The Hadley Cell as shown below demonstrates how the three different climate types around the tropics are created from the high and low pressure in the area.
On either side of the equator the pressure is low and the air is rising due to the heat. This causes humid conditions with a lot of rain (Clouds can always be seen from the satellite map) and very high temperatures due to the proximity to the Sun. These are the best conditions for tree and plant life to grow and this is why rainforests are abundant in this area.
In Savannah grasslands winds are high as the air is cooler and rushing back to the equator. These areas experience varying pressure from low to high producing a wet season and a dry season at different intervals of the year. This causes the vegetation to die back in the dry season due to lack of precipitation and flourish as soon as the wet season arrives due to the fact that the plants have adapted themselves to do this.
Outside of this area the Desert is located where conditions are harsh and vegetation rarely grows other than the cacti, which conserve water to survive.
The Hadley cell in Africa can be shown by the locations of the rainforests, Savannah grasslands and the Desert from the bands f types of vegetation. This pattern is apparent both south and North of the equator.
These different and extreme climates require both the vegetation and people to adapt to these harsh conditions. Tribes living in Savannas hunt large animals such as the buffalo due to the high amount of body mass that they possess.
The Buffalo itself is a grazing animal and it has adapted to these conditions by knowing what plants to graze in the dry season to obtain the most water.
Plants and trees in the Savannah are fire and drought resistant due to the fact that the Baobab Tree has a very thick trunk that can hold and efficiently store large quantities of water and not many branches.
Some people move back and forth from the Savannah and Desert depending on the season. The people move into the desert in the rainy season because if they don’t the Tsetse fly will cause disease to the people. Another method the Nomads use is “Slash and burn” farming. This method of farming allows the land to be used again and again because after the area of land has been farmed for a certain amount of time they will move on and farm somewhere else. This allows the same piece of land to be used because when the farmers return in a few years time the land will have regenerated.
In rainforests tribes people experience a rainy and dry season. In the rainy season large amounts of floods occur so in the Amazon people have built houses up on stilts or have floating houses, which are held down by anchors to prevent their housing from being destroyed.
They also use a method of farming called shifting cultivation where they clear an area for farming, farm it and then leave so that it may regenerate. This method is useful so long as the area cut down is too large and isn’t farmed for too long.