The Wolves of Yellowstone

In the 1920’s, government policy allowed the extermination of Yellowstone’s gray wolf (a keystone species) In 1995, through use of the endangered species act, the conservation community reintroduced the gray wolf to restore balance.

How did the reintroduction of the gray wolf led to changing river patterns in Yellowstone National Park? For the next 5 minutes brainstorm your ideas with a small group of peers. Record your ideas in the box provided on your worksheet

Write vocabulary words on your worksheet Ecology: the study of the interactions between organisms and the living (Biotic) and nonliving (Abiotic) components of their environment. Biotic factor: living things or biological influences within an ecosystem Abiotic factor: non-living factors that shape an ecosystem Ecosystem: a biological community of interacting organisms and their physical environment. Keystone Species: a species on which other species in an ecosystem largely depend, such that if it were removed the ecosystem would change drastically. Biodiversity: the existence of many different kinds of plants and animals in an environment

Sort the terms Abiotic Biotic You and your partner will be given a series of terms that are related to the Yellowstone. Sort the terms into either of the following categories. Abiotic Biotic

A Piece of the Puzzle The reintroduction of the Grey wolf caused a trophic cascade that resulted in the changing river patterns. Trophic Cascade: an ecological process which starts at the top of the food chain and tumbles all the way to the down to the bottom.

Organizing your thoughts The following activity will help you make connections and hopefully come to the correct conclusion. Remove all the abiotic factors EXCEPT the river. Though abiotic factors greatly affect an ecosystem we will focus mainly on the interactions between the biotic factors Clear your table. Place the wolf on the far left of the table and the river on the far right. Look at the remaining biotic factors and see if you can identify the link between the wolves and the rivers Hint: It is a result of many interconnected factors!