Energy in Ecosystems

This unit is designed as an introduction to ecosystems and to some of the ways that organisms interact within ecosystems. It explores several essential questions:

• What is an ecosystem?
• In what ways do living things interact in an ecosystem?
• How does energy flow through an ecosystem?
• What can individuals do to sustain ecosystems?

Geared for third- through fifth-grade classrooms, the unit is built around the following Performance Expectation standards from the Next Generation Science Standards (NGSS):

• 3-LS4-3 – Biological Evolution: Unity and Diversity. Construct an argument with evidence that in a particular habitat some organisms can survive well, some survive less well, and some cannot survive at all.
• 4-LS1-1 – From Molecules to Organisms: Structures and Processes. Construct an argument that plants and animals have internal and external structures that function to support survival, growth, behavior and reproduction.
• 5-PS3-1 – Energy. Use models to describe that energy in animals’ food (used for body repair, growth, and motion and to maintain body warmth) was once energy from the sun.
• 5-LS2-1 – Ecosystems: Interactions, Energy, and Dynamics. Develop a model to describe the movement of matter among plants, animals, decomposers, and the environment.

In exploring the concepts, students apply multiple science and engineering practices, such as asking questions, using models, and analyzing and interpreting data to understand the significant and complex issues involved.

The unit also integrates math, language arts, and other discipline areas in fun and creative ways, drawing upon both mathematics and English language arts benchmarks from the Common Core State Standards. Please see Standards Connections for a chart showing standards addressed in the unit.

Project Learning Tree’s philosophy of teaching students how to think, not what to think, is integrated throughout the unit. PLT enhances critical thinking, problem solving, and effective decision-making skills, teaching students to weigh options in order to make informed and responsible decisions.

Like all PLT materials, each activity in the unit is also correlated to the PLT Conceptual Framework. This framework outlines the core knowledge students will acquire while participating in PLT’s units and lessons.

The unit was also developed with an eye toward the North American Association for Environmental Education’s Guidelines for Excellence, which identifies characteristics of high-quality environmental education. Throughout the unit, students build content knowledge as they experience each supporting activity, and then culminate by exploring solutions to a problem in the local ecosystem.

This unit is designed to be flexible. You may use individual activities as stand-alone investigations or move through all six of the unit’s activities from beginning to end. In addition, you may use individual activities or the unit as a whole as the basis for other areas of study, including Unity and Diversity or Structures and Processes in science, Geography in social studies, or Reading and Writing in English language arts.

This unit is designed around the 5E Instructional Model, which incorporates the elements of engagement, exploration, explanation, elaboration, and evaluation (see Figure 1). This model is based on the constructivist approach to learning, which understands that learners build or construct their knowledge of the world based on their experiences. This instructional model incorporates a variety of instructional strategies such as student exploration, critical thinking, hands-on activities, scientific argumentation, project-based learning, STEM learning, and application of 21st century skills to move students to a deep understanding of concepts explored. Studies show that when taken together, these activities result in greater student engagement, comprehension, and achievement.

For more information about the 5E Instructional Model, see:

• The BSCS 5E Instructional Model: Origins and Effectiveness. Biological Sciences Curriculum Study.
• The BSCS 5E Instructional Model: Creating Teachable Moments by Rodger W. Bybee. NSTA Press.
• 7-minute video on the BSCS (Biological Sciences Curriculum Study) 5E Instructional Model by Nancy P. Moreno, PhD. BioEd Online, Science Teacher Resources from Baylor College of Medicine.

The unit also follows the guidelines for best STEM practices as outlined in NGSS’s eight Science and Engineering Practices.

1. 1. Ask questions (science) and define problems (engineering)
   2. Develop and use models
   3. Plan and carry out investigations
   4. Analyze and interpret data
   5. Use mathematics and computational thinking
   6. Construct explanations (science) and design solutions (engineering)
   7. Engage in argument from evidence
   8. Obtain, evaluate and communicate information

The overarching goal of this Energy in Ecosystems Unit is to help students see how all living things—including themselves—depend on ecosystems. Throughout the unit activities, students build their understanding of the living and nonliving things in ecosystems.

