Classroom Activities
Chain Reaction: Tracing the Ripple Effects of Fire
Objective: Students will explain how disturbances such as fire or grazing influence temperate grassland ecosystems.
After the students have learnt about this topic through readings and discussions, the activity will begin with a provocative question: how can one wildfire actually increase biodiversity in a grassland? In groups of four, students will receive a set of cards describing individual ecological events such as a fire removing dried grass, nutrients being released into the soil, woody seedlings dying off, sunlight reaching new grasses, deep grass roots surviving, native grasses regrowing, herbivores returning, and biodiversity increasing. They will work in their groups to arrange these cards into a cause-and-effect chain, connecting each event with arrows and explaining the relationships using transition language such as because, therefore, and as a result. The groups will then move around the room to compare their finished chains and debate which single event, if removed, would have the greatest impact on the overall outcome. In the end, each student will demonstrate his/her understanding by writing a Claim-Evidence-Reasoning (CER) response explaining why fire is considered an essential natural disturbance in temperate grasslands.
Biome Showdown: Grassland vs. Forest
Objective: Students will compare the characteristics of temperate grasslands and temperate forests.
The students will work in pairs for this activity. Each pair receives a set of materials representing both biomes; this could include photographs, climate graphs, soil profiles, and species cards. First, students will look closely at all the materials for both the grassland and the forest. As they examine each item, they will think about which biome it belongs to and what it tells them about that biome. Next, they will sort their evidence into a Venn diagram where one side of the diagram is labeled "Grassland," the other side "Forest," and the middle section is for things both biomes have in common. They will then organize their evidence under categories such as climate, precipitation, soil, plants, animals, disturbances, and human uses. Once the diagram is finished, students will answer a question together: which biome would better support large grazing mammals and why? They must use specific evidence from their Venn diagram to support their answer, not just a guess. For example, a student response may look like this: Grasslands provide open space, constant sunlight, and fast-regrowing grasses, all of which support the food needs and herd behavior of large grazing mammals. Forests, on the other hand, block sunlight with their tree cover or leaf cover (canopy) and don't provide the same open terrain or abundance of ground-level food, making them less suitable for large grazers. Finally, the class will come together for a short discussion. Each pair shares their answer and explains their reasoning, using the evidence they gathered to defend their choice to their classmates.
Dig Deep: Modeling Soil Beneath Two Biomes
Objective: Students will model and compare grassland and forest soil profiles.
Working in small groups of four or five, the students will construct two soil profiles side by side using clear plastic cups, dark potting soil, sand, clay, yarn to represent grass roots, and pipe cleaners to represent tree roots. One cup represents the deep, dark Mollisol typical of temperate grassland soil, while the other represents the more shallow, layered horizons of temperate forest soil. The students will compare the two models across root depth, organic matter content, soil color, and water retention. They conclude the activity by explaining, in writing, why temperate grassland soils rank among the most productive agricultural soils on Earth. An example of a Sample Student Response is: "Grassland soil is so good for farming because it has really deep roots, like our yarn showed. The roots go down really far, so when the grass dies, it adds a lot of dark, rich stuff called organic matter deep into the soil, not just on top. This makes the soil dark and full of nutrients that plants need to grow. Grassland soil also holds water well, so plants don't dry out. Forest soil doesn't have as much organic matter mixed in deep down, because the leaves and stuff just build up on top instead of getting mixed into the soil like grass roots do. That's why farmers like to plant crops in grassland soil, it already has everything plants need to grow big and healthy."
The Web We Weave: Modeling Interdependence
Objective: Students will model how organisms depend on one another.
Each student is given a card representing an organism such as grass, prairie dog, grasshopper, snake, hawk, or bacteria, after which the class will form a circle. Using yarn, they will then connect themselves to classmates according to real feeding relationships, building a physical food web. The teacher then removes one organism from the web, for instance, the prairie dog, after which students should then observe how many yarn connections go slack as a result. A class discussion follows, focusing on which organisms were affected and why removing a single species had such wide-reaching consequences. Students repeat the exercise with a different organism, such as an oak tree in a forest food web, and can extend the activity further by introducing an invasive species or a drought scenario and predicting how the web would change in response. Sample Student Response: "When the teacher removed the prairie dog, a lot of yarn went loose, not just one piece. The hawk's yarn went slack because hawks eat prairie dogs, so now the hawk doesn't have as much food. The snake's yarn went loose too, because snakes eat prairie dogs. Even the grass was affected in a different way, because prairie dogs dig burrows that help the soil, and other animals use those burrows too. This showed me that prairie dogs are connected to a lot of other organisms, not just one. If one animal disappears, it doesn't just affect that one animal; it affects everything connected to it, kind of like knocking down one domino and a bunch of others fall too. That's why removing just one species from an ecosystem can cause big changes for a lot of other living things."
Grassland or Forest-in-Waiting? A Silent Debate
Objective: Students will use evidence to explain why grasslands remain treeless.
Students begin by silently considering the question of whether a grassland is simply a forest that hasn't grown yet. There will be an "Ink" phase where they will write their own answer independently, along with two supporting pieces of evidence and one lingering question. They then pair up to compare responses, identifying similarities, differences, and the strongest evidence between their two answers, revising their own thinking as needed. Pairs share their reasoning with the class, and the teacher records the evidence on the board under two headings, "Evidence For" and "Evidence Against." At the end of the lesson, students revisit the original question one final time and revise their initial response using the new scientific evidence they've gathered. Example of a student sample response: Students begin by silently considering the question of whether a grassland is simply a forest that hasn't grown yet. There will be an "Ink" phase where they will write their own answer independently, along with two supporting pieces of evidence and one lingering question. They then pair up to compare responses, identifying similarities, differences, and the strongest evidence between their two answers, revising their own thinking as needed. Pairs share their reasoning with the class, and the teacher records the evidence on the board under two headings, "Evidence For" and "Evidence Against." At the end of the lesson, students revisit the original question one final time and revise their initial response using the new scientific evidence they've gathered.
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