Sahara: A Natural History

Dr. Patrick W. Colgan is the director of Research and Natural Lands at
the Royal Botanical Gardens.

The authors, residents of Lunenburg, divide their material into “The
Place Itself” and “The People Who Live There.” The 3.3 million
square miles that is Sahara are arid, stark, and dangerous. The clusters
of countries making up the region have interacted, chiefly militarily,
among themselves and with outside groups such as Europeans for
millennia. From the physical geography and trade routes, understanding
of the dynamics of the different areas emerges. The long-term geology,
with abundant fossils, involved a wet Holocene and drying ever since.
These conclusions are set in the context of models of climatic cycles.
Even the earthworm communities provide information on this. The sand
seas gobble up communities and occasional armies, with the wind-blown
dunes carrying sand, soil, and pathogens. There is some rainfall and the
behaviour of the desert and ocean interact. Surprisingly, aquifers
underlie much of the Sahara, resulting in a pattern of life-supporting
oases. Dominant features of the rock substrate are volcanic cores and
massi’s. Life is tenacious, with ephemeral plants that can germinate
quickly and drought-resistant animals. One acacia tree was recorded with
roots going down 115 feet. Rock paintings interestingly depict the much
richer fauna of the past.

The Sahara supports a population of two million divided into 10 groups.
The earliest people have left paintings and stone circles. The route
maps were obviously determined by availability of water, with major
centres being Agadez, Kano, and Timbuktu for the exchange of gold, salt,
and slaves (even today). There are six nomadic groups among whom there
is a good deal of feuding, with some surprises, such as the independence
of Tuareg women. Caravans can contain up to 500 camels, and a typical
day is detailed. Even smell is claimed to help some people to orient.
Despite some new things, de Villiers and Hirtle claim that the Sahara
remains essentially the same.

The text ricochets among general description, myths, quotes from
sources ranging from classical to modern times, and conversations.
Supporting the text are a few insufficient photographs and good
end-paper maps. This book is not a “natural history” (which would
require much more detail and illustrations) so much as an ethnographic
or literary history.