Kolla

the lower hot high-altitude zone of the Ethiopian highlands, reaching a height of 1,700–1,800 m. The average annual temperature is no lower than 20°C; however, on the eastern slopes, it is over 25°C. The hottest months are May and September. There are sharp seasonal contrasts of humidity on the mountain slopes, resulting in the formation of corresponding types of terrains. There are savannas on the mountains slopes and various types of forests in the river valleys. High-grass savannas and tropical evergreen forests are found in the most humid southern and southwestern regions of the kolla, and desert savannas are located in the northern regions of the western part of the zone and on the dry eastern slopes. The kolla is sparsely populated. Cotton, sugarcane, and coffee are cultivated in different regions of the kolla. Livestock raising is developed.