 

The unit supports learning as a developmental progression. It is designed to help students build on and revise their knowledge and skills, starting with their initial conceptions about the topic of ecosystems and moving toward a deeper understanding of the topic.

Activity	Summary of Student Learning
Pre-Assessment	Describe an ecosystem and explore some related terms. Label tree parts and explain their functions. Explore positive and negative human impacts on surrounding environments.
1: The Forest of S.T. Shrew	Describe and illustrate organisms that live in a forest ecosystem. Describe the interactions of living and nonliving things in a forest ecosystem. Identify ways that organisms living in a forest ecosystem get the food energy they need to live.
2: A Home for Many	Describe the ways in which animals and other plants depend on trees. Investigate a tree and observe what is living on its trunk and branches. Construct a graph showing the number of plants and animals in the observation area.
3: Web of Life	Conduct research about a plant or animal in the forest ecosystem. Using this information, create a model food web.
4: Power Plants	Make observations about photosynthesis. Devise experiments that test whether plants need specific elements to grow.
5: Every Tree for Itself	Participate in a simulation that represents a tree’s survival requirements. Discuss how foresters use their knowledge of competition among trees to manage forests.
6: Invasive Species	Research an invasive species that is a problem in your local area. Describe how invasive species impact the flow of energy in ecosystems. Create a method to inform the community about problems associated with local invasive species and how to prevent their spread.
Post-Assessment	Depict ecosystem energy flows using a labeled food chain or web. Create a cartoon that illustrates the process of photosynthesis. Identify different organisms that use a tree for a home.

To provide ample time for this unit, PLT recommends allowing at least 15 days (or 3 weeks) of 50-minute class periods. Note that some activities can be completed in as few as one or two class periods, while others will take longer. The suggested timeline below may vary with students’ grade, prior knowledge, and experience.

 

Activity	Suggested Time
Pre-Assessment	1 period (50 minutes)
1: The Forest of S.T. Shrew	1-2 periods
2: A Home for Many	1-2 periods
3: Web of Life	2 periods
4: Power Plants	2-4 periods
5: Every Tree for Itself	2 periods
6: Invasive Species	2-4 periods
Post-Assessment	1 period

Here are some helpful hints for adjusting the activities as you move through the unit:

• Use your creativity to modify the unit to fit your curriculum or learning program.
• Feel free to combine activities or parts of activities.
• The most time-consuming activity is Activity 4, which involves an investigation with living plants. (Note that it requires advance preparation that must be done several weeks ahead of time.) If time is limited, consider shortening it or reserving it for another time period (later in the year, for example).

This unit and its six activities are designed to be user-friendly and easy to navigate. You will find topic items related to the unit as a whole listed in the left-hand navigation bar. When you open a particular activity, tabs for the activity components will appear across the top.

 

Unit Components

All of the components of the unit may be found in the left-hand navigation bar. In addition to this Introduction, you will see listings of the unit’s Activities and Appendices.

– Energy in Ecosystems

• Introduction contains helpful information related to the entire unit.

– Activities

• The six instructional activities, plus pre- and post-assessment activities (described in more detail below).

– Appendices

• Standards Connections – A chart showing where various standards are addressed in the activities.
• Books and Other Resources – A list of fiction and non-fiction books, as well as other resources for enhancing student learning on the topic.
• PLT Conceptual Framework – The foundation of PLT’s curriculum, recently revised to incorporate the vocabulary of current education trends and to highlight the three dimensions of sustainability (environment, society, and economy).
• Acknowledgements – A listing of the many individuals involved in creating this E-Unit.
• Technical Support – Answers and trouble-shooting ideas for technical questions.

Activity Components

Each of the six individual learning activities contains all of the information needed to teach the lesson, including background information, standards connections, preparation instructions, material and time requirements, step-by-step instructions, student pages, assessment suggestions, and links to online resources.

Clicking on one of the Activities in the left-hand navigation bar will open up that learning activity. Once the activity is opened, new tabs will appear across the top containing the following activity components.

