Ecosystem Unit Study
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Introduction:
In fourth grade, the first science unit of the year is ecosystems. At the end of the unit, students are able to identify the components of an ecosystem, determine the plants and animals that live there, and what makes that possible. Students will also be able to apply the knowledge built in these lessons to other ecosystems not covered explicitly, using what they know. We chose to focus our STEM lessons on the adaptations of animals because they are the most distinguishing features of any ecosystem; the adaptations an animal has reveals much about the environment in which it lives. Using the lessons provided by Fairfax County Science Department, we laid the ground work for the students to be able to create and introduce a new animal into their chosen ecosystem. We were able to embed the STEM content into these previously written lessons by explicitly teaching fourth grade math content and technology standards. Students used their knowledge of ecosystems, needs, and adaptations to design a new animal that could survive in their ecosystem.
Focus Lessons:
Habitat Study
Students were prepped with background information by learning about what a habitat is and what it provides (food, shelter, water, space). We did a class simulation of a deer’s day. They were instructed to get food, water, and shelter each day for the deer to survive. We then introduced more deer into the habitat, and students experienced that resources were not unlimited and that space was another important need for survival. (Appendix A)
Next, students learned there are a variety of habitats in Virginia. They researched three different habitats in Virginia: Piedmont Meadows, Blue Ridge Forest, and Coastal Plain marsh. The different types of habitats result in a variety of plants, animals, water sources, shelter, and space. Students compared each habitat and concluded that they each provided different sources of water, shelter, food and space. They noticed that the animals and plants were different in each region due to the environment of the habitat. (Appendix B)
Adaptation Study
Students went to explore their school yard to discover various plants in our habitat. They learned that plants had specific structural adaptations that allowed them to succeed in their environment. For example, students concluded that plants with sharp thorns on the stem provide protection from predators. Students also noticed that some trees have leaves with a waxy coating on one side. The waxy coating on many leaves helps leaves retain the water necessary so that do not lose water too quickly. Those leaves were significantly greener than others.
In the next lesson, students participated in an experiment to learn about structural adaptations in animals. Students learned about different structural adaptations of insect mouthparts using tools as models. They drew conclusions on what type of food fits that mouth part. For example, if the insect’s source of food is a liquid, a straw like mouth would be most successful. They explored, tools for gripping, lapping, and tearing. By the end of the experiment, they were able to explain how different organisms use their unique structures to adapt to survive. (Appendix C)
Students learned the difference between structural and behavioral adaptations. Students watched various videos observing animals adapting to survive. The students categorized their observations and discovered that there were types of structural adaptations and behavioral adaptations. Behavior adaptations can help an organism to survive and succeed in its habitat. The adaptations are reasonable and serve a specific purpose. Only animals have behavioral adaptations, which reflect what the animal does to survive.
Food Web Study
For this focus, students learned about food chains and food webs. We engaged their understanding by building a food web as a class. Each student was an organism and we passed a ball of yarn to show the flow of energy that gets passed through a web. They saw how the organisms’ roles within the food web were all related and very important for the success of the entire ecosystem. The students investigated what would happen to a food chain if one population of organisms became extinct and how that affects the entire food web. They also explored the results of having too many of one organism in the food web. Students concluded that animals and plants are created to die for food for decomposers and have a predator to balance the ecosystem. All the living and non-living things in an ecosystem are connected. Students understand that an animal is not created to “live forever” or be “indestructible”. That the animal is a part of the life cycle and food web. It is a natural part of the ecosystems. (Appendix D)
Analyzing Climate Graphs
Math skills were integrated in this lesson so that the students could do further research on the habitat for their new organism. Students had a choice to research three regions: Piedmont, Blue Ridge, and Coastal Plain. They were given graphs that contain data on that region’s climate. The topics included: wind, snow, precipitation, heat index, and temperature. Students were taught how to read graphs and draw conclusions. When reading graphs, students learned to analyze intervals and the difference between line and bar graphs. Using the data of each region, students began to think about the necessary adaptations organism need to survive Virginia’s mild climate. (Appendix E)
Designing an Organism:
Using the information they learned about adaptations, food webs, and habitats, students begin the design process of planning to create their organism. They concluded that an organism can’t be 100 feet, for example, because it is not realistic. They understand that an organism cannot have unrealistic features because it will not fit in with their ecosystem. The students learn that each adaptation is instrumental in the survival of the animal to which habitat it belongs. Students plan out their organism’s structural and behavioral adaptations. They think about their organisms place in the food web, food, water, shelter, and space for survival. Students build their prototype of an animal that they want to introduce into the specific ecosystem using clay.
More math is integrated into this project when students need to scale their model up 3 times larger to be displayed on a poster. Their model will be labeled with measurements (cm, mm, inches, and feet) and accompanied by an explanation of its purpose for the survival of the animal. (Appendix F)
Conclusion:
Students used traditional and nontraditional methods to explore and understand ecosystems and the animals and plants that live in each one. Every animal has adaptations that keep it alive and thriving in their given environment. The test of students’ understanding was whether or not they could create an animal that could also survive in the ecosystem and what makes that possible. Students had to be able to explain the adaptations they chose and why those adaptations keep the animal alive. They need to be able to create a food web with their organism and show its role in the ecosystem. The learning stems not from the recitation of knowledge, but the application of all that is taught. As math and engineering is integrated in this science unit, students are also engaged with using 21st century skills. As learners collaborate to design an organism, they also will practice their communication skills when presenting their conclusions. They actively use their critical thinking skills and begin to practice thinking more globally throughout the unit. Teachers could incorporate more learning standards into the Fairfax County lessons, such as non-fiction text features by having students create displays presenting their organism. (Appendix G) In conclusion, this STEM unit is a holistic approach for students to authentically apply interdisciplinary subjects to their understanding of the natural world.
Appendix A: Deer Habitat Simulation Cards:
Appendix B: Habitat Research Cards:
Appendix C: Structural Adaptations:
Appendix D: Food Web Diagram:
Appendix E: Blue Ridge Graph:
Coastal Plain Graph:
Piedmont Graph:
Appendix F: Organism Planning Sheet:
Appendix G: Tri-Fold Presentation:3