesson, we will return to this poster to take a closer look at the levels of consumers (primary, secondary, tertiary), but today, I want to keep it simple!
To end our lesson today, we discuss the role of Decomposers and the importance of returning nutrients to the soil. Realizing that we don't have enough decomposers on our poster, we add a few pictures to help students visualize the presence of these organisms in the ecosystem: Adding Decomposers to Poster.
Here are a few examples of student posters during this time:
Throughout this conversation, most teams also take this as an opportunity to paste the pictures from the picture sort at the beginning of the lesson on their research papers: Adding Pictures to Posters and Adding Pictures to Posters 2. I suggest this activity as an option as I know the same goal (identifying the roles of organisms in a real world ecosystem) would be accomplished by simply circling organisms on the Yellowstone poster.
By the end of this lesson, most students have an understanding of the different roles (consumers, producers, & decomposers) of organisms within an ecosystem. This will serve as a foundation as students begin to study the interconnectedness of organisms within each role in future lessons.