– Overview

• Includes a brief description of the activity.
• Learner Objectives: State the skills and content learners are expected to gain through participation in the activity.
• Time Considerations: Recommends the time allotments for the core activity, including preparation (see Getting Ready).
• Standards Connections: Identifies the standards the activity helps to meet.
• Materials: Lists the materials needed to do the activity.
• Getting Ready: Describes how to prepare for teaching the activity.
• Key Vocabulary: Lists and defines terms used in the activity and links to a vocabulary-focused student page that can also double as a form of assessment. Note that the definitions listed in the Overview are geared for students, while the definitions that “pop up” within the activity text online are geared for the teacher.

– Background

• Contains relevant information that provides the teacher with an understanding and perspective for engaging the class in the activity.
• While geared primarily for the teacher, pieces may be shared with students as informational text.
• Glossary terms within the background are highlighted: rolling over these words on-screen will reveal definitions. (Note that these roll-over definitions may differ somewhat from the more student-friendly ones identified in the Overview for the activity and on the Key Vocabulary student pages.)
• Discussion Questions at the end of the section may be used to engage students in the Background content, however it is presented.

– Doing the Activity

• Provides step-by-step procedures for leading the lesson. The procedure is divided into sections according to the 5E model: Engage, Explore, Explain, and Expand. The fifth E (Evaluate), is dedicated as its own separate section (see below).
• Within the procedures, specific connections to standards are also highlighted: rolling over these areas with your cursor on-screen will reveal the relevant standard connection.

– Evaluate

• Provides suggestions and materials for assessing students’ understanding of the concepts covered in the activity and provides opportunities for students to apply what they have learned.
• Includes links to relevant student pages and assessment rubrics, where appropriate.

– Enrich

• Recommends strategies for enriching or extending students’ learning experience beyond the activity.

– Tools

• Includes copyright-free teacher and student pages used in the lesson, as well as a listing of additional resources (books, websites, and videos) that may support the activity.

The unit includes a list of both fiction and nonfiction books that we recommend for enhancing student learning on the topic of Energy in Ecosystems. Please note that this list is not exhaustive and that you may find other excellent books in your school or community library or at a local bookstore.

 

Each of the unit activities also contains specific suggestions for using the books with your students. Look for these suggestions in the Enrich section of each activity.

Providing students opportunities to learn outside enables them to explore the unit concepts up close in a real-life setting. And while it takes some planning and preparation to teach outdoors, the benefits are well worth the effort.

 

Teaching outdoors has been shown to improve students’ overall academic performance, self-esteem, and community involvement and helps students:

• Develop an interest in science and math through connecting with nature.
• Strengthen language, problem-solving, and communication skills.
• Exhibit self-initiation, control, and personal responsibility.
• Gain familiarity with and appreciation of nature.
• Develop a more expansive view of how the world works.
• Build skills for environmental stewardship.

Norms for Outdoor Learning

Before going outside, discuss appropriate outdoor behavior. Some sample norms may include:

• All living things, including plants, are to be respected and not injured in any way. Look, learn, and leave alone.
• Stay within the boundaries.
• Stay with a partner.
• Be safe.
• Bring all equipment necessary.
• Follow all directions.

Other tips

• Scout the study areas and walking paths for any safety issues before you head outside with students.
• Enlist the help of parents or older students to assist in monitoring students’ behavior and keeping them on task.
• Set up a meeting signal to get everyone together, such as raising your hand, clapping several times, or using a bird call.
• Point out that students are more likely to observe animals if they are quiet. “Stealth mode” is when everyone moves as silently as possible without using their voices.
• For the first several times that students study outdoors, provide short, focused investigations or read them a book outside.
• Being outside means “playtime” to some students. Be patient and allow students to practice appropriate behavior. Eventually they will get used to investigating the out-of-doors in an appropriate fashion.
• If students are not following rules, consider having an adult take one or two groups out at a time to complete the task while the rest of the class works indoors.
• Let students choose a partner, then have pairs “count off,” remembering their number. Whenever you need to make sure all are present, get the class together, and have the first pair begin counting.