A common claim of defenders of tropical rain forests is that because of the shallowness of rain forest soils cutting down those forests for crops or cattle grazing will lead to massive soil erosion and eventually create deserts in areas where lush forests once grew and provided a high percentage of the earth's biodiversity (Sponsel, Headland, and Bailey 1996; Burch 1994; The Burning Season 1994).

Complexity of Causes

However, the causes of desertification are much more complex than this scenario would suggest. It is true, for instance, that in the Mediterranean Basin deforestation over centuries has been a significant factor in desertification from Spain and the western part of North Africa in the west to Lebanon and Palestine in the east. Nevertheless, cutting down forests was only one among several human factors that advanced desertification in that region, along with climatic factors:

First and most fundamental are...