Background: In the rainforest plant and animal species are under great environmental stress from destruction of natural habitat or density-dependent factors (competition for food, living space, disease, and other resources). When this occurs, there exists interspecific competition (between species) for food or shelter. In English when a logging company cuts down 50 acres of land, many things may happen: destruction of plant life, possible species extinction, which causes a lack of shelter and food for many animal species. This creates greater competition for the few resources there are available, and again it's a game of survival of the fittest. This activity will demonstrate this process.
Grade Level: any
Duration: 10-15 minutes
Materials: Animal cards and rope
Setting: the larger the group, the larger the area needed Subjects: biology, physics
Objectives: Students will gain a better understanding of how animals feel under environmental stress. They will be able to explain how and why species extinction happens in the rainforest and in other ecosystems.
Method: Give each student an animal card and make sure each knows what the anima1 or plant is and what's unique about it. Laying the rope in a circular shape, with the two ends together, explain to the students that it is representative of a piece of tropical rainforest and they are representative of animals and plants that inhabit the rainforest. As they step into the circle, mention how they seem to have enough room in which to move about. "But, a cattle company has decided to cut down a part of the forest to run its operation!" Make the circle smaller, and explain that any animal that cannot fit into the circle becomes extinct. As you explain what other tragedies befall the forest (erosion, water pollution, lumber company, oil spill, forest fire, etc.) continue to make the circle smaller until only a few survivors remain.
Example of Animal Card: Rosy Periwinkle- a pink flower which gives children with childhood leukemia a 8 out of 10 chance of remission.
"Four-fifths of the nutrients in the rainforest are in the vegetation. This means that the soils are nutrient-poor and become eroded and unproductive within a few years after the rainforest is cleared." -Rainforest Action Network
The layer of topsoil in the rainforest is (on average) only a maximum of 3 inches thick. -Rainforest Action Network
"A typical four square mile patch of rainforest contains as many as1500 species of flowering plants, 750 species of tree, 125 mammal species, 400 species of birds, 100 of reptiles, 60 of amphibians, and 150 different of butterflies." (National Academy of Sciences)