Have you ever been hiking in the mountains? Maybe you have hiked to the altitude where suddenly you see no more trees growing. If you have, you know what a timberline is.

Above the timberline the environment is not good for the growth of trees. The air is too cold and windy, and sometimes ice and snow cover the ground much or all of the year. The climate above the treeline is called an alpine climate.

Notice the single little tree struggling to live in the photo to the left. Further up the mountain there are no trees at all. This little tree is at the timberline.