Serengeti over 80 percent of the Serengeti. The southeastern area lies in the rain shadow of the Ngorongoro Conservation Area's highlands and is composed of shortgrass treeless plains with abundant small dicots. Soils are high in nutrients, overlying a shallow calcareous hardpan due to natrocarbonatite eruptions from Ol Doinyo Lengai. A gradient of soil depth northwestward across the plains results in changes in the herbaceous community and taller grass. About west, acacia woodlands appear suddenly and stretch west to Lake Victoria and north to the Loita Plains, north of the Maasai Mara National Reserve. The sixteen acacia species vary over this
Serengeti low of in the lee of the Ngorongoro highlands to a high of on the shores of Lake Victoria. The highlands, which are considerably cooler than the plains and are covered by montane forest, mark the eastern border of the basin in which the Serengeti lies. The Serengeti plain is punctuated by granite and gneiss outcroppings known as kopjes. These outcroppings are the result of volcanic activity. Kopjes provide a microhabitat for non-plains wildlife. One kopje likely to be seen by visitors to the Serengeti is the Simba Kopje (Lion Kopje). The area is also home to the Ngorongoro Conservation