In this activity, students model trophic cascades, which are also explored in a variety of related resources, using cards of animal and plant species from seven different habitats. It is designed to illustrate the species relationships in a food chain and the effect of predators on the trophic levels below.

Trophic cascades have been described in numerous ecosystems, ranging from kelp forests ofthe Pacific Ocean, to arctic islands, to Central American jungles, to salt marshes. Trophic cascades occur when predators reduce the abundance or change the activity of their prey, thereby allowing species in the trophic level below to increase in number. These indirect effects by the predator can trickle down (or cascade) to many lower levels of the food chain.

This activity complements the concepts explored in the Exploring Trophic Cascades Click & Learn, the short film Some Animals Are More Equal than Others, and the Ecology of Rivers and Coasts and Patterns and Processes in Ecology Science Talks.