Ancient and modern perspectives on land degradation

Abstract

Concern over land degradation is not new, and is not solely the domain of geomorphology and soil scientists. Widespread and extensive reference to land degradation occurs throughout the world, and often has deep historical antecedents (Butzer, 1976b, 1982). There is increasing concern by a number of disciplines that land degradation has long term consequences to landscapes, and possibly society. In some cases land degradation is seen as a precursor and triggering mechanism to natural disasters, while social scientists have linked it to disruption of economic and political systems (Blaikie and Brookfield, 1987). Although the topic of land degradation is inherently interdisciplinary, because of its conceptual framework and intellectual breadth, geomorphology is an ideal discipline to address the multiple causes, management and prevention, and broader implications of land degradation. Moreover, because it strongly resonates with the general public, land degradation represents an opportunity for geomorphologists to communicate with a broad audience and make important societal contributions. Land degradation is commonly defined as a human or climatically induced process having negative consequences to the functioning of the land and related ecosystems, and suggest a long-standing perception that humans have played an unfavorable role, or had negative consequences, to landscapes. Most definitions also recognize explicit connections between distinct landscape components, such as hillslopes and floodplains (Fig. 1). Many studies on land degradation have understandably focused on hillslope processes (Clarke and Rendell, 2000; Harden and Matthews, 2000; Kirkby et al., 2002), often related to soil erosion (Cammeraat, 2004), changes in soil chemistry, or mass