120 likes | 276 Views
The Growing Desert. How desertification is affecting the continent of Africa. Desertification. Drought causes grasses to thin out in the Sahel. The bare dirt turns to dust. This process is called desertification.
E N D
The Growing Desert How desertification is affecting the continent of Africa
Desertification • Drought causes grasses to thin out in the Sahel. The bare dirt turns to dust. This process is called desertification. • Humans add to this natural process and we will discuss how in the following slides.
Overplanting • Farmers overwork the land because they cannot get enough food from one crop, so they plant multiple times in one season. • This practice strips the land of all nutrients and eventually nothing will grow.
Overgrazing • Animals eat the scattered clumps of grass. Since there is so little of it they eat it down to the ground. • The animals hooves then pulverize the root systems and the grass dies.
Water Wells • Extra water allows the communities to grow larger. • Desert biomes cannot support large animal, plant and human populations. • Think: What effect does our large population have on the amount of available water?
Deforestation • Tree roots keep the soil in place. • However, wood is the main source of fuel in this region and tree are cut down.
Quick Facts • In 1880, only 9.4% of the land on Earth was desert. • In 1950, that percentage increased to 23.3%. • In Nigeria, the Sahara spread 60 miles in less than 20 years.