The Decapolis region (Northern Jordan) as historical example of desertification? Evidence from soil development and distribution

Abstract

Historic land use was found to impact soil development directly in the Decapolis region in Northern Jordan, leading to re-distribution, not simply erosion and degradation of soils. Several authors proposed that land use had a strongly negative impact on soil development in semi-arid areas, leading to desertification. The term desertification was used to describe erosion, caused by land use, as the reason for an advance of deserts and the abandonment of ancient sites. However, evidence from Jordan shows that erosion is a most unlikely cause for the abandonment of historic sites. Land use lasting over centuries seemingly changed the character of the landscape and can be traced through distinct soil development. Soils may have been degraded since prehistoric times and it seems possible that major erosion in the Decapolis region was not primarily related to land use or increased rainfall, but to more frequent extreme events interrupting prolonged droughts. As global warming seems likely, it is important to consider the impact of climate on landscape development in future management plans.