Hint: You want to try and think about what you are reading to check if its 2 questions in the question.
Answer #1: The Savanna biome has had a lot of human impacts affect the environment and health of the Savanna. The African people use the Savanna land not just to live on but to graze their cattle and goats. The grasses get completely eaten and with no vegetation, the Savanna turns into a desert.
Answer #2: Humans have affected the savanna biome in many ways. The increased use of the savanna by humans has caused degradation of this biome. Extinction of animals in this biome is caused by humans releasing foreign species into the savanna. Humans have killed predators, built dwellings, and cleared land to be able to farm. Humans have done things like stopping natural fires and starting fires in this environment which kill many plants and animals if they get out of hand.