When competition for resources is unnecessary
Answer:
Desertification
Explanation:
Drought and leaching leave some parts of Africa without much water, which leads to some portions of the area to turn into a desert, which can prove disastrous for the plants and animals that now find themselves in a completely different habitat.
The Abbasids established the new position of vizier to delegate central authority, and delegated even greater authority to local emirs. The Abbasid dynasty ruled as caliphs from their capital in Baghdad, in modern Iraq, after taking over authority of the Muslim empire from the Umayyads in 750 CE.
