ABSTRACT
The green spots and strips of irrigation cultivation seen on a satellite photograph of the arid lands occupy a much smaller area than other types of land-use. Dry farming has been shown to fill in some of the gaps but by far the most ubiquitous economic response to dry lands is pastoralism. Pastoralism is also a way of life which has been subject to rapid changes in scale and distribution, changes which have been initiated by changes in the environment, as through climatic change or rainfall variability, or through social, economic and government pressures. Transhumant pastoralism, often associated with cultivation of cereals and fodder crops, as in the Tell of North Africa, may thus be explained as the rational response to environment at all levels of culture and technology. In many new lands pastoralism preceded cultivation as the new immigrants brought their domesticated animals on to the relatively virgin grasslands of western North America, South Africa and Australia.
