The Equatorial region is also called the lungs of the world because it has large tropical rain forests which act as a sink for carbon dioxide and provide us oxygen.
The trees found in the Mediterranean region have long roots and thick barks because they show xerophytic adaptation. In order to increase their efficiency of water absorption they have long roots. They have thick barks to reduce transpiration losses.
Tundra region has a low annual range of temperature because this region is cold throughout the year. Summers are mild.