During the ice ages, North America experienced cycles of warm and cold temperatures.

These changing temperatures (abiotic) affected the plant life (biotic) of the ecosystem.

The image to the left is a picture of the East Coast of North America 18,000 years ago.

At that time there was a large sheet of ice (shown in blue) covering much of this area.

Notice the five ecosystems below the ice sheet.

During the past 18,000 years the amount of ice has changed a lot. When the amount of ice changed, so did the ecosystems.

To see what the effects were, concentrate on the dark green area.

This is the taiga forest ecosystem, composed mostly of pine and fir trees.

Now, to discover how the taiga and other ecosystems changed, CLICK on the Start button.

What happened to the taiga forest as the glaciers retreated northward?

a) The taiga moved North (up).
b) The taiga ecosystem went extinct.
c) The taiga moved West (left).

Let’s explore how this works...

Take another look at the animation. Keep an eye on the dark green taiga ecosystem. Try again...