Tropical Africa and Asia, 1200–1500
Tropical Lands and Peoples
The Tropical Environment
The tropical zone falls between the Tropic of Cancer in the north and the Tropic
of Capricorn in the south. The Afro-Asian tropics have a cycle of rainy and dry
seasons dictated by the alternating winds known as monsoons.
While those parts of the tropics such as coastal West Africa, west-central Africa,
and southern India get abundant rainfall, there is also an arid zone extending
across northern Africa (the Sahara) and northwest India, and another arid zone in
southwestern Africa. Altitude also affects climate, with high-altitude mountain
ranges and plateaus having cooler weather and shorter growing seasons than the
low-altitude coastal plains and river valleys. Major rivers bring water from these
mountains to other areas.
Human societies adopted different means of surviving in order to fit into the
different ecological zones found in the tropics. In areas such as central Africa,
the upper altitudes of the Himalayas, and some seacoasts, wild food and fish was
so abundant that human societies thrived without having developed agricultural
or herding economies.
Human communities in the arid areas of the tropics relied on herding and
supplemented their diets with grain and vegetables obtained through trade with
settled agriculturalists. The vast majority of the people of the tropics were
farmers who cultivated various crops (rice, wheat, sorghum millet, etc.)
depending on the conditions of soil, climate, and water.
In those parts of South and Southeast Asia that had ample water supplies,
intensive agriculture transformed the environment and supported dense
populations. In most parts of sub-Saharan Africa and many parts of Southeast
Asia, farmers abandoned their fields every few years and cleared new areas by
cutting and burning the natural vegetation.
The tropics have an uneven distribution of rainfall during the year. In order to
have year-round access to water for intensive agriculture, tropical farming
societies constructed dams, irrigation canals, and reservoirs.
In India, Cambodia, and Sri Lanka, governments mobilized vast resources to
construct and maintain large irrigation and water-control projects. Such huge
projects increased production, but they were highly vulnerable to natural
disasters and political disruptions. In contrast, the smaller irrigation systems
constructed at the village level were easier to reconstruct and provided greater
Tropical peoples used iron for agricultural implements, weapons, and needles.
Copper, particularly important in Africa, was used to make wire and decorative