18.2

RAINFALL PATTERNS

Africa's west coast also receives a great deal of rain. The region around annual rainfall of more than Monrovia, Liberia, experiences an average 120 inches. In contrast, many parts of Africa barely get 20 inches of rain over the course of a year. In the Sahara and other deserts, rain may not

VARIETIES OF PLANTLIFE

All of Africa's regions contain a variety of vegetation. North Africa contains sizable oak and pine forests in the upper reaches of the Atlas Mountains. Mangrove tree roots are breeding grounds for fish. They also help to build up dry land by holding silt. In the next section, you will read about different ways that people in Africa have interacted with their environment.

Africa's Extremes

An enormous tropical rain forest stretches across Central Africa.

THE TROPICS

In fact, nearly 90 percent of the continent lies within tropics of Cancer and Capricorn, as you can see on the map to the right. In humid regions of the tropics, variance in temperature between winter and summer are slight. Differences in night and day tempera- saying describes nighttime as the "winter" of the tropics. tures tend to be greater than differences between seasons. An African

Sunshine and Rainfall

Sunshine a matter of extremes. receive too little. The amount Some parts get too much Rainfall in Africa is often rain, while other parts greatly from year to year as well as season to season. droughts in the 1980s and 1990s, and again in 2005-2006. of rainfall can vary East Africa, which endured several

RAIN FOREST

The major rain forests of Africa sit on the equator in The massive number of plants, leaves, home to hundreds of species of birds. the Congo Basin rain forest. It is also than 600 species of trees are found in the area of the Congo Basin. More and trees block out much of the sun- light that would otherwise hit the floor of the rain forest. For example, a fallen leaf in Europe decomposes in about a year. A leaf on the jungle floor in Africa decomposes in about six weeks.B Most animals in a rain forest live the canopy. The canopy refers to the uppermost layer of branches, about

THE DESERTS

Two deserts, Kalahari Namib, found in Southern Africa. In North Africa lies the Sahara, the largest desert stretches about 3,000 and also runs 1,200 miles from north to south. Temperatures can rise above 13o° in the summer, hot enough to cook an egg winter, temperatures can fall below freezing at night. 20o percent of the Sahara consists of sand. the Tibesti Mountains, located mostly in northwestern Chad, rise to heights of more than 11,000 feet. Travel in the Sahara is risky because of the extreme conditions.

TROPICAL GRASSLAND

many crops, but these conditions are perfect for growing grass. Tanzania. Its dry climate and hard soil prevent the growth of trees and grassland is the Serengeti Plain in northern Serengei endless Serengeti National Park, located within the Serengeti Plain, contains some of the best grasslands in the world.

AFRICA'S MODERATE AREAS

northern and southern tips of the continent. Clear, blue skies in these A Mediterranean climate exists on the winter-December and temperatures in Johannesburg, South Africa, average January in North Africa and June and places are normal. Rain falls usually only in the July in Southern Africa. Summer around 68°F.

A Grassy Continent

south of the equator. Africa's vegetation consists of grasslands, rain Africa's vegetation-like its climate-is almost mirrored north and forests, and a wide variety of other plant life.